University of Massachusetts Amherst L I B R R jivl/Mor Volume 67, Number 1 WINTER ISSUE, 2002 fleiJuCnaland Table of Contents Apple-pomace Compost and Pre-plant Monoammonium Phosphate for Improving the Growth of Newly Planted Apple Trees R.E. Moran and ].R. Schupp 1 Development of a Model for Predicting Flyspeck Risks in Blocks of Apple Trees A. Tuttte, C. Bergweiler, J. Hall, L. Reisner, S. Christie, W. Autio, and D. Cooley 5 Effects of Gibberellin Synthesis Inhibition on Feeding Injury by Potato Leafhopper on Apple K. Leahy, D. Greene, and W. Autio 9 Food Quality Protection Act: An Organophosphate Update - February 2002 G. Morm 13 Food Quality Protection Act: Cumulative Risk Assessment for the Organophosphate Pesticides R. Spitko 16 Commercial-orchard Evaluation of Traps for Monitoring Plum Curculio: 2001 Results R. Prokopy, B. Chandler, and ]. Pinero 17 An Odor-baited "Trap-tree" Approach to Monitoring Plum Curculio R. Prokopy 23 IMPORTANT SUBSCRIPTION RENEWAL INFORMATION 25 rleu/Cngiand Editors: Wesley R. Autio William J. Bramlage Publication Information: Fruit Notes (ISSN 0427-6906) is pub- lished each January, April, July, and October by the University of Massachu- setts in cooperation with the other New England state universities. The costs of subscriptions to Fruit Notes are $10.00 for United States ad- dresses and $12.00 for foreign ad- " dresses. Each one-year subscription begins January 1 and ends December 31. Some back issues are available for $3.00 (United States addresses) and $3.50 (foreign addresses). Payments must be in United States currency and should be made to the University of Massachusetts. Correspondence should be sent to: Fruit Notes Department of Plant & Soil Sciences 205 Bowditch Hall University of Massachusetts Amherst, MA 01003 All chemical uses suggested in this publication are contingent upon continued registration. These chemicals should be used in accordance with federal and state laws and regulations. Growers are urged to be familiar with all current state regulations. Where trade names are used for identification, no company endorsement or product discrimination is intended. The University of Massachusetts makes no warranty or guarantee of any kind, e.xpressed or implied, concerning the use of these products. USER ASSUMES ALL RISKS FOR PERSONAL INJURY OR PROPERTY DAMAGE. Issued by UMass Extension, Stephen Demski, Director, in furtherance of the acts of May 8 and June 30, 1914. UMass Extension offers equal opportunity in programs and employment. Apple-pomace Compost and Pre-plant Monoammonium Phosphate for Improving the Growth of Newly Planted Apple Trees Renae E. Moran Department of Animal and Horticultural Sciences, University of Maine James R. Schupp Hudson Valley Laboratory, Cornell University In many orchards in the Northeast, early yield is limited by tree growth, and trees are typically not cropped until the third or fourth season because growth IS not vigorous. Management practices that encourage rapid early tree growth and early fruit production result in economic advantages to growers by hastening a return on investment. Decreasing the time required for trees to fill their space would allow growers to increase early yields. Increasing early tree growth can be accomplished by adding organic matter or phosphorus fertilizer to the planting hole. Adding compost as a source of organic matter to planting holes affected young apple tree growth in experiments in Massachusetts and Maine. Organic matter is often low in many existing orchard soils. Increasing soil organic matter improves its water and nutrient holding capacities, which enhances root regeneration and promotes overall tree vigor, but the effects of planting-hole treatments are most visible during the year of planting. As root growth extends beyond the volume of the planting hole, the effects of planting-hole treatments diminish. If organic matter amendments were broadcast throughout the orchard soil, perhaps the beneficial growth response could be sustained for a longer period. For pre-plant compost to be a feasible management practice, an economical, local source of compost must be available. University of Maine Cooperative Extension developed an apple-pomace composting project in cooperation with Chick Orchards in Monmouth, Maine. Apple pomace from the cider operation was mixed with leaf waste from the local waste transfer station, and chicken manure from a local egg farm at a 2:6: 1 ratio by volume. Wood ash was used to adjust the pH to 5.8 prior to composting. Composting reduced the volume of apple-pomace waste by 50% and converted it into a soil amendment with highly desirable characteristics. Newly transplanted trees have impaired root systems, so P fertilizer is often recommended for new plantings. Since P is very immobile in soil, this nutrient is more beneficial when it can be incorporated prior to planting. Research in British Columbia has shown that monoammonium phosphate (MAP 1 1-55- 0) fertilizer, incorporated into the soil used to fill the planting hole, increased tree growth in the first 2years after planting and increased flower production and fruit set in the early years of the planting. The addition of MAP to the planting hole has become a common practice in B.C. orchards, especially when replant problems are anticipated. It has been suggested that root uptake or utilization of P may be more efficient in the presence of ammonium. Moreover, MAP could be influencing tree growth by providing N. This study was performed to determine if pre -plant-incorporated apple-pomace compost and MAP, either alone or in combination, would improve early apple tree growth and precocity. Methods This experiment was conducted at Highmoor Farm in Monmouth, Maine, on land which had been fallow for 6 years, but in continuous apple production Fruit Notes, Volume 67, Winter, 2002 for the previous 37 years. The soil was a fine sandy loam, with a pH of 6.8 and an organic matter content of 4.7% before the addition of fertilizer or compost. Macoun/B. 9 apple trees were planted using a tractor- mounted tree planter on May 1,1998 into plots that had received one of the following combinations of pre- plant treatments: 1 ) urea fertilizer without compost; 2) MAP fertilizer without compost; 3) both compost and urea; and 4) both compost and MAP. Each plot consisted of three trees at a spacing of 6 feet between trees and 18 feet between rows. Cortland/B. 9 trees were planted as a buffer between plots. Prior to planting, MAP was applied to the plots at a rate of 332 lbs. per acre and urea at a rate of 79 lbs. per acre, so that each treatment received an equivalent amount of N (1 .44 oz. per tree). Apple-pomace compost was spread over the planting strip and leveled to a uniform thickness of 4 inches. All plots were then roto-tilled to a depth of 6 inches. The trees were unfeathered whips, headed to a height of 28 inches at planting. The trees were attached to a galvanized conduit stake supported by a single wire at 7 feet. The trees were minimally pruned, and trained to the vertical axis system. Insecticides, fungicides, and herbicides were applied as needed. Results Tree growth was increased by compost, but not by MAP. Compost increased trunk diameter in the first two seasons, but by the third season, trunk diameter was similar in both plots (Figure 1). Annual shoot ;£ 0.8 "S 0.6 E CD ^ 0.4 -^ c .- 0.2 H I I No Compost H Compost 200 One" Two' Three One* Two Three Two Three* Four Three' Figure 1 . Tree growth characteristics with and without pre-plant-incorporated compost. * Indicates that compost had a significant effect in the indicated year after planting. Fruit Notes, Volume 67, Winter, 2002 Table 1. Orchard soil properties following compost (year of planting). soil incorporation of phosphorous or apple pomace Treatment pH Organic P matter (%) (lbs / acre) K (lbs / acre) Mg (lbs / acre) Ca (lbs / acre) Urea 6.4 MAP 6.4 Compost-Urea 6.9* Compost-MAP 6.8* 4.5 4.4 5.3* 5.6* 9.9 13.0 79.6* 86.8* 285 272 679* 612* 291 301 496* 457* 2144 2071 3258* 3093* * Indicates a significant effect due to compost at odds of 1 9 to 1 . growth was increased by compost in the first season, but not significantly in the second or third season. By the third season, tree height was greater with compost. Compost increased the amount of bloom. MAP had no effect on trunk growth, shoot growth, number of growing points, or tree height in any season of the study. We were unable to determine if the increases in tree size and flowering were large enough to increase early yield, because the trees did not attain sufficient size to permit cropping until after the third growing season. The trees in this study were on B.9 rootstock, which is less vigorous than M.9 EMLA, and may be insufficiently vigorous for spur-type varieties such as Macoun in northern New York and New England. Tree growth was increased by pre-plant- incorporated apple-pomace compost, similar to results of other studies that showed organic matter added to the planting hole increased shoot growth and trunk girth. In those studies, the effect of planting hole treatments was no longer evident by the second or third season, and this result was attributed to roots growing beyond the planting hole. In our study, the effect of pre-plant organic matter on trunk diameter and shoot growth also diminished with time. The diminished effects observed in our study were possibly due to the depletion of soil K, Mg, and Ca (data not shown). Soil K in the compost plots was twice as great as in non-compost plots, but this difference was much smaller by the third season. Although trunk and shoot growth differences diminished with time, o 4 3.5 3 2.5 2 H 1.5 1 0.5 0 2.5 S^ 2 E i 1.5 C/) TO CL ' N+— TO ^ 0.5 n No Compost Compost One' Two* Three' One" Two* Three" Figure 2. Leaf nitrogen and potassium with and without pre-plant-incorporated compost. *Indicates that compost had a significant effect in the indi- cated year after planting. Fruit Notes, Volume 67, Winter, 2002 the greater tree height and bloom were evident in the third season indicating that the cumulative effect of compost on tree size was not short-lived. Soil fertility was enhanced by the addition of compost, but little influenced by the addition of MAP, as shown for the year of planting in Table 1. The addition of compost resulted in higher soil pH and cation exchange capacity in each of the three seasons after planting, compared to the plots without compost (data not shown). Compost increased both soil organic matter and P, while MAP and urea had no effect. Compost also increased soil Mg, Ca, and K. Compost increased tree growth and flowering by improving soil fertility and tree nutrient status, and most likely, by increasing soil water holding capacity and soil aeration. An increase in the water holding capacity of the soil would have been advantageous in 1998, when the newly planted trees were generating new roots to replace those lost in transplanting, and in 1999, a season in which little precipitation occurred before September. Foliar nutrient status was favorably affected by compost (Figure 2). Compost increased leaf N and K compared to trees in plots without compost in all three seasons after planting. Leaf P and Ca were not affected by compost. There was no difference between urea and MAP in their effect on leaf N or K, or leaf P, Ca, or Mg. Compost decreased leaf Mg in the first season after planting, but had no effect in the second or third season. The large increase in soil K following compost incorporation may have interfered with Ca and Mg uptake, so that even though soil Ca and Mg were greater, foliar levels were not. Leaf micronutrients were not affected by any of the pre-plant treatments. Pre-plant incorporation of P fertilizer had no effect on tree growth or flowering in this study. In British Columbia, P fertilization previously has been shown to increase flowering when it results in greater leaf P. In our study the soil level of P was within the optimum range before treatment, and was increased to above optimum by compost. Although the level of P in the soil was increased with compost, there was no increase in foliar P. These results are consistent with most previous studies in showing no benefit from P fertilization for apple. Conclusions Pre-plant compost incorporation was more effective than P fertilization for increasing tree growth during the establishment years. The practice of adding P to the planting hole may not be appropriate for Northeastern sites, particularly those where the soil test indicates that P is adequate before planting. Soil incorporation of compost increased tree growth and flowering into the third year after planting. This was most likely due to improved N and K status of the trees, and through improved soil aeration and water-holding capacity. Our results suggest that trees planted in soil amended with apple-pomace compost would poten- tially fill their space more quickly and be able to support more fruit growth in the first years of cropping. Ackno H'ledgem en ts This project was supported in part by a grant from the New England Tree Fruit Growers Research Committee. The authors wish to thank Chick Orchards for supplying the compost, and the technical staff at Highmoor Farm for their assistance with this research. Special thanks go to John McCue, Sheri Koller, and Michelle Handley for maintaining this project during the transition between project leaders. «JU %1^ %j> %1# %1^ #^ ^J^ ^1^ #J^ #1^ Fruit Notes, Volume 67, Winter, 2002 Development of a Model for Predicting Flyspeck Risks in Blocks of Apple Trees Arthur TYittle, Christopher Bergweiler, James Hall, Lisa Reisner, Steven Christie, Wesley Autio, and Daniel Cooley University of Massachusetts For several years, we have been working toward the elimination of summer fungicide applications in apple orchards. The positive economic and environmental impacts of achieving this goal are considerable. Unfortunately, in the absence of fungicides, the severity of flyspeck disease, and to a lesser extent sooty blotch, can be significant. In apple trees which are not sprayed in the summer, flyspeck incidence varies dramatically, from barely existing in some blocks of apple trees to infesting more than half the fhiit in others. How do we decide which trees need spraying and which do not in a given year or month? We know that the flyspeck fungus needs very high relative humidity (97-100 %) to develop. By tracking leaf wetness, rainfall, relative humidity, and temperature we can estimate when specks will first show up in unsprayed trees in or near an orchard. We can also estimate when spray residues will be removed from apple trees by rain, thanks to studies performed by Dave Rosenberger at Cornell University's Hudson Valley Laboratory. It remains a challenge, however, to estimate severity of symptoms at harvest for a given block of trees. Certain characteristics of blocks of apple trees, such as slope, relative altitude in the orchard, and spacing of rows and alleys are likely to influence air drainage and relative humidity in the blocks. The size and openness of tree canopies will also affect the humidity surrounding an apple. The consensus among plant pathologists working with apples is that the inoculum for flyspeck disease overwinters on the waxy cuticle of alternate host plants like blackberry, oak, grape, and maple in wooded or shrubby borders near the apple trees. Within the orchard block, flyspeck does not colonize apple twigs. Flyspeck that grows on fruit is removed at harvest or decays over the winter on drops. The orchard border is home to over 100 species that maintain waxy cuticle suitable for flyspeck and sooty blotch over a 12-month period on first year growth. Many relationships involving the block and the borders seem worthy of investigation. Number and size of borders around a block, distance between a block and its borders, density of alternate host plants in the borders, and density of the fungus on those hosts might all have significant impacts on summer diseases in fruit at harvest. We study these factors and their relationships to flyspeck disease development in order to create a predictive model to help growers safely reduce fungicide inputs. We reported on the first part of this study in the Spring 1996 issue of Fruit Notes. This experiment took place in six orchards over the 1995 and 1996 growing seasons. In each orchard, pairs of similar blocks of apple trees were chosen. Some orchards dedicated as many as 13 pairs of blocks to this experiment. At each orchard, one block received no fungicide after primary scab season (approximately June 15), while the other block was managed according to the grower's preferences using standard first-level IPM. Flyspeck incidence was recorded weekly by examining 200 fruit in each block from late-July through mid-September. For each block, the following orchard site characteristics were evaluated and compared statistically to the flyspeck incidence or severity data: slope of the ground, relative elevation of the block compared to other blocks in the orchard, closeness of shrubby or wooded borders to the apple trees, density of a major alternate host plant in the borders (blackberry), severity of flyspeck infestation on those host plants, and density of apple tree canopies. Table 1 lists the orchard site factors that had the greatest effects on the flyspeck counts that were done in the in 2-week period leading up to harvest in 1995 and 1996. Unless otherwise noted, analyses for this report were performed on data from the blocks which Fruit Notes, Volume 67, Winter, 2002 Table 1. Characteristics of blocks of apple trees or adjacent wooded or shrubby borders that positively affected the amount of flyspeck on apples: in order of significance. August 20 through harvest August 20 through harvest August 29 through harvest 1995 1996 1995, 1996, 1998, and 1999 1. Lack of slope of block 1. Density of flyspeck on 1. Density of flyspeck brambles in border on border host plants 2. Low relative elevation 2. Lack of slope of block 2. Number of borders within the orchard 3. Height of apple trees 3. Closeness of apples to borders 4. Density of brambles in 4. Lack of slope of block border 5. Closeness of apple trees to a border 1 received no summer fungicide. First-level IPM blocks did not have enough flyspeck to analyze. In 1 995, there were more flyspeck symptoms in blocks that were relatively flat than in steep-sloped blocks (r", or amount of variation explained, was 0.17, or 17%), and the amount of flyspeck was higher in blocks that were relatively low in elevation within the orchard (r- = 0. 12). Other factors that had positive but less significant impacts (r^ < 0.03) were height of apple trees, proximity of apples to border areas, and density of host-plants in the borders. hi 1996, the significant site factors (Table 1) were density of flyspeck on host-plants in borders (r^ = 0.13), lack of slope of the block (r^ = 0.05), and height of the apple trees (r^ = 0.04). The factors which contributed only marginally to explaining the variability in flyspeck incidence (r^ < 0.03) were number of borders adjacent to a block of apple trees and proximity of brambles in the borders to the apples. In summary, the site factors that were the most important during 1995 and 1996 (explained at least 10% of the variability) were slope and relative elevation in 1995 and density of flyspeck on host- plants in borders in 1996. In 1997-1999, a different group of blocks was evaluated for site factors and flyspeck infection. In this experiment, two of the key factors were planting density/tree size and IPM level. A main objective of the study was to evaluate the effectiveness of the range of IPM strategies that had been developed using fairly large semi-dwarf trees on plantings that included dwarf trees at high densities. Each of eight participating orchards provided two blocks of low density/large trees, two blocks of medium density/medium-sized trees, and two blocks of high density/small trees. The blocks that had the same planting density were divided into two groups: half were managed with first-level IPM strategies and half with "third-level" IPM strategies. The progression to third-level IPM was marked by the integration of advance pest-management strategies with horticultural strategies at the level of the whole orchard. The third-level blocks, which were seeded with beneficial mites and were managed with biologically- based third-level strategies for insects, received reduced rates or frequencies of fungicide applications, little or no EBDC fungicide, and only captan or benomyl after June 15. The first-level blocks were managed with the growers' choices of materials and frequencies of application. The blocks within a pair were not contiguous. They were often at either end of a long section of 'Mcintosh' or 'Cortland' rows and were bordered by a wide variety of habitats. Some of the 48 blocks were surrounded by other rows of apple trees, some by grassy fields, others by dense woods or shrubby hedgerows. During each growing season, the blocks and their surrounding borders were rated for static orchard factors which had proved significant in the earlier study. Fruit Notes, Volume 67, Winter, 2002 These included: number of borders potentially influencing flyspeck development in an orchard block, distance between the trees and the borders, severity of flyspeck in alternate host plants in the borders, density of host plants themselves, foliar density of trees, height and diameter of tree canopies, slope and relative elevation of the block with respect to the orchard as a whole, and planting density of the block (no. trees/ acre). We examined all known host plants (from the ground to 6 ft. above ground), not just blackberry. Apples in the adjacent blocks were examined weekly or bi-weekly from mid-July to harvest. At the end of each growmg season we looked at the effect of each of the above-mentioned site factors (and all factors combmed) on the amount of flyspeck on the apples, to begin deriving a predictive model for flyspeck mcidence at harvest. Prelimmary stepwise regression analyses done separately for each year suggested the importance of four variables: density of flyspeck on alternate host plants in ttie borders, number of borders, distance from apples to border, and slope of the block. The other site factors did not explain substantial amounts of the variation in flyspeck incidence. Combining data collected from unsprayed control trees from the years 1995, 1996, 1998, and 1999, we conducted a preliminary assessment usingg flyspeck incidence data from various dates. Data from 1997 were not used, because all blocks received summer fungicide sprays. Dates at or near harvest varied from year to year primarily due to cultivar and weather factors. Ultimately, we decided on a range of dates allowing maximum inclusion of orchards in the data set. Data from harvest or near-harvest ranged from 29 August to 23 September for the 4 years used in the analysis. We concluded the static factor phase of model building by combining these four independent variables with the most inclusive range of harvest dates and a fifth derived variable, inoculum index. Inoculum index was expressed as the product of amount of flyspeck on alternate host plants and the density of those plants in t 60 a. S-40 e 20 - a (A c: ■O flyspeck incidence=inoculum index+no. of borders+slope R-=0.27 • • • • ^ • / * * • 0 20 40 60 80 100 Actual flyspeck incidence (% apples infected) at harvest Figure 1. Predicted versus actual flyspect at harvest in Massachusetts orchards, 2000. Fruit Notes, Volume 67, Winter, 2002 orchard borders. The best flyspeck prediction model included inoculum index, number of borders, and slope. We applied the model parameters derived here to flyspeck incidence at 1 3 orchards in 2000 and compared the resulting predicted values with observed flyspeck incidence. The best-fit regression for the data (R^=0.27) is presented in Figure 1. Given the high "background noise" of variability in this kind of investigation (different years, orchards, blocks, sizes of trees, cultivars, prunmg regimens, types of borders, etc.), we were gratified to see almost 30% of the variability in flyspeck incidence explained by these three site factors. We applied the same model in 2001 to predict flyspeck in 1 1 of the same orchard blocks used in 2000. The relationship between model-predicted flyspeck and actual flyspeck in the apples was not close (only 2% of the variability was explained). However, 2001 was very dry during most of the growing season, and 2000 was a very wet year. Weather factors as well as differences in blocks at the different sites may have made a bigger difference in a drier year. We plan to develop a more comprehensive flyspeck model that combines static orchard factors with dynamic weather factors such as leaf wetness and rainfall. It would be useful to adjust for accumulations in moisture during a growing season. We may find that we need different models for wet years as opposed to dry years. The starting point, however, and key factor in rating a block for flyspeck risk will probably always be a measure of how much inoculum is in the orchard border areas at the beginning of the growing season. This study identifies several factors which can combine to produce an environment which supports flyspeck: density of flyspeck on alternate host plants in borders, number of borders, distance from apples to border, and slope of the block. Modification of this environment in a number of ways, such as summer pruning, clearing-back borders or removing host plants or inoculum, or using high-density dwarf plantings could reduce flyspeck pressure considerably. The most stable management plans will involve several strategies, such as border management, orchard design, aggressive pruning, monitoring weather components, and careful fungicide selection and timing. A cknowledgem en ts We are grateful to the growers who participated in the three phases of this study: Keith Arsenault, Gerry Bieme, Bill Broderick, Dave Chandler, Dave Cheney, Aaron and Dana Clark, Tom Clark, Don & Chris Greene, Tony Lincoln, Wayne Rice, Dave Shearer, Joe Sincuk, Tim Smith, Mo Tougas, Bob Tuttle, and Steve Ware & the folks at Davis Farms. This work was also supported by State/Federal IPM Funds, SAKE Grant #97 LNE 97-90 (USDA 96-COOP-1-2700), and a Northeast Regional IPM Competitive grant. *%1^ %S^ %1^ %i^ #1^ ^Tg% ^Jg% ^J^ Fruit Notes, Volume 67, Winter, 2002 Effects of Gibberellin Synthesis Inhibition on Feeding Injury by Potato Leafhopper on Apple Kathleen Leahy, Duane Greene, and Wesley Autio Department of Plant & Soil Sciences, University of Massachusetts Overview Although the gibberellin synthesis inhibitor Apogee (prohexadione-calcium) was introduced in apple primarily as a horticultural tool to reduce shoot length and thereby decrease the amount of necessary pruning and associated costs, the inhibition of gibberellin synthesis has also shown beneficial effects in controlling some important pests of apple. The most dramatic effect has been seen on the shoot-blight phase of the bacterial disease fire blight, but some effects have also been seen on flush-growth-feeding insects such as green apple aphid and obliquebanded leafroller. To date, however, no studies have been published on the effects of Apogee on potato leafhoppers Empoasca fabae (Harris) (Byers et al., 1997; Paulson and Hull, 1999;Yoderetal., 1999). Potato leafhoppers are occasional orchard pests in the mid-Atlantic and Northeast. These insects are not able to winter in the north. They overwinter in the southern United States and migrate northward on storm systems over the course of the spring and early summer. In apple, they feed in vascular tissue in rapidly- developing shoot tissue. In mature trees, this injury is not generally considered serious, although in young trees it may be necessary to apply control measures for a moderate to severe infestation. There is, however, some evidence that potato leafhoppers may play a role in facilitating the shoot-blight phase of fire blight, by introducing feeding wounds in susceptible tissue on which Erwiuia amylovora, the bacterium which causes fire blight, is growing epiphytically (on leaf surfaces), allowing the bacteria to invade the leaf and cause infection (Koehler, 2000; Pfeiffer et al., 1999). Since potato leafhoppers feed directly on tissue likely to be affected by gibberellin synthesis inhibition, we thought that the possibility of suppressing or even completely controlling these leafhoppers with Apogee or a similar gibberellin synthesis inhibitor was strong enough to warrant further study. This work was done as part of a larger study looking at the interactions of gibberellin synthesis and potato leafhoppers with fire blight. Materials & Methods A 200-tree section of a block of 15-year-old Mclntosh/M.7 at Scott Farm in Dummerston, Vermont was used for the study. A randomized-complete -block design was used, with ten replications and two trees per treatment within each replication. Buffer trees were employed within the row, and a buffer row was employed between treated rows. Apogee was applied at the rate and timings recommended for commercial growers in this area, 12 oz per 100 gallons dilute at early petal fall (May 12) and a second application at the same rate when growth would have been expected to resume, June 1 . There were two levels of two treatments used in this experiment: Apogee treated and non-treated, and potato leafhoppers excluded or permitted. The insecticide Provado (imidacloprid) was used for exclusion, at the highly reduced rate of 0.5 oz per 100 gallons dilute recommended by researchers at the Cornell Hudson Valley Laboratory (Scaffolds newsletter, June 2001). Provado was applied when potato leafhoppers began to appear in the orchard, June 22, and was re-applied when numbers appeared to be resurging, July 20. Shoot length was measured using a measuring tape Fruit Notes, Volume 67, Winter, 2002 on five shoots per tree ( 1 0 shoots per tree for the first two sample sessions) at 10-day intervals beginning at petal fall to assess the effectiveness of the Apogee treatment. Potato leafhopper injury was evaluated with a spectrophotometer early in the season, but this method became cumbersome and was eventually supplemented with a visual rating scale of injury, with 0 being no visible injury and 5 being severe injury. Because of the high mobility of potato leafhopper adults, which were the predominant life stage, we did not succeed in getting a reliable count of leafhopper numbers per shoot, hi future studies a field-adapted vacuum cleaner device may be used for this purpose. Results & Discussion Shoot length measurements showed that Apogee had a highly significant effect on shoot growth (Figure 1), both in the presence and absence of potato leafhoppers. Potato leafhoppers arrived later than usual in New England and did not reach high numbers in any location, leading to a fairly low damage level in the control. Using the visual rating scale assessment of leafhopper injury, Apogee and Provado, individually, had a highly significant effect on reducing leafliopper injury (Figure 2). Where both materials were used together, leafhopper injury was singificantly lower than where either material was used alone. On the last assessment date, August 15, 200 1 , the average level of feeding injury where Apogee was used alone was 0.83, where Provado was used alone was 0.78, and where both were used together was 0.3 1 . Untreated control trees showed an injury level of2. 13 for this date. Thus, there appears to be a substantial benefit to potato leafhopper control using Apogee either alone or in combination with insecticide. The mechanism by which gibberellin inhibition affects leafhopper feeding is not known and will be investigated further. The enhanced effect of Apogee plus insecticide may be due to the reduction in new. 40 35 30 - §25- c g 20- -1 15 - 10 5 r. ■^■■-V ■ , Figur Provado only No Treatment Apogee only Apogee + Provado e 1 . The effects of Apogee and Provado on shoot growth of 15-year-old Mclntosh/M.7 trees. 10 Fruit Notes, Volume 67, Winter, 2002 ox a B a O 2.5 0.5 0 1 Notrt Apogee Provado Ap + Prov Figure 2. Potato leatTiopper damage (0-5 scale, with 0 being no injury and 5 being severe injury) on 15- year-old Mclntosh/M.7 trees as affected by Apogee and Provado. untreated leaf area where shoot growth is inhibited. For Apogee alone, it is possible that visual or chemical cues used by the insects are muted by the treatment, or it could be that the leafhoppers begin feeding but find the treated plant unpalatable. Behavioral studies of potato leafhoppers exposed to Apogee-treated and nontreated foliage separately and in choice situations will be conducted to try to elucidate the nature of the response. Regardless of the reason, however, the fact that injury appears to be reduced by the inhibition of gibberellin synthesis is of significance for growers needing to control this insect. Specifically, where Apogee has been used and leafhopper numbers are not exceptionally high, there may be no need for an insecticide directed at the leafhoppers. In cases where a severe fire blight outbreak is in progress and leafhopper numbers are high, an insecticide may still be warranted, and should hopefully have greater efficacy in combination with the Apogee. More work needs to be done to understand the nature of the effects of gibberellin synthesis inhibition on leafhoppers and on to understand the relationship between potato leafhoppers and fire blight. In addition. it would be enlightening to repeat the experiment under higher populations of potato leafhopper and see whether or not the effects continues to hold true, or are muted or enhanced under such conditions. References Byers, R.E., Yoder, K.S., and Smith, A.H. Jr. 1 997. The effect of BAS-125W on apple tree growth, fruit quality and fire blight suppression . HortScience 32:557. Hildebrand, M., Dickler, E., and Geider, K. 2000. Occurrence of Erwinia amylovora on insects in a fire blight orchard. Phytopathology 148:251-256. Koehler, GW. ed. 2000. 2000-2001 New England Apple Pest Management Guide. Maredia, K.M., Whalon, M.E., Gage, S.H., and Kaeb, M.J. 1998. Observations of first occurrence and severity of potato leafhopper Empoasca fabae (Harris), (Homoptera:Cicadellidae) in the North Central and Eastern United States. Great Lakes Entomologist 31:73-84. Paulson, G.S. and Hull, L.A. 1999. Influence of Apogee Fruit Notes, Volume 67, Winter, 2002 11 on selected apple and pear pests. Proceedings, 75th Cumberland-Shenandoah Fruit Workers Conference, Winchester, VA. Pfeiffer, D.G., Killian, J.C, and Yoder, K.S. 1999. Clarifying the roles of whiteapple leafhopper and potato leafhopper (Homoptera:Cicadellidae) in fire blight transmission in apple. J. Entomol. Soc. 34:314-321. Plurad, S.B., Goodman, R.N., and Enns, W.R. 1967. Factors influencing the efficacy of Aphis pomi as a potential vector for Erwinia amylovora. Phytopathology 57:1 060- 1063. Sterner, P.W. and Lightner, G.W. 1992. Maryblyte 4.2: A predictive program for forecasting fire blight disease in apple and pear. University of Maryland. Yoder, K.S., Miller, S.S., and Byers, R.E. 1999. Suppression of fire blight in apple shoots by Prohexadione-calcium following experimental and natural inoculation. HortScience 34:1202-1204. *%3^ %3^ %JU %Si^ ^f% #1^ ^lg% ^j^ 12 Fruit Notes, Volume 67, Winter, 2002 Food Quality Protection Act: An Organopliosphate Update - February 2002 Glenn Morin New England Fruit Consultants, Montague, MA As the six-year anniversary of the Food Quahty Protection Act (FQPA) approaches, EPA continues to focus on the regulation of the organophosphate (OP) compounds. The protocols for tolerance reassessment mandated by the FQPA were previously not described, and the methodology by which they are ultimately evaluated will be used to review the other classes of compounds in the future. Therefore, EPA has proceeded cautiously, opened the procedure to public review, and provided for stakeholder input at each step of the six-phase review process. This process allows for the development of risk- management recommendations by EPA and, when combined with the previously ongoing re -registration process, ultimately results in the publication of a Re- registration Eligibility Document (RED). The RED finalizes the regulatory process and outlines the conditions under which continued use of the product may occur. In the case of the organophosphates, which must still undergo a cumulative risk assessment as a class of compounds (see related article in this issue oi Fruit Notes), EPA has issued Interim Re-registration Documents (IRED). These documents may include risk reduction measures and other label changes that will take effect prior to the final RED, which will be released once the cumulative risks of the OP's have been considered fully. It is anticipated that EPA will conclude its review of the organophosphates sometime later this year. All seven of the active ingredients most commonly used in commercial tree fruit production are currently in the final phase of the individual risk assessment process. The following is a summary of EPA's findings and actions as of February 18, 2002. Azinphos methyl - Initial label amendments for azinphos methyl (Guthion) that effected tree fruit production were voluntarily put in place by the registrants prior to the 1999 growing season primarily in response to EPA's concerns regarding dietary risk to children. Further discussions among the registrants, EPA, and the stakeholder community directed at reducing the risk to agricultural workers and the environment have continued since the release of the revised risk assessment in the summer of 2000. The results of these discussions were made available for public comment on November 28, 2001 in the form of an IRED. This document proposes the cancellation of 28 crop uses (including nectarines), a four-year phase out of seven crop uses (including peaches) and a 4-year, time-limited registration for eight crop uses (including apples, pears, and sweet cherries). Some highlights of the proposed label changes concerning apple production are as follows: limit of 3.5 lbs ai/acre per season east of the Mississippi, 4.0 lbs ai/acre west of the Mississippi; increase REI to 14 days for all activities; require enclosed cabs or maximum personal protective equipment (PPE) for applicators; require closed mixing systems or water soluble bags and closed transfer systems for mixing/ loading; add 25-foot buffer zones for permanent surface water; add spray drift language; and prohibit pick-your-own (PYO) usage or restrict application to early season or establish 30 day pre harvest interval (PHI) for PYO operations. The public comment period for this document ended on January 28, 2002. Questions concerning which label amendments will ultimately be required, the timeframe Fruit Notes, Volume 67, Winter, 2002 13 for implementing these changes, and the disposition of product already in the distribution system remain unanswered at this time. However, the registrant is optimistic that no label changes will take effect for the upcoming growing season. Phosmet - EPA released its revised risk assessment for phosmet (Imidan) at a technical briefing in February 2000. This document indicated that dietary risk was not an issue for this compound and that exposure to handlers could be managed satisfactorily with increased PPE and engineering controls. An IRED for phosmet was made public simultaneously with that of azinphos methyl (AZM) in the fall of 2001. Similar to AZM, EPA's present concerns center around risks to agricultural workers and ecological risks. Proposed agricultural use changes that affect tree-fruit producers fall into two categories: 1) continued registration with new labeling requirements for 33 crop uses (including sweet and tart cherries) and 2) a 5 -year, time-limited registration for nine crop uses (including apples, apricots, nectarines, peaches, pears, and plum/prunes). Some highlights of the proposed label changes concerning apple production are as follows: increase REI to 3 days; require enclosed cabs or maximum PPE for applicators; require water soluble bags and closed transfer systems; add spray drift language; and prohibit application during bloom period. The registrant has reached an agreement with EPA that allows for all product currently in the distribution system or in possession at the farm level to be used under the current label until all inventories have been depleted. All product sold by the registrant after June 30, 2002 will reflect the changes mandated by the IRED. Diazinon - In December of 2000, EPA released its revised risk assessment for this active ingredient. EPA concluded this active ingredient posed significant risk to birdlife as currently labeled and was a common contaminant of surface water. Risk mitigation measures center largely on phasing out, over the next three years, most residential uses of products containing diazinon (Spectracide) whether applied for structural or lawn- care purposes. Although agricultural uses contributed little in this regard, risk to agricultural workers who apply these products or harvest treated crops was of concern. When the IRED IS made public, it is expected that EPA will proposed the cancellation of about 30% of the current agricultural uses and require "Restricted Use" classification for the remaining uses so that applications will be limited to trained, certified applicators. Discussions with the registrant and other stakeholders are ongoing. Malathion - The revised risk assessment for malathion was presented at a technical briefing in November, 2000. Malathion is a lower priority for regulatory action since it is used on less than 10% of the nation's apple acreage. EPA's analysis suggested that dietary risk, drinking water risk, and ecological risks were of little or no concern. However, risks to mixers/loaders/applicators and risk to workers entering treated areas for post-application activities were cited. Although the IRED has yet to be posted, additional personal protective equipment (PPE) for handlers and longer restricted entry intervals (up to 6 days) are expected to be included. Methyl parathion (Penncap-M) - EPA has previously announced acceptance of the registrant's voluntary cancellation of many of the significant food crop uses for this material including apples, peaches, pears, nectarines, cherries, and plums in order to address the Agency's concern of dietary risk to children. Chlorpyrifos (Lorsban) - EPA severely restricted the use of this material on apples, tomatoes, and grapes shortly after the release of the revised risk assessment in August of 2000, again, due to dietary-risk issues. Post-bloom use on apples has been prohibited since December 31, 2000. The IRED was published in the Federal Register on November 14, 2001 for which the public comment period ended in mid January. The first step of the review process mandated by the FQPA is drawing to a close for the organphosphate compounds. EPA will soon conclude the evaluation of these active ingredients on an individual basis. This initial evaluation contains a risk assessment that considers all potential routes of exposure including dietary, drinking water, residential, and occupational means. The second phase, cumulative assessment of the 14 Fruit Notes, Volume 67, 'Winter, 2002 risk posed by OPs as a class of compounds, has already begun. EPA and USDA convened an advisory panel, the Committee to Advise on Reassessment and Transition (CARAT), to assist in this process in February 2000. Dr. Robin Spitko of New England Fruit Consultants is a member of this committee and has been monitoring the proceedings for the tree-fruit industry in the Northeast. Further information can be found at http:// vvww.epa.gov/pesticides. *^1^ ^If ^I^ ^t^ ^{^ ^J^ ^J^ ^1% Fruit Notes, Volume 67, Winter, 2002 15 Food Quality Protection Act: Cumulative Risk Assessment for the Organophosphate Pesticides Roberta Spitko New England Fruit Consultants, Montague, MA The primary focus of EPA's Office of Pesticide Programs activities over the past year has been the development of a cumulative risk assessment for the organophosphate pesticides (OPCRA). This risk assessment is the most complicated, comprehensive attempt to measure cumulative exposure to a particular group of pesticides that has ever been undertaken. The OPCRA final document exceeds 5,000 pages in length. The methodologies developed by EPA to collect and analyze the data are extremely sophisticated and complex and have also been a source of much controversy in the agricultural stakeholder community. EPA is relying heavily on the advice of the FIFRA Science Advisory Panel, a panel of expert scientists, especially those in statistical modeling and toxicology, for validation of the methods used. These methodologies have been developed over the past 5 years, and represent a significant advance in EPA's abilities to evaluate pesticides in a comprehensive manner. It must be emphasized that the current risk assessment, which was released in January 2002 for public and scientific comment, is a preliminary assessment. The Agency expects a large number of comments to be submitted until the comment period closes on March 8, 2002. A cumulative risk assessment is the process of combining exposure (the amount of pesticide to which an individual is exposed) and hazard (the health effects a pesticide could cause) from all substances that share a common mechanism of toxicity. In assessing hazard associated with the organophosphate pesticides, EPA analyzed their common method of toxicity, inhibition of acetylcholinesterase, as the means for assessing risk. The goal of the organophosphate cumulative risk assessment (OPCRA) is to measure the probability of exposure to more than one organophosphate pesticide and to assess the effects of this combined exposure. The assessment incorporates possible OP exposures from structural, recreational, and drinking water, as well as from OP residues in consumed food. Each component of the risk assessment uses the best available data: data from surveys of what people eat and drink, of their activities involving pesticide use around the home and workplace, and monitoring studies of pesticide residues in these environments. A comprehensive assessment of the organophosphates may raise concerns with growers about further restnctions on materials available for crop production. However, the results of the OPCRA may not have much effect on current OP use. Much work has been done previously on the individual organophosphates to reduce their risks as they go through the FQPA-mandated tolerance reassessment process. The risks for the individual OPs will be factored into the cumulative equation at these lower levels. Most structural and home-garden uses have already been cancelled or significantly curtailed. Routes of exposure through drinking water have already been determined to be negligible. It must be noted again that the recently released OP cumulative risk assessment is preliminary. EPA is continuing to seek input from the scientific community and stakeholders and is aware that revisions and refinements will be necessary. Determining cumulative exposure is a huge task, and this is the first time EPA has attempted develop a comprehensive profile of human exposure to a group of chemicals with common modes of toxicity. It will be an evolving process that will take years to refine. Following the comment period closure of March 8, 2002, EPA will consider submitted comments and plans to issue a revised risk assessment in the summer of2002. The preliminary OPCRA may be accessed at www.epa.gov/pesticides/cumulative. *%X^ %1> %i^ %9^ ^J^ ^J^ ^f% ^J^ 16 Fruit Notes, Volume 67, Winter, 2002 Commercial-orchard Evaluation of Traps for Monitoring Plum Curculio: 2001 Results Ronald Prokopy, Brad Chandler, and Jaime Pinero Department of Entomology, University of Massachusetts In the 2000 issue oi Fruit Notes, we reported our year 2000 tests in which we compared odor-baited with unbaited traps of three types (pyramid, cyHnder, and Circle) for monitoring plum curculios (PC's) m commercial apple orchards. Results suggested that traps baited with grandisoic acid alone (= synthetic male sex pheromone) captured no more PC's than unbaited traps. However, when grandisoic acid was combined with any one of three different synthetic host fruit volatiles (benzaldehyde, ethyl isovalerate, or limonene), captures by baited traps were about twice as great as captures by unbaited traps. Addition of the synthetic fruit volatiles decanal, hexyl acetate, and trans-2- hexenal to grandisoic acid did not enhance captures. Here, we report results of 2001 studies in commercial orchards in which we further evaluated the best odor combinations found in 2000, again in association with pyramid, cylinder, and Circle traps. Materials & Methods The three types of traps were: (a) black pyramid traps (24 inches wide at base x 48 inches tall) placed on the ground next to apple tree trunks, (b) black cylinder traps (3 inches diameter x 1 2 inches tall) fixed vertically onto horizontal branches within tree canopies, and (c) aluminum-screen "Circle" traps (developed by a grower named Edmund Circle in Alabama for pecan weevil), wrapped tightly around the base of tree trunks so as to completely encircle the trunk and afford maximum chance of intercepting adults walking upward. The three synthetic components of host fruit odor were benzaldehyde, ethyl isovalerate, and limonene. Each was purchased from Aldrich Chemical Company and was deployed in small polyethylene vials that fit into the screen-funnel top of a boll weevil trap that capped each pyramid, cylinder, or Circle trap. The release rate of each compound was about 10 milligrams per day (achieved by adjusting the type or number of vials per trap according to compound volatility). Each baited trap also contained a plastic dispenser of grandisoic acid (obtained from Great Lakes IPM) designed to release about 1 milligram of pheromone per day. Traps were deployed in four plots of apple trees in each of 12 commercial orchards. Each plot consisted of seven perimeter trees. Each tree (save one) contained one baited or one unbaited trap of the above three types. All three baited traps in a plot received the same odor. In each orchard, each of three plots received a synthetic fruit volatile in combination with grandisoic acid. The fourth plot received grandisoic acid alone. All traps were deployed at pink (May 2-4). Traps were examined for captured PC's beginning at petal fall (May 14-16) and every 3-4 days thereafter for 7 weeks until June 28-30. Vials of benzaldehyde and dispensers of grandisoic acid were renewed on May 28-30 (about mid-way through the experiment). At each trap examination, 10 fruit on each of the six trapped trees per plot (= row 1 trees) and five fruit on each of six corresponding but untrapped trees on interior rows 3,5, and 7 were examined for PC oviposition scars. In all, 102,800 fruit were examined for PC injury. All plots received two or three sprays of azinphosmethyl or phosmet to control PC. Results Figure 1 shows that across the entire PC season, Circle traps baited with benzaldehyde plus grandisoic acid (GA) captured numerically more PC's than any other type of baited or unbaited trap, although not significantly more than unbaited Circle traps in the Fruit Notes, Volume 67, Winter, 2002 17 a. 2-5 1 I i 2 L I : 1-5 ; 1 2^ a I BEN+GA IB baited D unbajted BC BC BC 2.5 - EIV-KJA . ■ baited D unbailed 1 2 • Q. AB AB ^_ AB = 1- C ^ 0.5 - BC BC 0 ■ BC a. 0.5 pyramid cylinder LIM+GA Circle e baited D unbailed pyramid cylinder Circle AB AB AB BC •»H"- 2.5 • GA @ baited D unbailed 2 ■ AB 1.5 ■ ^■1 AB HH 1 ■ HH BC OS ■ BC BC BC B~ n ■ «W pyramid cylinder TRAP TYPE Circle pyrannid cylinder TRAP TYPE Circle Figure 1. Mean number of PC's captured by each type of odor-baited and unbaited trap placed on perimeter-row trees. Among all bars in this figure, those superscribed by the same letter are not significantly different from one-another at odds of 19 to 1 . 1 - 0.8 - 0.6 ■ 0.4 0.2 0 BEN+GA ■ baited D unbaited I -\ 0.8 0.6 0.4 0.2 0 pyramid cylinder LIM+GA Circle ■ baited D unbaited 1 1 0.8 0.6 0.4 0.2 0 EIV+GA @ baited D unbaited pyramid 1 0.8 0.6 0.4 0.2 ■ 0 cylinder GA Circle B baited D unbaited BWP |V*^J_ 3_ pyramid cylinder TRAP TYPE Circle pyramid cylinder TRAP TYPE Circle Figure 2. For each trap type, degree of correlation between total amount of PC captures on perimeter- row traps and percent sampled PC injury to fruit on penmeter-row trees in plots having that odor. The higher the R^ value, the greater the extent of the correlation. An asterisk (*) indicates a statistically significant correlation at odds of 19 to 1. 18 Fruit Notes, Volume 67, Winter, 2002 1 0.8 0.6 0.4 0.2 0 1 0.8 0.6 0.4 0.2 0 BEN+GA ■ baited D unbaited 1 -l EIV+GA ■ baited D unbaited 0.8 - 0.6 - 0.4 - 0.2 - ■H 1 n- ^=r^ . pyramid cylinder LIM + GA Circle @ bailed D unbailed pyramid pyramid cylinder TRAP TYPE Circle 1 0.8 0.6 0.4 0.2 0 cylinder GA Circle @ baited □ unbailed j: J I pyramid cylinder TRAP TYPE Circle Figure 3. For each trap type, degree of correlation between phenology (time during the season) of PC captures on perimeter-row traps and phenology of mjury to fruit on perimeter-row trees m plots havmg that odor. The higher the R^ value, the greater the extent of the correlation. There were no statistically significant positive correlations. same plots, or Circle traps baited with ethyl isovalerate plus GA, limonene plus GA, or GA alone. For each type of odor bait, pyramid and cylinder traps captured numerically fewer PC's than Circle traps. Figure 2 shows, for each odor and trap type, the degree of correlation between the total (season-long) amount of PC captures and the percent sampled perimeter-row fruit injured by PC's in plots having that odor and trap type. A significant positive correlation would indicate that orchards which showed comparatively many captures for a given odor and trap type also showed a comparatively large amount of PC injury, whereas orchards which showed comparatively few captures also showed a comparatively small amount of PC injury. Among all odors and trap types. Circle traps baited with benzaldehyde plus GA showed the highest degree of positive correlation (0.75) between trap captures and injury. What this means is that after the PC season has ended, one can look back and say with high confidence that the extent of PC captures by Circle traps baited with benzaldehyde plus GA reflected quite well the extent of PC injury that occurred on trapped and other trees in the same plot. Figure 3 shows, for each odor and trap type, the degree of correlation between the phenology (time of season) of PC captures and the phenology of PC injury to perimeter-row fruit in plots having that odor and trap type. A significant positive correlation would indicate that a sampling period during which comparatively many trap captures occurred also was a sampling penod in which a comparatively large amount of injury was initiated, whereas a sampling period during which comparatively few (or no) trap captures occurred was a sampling period in which comparatively little (or no) fruit injury was initiated. Among all odor and trap types, no trap showed a significant positive correlation between phenology of captures and phenology of injury. In fact, the highest degree of positive correlation for any trap type was only 0.20, and the correlation for Circle traps baited with benzaldehyde plus GA was a mere 0.01. What this means is that during the PC season, one could not have any confidence whatsoever that the extent of PC captures during any particular 3- to 4-day period reflected the amount of PC injury that was initiated during that period, even for the best-performing trap. A deeper look into the phenology of captures by Circle traps baited with benzaldehyde plus GA and the Fruit Notes, Volume 67, Winter, 2002 19 1.2 1 r ^ 1 - \ '* - 5 MEAN No. 0.8 - \ - -•- - INJURY - 4 MEAN % PCs TRAPPED 0.6 - \ * . 3 FRUIT INJURY 0.4- Vii^---^-^'*'"^---^^ - - 2 0.2 - A . * * * - 1 U n r U PK-PF 0-2 WK AFTER 2-4 WK AFTER 4-6 WK AFTER PF PF PF Figure 4. For Circle traps baited with benzaldehyde plus GA, a graphic display of PC captures and | amount of PC injury to fruit during each of four 2-week periods from pink (PK) to 6 weeks after petal fall (PF). 160 ■ Gab, Fuji, Jonagokd D Mcintosh, Empire ■ Gala, Fuji, Jonagokd n Mcintosh, Empire TRAP CAPTURES FRUIT INJURY Figure 5. Total captures of PC's on perimeter-row traps and PC injury to perimeter-row fruit in six blocks of apple trees comprised of Gala, Fuji, or Jonagold as perimeter-row cultivars versus six blocks comprised of Mcintosh or Empire as perimeter-row cultivars. phenology of PC injury is helpful in understanding the lack of relationship between these two entities. As shown in Figure 4, PC captures were greatest during the period of pink to petal fall but were low during each 2-week period thereafter. Conversely, PC injury to fruit was low (about 1 .5%) during the first 2 weeks after petal fall, but increased in essentially a linear fashion until 4 to 6 weeks after petal fall, when it reached about 5.3%. Thus, the trends depicted in Figure 4 show clearly that the steady rise in PC fruit injury on perimeter-row trees from petal fall to 6 weeks thereafter was not accompanied by a rise in PC captures by perimeter-row Circle traps baited with benzaldehyde plus GA, accounting for the lack of correlation between these variables. Figure 5 shows that PC captures by all perimeter- row traps combined and PC injury to perimeter-row fruit were about 60% and 140% greater, respectively, 20 Fruit Notes, Volume 67, Winter, 2002 I? 140 1 120- 100 80 60 40 20 0 ■ woods D hedge Dopen TRAP CAPTURES E r .2, * = 9 5 1 ■ woods D hedge 4 • 1 . Dopen 2 ■ 1 - 0 ■ FRUIT INJURY Figure 6. Total captures of PC's on perimeter-row traps and PC injury to perimeter-row fruit in blocks of apple trees whose front rows bordered woods, hedgerow, or open field (four blocks of each type). in blocks having Gala, Jonagold, or Fuji as perimeter- row cultivars, compared with blocks having Mcfritosh or Empire as perimeter-row cultivars. The average number of insecticide sprays applied against PC was the same in each case (2.7). Figure 6 shows that PC captures by all perimeter- row traps combined were greatest for blocks bordered by woods, intermediate for blocks bordered by hedgerows, and least for blocks bordered by open field. However, PC injury to perimeter-row fruit was greatest for blocks bordered by open field. The average number of insecticide sprays applied against PC was about the same in each case (2.8, 2.8, and 2.5, respecfively). Figure 7 shows that season-long PC injury to fruit on perimeter-row trees (row 1) averaged about 12 times greater than on trees of interior rows 3, 5, or 7. U Oh S a ROW Figure 7. Mean percent PC-injured fruit on perimeter-row trapped frees(row 1) compared with injury on non-trapped trees of interior rows 3, 5, and 7. Fruit Notes, Volume 67, Winter, 2002 21 Conclusions Circle traps baited with benzaldehyde plus GA, when positioned so as to completely surround trunks of perimeter-row apple trees, captured numerically more PC's than any other trap type and afforded a strong positive correlation between total amount of trap captures and total amount of PC injury to perimeter- row fruit. The year 2001 was the first year we used Circle traps in this position on a tree (formerly they were placed on lower limbs near the trunk and provided a weaker correlation between total captures and total injury). The strong correlation obtained in 2001 suggests that tree-trunk Circle traps baited with benzaldehyde plus GA, if distributed along perimeter- row apple trees, can be an excellent indicator of "hot spots" requiring special attention for controlling PC as well as "cool spots" requiring lesser attention. Unfortunately, no trap type showed even a moderate positive relationship between the time of occurrence of PC captures and the time of occurrence of PC injury to fruit. As depicted in Figure 4, even for our best trap type (tree-trunk Circle traps baited with benzaldehyde plus GA), captures fell off dramatically soon after petal fall, whereas fruit injury rose steadily. Thus, even for this best trap, the data obtained in 200 1 indicate that low trap captures after petal fall cannot be relied upon as indicative of the lack of need to spray against PC. As revealed by other studies that we conducted in 2001 , there are at least three reasons why all three types of traps used here may fail to capture representative numbers of PC's active in canopies of commercial orchard trees after petal fall. First, organophosphate insecticide spray droplets falling on traps can be repellent to PC's for 10 days or more after application. Such droplets can also be repellent when on tree limbs and branches, but repellency apparently is substantially overcome by positive chemical stimuli inherent to surfaces of limbs and branches. Such positive stimuli are lacking on surfaces of current traps. Second, at temperatures greater than about 70°F, especially when accompanied by sun, PC's tend to fly directly into tree canopies, thereby bypassing Circle and pyramid traps associated with tree trunks. Temperatures tend to be higher than 70°F after petal fall. Third, the release rate of benzaldehyde from vials placed inside of trap tops ( 1 0 milligrams per day) is sufficient to attract PC's from a distance, but may be repellent at close range. As tree fruit grow and themselves release increasing amounts of benzaldehyde and other attractants, there may be an increasing tendency for attractive volatiles from the fruit to outcompete attractive volatiles placed in traps. Our attempts to increase the amount of benzaldehyde used in association with traps, so as to be more competitive with fruit volatiles, have been accompanied by a decrease (rather than an increase) in PC captures owing to repellency. Together, these three shortcomings may limit the usefulness of Circle, pyramid, and cylinder traps placed at or within canopies of commercial-orchard trees for monitoring the extent of threat by PC's after petal fall. Both cultivar composition of perimeter-row trees and border area composition had an influence on extent of trap captures and fruit injury by PC. As in 2000, perimeter-row trees of Gala, Jonagold, or Fuji experienced considerably more PC pressure than perimeter-row trees of Mcintosh or Empire, even though there was no difference in frequency of insecticide applications. Also, as in 2000, trap captures were greater in blocks bordering woods than in blocks bordering hedgerows or open field. Finally, PC injury to fruit on trees that received traps was far greater than PC injury to fruit on interior trees, suggesting that attractive odor placed on perimeter-row trees acts to concentrate PC's there and reduce penetration into the orchard interior. Ackno wledgm ents. We are grateful to the following growers for participating in this study: Keith Arsenault, Gerry Beime, Bill Broderick, Dave Chandler, Tom Clark, Don Green, Tony Lincoln, Joe Sincuk, Mo Tougas, and Steve Ware. This work was supported by Massachusetts State Integrated Pest Management Funds, Northeast Regional Competitive Integrated Pest Management Funds, Northeast Regional Sustainable Agricultural Research and Education Funds, and the New England Tree Fruit Growers Research Committee. *%1# %i^ %3^ ^f^ ^j^ ^j|% ^1^ ^j^ 22 Fruit Notes, Volume 67, Winter, 2002 An Odor-baited "Trap-tree" Approach to Monitoring Plum Curculio Ronald Prokopy Department of Entomology, University of Massachusetts As described in the preceding article, there are shortcomings associated with placement of plum curculio (PC) monitoring traps in commercial orchards for purposes of determining when a spray is needed to protect fruit against PC damage. Shortcomings are particularly evident during the middle and latter part of the PC season, when trap captures remain low irrespective of trap type or attractive odor, but damage increases. One of the principal shortcomings involves need for baiting traps with an increasing amount of synthetic attractive fruit odor as the PC season progresses in order that odor might compete effectively with the increasing amount of attractive odor emitted by developing fruit in the tree canopy. When used in association with traps, increasing amounts of synthetic fruit odor become repellent at close range. One possible solution to this dilemma could be to create a "trap tree" where the tree canopy itself is baited with a high amount of attractive fruit odor. Rather than using amounts of PC's captured by traps as a potential but indirect indicator of level of PC egglaying activity, one would use amount of freshly injured fruit on the trap tree as a direct indicator. A few such trap trees per orchard could provide valuable information on sudden rises in PC damage and hence on the need to apply a protective spray. Placement of attractive odor directly on tree branches would eliminate problems of close- range repellency associated with placement of odor on or in traps. In 200 1 , 1 conducted a preliminary trial of this new lij 0. U. LU HI 3 C^ 6 -I 5 - 4 - 3 - 2 - ■ BAITED TREES dUNBAITED TREES WEEKS AFTER PETAL FALL Figure 1. Amount of fruit injured by plum curculio on baited perimeter-row trap trees and on unbaited trees midway between trap trees. Fruit Notes, Volume 67, Winter, 2002 23 approach to monitoring PC's in a small block of apple trees in Clarkdale Fruit Farm in Deerfield. Materials & Methods The entire study was conducted along a 125-yard section of perimeter-row apple trees bordered by woods. The trees were mixed cultivars on M.26 rootstock. On May 2 (mid-pmk), every sixth tree was baited with two dispensers of grandisoic acid (each releasing about 1 mg per day) and eight dispensers of benzaldehyde (each releasing about 10 mg per day). All dispensers were replaced with fresh ones on May 30. One week after petal fall and weekly for 4 more weeks, 20 fruit were examined on each of the five trap trees and on each of four unbaited trees midway between trap trees. Fruit were counted as injured if a PC egglaying scar was evident. The trees received two applications of insecticide to control PC without use of fi-uit sampling information in guiding timing of spray. Results Figure 1 shows that fruit injury on the baited-trees averaged about eight times greater than on unbaited trees for samples taken at weeks 1 and 2 after petal fall and about five times greater than on unbaited trees for samples taken at weeks 3, 4, and 5 after petal fall. As the PC season progressed, some of the injured fi-uit on both types of trees fell to the ground, but total injury remained the same or increased owing to appearance of fresh injury. Conclusions The results of this preliminary test are very encouraging in that baiting perimeter-row trees with attractive odor acted to concentrate immigrating PC's on the "trap trees." Further research is necessary to optimize the composition and amount of attractive odor before this approach can be recommended for widespread use in monitoring PC's in commercial orchards. Conceivably, a few odor-baited "trap trees" along perimeter rows of an orchard might serve not only as focal trees for monitoring extent of fresh injury caused by PC but, if sufficiently attractive, might also serve to aggregate enough of the immigrating PC population to permit spraying only trap trees, allowing other trees to remain unsprayed against PC. Ackno wledgm ents Thanks to Tom Clark for cooperating in this experiment, and Jaime Pifiero for preparing the figure. *%S^ %i^ %3^ %ju ^j^ ^f% ^g% #j^ 24 Fruit Notes, Volume 67, Winter, 2002 Name: Orchard Name: Address: City, State, Zip Code: Subscription Renewal If your address label has 1999. 2000, or 2001 in the upper right-hand comer, then your subscription has expired, and this will be you last issue. If you wish to continue to be a subscriber, please check the mailing label (on the back cover of this issue, i.e. the reverse side of this form) and correct the information as necessary. Choose the number of years for your subscription, and return the form with a check for the appropriate amount. Thank you. CHECK ONE: One year Two years Three years 1 $10.00* D $19.00* J $27.00* Subsciptions for non-US addresses are $12, $22, and $32 for one, two, and three years, respectively. Make check payable in US currency to: UNIVERSITY OF MASSACHUSETTS. Send this form along with payment to: Fruit Notes of New England Department of Plant & Soil Sciences 205 Bowditch Hall University of Massachusetts Amherst, MA 01003-9294 Fruit Notes, Volume 67, Winter, 2002 25 Fruit Notes University of Massachusetts frOH Department of Plant & Soil Sciences ilOteS 205 Bowditch Hall tliyU Amherst, MA 01003 Nonprofit Organization U.S. Postage Paid Permit No. 2 Amherst, MA 01 002 --1 SERIAL SECTION UMASS AMHERST, MA 01003 Account No. 2-22914 Table of Contents Flyspeck Disease Management: Comparison of Flint versus Captan m Every-row versus Perimeter-row Sprays A. Baj, A. Tuttle, and D. Cooley 1 Thmnmg Mcintosh Apple Trees With Blossom Thinners, With and Without Post-bloom NAA: A Report to the New England Tree Fruit Growers Research Committee J. Schupp and D. Greene 9 Evaluation of New Apple Varieties, 1998 Observations: A Report to the New England Tree Fruit Growers Research Committee D. Greene 13 Influence of Odor-bait, Cultivar Type, and Adjacent Habitat Composition on Performance of Perimeter Traps for Controlling Apple Maggot Flies S. Hoffmann, R. Mittenthal, B. Chandler, G. Lafleur, S. Wright, P. Appleton, M. Becker, 5. Dynok, and R. Prokopy . .20 Editors: Wesley R. Autio William J. Bramlage Publication Information: Fruit Notes (ISSN 0427-6906) is pub- lished each January, April, July, and October by the University of Massachu- setts in cooperation with the other New England state universities. The costs of subscriptions to Fruit Notes are $10.00 for United States ad- dresses and $12.00 for foreign ad- dresses. Each one-year subscription begins January 1 and ends December 31. Some back issues are available for $3.00 (United States addresses) and $3.50 (foreign addresses). Payments must be in United States currency and should be made to the University of Massachusetts. Correspondence should be sent to: Fruit Notes Department of Plant & Soil Sciences 205 Bowditch Hall University of Massachusetts Amherst, MA 01003 All chemical uses suggested in this publication are contingent upon continued registration. These chemicals should be used in accordance with federal and state laws and regulations. Growers are urged to be familiar with all current state regulations. Where trade names are used for identification, no company endorsement or product discrimination is intended. The University of Massachusetts makes no warranty or guarantee of any kind, expressed or implied, concerning the use of these products. USER ASSUMES ALL RISKS FOR PERSONAL INJURY OR PROPERTY DAMAGE. Issued by UMass Extension, Stephen Demski, Director, m furtherance of the acts of May 8 and June 30, 1914. UMass Extension offers equal opportunity in programs and employrtienl. Flyspeck Disease Management: Comparison of Flint versus Captan in Every-row versus Perimeter-row Sprays Andrew Baj, Arthur Tuttle, and Dan Cooley Department of Microbiology, University of Massachusetts In 2001, we began a 4-year study to evaluate new This study seeks to determine if the strategy of pesticides (in this case, the environmentally benign spraying only the two perimeter-rows in blocks of apple fungicide, Flint, for flyspeck disease) for apple pests trees during the summer months is adequate to man- and a pesticide-reduction strategy (spraying only the age the disease at six orchards in Massachusetts. If two rows of apple trees on the perimeter of the block), proven efficacious, this strategy could help offset high Flyspeck (FS) disease, like apple maggot fly and plum costs of new materials and help reduce the pesticide curculio, survives the winter on or in plant material in load on the environment, the wooded or hedgerow borders and often infests an orchard block with a significant disease gradient which Materials & Methods decreases with distance into the block (Cooley, 1996). The 2001 insect pest management results of the study The experiment took place in blocks of apple trees were reported in Fruit Notes 66:14-18. at orchards in six Massachusetts towns: Harvard, Ber- xxxxxxxxxxxxxx xxxxxxxxxxxxxx xxxx xxxxxxxxxxxxxx xxxxxxxxxxxxx xxxxxxxxx xxxxxxxxxxxxxx xxxxxxx xxxx xxxxxxxxxxxxxx xxxxxxxxxxxxxx xxxxxxxxxxxxxx xxxxxxxxxxxxx xxxxx xxxxxxxxxxxxx xxxxxxxxxxxxx Border area Border area Border area Border area Flint (2.0 oz./acre) Captan 80 (2.5 Ib./acre) Flint (2.0 oz./acre) Captan 80 (2.5 Ib./acre) 4- + + + -1^ + + + -H -I- -I- 4- -I- -I- -I- + -I- + + + + + + + -I- + + + -I- -I- -I- -I- -I- -t- -I- -I- + + + + + + + + + + + + + + + -I- 4--I- -I--I- + + + + + + + + + + + + + + + + + + + + + + + -(-+ + + + + + + + + + -I- + -1- -t- -I- + -t- + + -I- + + -(- + + -I- -1- -H -I- -I- -I- -I- -I- -I- -I- -I- -I- + + + + + -1- 4- + + -I- + -I- -I- -I- -I- -(- -I- -I- + + + + + + + + + -I- -I- -I- + -I- 4- + + -I- + + + + + + + + + Key: + = sprayed tree, — = unsprayed tree, X = trees, shrubs, and vines Figure 1 . An example of a perimeter-row spray block with fungicide rates in six Massachusetts apple orchards, 2001. Fruit Notes, Volume 67, Spring, 2002 Key: Each block below represents a block of apple trees 7 rows deep by approx. 35 trees wide. Cardinal directions are noted with a capital letter. Principal border is shown at top of block. Host density ratings ranged from 1 (none to very few scattered) to 4 (continous deep patches of host plants). Flyspeck (FS) density ratings range from 0 (none) to 3 (high). Berlin Site Harvard Site W Woods Host den. 4 FS den. 2 S Woods N Woods Host den. 4 Host den. 3.5 FS den. 2 FS den. 1 Hawley Site E Woods Host den. 4 FS den. 0 (ns) S Woods Host den. 4 FS den. 0 (ns) Warren Site W Woods Host den. 3.5 FS den. 1 S Hedgerow Host den. 2 FS den. 0 (ns) W Hedgerow Host den. 3 FS den. 1 N. Brookfield Site N Woods Host den. 3.5 FS den. 1 W Hedgerow Host den. 2.5 FS den. 1 Shelburne Site E No Borders within 1 00m Figure 2. Evaluation of alternate host density and flyspeck (FS) density in border area habitats at six apple orchards in Massachusetts, 2001 . Fruit Notes, Volume 67, Spring, 2002 Table 1 . Fungicide application schedule for 6 orchards in Massachusetts, 2001. Site Harvard 23-May 31 -May 18-Jul 08-Aug Berlin 23-May 31 -May 13-Jun 18-Jul 08-Aug Warren 25-May 02-Jun 16-Jun 19-Jul 10-Aug N. Brooktleld 25-May 02-Jun 24-Jun 19-Jul 10-Aug Shelbume 24-May 01-Jun 18-Jul 09-Aug Hawley 10-Jun 18-Jul 09-Aug * Bold-face font indicates full cover spra> ; otherwise 2 row vs. 7 row spray applied. lin, Warren, North Brookfield, Shelbume, and Hawley. Cultivars within the blocks were primarily mid-to-late season, with planting densities ranging from 100 to 1000 trees per acre. The minimum block size was seven rows deep by 28 trees long (Figure 1). Rows of trees were divided into four sections, by colored flagging, to correspond with the four separate post-petal-fall pesticide treatments. There were two treatments us- ing new, environmentally friendly materials (the fun- gicide, Flint, and the insecticide, Avaunt) and two treat- ments using conventional materials (the fungicide, cap- tan, and the insecticide, Guthion). For each of these treatments, there was a two-row perimeter-spray plot and a full seven-row spray plot. During the early season (up through petal-fall) the growers applied fungicides of their choice. Petal-fall occurred in mid-May at five of the six sites, with the exception being Hawley, which reached petal-fall on May 31. After petal-fall, the sites were sprayed ac- cording to the experimental protocol with the University's air-blast sprayer. In early June, border areas within 100m of the ex- perimental blocks were surveyed for alternate FS-host density and density of FS on such hosts. Host density was estimated on a four-point scale, and FS density was estimated on a three-point scale after examining known host plants throughout the border for fifteen minutes (Figure 2). If any FS was found, a more pre- cise measure was taken by examining 25 stems on al- ternate hosts every 1 Om along the border. Sprays applied by the University (Table 1 ) prior to June 10 were full cover sprays, meaning all trees re- ceived fungicide. Captan 80 was applied at 1.75 pounds/acre and Rubigan at 4.0 ounces/acre. At three sites, scab persisted, so one additional unplanned cover spray was needed in mid-June. For such applications, Flint was applied at 2 ounces/acre. Fungicides were applied twice in the summer, with one spray on July 1 8 or 1 9 and the other on August 8 or 9. The two Flint treatments were applied to trees at a rate of 2.0 ounces/acre, and Captan 80 was applied at 2.5 pounds/acre. All sprays were delivered with the equivalent of 150 gallons per acre. FS counts began July 15. One hundred fruit were sampled in rows 1,3, 5, and 7, in each of the four spray treatments. Four hundred fruit were counted per treat- ment, and 1600 fruit per block. Distance between rows ranged from 8m (Shelbume) to 3m (Hawley). The sample area was comprised of the bottom 6 feet of fruit, on all sides of the tree. The typical sample was 20 fruit, from five trees, within each row. Also, the first and last tree of each row, for each treatment, was not sampled, since such trees could have been affected by spray drift. Samples occurred weekly or semi weekly until early September, when they were conducted weekly. Counts continued until harvest, with the last count on October 1 . Fruit Notes, Volume 67, Spring, 2002 r- »2 s? ? 2 S? vO ^ sO 0^ 0^ 0^ S? -^ sO N? N? 0^ 0^ 5^ tf^ 2 JS s? ^ nO vO v^ ^ 0^ 0^ 0^ tfN .0 ^ 0^ 0^ ss ^ 0 ZZ 0 0 00^ ■^ 0 0 <*1 0 0 0 ■^ 0000 0 0 0 0 g Di •0 o w o 0 [- T m r- — CO fS - ^- V " 0 v (^ (N 0 — ^ 0 0 0 0 "« f3 a> o =s •= 0 E ul ^5 E o f-) ■o ^c * > 0 0. * fu 0 — (N r^i (^J — (N 0 — ' z z z z J= U- -o ^ rt c ^ o w a. >* S I Vl c= u CJ ^ § I __»/-,_ — _ "* — 00 ^ ^ TT "^ ^ c^ rn r^ rn m 0 « 0^ °^ ON On ON < < < < — — 0 _ ■5 ra oj rn si ^ ^ r-l '^ yr, '^ yr, rr\ Os -t ^^ 5 -^ r*-i r- r- r- r- -? r- ^r-r-- z z z z O^ OS 0^ ON S^ _1J TD ^ "H CL U 5^ rt 0 V- C^ 0 c ^ (/I E E E E 0 _u 0000 CL 0000 2 Cl CO *-- j: «-. SI *^ JZ — .c SZ. JZ SZ ■^ ji: w w « — — j= — j= — J= — J= c c c c x: ^ -C w C 0 ao t/> ^ Wl w ^ w 5 W 3 1/1 ■— D 3 3 1/5 > 0 0 0 0 > c/^ on on -> on > ss&> zS^ 0 z ^ z 3= z "s ? ? S LU UJ on ^ 0 m 00 ^ ■0 2 c «-° 0 ii 0 OJ 0 OJ (U 0 1> a> m u w J 3 It 3 u "3 (u "5 i> "3 u "5 u "5 u 3 w 3 0 -3 OJ 3 u "5 -u 3 D. D. t^ a. '^ D- (;= a.^ CL c: a-c: 0.^ a. <;= D. ^ CLt^ CH^ Q."*: CL u. u - TO t f U 0 '^' ca ■^ E -0 1» ,— 0 0 0 0 0 0 VI 0 3 2 '-0 0 ■0 c 0 « 00 00 00 c 00 c 00 c 00 c: -0 Sbg « nJ eg CS 2 — 2 •0 0 if C P3 a. C H. c D. C 0. C H. c a. c i'r <"^ 3 U rt «i — « 'SZ cq cs -jz rt Oij , c E u. i: U iZ 0 u- U u. U tZ 0 u. CJ U- OJ -0 ^ II 0 _ ra ■a 0 u JD U— "o H G u P3 M c CL c ? -0 c t 0 >^ ra F CQ 0 oa Z 3 u 1 a: 0 C * * « « « Fruit Notes, Volume 67, Spring, 2002 f, ^n aj zu > u S "S I'; - X a (/5 ■a .4^ s « C u 100 80 60 40 20 H 0 -20 - -40 - -60 -80 Perimeter-rows captan treatment r^=0.10 95% Confidence Interval 0 10 20 30 40 50 — I — 60 70 Distance to Principal Border (m) Figure 4. Percentage of apples infected with flyspeck at harvest versus the distance to princi- pal border (parallel to the block): Harvard, Berlin, Warren, North Brookfield, perimeter-rows captan treatment, 2001 . FS was discovered in row 1 at the Harvard site on July 16, in both the Flint (9%) and captan (13%) pe- rimeter-rows spray treatments. At the Berlin site, FS was found initially on August 27, in rows 3, 5, and 7, of all but the seven-row Flint treatment. FS was first discovered at the Warren site on August 29, in row 5 of the perimeter-row captan treatment. At the North Brookfield site, FS was found on August 15, in both the perimeter-rows Flint and captan treatments. The Shelbume site first had apples infected with FS on August 16, in the unsprayed rows of the perimeter- row spray treatments of Flint and captan. FS was not found at the Hawley site, despite counts continuing into early October. It was not surprising, given the absence of FS on alternate host plants within the sur- rounding border in June. When harvest counts (September 6 to 13) from all treatments and all rows of all sites were compared (Fig- ure 5, upper graph), Flint treatments had as little or less FS than captan treatments in rows 1 , 3, and 7. The perimeter-rows Flint count (6% infected fruit) was slightly higher than the perimeter-rows captan treat- ment (5%), but overall, Flint compared favorably to captan. The lowest average FS incidence was found in the seven-row Flint treatment. The perimeter-row captan treatment had the most FS, with 17% of fruit infected in row one. This high average number was greatly intluencedby the 100%) incidence in this treat- ment and row at the Harvard site. When the Harvard data were omitted (Figure 5, lower graph), FS inci- dence in this row and treatment was reduced to \%. Row 5 of the perimeter-row Flint treatment had the next highest FS incidence, with ?%> of fruit infected. With Harvard omitted, FS incidence in row 5 of all treatments was greater or equal to the FS incidence in rows 3 and 7 of the respective treatment. Fruit Notes, Volume 67, Spring, 2002 ■ 2 Row Flint • 2 Row captan 80 —A— 7 Row Flint —X— 7 Row captan 80 18% 16% ^ 14% - u s 12% - ■4^ R 10% - £ a 8% - -< "O 6% - lU ^ u 4% - 3 5 Row Position Relative to Border All 6 Sites 9/6-9/13 -♦- 2 Row Flint - 2 Row captan 80 —A— 7 Row Flint -^ \3^ %S^ ^1^ ^f% ^j% #^ Fruit Notes, Volume 67, Spring, 2002 Thinning IVIclntosli Apple Trees Witli Blossom Thinners, With and Without Post-bloom NAA: A Report to the New England Tree Fruit Growers Research Committee James R. Schupp Hudson Valley Laboratory, Cornell University Duane W. Greene Department of Plant and Soil Sciences, University of Massachusetts The objective of these studies was to test the efficacy of blossom thinners to replace carbaryl for obtaining selective thinning of Mchitosh apples. Evaluation in Maine Materials & Method Mature Rogers Mclntosh/M.7 apple trees growing at Highmoor Farm, Monmouth, ME were selected for uniform bloom. Treatment plots were surrounded on all sides by one or more buffer trees, to prevent over- spray. All thinning treatments were applied with an airblast sprayer calibrated to apply 135 gallons of dilute spray per acre, with 70% of the spray delivered to the top half of the tree canopy. Blossom thinning treatments were applied May 1 2, 1 998 when 70 to 80% of the blossoms were open. The weather at the time of application was sunny, temperatures was 72° F, with a 4 to 6 mph wind from the west. Blossom thinning treatments were: 1 . Untreated control 2. Ammonium thiosulfate (National Chelating), 5 gallons per acre 3. Wilthin (Entek Corp.), 12 quarts per acre 4. Endothall (Elf Atochem), 2 pints per 100 gallons 5. NAA, 12.5 ppm For plots that received post-bloom thinner, six ppm NAA was applied on May 27,1 998 when fruitlet diameter was 10 mm. The weather at the time of application was sunny, temperature 64° F, with a 1 to 2 mph west wind. The treatments were arranged as a split plot design. Blossom thinners were the main plot treatment, postbloom NAA was the sub-plot treatment, and there were five replications. Fruit set was evaluated by limb counts and by cluster counts. All the flower clusters on one or two limbs per tree were counted at pink. The limb circumference was measured, and limb cross-sectional area (LCA) was calculated. The number of fruit on each limb was counted, and fruit set was calculated as the number of fruit per 100 clusters and as the number of fruit per LCA. Fruit counts were done shortly after petal fall and again in July to evaluate both initial and final set. Twenty-five fiower clusters on each tree were tagged, and the number of fiowers on each cluster was recorded. The number of fruit on each cluster was counted and fruit set was calculated as the ratio of fruit to flowers for each cluster. Yield per tree was determined in a single picking The Maine portion of this study was conducted at the University of Maine Highmoor Farm, during the time that Dr Schupp was with the University of Maine. Fruit Notes, Volume 67, Spring, 2002 at harvest. Fruit size distribution was categorized using a FMC Weight Sizer (PMC Corp. Lakeland, FL). The weight sizer was adjusted to divide the fruit into four diameter size categories: 57-63 mm, 64-69 mm, 70-75 mm, and greater than 75 mm. Twenty fruits of the 70-75 mm category were selected from each tree for fruit quality analysis. Red fruit color and russet were estimated visually. Fruit firmness was measured on the EPT-1 firmness tester (Lake City Technical Products, Inc. Kelowna, BC, Canada), with two opposing punctures per fruit. The soluble solids of the fruit were determined using an Atago PR-101 digital refractometer (Misco Products Divn., Cleveland, OH). Seed number was counted. set, especially on control trees, however, the rankings of the treatments remained essentially unchanged. There were no treatment interactions on fruit set, yield or fruit characteristics between blossom thinners and post-bloom NAA in this study. Wilthin, endothall and NAA applied at bloom reduced yield (Table 1). PostbloomNAA had no effect on yield. There were no significant effects of thinners on fruit size distribution (data not presented). There were no treatment etfects on fruit red color, fruit firmness, soluble solids concentration, or seed number (data not presented). Fruit from trees treated with Wilthin had higher incidence of russet than fruit irom NAA- or endothall- treated frees (Table 1 ). Results Discussion Fruit set was reduced by all blossom thinners, while post-bloom NAA had no effect on fruit set (Table 1). Final fruit set was much less than the initial Environmental conditions during bloom and for the following month were characterized by warm temperatures and high sunlight, making favorable Table 1 . Effect of ammonium thiosulfate (ATS), Wilthia endotliall, and NAA used as blossom thinners and NAA used as a postbloomthumer on fhut set and fhut size of Rogers Mcintosh'. Maine. Initial set Final set Fmit/cnr Fmit/100 Fruit/cm" Fnut/100 Russet Yield/ limb cross- blossom limb cross- blossom Skin surface tree Treatment sectional area clusters sectional area clusters (%) (kg) Blossom thinners Control 17 a 143 a 3.4 a 31a 15 ab 67 a ATS 5 gal/acre 8b 91b 2.5 ab 28 ab 13 ab 60 ab Wilthin 12 qt/acre 4b 43 c 1.5 b 17c 28 a 50 c Endothall 2 pt/acre 8b 93 b 1.4 b 16c 9b 40 d NAA12.5ppm 8b 105 b 2.0 b 24 b 10b 55 be Postbloom NAA None 9 95 2.1 22 12 52 NAA 6 ppm 9 95 2.2 24 18 57 Significance Blossom thinner (BT) * *** ** « * * Postbloom thinner (PBT) NS NS NS NS NS NS BTxPBT NS NS NS NS NS NS 1 10 Fruit Notes, Volume 67, Spring, 2002 conditions for initial fruit set. All the blossom thinners were effective in reducing the initial fruit set and number of fruit per flower cluster during this period. A prolonged period of heavy cloud cover from June 1 3 to June 17, 1998 resulted in heavy June drop for all the trees in this study. This episode of fruit drop commenced on June 23, and was more severe than the fruit drop caused by blossom thinners. Much of the potential effect of chemical thinners on yield and fruit characteristics at harvest was obscured by this natural fruit drop. The most effective blossom thinner, Wilthin, caused severe phytotoxicity and fruit russet. Future studies should address this concern by evaluating the effect of lower rates of Wilthin. These data indicate that blossom thinners show some promise. More study is needed to select the best chemicals and to optimize their use. Evaluation in Massacliusetts Materials & Methods A block of mature Marshall Mclntosh/M.26 apple trees growing at the University of Massachusetts Horticultural Research Center, Belchertown, MA were selected. Treatment trees were selected so that a buffer tree was located on each side of a treatment tree to prevent spray drift. Prior to bloom 2 limbs per tree, 1 0 to 15 cm in diameter, were selected and tagged. At Table 2. Effects of Ammonium thiosulfate (ATS), Wilthin, endothall and NAA used as blossom thinner alone or combined with a postbloom NAA application. Fruit set Postbloom Fruit/cm" Fruit/ Fruit NAA limb cross- 100 blossom weight Treatment (6 ppm) sectional area clusters (g) Control 6.9 a 66 a 146 e NAA + 5.9 a 55 a 158d ATS 6 gal/acre - 1.9b 23 b 175 abc ATS 6 gal/acre + 2.6 b 22 b 184 a Wilthin 12qt/acre - 2.6 b 28 b 170 be Wilthin 12 qt/acre + 2.2 b 21b 182 ab Endothall2pt/100gal - 3.1b 25 b 164 cd Endothall2pt/100gal + 3.3 b 37 b 158d NAA 12 ppm - 6.1 a 62 a 171 be NAA 12 ppm + 5.7 a 61 a 177 ab Significance Blossom thinner (BT) *** *** *** NAA NS NS ** BT X NAA NS NS NS Within columns, means not followed by th e same letter are significantly different at odds of 19 to 1. Fruit Notes, Volume 67, Spring, 2002 11 the pink stage of flower development all blossom clusters were counted on the two tagged limbs. Blossom cluster density was calculated using LCA. Trees were replicated based upon blossom cluster density. All thmnmg treatments were applied with an airblast sprayer calibrated to apply 125 gallons of dilute spray per acre. Blossom thinner treatments were applied May 4, 1998. Full bloom occurred about 0.5 day before application. Weather at the time of application was partly sunny and warm with temperature reaching 70°F soon after application. Blossom thinning treatments were: ATS, Wilthin, and endothall thinned significantly and comparably (Table 2). NAA did not thin when applied as a bloom thinner. NAA at 6 ppm did not thin when applied alone at the traditional postbloom timing or when applied following any of the blossom thinner treatments. All blossom thinning treatments increased fruit size. NAA, when applied as a bloom thinner, increased fruit size even though it did not significantly reduce crop load. Likewise, the postbloom 6 ppm application of NAA alone increased fruit size although crop load was not significantly reduced. There were no blossom thinner X NAA interactions. 1 . Untreated control 2. Ammonium thiosulfate (National Chelating) 6 gallons/acre 3. Wilthin (Entek Corp.), 12 quarts per acre 4. Endothall (Elf Atochem), 2 pints per 100 gallons 5. NAA 12 ppm For plots that received post -bloom thinner, 6 ppm NAA was applied on May 18, 1998 when fruit size averaged 9.0 mm. Weather at the time of application was sunny, warm and breezy with temperature at 76 to 78°F at application time and a high temperature of 80° F was reached later in the day. Treatments were arranged as a split plot design. Blossom thinners were the main plot treatment, postbloom NAA was the sub- plot treatment, and there were seven replications. Fruit set was evaluated by first counting all persisting fruit on the tagged limbs at the end of June drop in July. The fruit set was calculated by dividing the number of fruit by the LCA. At the normal harvest time on September 10, 40 fruit from each tree were harvested randomly from around the periphery of the tree. The harvested fruit were then taken to the lab where total weight was taken and the average fruit size calculated. Observation of the harvested fruit indicated that there appeared to be no russet attributed to treatment. Results Soon after application phytotoxic effects were observed on the flower petals and leaves of all blossom-thinned trees except those receiving NAA. Discussion ATS, Wilthin, and endothall were used in previous years on apples at rates of 1 %, 6 qts/acre and 1 .5 pints/ 100 gallons, respectively, with disappointing results. Little phytotoxicity was noted and minimal thinning recorded. Higher rates were used this year in an attempt to locate a rate where some thinning would be achieved. Cool, damp, rainy weather immediately preceded the application of blossom thinners in Massachusetts. We speculate that the large amount of phytotoxicity was attributed to greater penetration of the thinner into the leaves because of the cool, cloudy, and rainy weather the week before application rather than due to an excessively high amounts of thinner. While we have noted for years that absorption following a cool wet penod can be increased, this may be even more important when the thinner of choice, thins by burning. It IS also interesting to note that fruit size was increased significantly even though crop load was not reduced significantly. Crop load may have been reduced enough to increase fruit size. It is also interesting to note that early thinning at bloom time may actually increase fruit size more than by thinning later. Note fruit size on trees treated with post bloom NAA as compared with NAA used as a blossom thinner. These data suggest that blossom thinning is a viable and eftective way to reduce crop load. More study is necessary to select the best chemical and concentration to achieve appropriate thinning. ^f^ ^I^ %S^ %S^ %1^ #1^ ^{^ #1^ ^{^ ^{^ 12 Fruit Notes, Volume 67, Spring, 2002 Evaluation of New Apple Varieties, 1998 Observations: A Report to the New England Tree Fruit Growers Research Committee Duane W. Greene Department of Plant and Soil Sciences, University of Massachusetts During the growing season I evaluated about 1 25 named varieties and numbered selections. Below are my observations on the performance of many of these in 1998. Arlet I continue to be on the fence with this apple. It has good, but not outstanding flavor. It does not suffer from biennial bearing, and fruit size is good. It russets here, up to 25% of the surface, it drops and it does become greasy. A drop control compound is appropriate with Arlet. I am cooperating with Sarah Weis on storage of Arlet this year to get a better assessment of its postharvest life. Autumn Gold This is my first year with this cultivar and I had j ust a couple of fruit. I believe that I harvested it too late, October 19. It is a medium to large apple with some russet and is not too attractive. The ones I tasted were neither crisp nor juicy but I believe that they were overmature. There were longitudinal cracks in the pedicel end, throwing up a red flag. Flavor was of bananas, fruity and very pleasant. It had a good sugar to acid ratio. I rated the flavor very high, even with the faults. AA 62 (Stellar) I continue to favor this attractive lemon yellow apple. It is extremely attractive and has a large L/D ratio (over 1 .05) even here. It has no russet but it is exfremely susceptible to apple scab. Flesh is crisp, juicy, fruity, and very good. One thing that I did note this year is that at harvest it had an ethanol (aldehyde) taste that detracted from the flavor. It did have some moldy core this year. I have noted this in other apples in the past including HoneyCrisp. I will continue to look at this one. AA122 This is the first year of evaluation of this oblate deep yellow apple. It has white inconspicuous lenticels and yellow flesh. The flavor was OK, being slightly sweet with a bitter after taste. It was rated in the middle of the pack. If it does not have outstanding flavor or crispness, the evaluation time of this apple will be short. Braeburn It IS a somewhat unlikely candidate to be grown in New England because of late maturity. It blooms profusely and set can be excessive if not thinned very well. I have used three applications of 6 ppm NAA with or without carbaryl on Braeburn with success. Fruit size is good and color is acceptable. It is not very good at harvest but after a period of cold storage it does taste very good. It has good postharvest life. I do recommend planting this apple in New England. Cameo*** I consider this to be one of the best new cultivars. It ripens in mid-October here. It has good L/D ratio Fruit Notes, Volume 67, Spring, 2002 13 and quite good if not quite different color. It is a highly striped apple with about 80% of the surface a dark reddish brown color. It is a very grower-friendly tree. This tastes like a very good Delicious but the taste is very mild. While I never hope that is will be sold as Delicious, I think that it will appeal to people who actually do have taste for it but are attached to the unfortunate versions of Delicious available today. I am high on this apple and think that it will sell here in the East. It does have biennial bearing tendencies. COOP 25 (Scarlet O 'Hara) This IS a medium sized brownish red apple that I have liked for two years. It can be picked, and actually tastes very similar when harvested over a 4-week period from late September to late October. It is one of the crispest and best storing apples I evaluate. It stores better than Fuji or Braebum but not quite as well as HoneyCrisp. It has a mild, fruity, vanilla flavor with a good sugar to acid ratio. I would plant this even if it were not a scab resistant apple. Anyone who is looking for a versatile scab resistant apple should be looking at this. It is very susceptible to fire blight so areas where this is a problem should proceed very carefully. were sent to me by Stark from the Delbard Nursery in France that fruited for the first time this year. It has an 80% dark maroon surface and looks like a Delicious. Harvest date was on August 24, just about with Ginger Gold. It has a distinctive sweet perfumy flavor. It is quite crisp and veryjuicy but the skin in tough. I rated it quite high and noted that it was a very good apple. Delgorov This is an extremely attractive bright orange-red apple that is about 80% red striped. It is medium small, fairly crisp, juicy, but the flesh seems somewhat dry. I noted that it was a fairly good apple with a good sugar to acid ratio. Harvest is 2 weeks before Gala. Deljoron The color of this apple is almost 100% dark burgundy red. It in many ways reminds me of an Empire in appearance and taste. The flesh is white with a tinge of green. The skin is smooth somewhat tough, with many tan lenticels. It ripens about with Delicious. I was favorably enough impressed with it at harvest to note that I should continue to look at it. COOP 37 Delorina I have looked at this cultivar for three years now. It is very similar to GoldRush in appearance and time of ripening. It is somewhat attractive with a 20 to 30% orange cheek. It has a strong vanilla taste, veryjuicy, and medium in size. I rate it good but not exceptional, although my tasting notes include the comment 'look at again'. Creston This was a difficult year for apples that are not highly colored because of the heat. Creston suffered, and consequently it was not very attractive. However, compared with other apples evaluated it was one of the crispest and juiciest. It was also rated very high in flavor, and overall as being very desirable. It was also large. We should continue to evaluate this apple. Dalrouval This is one of the several selections of apples that A small dark cherry red apple ripening with and looking somewhat like Delicious. It has yellow flesh with yellow flecks, slightly sweet, moderate acidity, and IS somewhat crisp and juicy. Flavor is tangy and slightly fruity. I rated it fairly high. Delshel This is a an extremely dark red, medium to small apple that is Gala-like in appearance. It has scarf skin and reminds me to a very large extent of Buckeye Gala. It has prominent tan lenticels and a pleasant fruity taste. It ripens about two weeks before Gala. I rated this quite high. Enterprise The quality of this apple improved immensely this year. It was near the bottom of the list last year. While not on the top, it did move up quite a bit. What is the 14 Fruit Notes, Volume 67, Spring, 2002 difference? We had a very hot summer and I beUeve that was the difference. It was extremely attractive, medium size, sweet, crisp, juicy, and shghtly fruity. Last year I described its flesh as tough, dry, and sawdust-like. The bottom Ime here is that it is meant to be grown in warmer climates. In warm years it will be very good. Fiorina I hear very little about this apple, but it is very good, especially for a disease resistant apple. It is very attractive and its skin is glossy like a HoneyCrisp. It is somewhat crisp, very juicy, with a good mild buttery flavor. Fruit size is medium. I rated it very high. Fortune Although red color development was delayed, it did come along. It was not very firm or crisp this year and acidity was rather high. Although it was not at the top of the list flavor, overall I rate it as an above average apple. The iiTegular shape is a problem as is its mammoth size. I have serious reservations about whether this will make it with all of the good competition. Fuknishiki This is the first year I evaluated this apple and it may be my last. It is not attractive with 70% pinkish red color. It has scarf skin and the flesh is greenish yellow. The skin is extremely tough, and the flesh is a nondescript, chalky and astringent flavor. It is not very good. Fukutami A small bright cherry red apple. While the cosmetics are good, the taste is not. Although it is somewhat sweet, the flavor is masked by extremely high acidity even when it has watercore. It is not good enough. Gala Supreme A year ago I was quite impressed with Gala Supreme. I am out of favor with this apple now for several reasons. It has no better than "good" appearance. It can be quite tart at harvest even though sugars are quite high. The flesh is grainy and the taste is nothing spectacular. It has a chalky aftertaste that I attribute to high tannins. It has problems in storage in that it loses firmness rapidly. Ginger Gold The luster of this apple was not tarnished this year. It remains a very crisp, juicy, mild tasting apple that has a great deal of customer appeal. It is often harvested too early, when it is still too green. Even at this stage it is good, certainly better than most. It does not hold up well in storage so only those that can be sold at harvest should be planted. It holds up well on the tree. If one follows starch ratings, it loses starch very slowly. It may go from 2 to 5 ( on a scale of 8 ) over a 2.5 week period, whereas others lose starch much faster. This is definitely a winner in New England. Golden Supreme This is a very high quality apple, both in looks and in quality, but its faults may kill it. It is not precocious, and it IS quite biennial. It ripens irregularly and extensive preharvest drop is possible. Under ideal conditions it is an absolutely beautiful apple. I still like this one a lot and I am not willing to give up on it. It does store quite well. GoldRush We had a hot summer and consequently this did much better than it has in the past. Normally it is small, russeted, with high acidity. Acidity does mellow in storage, but not enough. This year it did do better, but it will never be a good apple for us unless global wanning pushes the mid- Atlantic region weather up to New England. I do not recommend it for this area. Hampshire For New England or for cooler areas, I believe that Hampshire has a place. It is medium size plus, quite uniform in size, and attractive. It has a very mild taste at harvest. The apple mellows after 4 to 6 weeks in storage giving it a very tender yet pleasing taste and texture. It holds up well in CA storage. I recommend Fruit Notes, Volume 67, Spring, 2002 15 planting Hampshire, at least on a limited basis until we get more out there to evaluate. Hardy Cumberland This is a very attractive nearly 100% blush dark red apple. It has somewhat of an irregular shape. Flavor is good but mild, not sweet, crisp, or juicy. I evaluated it over a 3-week period from the end of September to October 19, with similar results. I will continue to look at this, since I have not formed an opinion yet, other than it is good. HotteyCrisp The popularity of this apple is amazing but it has so many things going for it that it deserves it. It is the crispest and best storing apple that I have ever worked with. Fuji is not even in the same category, but neither are any other apples currently under test. Its faults or problem are surfacing including leaf hopper suscepti- bility???, poor growth, lack of color, off tastes to mention a few. However, this apple has staying power and it will be a dominant player at least in the East for many years to come. We must work through the apparent problems. I could mention many things here but I believe that this apple has so much potential that a whole article should be devoted to it. I am on my third planting of HoneyCrisp, with no intention of slowing down. Hiianguan This IS not an attractive or visually appealing apple. It has 70% brownish red color that is somewhat striped and mottled. It is quite crisp and very juicy. The juice is extremely thick, unlike most other apples. It has an extremely strong vanilla taste, to the point of being objectionable. It is no better than medium size. The poor appearance, the size problem and the very strong flavor lead me to conclude that this is an apple that will not make it. Huashiiai Huashuai is in the middle of the pack on too many characteristics. It lacks too many distinguishing features to have a bright future. It is very Delicious- like in appearance and taste. It lacks character/flavor. It IS not crisp enough or juicy enough to overcome other deficiencies. It is similar to Cameo in some respects, but Cameo will win because it is larger, has better color, is more attractive, and I believe it tastes better. Hudson '5 Golden Gem I have fruited this wonderful apple for several years but have not reported on it because it is different, a fringe apple. It is a completely russeted apple that ripens in Golden Delicious time. The size is medium to large, and the shape somewhat oblate to conic. The taste IS pear-like, but lacking the grit. Everyone that tastes this apple just loves it. It is somewhat sweet but with enough acid and tannins to give it character. The appearance is so different that it attracts attention. We are planting two apple varieties in quantity this year, Honeycrisp is one and Hudson's Golden Gem is the other one. Kinsei This IS quite an unattractive apple that has very good flavor. Where does it fit in? I do not know. I still favor it and feel that it can develop a following if properly promoted. It is not large enough or attractive enough to be a dominant apple, but it may have a place. It stores very well. I found out this year that it is very susceptible to apple scab, in the Mcintosh category. Kitanosachi This IS another one of the Japanese apples that makes me ask why? It is small with dirty red striping. Flesh is green with a whitish tinge and the flesh feels soft even though it is not. Even in the third week in August there are better apples. Monidel This IS the first year of evaluation of this apple. Shape is oblate to truncate, size medium to large, with a light striped cherry red color, but only moderately attractive. It is crisp, juicy, spicy, with a good sugar to acid ratio. Vanilla and licorice are quite prominent. It ripens at the end of August when the only real 16 Fruit Notes, Volume 67, Spring, 2002 competition is Paulared, Ginger Gold, and Sansa. My notes indicate that this is a good apple that should be evaluated more, and I underlined it. Murasaki It is medium in size and bruises easily. Flesh is somewhat soft. It has an anise flavor that is almost completely masked by very high acidity. It ripens about with Pristine, and if given a choice, I would select Pristine. Quite irregular in shape and 100% muddy red color characterize the appearance of this apple. It had watercore in the second week of October but it was still not sweet. Even though this was the first year of evaluation, I believe that I will pull it out. NJ 55 (Sun crisp) I put Suncrisp in the same category as some of the other apples that originated from the mid-Atlantic region. We had a hot year last year and it did much better than it has in the past. It develops a very attractive orange red color in mid-October. Acidity was down, sugars were up and flavor was very good. It was a very good apple. It also stores well. In warm years we can look forward to a very good tasting apple in Suncrisp. NJ90 There are few apples evaluated this year that are as attractive as NJ 90. It is a flat Mcintosh type that has a deep dark red color. It has excellent flavor that I characterize as perfumy vanilla. It is extremely crisp, slightly sweet, with a generous dose of acid and tannins. The major drawback to this apple is that the skin is extremely tough, so much so that it may be fatally flawed. NJlOO This is a fairly attractive yellow apple that has no russet. I rated it quite high in appearance, flavor, and overall, with good sugars and acid. It is somewhat crisp and very juicy. Ithasa very distinctive flavor. It ripens at the end of September. Last year I did not rate it too high so further testing is necessary to see how this one sorts out. NJ107 This is an extremely attractive white-yellow apple. NJ109 An extremely attractive glossy yellow color characterizes this apple. It is crisp, juicy with a very mild flavor, so mild that I hardly taste anything. It ripens just after Ginger Gold so the competition may be too great for this apple. Although it is more attractive than Ginger Gold, it is not better in any other attribute. NJ112 I rated NJ 1 1 2 in the middle of the pack in a number of areas. It has a fairly attractive red color covering 80 to 90 % of the surface. The flavor is OK but not outstanding and the skin is a little chewy. Fruit have moldy core. It ripens in the first week in October when there are many good fruit available. Just because there are many better ones, this will not make it. NJ116 I evaluated this apple four times over a three week period starting on August 3 . It acts like a summer apple in that ripening is uneven, and there can be mealy apples on the tree while others are not ripe yet. It is an extremely attractive yellow apple, that for the most part I rated very high. It is crisp and juicy, and perhaps its best trait is its earliness. It is similar to other NJ yellow apples in that it is tart, has very weak flavor, and is very attractive in that it is russet free. It is a viable option for an early apple. NY 460 I suspect that no one will comment on this apple. However, I think that it is an excellent one. It has the same parents as Fortune, Schoharie Spy X Empire. It is very attractive, somewhat ribbed with some truit having an irregular shape. Size is large but not too large. It is crisp, firm, juicy and a very pleasant apple to eat. It IS very susceptible to apple scab. It also Fruit Notes, Volume 67, Spring, 2002 17 inherited the lack of precocity associated with Northern Spy. It is a great apple to eat, and I guess I will be one of the few who will have that opportunity. I understand that this was one of Roger Ways personal favorites. NY 73334-35 I evaluated a number of NY scab resistant apples this year and this is probably the best. It ripens in mid October. It is large, extremely crisp and juicy and quite attractive with 80 to 90% red color. The acidity is fairly high and this may mask some of the flavor. Essentially, it is a good apple. Natco 3 This is a very distinctive apple and for that reason alone it deserves comment. It is a very typey yellow apple that has cosmetic/russet problems. It has prominent tan lenticels and an orange red cheek similar to Suncrisp. Other than the shape the distinctive feature of this apple is its very strong taste. It has a strong perfume-banana flavor with juice that is buttery and extremely thick. It is one that I think that you would either love or hate. The skin is chewy with elevated levels of tannins. Pristine I am not a big fan of Pristine but in the first week in August there are not too many choices of yellow apples. This year the Pristine in my NE- 1 83 block was totally off. They can be very biennial. Ifit is harvested when not completely yellow the acids will be very high and it will have very little flavor. It does have licorice taste when it is ripe. I do believe that this is another one of those apples that will do better in a warmer climate. Runkel Runkel develops good red color before it is ready to harvest. It is large with 80 to 90% red color at harvest time in October. The flavor is good, truity, tropical. When it is ripe the flesh may be somewhat soft and the skin appears to be tough. It is quite susceptible to apple scab. Overall it was a good apple. Sansa This is still one of the top apples that I recommend. It IS very Gala-like, only ripening 2 weeks earlier. It is a lousy looking tree and it has the appearance of having apple mosaic virus, but this is genetic. I am totally convinced that an apple such as this has a place early in the season. Some people like it better than Gala. It is a weak tree and we must work to keep it growing well. In taste evaluation it comes out very high. Shizuka I continue to like this apple although I am seeing more of its faults. At harvest it was rated highest of all of the good apples in NE-183 for crispness, juiciness and flavor. The only apples that were rated higher, relative to being overall desirable, were Sansa and Golden Supreme. This is one of the apples in our storage test this year. It is softer than Mutsu at harvest and it does not hold up in storage as well as Mutsu. I have not tried it in CA storage yet, but in regular storage it is pretty well shot by the end of January or earlier. Sunrise Sunrise is an excellent apple if you harvest it on the right day. It acts like a summer apple in that it ripens variably, and when it develops good red color it has lost much shelf life. I agree with research in British Columbia that reports that it must be harvested much earlier, at starch level readings of 2 to 3 (on a scale of 8) to have good shelf life. If placed in cold storage it will deteriorate rapidly. I do not recommend this apple because of the multiple harvests and the problem with short shelf life. Takane It IS very similar to Fuji. It is medium size, with a rather unattractive pinkish red color. The taste is similar to Fuji but perhaps better m that it may be sweeter and have more fruity aromatic flavor. It does not have the flesh firmness of Fuji. I will continue to look at this apple but I think that Fuji has the edge in appearance, and firmness. 18 Fruit Notes, Volume 67, Spring, 2002 Zestar (MN 1824) This was another pleasant surprise from Minne- sota. It is a large apple that has about 60% of the surface with a pinkish red color. It is not very attractive but it does have other attributes. It is my understanding that it is meant to compete with Paulared. It ripens about 5 days ahead of Paulared. It is crisp and juicy but the flesh does not seem as dense as others, almost pithy but not necessarily objection- able. It is a very pleasant apple to taste. It is slightly perfumy, sprightly, and yes, zesty. It is an apple that grows on you, almost addictive. I believe that it will compete successfully with Paulared even though it is not as attractive. *%1^ %X^ %i^ ^i^ ^J^ ^lg% ^J^ ^J^ Fruit Notes, Volume 67, Spring, 2002 19 Influence of Odor-bait, CultivarType, and Adjacent Habitat Composition on Performance of Perimeter Traps for Controlling Apple Maggot Flies Sara Hoffmann, Robin Mittenthal, Brad Chandler, Gerald Lafleur, Starker Wright, Paul Appleton, Max Becker, Sara Dynok, and Ron Prokopy Department of Entomology, University of Massachusetts Apple maggot flies (AMF) that immigrate into commercial apple orchard blocks from surrounding areas containing unmanaged host trees are the flies responsible for the great majority of infestation of fruit in commercial orchards. Previously, we have found that using perimeter-row, odor-baited red spheres to intercept immigrating AMF is an effective control method. More specifically, our findings have suggested that surrounding an apple orchard block with spheres baited with butyl hexanoate (BH) and placed 5 m apart will effectively prevent AMF from penetrating into the block. Here, we present the results of experiments conducted in 2000 and 2001 designed to determine whether (1) spacing spheres 10 m apart on perimeter- row apple trees is as effective as spacing spheres 5 m apart in preventing AMF penetration into orchard blocks, (2) perimeter-row spheres baited with a five- compound blend of fruit odor volatiles are more effective than traditional BH-baited spheres in preventing AMF penetration into interiors of blocks, (3) the presence of AMF-susceptible compared with AMF-tolerant cultivars comprising front-row apple trees affects front-row-trap captures and AMF penetration into interiors of blocks, and (4) adjacent habitat affects AMF population numbers immigrating into commercial orchards. Materials & Methods In 2001, 10 Massachusetts commercial orchard blocks were involved in our experiment (initially, we used 12 commercial orchard blocks in 2001, but for the purpose of this article, we excluded two of them due to unusually high AMF populations that would blur data trends in the remaining 10 blocks). Five blocks had front-row cultivars that were comparatively susceptible to AMF (Gala, Jonagold, or Fuji) and five blocks had comparatively tolerant front-row cultivars (Mcintosh or Empire). Each orchard block had an adjacent habitat of woods, hedgerow, or open field. Each block in the 1 0 commercial orchards was divided into three plots (Figure 1). Plots A and B had a 45m length of front row and a depth of seven rows. The front row in plots A and B contained five sticky red spheres, spaced 10m apart. Each was baited with either the five-compound blend (BH, hexyl butanoate, butyl butanoate, pentyl hexanoate, and propyl hexanoate) or BH alone. Plots A and B received no insecticide spray to control AMF. Plot C (termed grower sprayed) had a 30m length of front row and a depth of seven rows. It was sprayed by the grower two or three times with an organophosphate insecticide to control AMF. Each of the two sides of plots A and B, as well as the back row (row 7), contained red spheres spaced 5 m apart, baited with butyl hexanoate. Plot C had no perimeter, side, or back-row spheres. Rows 3 and 4 contained six unbaited sticky red spheres (four in the grower-sprayed plot due to the smaller size) to monitor AMF penetration into the interior of plots. Traps were deployed in late June and remained through the beginning of October. Every 2 weeks, traps were cleaned and captured AMF were counted. The protocol for our 2001 experiment was based on results of a test conducted in 2000, in which we evaluated AMF penetration into orchard blocks by 20 Fruit Notes, Volume 67, Spring, 2002 Woods, hedgerow or open field 45 m 45 m 30 m 30 m PLOT A PLOTB PLOTC Figure 1. Schematic illustration of the 2001 season block layout for evaluation of sticky red sphere traps for controlling AMF: ? = odor-baited traps, wherein front-row traps in Plot A were baited with a five-component blend, front-row traps in Plot B were baited with butyl hexanoate, and all other baited traps received butyl hexanoate; ? = unbaited interior monitoring traps in rows three and four; x = unbaited apple trees. No insecticide was applied to any tree in Plot A or Plot B, but was applied two to three times to all trees in Plot C in July and August. comparing AMF captures on red spheres baited with the five-compound blend and placed either 5 or 10 m apart on front-row trees. Methods were, in general, similar to those for 200 1 with the following differences: (1) for 2000, we included data for all 12 orchard blocks initially considered for 2001, (2) in 2000, the perimeter row of each plot was only 30 m long, and (3) in 2000, fraps placed on sides and back rows were spaced 10 m apart. Results of that study are also presented in this article. Results Results from 2000. Experiments that we conducted in 2000 show that across all five sample periods and all 12 orchard blocks, about 26% more wild AMF were captured per trap on front-row traps that were spaced 5 m apart (mean=27) than 10 m apart (mean=22), but there was virtually no difference in wild AMF penetration into interiors of the plots (respective means of 9 and 8/trap/plot) (Figure 2A). Thus, front- row traps that were spaced at 5 m or 1 0 m apart captured about three times more wild AMF per trap than interior monitoring traps. Interior-row traps in grower-sprayed plots captured 33 and 12% fewer AMF, respectively, than interior-row traps in plots with perimeter traps 5 or 10 m apart. The ratio of front-rovv/interior-row trap captures was markedly higher for tolerant cultivars (3.8:1) than for susceptible cultivars (2.3:1) (Figure 2C and E). For susceptible cultivars, interior monitoring traps in trapped plots captured about 45% more AMF than interior monitoring traps in grower- sprayed plots (Figure 2C). For tolerant cultivars, interior traps in trapped plots captured about 6% fewer AMF than interior traps in grower-sprayed plots (Figure 2E). Overall AMF captures in 2001. In 2001 (with much higher AMF population numbers than in 2000), across all six sample periods and all 1 0 orchard blocks, 57% more wild AMF per trap were captured by front- row traps baited with the five-compound blend (termed blend plots) than by front-row traps baited with BH (termed BH plots)(Figure 2B). Unbaited interior monitoring traps in BH plots captured about 1 3% more AMF than interior traps in blend plots and about 47% more AMF than interior traps in the grower-sprayed plots (about 7/trap/plot). About seven times more wild AMF per trap were caught by front-row traps in blend plots than by interior monitoring traps, whereas only about five times more wild AMF were caught by front- row traps in BH plots than by interior traps. The effect of front-row cultivar type on AMF Fruit Notes, Volume 67, Spring, 2002 21 A _ All Cultivare: 2000 ■ ^"""^r^"- B J All Cultivars 2001 ■ BLBgD ° a 5m apart D- S- 120 , a BH f 120 1 n sprayed 1 □ SFRAYHD a 100 ■ a 100' 3 a. S 80. 3 80 . •u "t= 60. t3 1 60. 5 |t 1 S 40. a* r-F-, E It i^ 1 20. 3 C c 0 ■ i1 *f*i^ in g 20. c (9 1 *^ ■ 4) Front row Interior Back row S 04 Front row Interior Back row 1 Monitoring rrxsnitoring C _ Susceptible Front Row Cultivars: 2000 D 5 Susceptible Front Row Culti\«rs: 2001 5 t 120 T -r ■ BLEND 1 120. ■ 10 m apart □ 5 m apart 1 t 100 i 3 80 dBH D SPRAYED 1 100- n sprayed II §■ 80- u ■_. V = 60 mr S 60- T3 ■ T -a '? 40- 1 20. 3 C I 1 ! "0 f ¥ r **>-. m^ 1 20 3 0 1 t^ 1 c 0 ■ 3 2 Front row Interior Back row 5 Front row Interior Back row 1 Monitoring monitoring E Tolerant Front Row Cultivars: 2000 F S Tolerant Front Row Culti\Qrs: 2001 s t 120, -BLEND 1 120, ■ 10m apart a 5m apart S- 120, 1 100. dbh d sprayed K 100. 2 n. D sprayed §■ 80. S 80. £ 60. e 60- 2 ? 40. i ■? 40. 1 ■ ^T :an number o o i*] -^ m^ E 20- 3 i 0- _Ml . **r^ , B_ \-^ — 1 — I— ^ — 1 1 1 ^ — 1 — 1 D s Front row Interbr Back row 1 .2 Front row hterior Back row 2 .. monitoring Monitoring Figure 2. For 2000 and 2001, across all sample penods sum of mean numbers of wild AMF captured by odor- baited spheres placed on front rows or back rows of plots or unbaited spheres placed at interior of plots for all | plots (A and B) and for plots where the front rows were composed of susceptible (C and D) or tolerant cultivars 1 (E and F). In 2000, only the five-compound blend was evaluated. In 2001, all ft-ont-row traps were placed 10 m | apart. 1 captures in 2001. For susceptible cultivars, front-row traps in blend plots captured somewhat more wild AMF per trap than front-row traps in BH plots (about 33% more), whereas for tolerant cultivars, front-row traps in blend plots captured substantially more ( 1 36% more) wild AMF than front-row traps in BH plots (Figure 2D and F). Front-row traps in blend and BH plots of susceptible cultivars captured substantially more AMF (85% and 228% more, respectively) than front-row traps in corresponding plots in tolerant cultivars. When 22 Fruit Notes, Volume 67, Spring, 2002 averaged across both types of trapped plots and grower- sprayed plots, interior monitoring traps in susceptible cultivars captured substantially more ( 1 30% more) wild AMF than in tolerant cultivars. The ratio of front-row- trap/interior-row-trap captures in blend and BH plots was the same within each cultivar type as it was for both cultivars together (about 7: 1 for blend and about 5:1 forBH). Effects of adjacent habitat in 2000 and 2001. In 2000, of the total number of AMF captured by all traps in all orchards, 41% were captured in blocks adjacent to woods (Figure 3). A similar percentage (37%)) was captured in blocks bordering hedgerows. The smallest percentage of total captured flies was found in blocks bordering open fields (21%). In 2001, blocks bordering hedgerows had the highest percentage (47%) of total fly captures, followed by orchard blocks bordering woods (32%), and blocks that were adjacent to open fields (21%)) (Figure 3). Conclusions In 2000, in the same orchards studied in 200 1 , data suggested that there was virtually no difference in AMF penetration into orchard blocks when front-row traps baited with the five-compound blend were placed either 1 0 m or 5 m apart. In 200 1 (with front-row traps spaced 10 m apart), front-row traps in blend plots captured more flies than front-row traps in BH plots. Although there was little difference in the mean number of wild AMF that penetrated into the interior of the two baited plots, the ratio of front-row to interior-row-trap captures was higher when front-row traps were baited with blend. Inasmuch as blend appears to be more capable than BH of drawing AMF to the vicinity of traps (based on front-row-trap captures), these data suggest that blend odor-bait is better than BH in preventing AMF from penetrating into the interior of orchards. Orchard blocks with tolerant front-row cultivars experienced substantially more AMF captures on front- row traps baited with blend than BH. The difference was much less for blocks with susceptible front-row cultivars. This suggests that baiting front-row traps with blend in tolerant cultivars attracts many more flies than baiting tolerant trees with BH. In both 2000 and 200 1 , and in trapped as well as grower-sprayed plots, more total AMF were captured in orchard blocks with susceptible front-row cultivars than in those with tolerant front-row cultivars. However, the ratio of front-row to interior-row-trap captures remained the same regardless of cultivar. This suggests that each odor bait is just as effective in one cultivar type as it is in the other cultivar type in preventing AMF penetration into the orchard interior. Percent of Total AMF Captures 2000 2001 woods 42% Figure 3. In 2000 and 2001, across all blocks, all traps, and all sample periods, percentage of the total AMF captures according to adjacent habitat (woods, hedgerow, or open field). For the purpose of this figure, all 12 orchard blocks were considered in 200 1 . Fruit Notes, Volume 67, Spring, 2002 23 Results from both 2000 and 2001 show that orchard blocks that have woods or hedgerow as adjacent habitat are subject to higher AMF pressure than blocks bordered by open field. Orchard blocks that bordered an open field had consistently lower fly captures than blocks that bordered either woods or hedgerow (habitats that typically support wild host plants). Based on our findings, it appears that odor-baited red sphere traps are effective in preventing AMF penetration into orchard blocks when they are spaced at 10 m apart on the perimeter row, especially when baited with blend. Regardless of cultivar type, the blend bait appears to be better than the BH bait at preventing flies from penetrating into the interiors of orchard blocks. In 2002, we plan to evaluate further the capability of different odors on perimeter-row traps for intercepting wild AMF immigrating into commercial orchards. Ackno yvledgm eiits We are grateful to the following growers for participating in this study: Keith Arsenault, Gerry Beime, Bill Broderick, Dave Chandler, Tom Clark, Don Green, Tony Lincoln, Joe Sincuk, Mo Tougas, and Steve Ware. This work was supported by Massachusetts State Integrated Management Funds, Northeast Regional Competitive Integrated Pest Management Funds, and Northeast Regional Sustainable Agricultural Research and Education Funds. *%S^ %Si^ %3^ %s^ #J^ ^^ ^J^ ^J^ 24 Fruit Notes, Volume 67, Spring, 2002 Notts Fruit Notes University of Massachusetts Department of Plant & Soil Sciences 205 Bowditch Hall Amherst, MA 01003 Nonprofit Organization U.S. Postage Paid Permit No. 2 Amherst, MA 01 002 -1 SERIAL SECTION UMASS AMHERST, MA 01003 Account No. 2-22914 UM/Morr Per Volume 67, Number 3 SUMMER ISSUE, 2002 rleu/ungland Table of Contents Comparing the Harvest and Storage Characteristics of Mutsu and Shizuka Apples S. Weis, D. Greene, and W. Bramlage 1 1-MCP: How Useful Can It Be on New England Apples? 5. Weis and W. Bramlage 5 Species Composition of Third-generation Leafminers in Massachusetts Apple Orchards: 1997-1999 5. Wright, B. Zhao, and R. Prokopy 10 Population Dynamics of Leafminers and Their Parasitoids in Massachusetts Apple Orchards: 1999 Studies B. Zhao, S. Wright, and R. Prokopy 14 Performance of the V Series Apple Rootstocks During Six Growing Seasons W. Autioand]. Krupa 18 Editors: Wesley R. Autio William J. Bramlage Publication Information: Fruit Notes (ISSN 0427-6906) is pub- lished each January, April, July, and October by the University of Massachu- setts in cooperation with the other New England state universities. The costs of subscriptions to Fruit Notes are $10.00 for United States ad- dresses and $12.00 for foreign ad- dresses. Each one-year subscription begins January 1 and ends December 31. Some back issues are available for $3.00 (United States addresses) and $3.50 (foreign addresses). Payments must be in United States currency and should be made to the University of Massachusetts. Correspondence should be sent to: Fruit Notes Department of Plant & Soil Sciences 205 Bowditch Hall University of Massachusetts Amherst, MA 01003 All chemical uses suggested in this publication are contingent upon continued registration. These chemicals should be used in accordance with federal and state laws and regulations. Growers are urged to be familiar with all current state regulations. Where trade names are used for identification, no company endorsement or product discrimination is intended. The University of Massachusetts makes no warranty or guarantee of any kind, expressed or implied, concermng the use of these products. USER ASSUMES ALL RISKS FOR PERSONAL INJURY OR PROPERTY DAMAGE. Issued by UMass Extension, Stephen Demski, Director, in furtherance of the acts of May 8 and June 30, 1914. UMass Extension offers equal opportunity in programs and employment. Comparing the Harvest and Storage Characteristics of IVIutsu and Shizulested 9/10 Check 0 0.04 17.2 0 90 743 10.7 3 175 972 9.2 100 1-MCP 0 0.04 17.2 0 90 52 12.4 3 175 816 11.6 0 Retain ""-treated fruit harvested 10/1 Check 0 2.2 14.4 0 90 381 10.1 0 150 649 9.1 0 1-MCP 0 2.2 14.4 0 90 1 12.3 0 150 35 10.8 0 1 firmer than the untreated ones at all evaluations. Treated fruit also became yellower with time, but were generally less yellow than the controls. Harvest date did not influence the effect of 1-MCP; harvest differences were retained, but not changed. Mcintosh. Mcintosh is of particular interest in New England and two experiments were conducted. In the first, three strains (Rogers, Morspur, and SpurMac) were harvested on September 10 when the fruit were just beginning to produce ethylene. The strains were all treated as described above, and stored at 32F in air for 90 or 175 days, plus 7 days at 70F prior to evaluation. In the second experiment, some Retain'" treated fruit were harvested on October 1 , and treated and stored the same as the strains, except for a maximum of 150 rather than 175 days. This is a late harvest date, and fruit averaged over 2 ppm internal ethylene at harvest. The three strains all responded similarly to 1 -MCP so only their averages are presented in Table 3. (Note that Rogers were about 3/4 pound softer than the Fruit Notes, Volume 67, Summer, 2002 others, but this was true across time and treatment and was not treatment-re- lated). Untreated fruit accu- mulated very high ethylene concentrations, and 1-MCP only delayed the rise, the fruit eventually reaching about the same level as the untreated ones. Untreated ones softened excessively, although it should be noted that they were stored beyond the normal limits for Mcin- tosh. 1-MCP-treated fruit also softened, but much less, and were still acceptably firm after the longer storage time. The untreated fruit also scalded during the longer storage time, whereas 1- MCP treatment prevented this from happening. The Retain"" treated fruit harvested three weeks later responded much the same as the three strains, except that ethylene increased far less and no scald developed. These differences are not likely associated with 1 -MCP, but rather occurred because Retain™ has the effect of reducing ethylene, and late harvest reduces scald. Delicious. Redchief Delicious were harvested on October 1 and October 1 1 , treated with 1 -MCP, and stored in 32F air for 90 or 1 50 days, and then for 7 more days at 70F. Subsamples were weighed at harvest, placed in paper bags, and stored like the others, and reweighed at removal from storage and again after 7 days at room temperature. Fruit from the two harvests responded the same to treatment and storage, so in Table 4 the means of the two harvests are presented. Ethylene content of untreated fruit increased substantially with storage time and after transfer to 70F. 1 -MCP again caused ethylene content during storage to fall below that at harvest, but it rose over time and during fruit warming, although it never approached the ethylene levels of untreated fruit. Untreated fruit softened greatly during storage and at room temperature. 1-MCP treated fruit also softened, but not nearly as much as the untreated fruit. Both treated and untreated Delicious lost weight during and following storage, but 1-MCP reduced the Table 4. Effects of 1-MCP on internal ethylene concentration, fruit firmness, and weight loss of Redchief Delicious apples after 32F air storage for 90 or 150 days, each followed by 1 week at 70F to evaluate shelf life. Fruit Treatment Storage time (days) Ethylene (ppm) Firmness (lbs) weight (grams) Weight loss (%) Check 0 32 17.4 164 90 159 14.8 158 3.2 90+7 309 13.9 156 4.6 150 266 13.2 150+7 401 12.7 1-MCP 0 32 17.4 166 90 12 15.9 162 2.7 90+7 62 16.1 159 4.0 150 41 15.4 150+7 93 15.2 « size of this loss. Spigold. In order to determine if 1-MCP could inhibit ethylene production even if fruit were already producing substantial ethylene, Spigold were har- vested October 22 (very late!) with average Starch Index of 7.6 (Cornell generic chart) and average internal ethylene concentration of 3 1 ppm. Fruit were treated like the other cultivars, and stored for 90 or 1 50 days in 32F air, plus 7 days at 70F. Table 5 shows that the ability of 1-MCP to reduce ethylene production was significant despite the fact that the fruit were already producing a substantial amount of ethylene prior to the 1-MCP treatment. 1-MCP treated fruit were firmer, too, although there was substantial fruit- to-fruit variation in firmness due to very large fruit sizes. Discussion Treatment with 1-MCP consistently resulted in firmer fruit following cold storage. This firmness advantage remained or was enhanced after fruit were left at room temperature for a week. 1-MCP-treated fruit did, however, soften over time, just not as much as did the untreated fruit. Ethylene production was suppressed well into the storage period. The duration of this suppression was cultivar dependent. Ethylene production was essentially shut down by 1-MCP Fruit Notes, Volume 67, Summer, 2002 Table 5. Effects of 1-MCP on internal ethylene concentration and fruit firmness on Spigold apples harvested October 22 following 32F air storage for 90 or 150 days, each followed by 1 week at 70F to evaluate shelf life. 90 days cold storage 1 50 days cold storage 1-MCP applied At harvest 1 day warm 7 days warm 1 day warm 7 days warm Check 1-MCP Check 1-MCP 31 14.6 Internal ethylene concentration (ppm) 180 359 209 49 39 64 Firmness (pounds) 10.2 10.0 9.4 11.0 11.8 10.6 384 185 9.1 10.0 treatment for at least 150 days in Gala. Ethylene production in 1-MCP treated Mcintosh reached levels of control fruit by 1 75 days of cold storage in fruit which had not been treated with Retain"". Weight loss during cold storage was significantly reduced in Delicious, and weight loss during a week at room temperature following cold storage was reduced by 1- MCP treatment of Mcintosh (data not shown) and Delicious. A very significant result was that all cultivars harvested on different dates showed the same results between harvest dates, except that changes that occurred before harvest were not reversed. Thus, 1- MCP had some benefit regardless of ripeness at harvest. Two important effects were not measured. We did not measure volatile production (or aroma), although we did observe that aroma was lacking in the 1 -MCP-treated Gala following storage. We did not do taste tests, as the product is not registered for use. The only 1 -MCP-treated fruit which fully recovered ethylene production were the non-Retain™ Mcintosh harvested on September 10 and stored for 175 days in 32F air. Even these fruit retained their firmness advantage over untreated fruit and did not develop superficial scald as the other fruit did. The Ginger Gold, Retain'"-treated Mcintosh, Delicious, and Spigold which had been treated with 1-MCP all started produc- ing more ethylene after a time in storage, but did not come close to catching up with their untreated counterparts. Based on this preliminary investigation, 1 -MCP treatment appears promising for increased firmness retention in a broad spectrum of apple cultivars, including Mcintosh as well as for scald control. We observed scald only on Mcintosh m this study, but others have observed similar results on other cultivars, so a general response may exist although further tests are essential. Since maximum 1-MCP effect may depend on early harvest, at least in some cultivars, scald protection would be an extremely valuable benefit. Combining 1-MCP treatment with CA might enhance the effect of either one alone. Taste tests will be essential to determine if the firmness advantage is offset by losses in flavor or aroma. If so, this is likely to be cultivar dependent. Seasonal variation in effectiveness of 1 -MCP has been reported, so we need to determine how repeatable these results are. Finally it remains to be determined how 1-MCP can be applied efficiently on a commercial scale. Nevertheless, despite these issues, this is an extremely interesting new material. A cknowledgm ent We would like to thank Harlow Warner of AgroFresh, Inc . for supplying the 1-MCP used in these experiments. it it it it it Fruit Notes, Volume 67, Summer, 2002 Species Composition of Tliird- generation Leafminers in IVIassachusetts Apple Orchiards: 1997-1999 Starker Wright, Baige Zhao, and Ronald Proliopy Department of Entomology, University of Massachusetts In Massachusetts, leafminers (LM) have been a consistent threat to the quality of apple foliage in commercial orchards ever since their initial rise to prominence in the late 1970s due largely to the onset of resistance to organophosphate insecticides. Over the past 10 years or so, LM in Massachusetts orchards exhibited three rather distinctly different patterns of population growth. In some orchards, growth has been slight or at most moderate, never exceeding a threshold requiring insecticide treatment. In other orchards, growth also has been slight, owing to annual or biannual application of a preventative insecticide spray against LM. In still other orchards, populations have undergone a period of explosive grov^h, followed by rapid decline subsequent to insecticide treatment, only to be followed by another period of explosive growth. Several factors might account for these observed differences in characteristic form of LM population growth. They include: (1 ) amounts, types and timings of pesticides directed against other orchard pests, (2) amounts, types and timings of pesticides directed against LM, (3) the nature of the habitat adjacent to commercial orchards, (4) the species composition and diversity of parasitoids that can provide biocontrol of LM, and (5) the species composition of LM themselves. In regard to the latter, through the 1980s, commercial orchards in Massachusetts were dominated by the apple blotch leafminers (ABLM) Phyllonorycter crataegella, which is native to the USA and infests a rather wide variety of plant species. During the 1990s, however, we saw a rise in numbers of spotted tentiform leafminers (STLM) Phyllonorycter blancardella, which is an introduced species from Europe and infests only apples and crabapples. Here, we report results of a study conducted from 1997-1999 aimed primarily at characterizing the species composition of third-generation LM in 12 commercial apple orchards in Massachusetts during this three-year period. Our secondary aim was to attempt to relate LM species composition with LM population density and patterns of insecticide use against LM. Other articles in this and future issues of Fruit Notes will deal with LM populations as influenced by parasitism, border area composition, and type of perimeter-row cultivar. Materials & Methods In November in each of three years (1997-1999), we sampled 10 leaves on each of 30 trees in each of 12 commercial orchards, pointing blindly toward the tree canopy and picking the first leaf encountered by hand. We counted the total number of third-generation mines in the 300-leaf sample. After this, we picked as many mine-infested leaves as could be found in a one-hour search of the orchard (maximum of 300 leaves) and returned them to the laboratory for examination of pupae under a microscope. Pupae can be classified according to LM species on the basis of the structure of minute "hooks" present on the posterior end. In 1999, we also sampled mined leaves from four orchards that had been abandoned for at least 5 years. Results To facilitate presentation of results, sampled commercial orchards are grouped according to three geographical areas in Massachusetts: Orchards A, B, and C in the west, orchards D, E, F, and G in the center, and orchards H, I, J, K, and L in the east. Data in Table 1 show that in each of these three geographical regions, at least one sampled orchard experienced a rather high LM density level in at least one of the three years, and at least one sampled orchard 10 Fruit Notes, Volume 67, Summer, 2002 Table 1. Density of third -generat ion leafminers in 12 commerc al and 4 unmanaged apple orchards in | Massachusetts (1997-1999). Number of mines per 100 leaves Orchard Location 1997 1998 1999 A Ashfield 54 104 21 B Shelbume 11 3 15 C Colrain 5 6 9 D Belchertown 31 11 13 E Brimfield 65 38 23 F Warren 304 80 89 G Brookfield 51 191 11 H Princeton 9 33 7 I Leominster 203 311 22 J Sterling 11 9 7 K Sterling 6 7 11 L Northboro ~ 305 5 M Ashfield* — — 15 N Deerfield* — - 23 O Leominster* — - 8 P Sterling* ~ — 11 * Abandoned orchards. remained at a rather low LM density throughout the three years. Similarly, data in Table 2 show that in each of the three geographical regions, at least one sampled orchard was dominated by ABLM across the three years and at least one other commercial orchard was dominated by STLM across the three years. Thus, neither the population density nor the species composition of LM appeared to be affected by geographical location within Massachusetts. In all, there were five commercial orchards (A, F, G, I, L) wherein the density of third-generation mines reached 100 per 100 leaves in at least one of the three years (Table 1). In three of these five orchards (A, F, I), the dominant species each year was STLM (Table 2). In the fourth orchard (G), ABLM dominated in 1997 but STLM in 1998 and 1999. In the fifth orchard (L), ABLM dominated each year. In the remaining seven orchards (B, C, D, E, H, J, K), the density of third-generation mines did not reach 100 mines per 100 leaves in any of the three years (Table 1). In six of these seven orchards, the dominant species each year was ABLM (Table 2). In the seventh orchard (D), ABLM was distinctly dominant m 1997 but STLM was distinctly dominant in 1998 and 1999. Thus, the highest densities of leafminers were associated largely with dominance by STLM, whereas lower densities were associated largely with dominance by ABLM. As summarized in Table 3, none of the four abandoned orchards (M, N, O, P) received an insecticide treatment against LM during any of the three years, and five of the commercial orchards (A, D, F, G, I) received no insecticide treatment against LM in 1997 and 1998, although four of the five received such treatment in 1999. All nine of these orchards were dominated by STLM in 1998 and 1999. In contrast, seven of the commercial orchards (B, C, E, H, J, K, L) received an insecticide treatment targeted against LM in two or all three years. Each year, all seven of these orchards were dominated by ABLM. Thus, no or infrequent spraying against leafminers appears to be associated with the nse of STLM to the status of dominance, whereas frequent spraying seems to be associated with dominance by ABLM. Our data are insufficient for establishing a relationship between time since application of an insecticide against leafminers and the rise of ABLM to dominance, although the data in Table 3 for 1 999 for orchards A, D, G, and I suggest that such a rise to dominance by ABLM does not occur during the same year that insecticide is applied. Conclusions Results of this three-year study suggest that dominance in species composition of LM in Massachusetts orchards was (1) not associated with any particular geographical region within the state, (2) was apparently associated with LM density, and (3) was apparently associated with frequency of insecticide Fruit Notes, Volume 67, Summer, 2002 11 Table 2. Species compositi on of third-generation leaftniner pupae in 12 commercial apple orchards (1997-1999) and four abandoned apple orchards (1999) in Massachusetts. Appl s blotch leafminer = ABLM. Spotted tentiform leafminei = STLM. 1997 1998 1999 No. ABLM STLM No. ABLM STLM No. ABLM STLM Orchard Location pupae (%) (%) pupae (%) (%) pupae (%) (%) A Ashfield 25 16 84 20 20 80 245* 4 96 B Shelbume 19* 100 0 20 100 0 90* 100 0 C Colrain 24 100 0 33* 91 9 178* 100 0 D Belchertown 109 80 20 90 28 72 121* 8 92 E Brimfield 181* 98 2 76* 96 4 139* 93 7 F Warren 250 29 71 83 11 89 86 24 76 G Brookfield 199 71 29 124 2 98 13* 8 92 H Princeton 18* 100 0 44* 98 2 161* 89 11 I Leominster 19 11 89 94 14 86 164* 4 96 J Sterling 113* 90 10 84* 94 6 189* 69 31 K Sterling 102* 95 5 58* 99 1 184* 87 13 L Northboro 23* 100 0 33 100 0 79* 100 0 M** Ashfield — — — — — — 18 0 100 N** Deerfield — — — ~ — -- 122 0 100 O** Leominster — — — — — — 14 0 100 P** Sterling — — ~ — ~ — 58 14 86 * Indicates that either Pounce, Asana, Provado, or Agri- Viek was applied against first-generation LM that- year. ** Abandoned orchards. Table 3. Relationship between frequency of application species in Massachusetts orchards. of insecticide against leafminers and dominant leafminer Orchards Insecticide applied against LM Dominant species of LM 1997 1998 1999 1997 1998 1999 Abandoned (M.N.O.P) Commercial (A,D,F,G,1) Commercial (B,C,E,H,J,K,L) None None None None B, E,H,J,K,L C,E,H,J,K None A,D,G,1 B,C,E,H,J,K,L STLM STLM* ABLM STLM STLM ABLM STLM STLM ABLM * ABLM in orchards D and G 12 Fruit Notes, Volume 67, Summer, 2002 application targeted against LM. With little exception, dominance by STLM in commercial orchards was associated with higher LM population density and no or infrequent use of insecticide to control LM. Conversely, dominance by ABLM was associated with lower LM population density and rather frequent use of insecticide to control LM. In any scientific investigation, establishment of a strong association or correlation between two variables should not be taken to imply cause and effect. Further study is needed to determine the true cause or causes underlying the dominance of ABLM or STLM in a given orchard. Even so, one can postulate a possible scenario with the following steps: (1) dominance of STLM in abandoned apple orchards either because of apple being a more favored host of STLM than it is of ABLM, because STLM is less susceptible to parasitism than is ABLM, because STLM is a better competitor for host resources than is ABLM, or a combination of these, (2) movement of STLM adults into an orchard currently colonized by ABLM, (3) more rapid and extensive buildup of STLM in commercial orchards than is characteristic of ABLM, leading to (4) application of a targeted insecticide against LM that exerts a greater effect on STLM than ABLM and results in (5) temporary dominance by ABLM. Further study is needed to evaluate this possible scenario. A cknowledgem en ts We thank the apple growers who participated in this study: John Blanchard, Bill Broderick, Dave Chandler, Dave Cheney, Dana Clark, Tom Lincoln, Dave Chandler, Joe Sincuk, Tim Smith, Mo Tougas, and Bob Tuttle. We are also grateful for the support of a USDA Northeast Region S ARE grant and State IPM funds. "k i: "k ic "k Fruit Notes, Volume 67, Summer, 2002 13 Population Dynamics of Leafminers and Their Parasitoids in IViassachusetts Apple Orchards: 1999 Studies Baige Zhao, Starker Wright, and Ronald Prokopy Department of Entomology, University of Massachusetts In the preceding article, we presented information on the species composition of third-generation leafminers found in 12 commercial and four abandoned Massachusetts apple orchards during 1997, 1998, and 1999. Results showed that each year, all four abandoned orchards and three of the commercial orchards were dominated by spotted tentiform leafminers (STLM). Conversely, each year seven of the commercial orchards were dominated by apple blotch leafminers (ABLM). Two of the commercial orchards were dominated by ABLM in 1997 but by STLM in 1 998 and 1 999. We concluded that the degree to which apple is a preferred host of STLM relative to ABLM and the degree to which STLM relative to ABLM is susceptible to insecticides could be principal factors associated with dominance by STLM vs. ABLM but suggested that parasitoid species composition and abundance might also be contributing factors. Here, we present information on the species composition and abundance of leafminers and their principal parasitoids for each of the three generations of leafminers that occurred in 1999 in these 12 commercial and four abandoned orchards. Materials & Methods In June, August, and November of 1999, we sampled 10 leaves on each of 30 trees in each commercial and abandoned orchard for total numbers of first-, second-, and third-generation mines, respectively, in each 300-leaf sample. After taking each sample, we collected as many infested leaves (containing tissue-feeding mines) as possible during a 1 -hour search of the orchard up to a maximum of 1 00 mines per orchard for the first and second generations and 300 mines per orchard for the third generation. Mined leaves were returned to the laboratory for examination under a microscope to determine presence and identity of parasitoids and identity of leafminers. A complete categorization of the extent of parasitism of mined leaves would include presence of holes in leaf tissue made by parasitoid adults seeking to feed upon leafminer larvae as well as presence or evidence of parasitoid eggs. Because such evidence of parasitism was very difficult to determine with certainty, we confined our confirmation of parasitism to presence of parasitoid larvae, pupae (or their remains), and adults. Consequently, the values presented here for extent of parasitism of leafminers were undoubtedly lower than actual percentages occurring in orchards. Results Data in Table 1 show the abundance of leafminers in each generation in each orchard. Data in Table 2 show the species composition of leafminers and percentages of leafminer larvae parasitized by the two dominant parasitoids {Sympiesis tnarylandensis and Pholetesor ornigis) in each generation in each orchard. Owing to insufficient abundance of first-generation mines in some orchards, there are some unfortunate gaps in the data set for this generation of leafminers. In the four abandoned orchards (M, N, O, P), STLM was the exclusive (or nearly exclusive) leafminer species present in each of the three generations. In five of the commercial orchards (A, D, F, G, I), STLM dominated in the second and third generations. STLM dominated also in the first generation in two of these orchards (A and I). ABLM slightly dominated STLM in the first generation in Orchard D, and no first-generation data were available for Orchards F and G. In the other seven commercial orchards (B, C, E, H, J, K, L), ABLM was markedly dominant in the second and third generations as well 14 Fruit Notes, Volume 67, Summer, 2002 Table 1. Density of first-, second-, and third-generation leafminers in 12 commerc al and four abandoned apple orchards ir I Massachusetts in 1999. Number of mines per 100 leaves First Second Third Orchard generation generation generation A 6.7 2.5 21.0 B 4.3 9.5 14.5 C 0.7 22.5 8.5 D 1.3 0.5 12.5 E 1.0 5.0 23.0 F 0.3 29.0 89.0 G 0.0 2.5 10.5 H 1.0 3.0 7.0 I 19.7 6.5 21.5 J 0.0 0.0 7.0 K 0.3 2.0 10.5 L 5.3 0.5 4.5 M* 23.7 8.0 15.0 N* 17.5 4.5 23.0 O* 70.0 17.0 8.0 P* 15.7 2.0 11.0 * Abandoned orchards. as in the first generation where data were available (B, C, E, J). Thus, with the exception of Orchard D, data indicate that the leafminer species that dominated in the first generation remained dominant in the second and third generations. To faciHtate comparisons, the 16 orchards were categorized into four groups (Table 3). Data in Table 3 show that for abandoned orchards M, N, O, and P, all of which were dominated by STLM and none of which received insecticide in 1999, LM population density decreased (on average) by more than half from the first to the third leafminer generation. In contrast, for commercial orchard F, likewise dominated by STLM and likewise having received no insecticide treatment against LM in 1999, LM population density increased 89-fold from the first to the third leafminer generation. In commercial orchards A, D, G, and I, also dominated by STLM but having received an insecticide treatment against LM in May of 1999, LM population density increased by an average of about two-fold from the first to the third leafminer generation. Finally, in commercial orchards B, C, E, H, J, K, and L, dominated by ABLM and having received an insecticide treatment against LM in May of 1999, LM population density increased by an average of about five-fold from the first to the third leafminer generation. For all four categories of orchards, parasitism by S. maiylandensis decreased progressively from the first to the third LM generation, averaging (across all generations) 36% for abandoned orchards, 26% for commercial orchards dominated by STLM and treated against LM in 1 999, and 18% for commercial orchards dominated by ABLM. Parasitism by P. ornigis across all three generations averaged 1 1 % for abandoned orchards, 9% for commercial orchards dominated by STLM and treated against LM in 1999, and 2% for commercial orchards dominated by ABLM, with no consistent trend toward increasing or decreasing abundance across generations. Together, data in Table 3 suggest that the high amount of total parasitism of LM (47%) in the abandoned orchards may have been a principal factor associated with the decrease rather than an increase in LM population density from the first to the third LM generation. The level of total parasitism in Orchard F was only about one-third that in the abandoned orchards and was insufficient to prevent the 89-fold increase in LM population density from the first to the third generation. The substantially greater amount of total parasitism (35%) m STLM-dominated orchards treated against LM in 1999 than total parasitism (20%) in ABLM- dominated orchards treated against LM m 1999 may have played a role in the lower rate of first-to-third- generation LM population growth in the former (two- fold) compared with the latter (five-fold). Finally, the data m Table 3 indicate that P. ornigis parasitoids were considerably more abundant in abandoned as well as LM-treated orchards dominated by STLM than in LM-treated orchards dominated by Fruit Notes, Volume 67, Summer, 2002 15 Table 2. Species composition of leafminers and percentages of leafminer larvae parasitized during the first, second, and third generations of leafminers in 12 commercial and four abandoned app e orchards in | Massachusetts in 1999. Orchard First generation (%) Second generation (%) Third generation (%) No.* ABLM ** S.m.*** P.o*** No . ABLM S.m. P.O. No. ABLM S.m. P.O. A 87 13 26 20 98 20 15 4 58 4 6 38 B 103 100 9 0 100 100 12 0 57 100 23 7 C 43 100 9 7 93 100 10 2 88 100 9 2 D 100 55 53 0 68 42 31 2 57 8 1 7 E 88 100 55 0 98 97 15 0 145 93 2 0 F - - - - 104 7 15 1 15 24 10 0 G - - - - 100 18 47 2 8 8 0 0 H - - - - 100 98 15 0 126 89 - - I 38 17 50 16 102 8 39 4 202 4 4 6 J 50 100 22 2 97 70 32 0 177 69 8 0 K - - - - 102 100 26 9 113 87 2 0 L - - - - 90 79 43 0 49 100 7 0 M 100 0 52 11 103 0 41 18 12 0 43 12 N 88 0 46 14 50 0 12 2 86 0 27 6 O 92 0 69 1 58 0 52 2 8 0 0 13 P - - - - 77 0 30 12 47 14 6 30 * Numbers of mature mines examined. ** Percent of total pupae identified as ABLM; remaining percent was STLM. *** Percent of LM larvae parasitized by Sympiesis maiylandet isis (S m.) or Pholetesor omigis (P.o •)• Table 3. Relationship betweer leafminer-targeted insecticide treatments. dominant species and population buildup of 1 jafminers and extent of parasitism of leafminers m Massachusetts ore lards in 1999. Numbe of mines per 100 Parasitism by S Parasitism by P omigis Insecticide leaves marylandensis (%) (%) treatment against LM Dominant species of First Second Third First Second Third First Second Third Orchards m 1999 LM gen. gen. gen. gen. gen. gen. gen. gen. gen. Abandoned (M.N.O.P) No STLM 32 8 14 56 34 19 9 9 15 Commercial (F) No STLM 1 29 89 - 15 10 -- 1 0 Commercial (A,[),G,1) Yes STLM 7 3 16 43 33 3 12 3 13 Commercial (B,C,E,H,J,K,L) Yes ABLM 2 6 11 24 22 9 2 2 2 1 16 Fruit Notes, Volume 67, Summer, 2002 AELM, suggesting a possible preference of P. ornigis for STLM. Conclusions Several of the data trends shown and discussed here and in the preceding article for Massachusetts orchards are similar to trends reported earlier by Chris Maier, whose outstanding work on leafminers in Connecticut orchards inspired our studies. Notable among the trends for both Connecticut and Massachusetts are ( 1) a strong tendency toward a shift in dominance from ABLM to STLM with decreasing frequency of annual insecticide treatment against LM, (2) a strong tendency toward lower parasitism of LM in sprayed than unsprayed (abandoned) orchards, and (3) generally greater levels of LM parasitism by S. maiylandensis than by P. ornigis, especially among populations of ABLM. Parasitoids alone appear to be sufficient to exert effective population suppression of LM in abandoned orchards and may have contributed to population suppression of LM in those commercial orchards designated here as A, D, F, G, and L which received no insecticide treatments against LM in 1997 and 1998. Even so, four of these five STLM-dominated orchards (A, D, G, I) did require a LM -targeted treatment in 1 999, suggesting that parasitoids alone were insufficient to effectively suppress STLM below potentially damaging levels. The lowest levels of LM parasitism found in 1999 were in orchards designated here as B, C, E, H, J, K, and L, all of which were dominated by ABLM and all of which received a LM-targeted insecticide in 1999 (all seven of these orchards also received a LM- targeted insecticide in 1997 and/or 1998). The 89-fold level of first- to third-generation population increase in STLM-dominated Orchard F in 1999 was explosive in comparison with the decrease in average first- to third-generation population density that characterized STLM-dominated abandoned orchards in 1999. For reasons yet unknown but possibly associated with apple being the principal host of STLM and only one among many different hosts of ABLM, unattended populations of STLM in commercial orchards could represent a greater threat than populations of ABLM. We hope to explore this possibility in future research. A cknowledgements We thank the apple growers who participated in this study: John Blanchard, Bill Broderick, Dave Chandler, Dave Cheney, Dana Clark, Tony Lincoln, Dave Shearer, Joe Sincuk, Tim Smith, Mo Tougas, and Bob Tuttle. We are also grateful for the support of a USDA Northeast Region SARE grant and state IPM funds. it it it *k it Fruit Notes, Volume 67, Summer, 2002 17 Performance of the V Series Apple Rootstocks During Six Growing Seasons Wesley Autio and James Krupa Department of Plant & Soil Sciences, University of Massachusetts The Vineland (V) series of apple rootstocks was from open pollinated seeds from Kerr applecrab (a cross between Dolgo crabapple and Haralson apple). Dr. Aleck Hutchinson collected seeds from 1957 through 1960. Trees were planted in Vineland, Ontario, and seedlings were selected based on the potential for dwarfing, hardiness, ease of propagation, and field resistance to powdery mildew, fireblight, and wooly apple aphid. By 1971, when the rootstock breeding project was terminated in Vineland, seven clones (V.l, V.2, V.3, V.4, V.5, V.6, and V.7) had been selected. The first evaluation of these clones as rootstocks began with a tnal in 1974. In these early evaluations, V.l and V.3 were determined to produce trees similar to M.9 in size, V.2 produced M.26-sized trees, and V.4 resulted in trees similar in size to those on M.7. The Vineland rootstocks were almost forgotten for a number of years, but interest was rekindled in the early-mid 1990s. V.l and V.3 were included in NC-140 trials, a New England/Nova Scotia trial, and a Northeastern U.S. trial. (For more details of the history of the Vineland series, see the following article: Elfving, D.C., I. Schecter, and A. Hutchinson. 1993. The history of the Vineland (V.) apple rootstocks. Fruit Varieties Journal Al •.52-5%.) To study performance of the V rootstocks under Massachusetts conditions, a small trial was estab- lished in 1 996 at the University of Massachusetts Cold Spring Orchard Research & Education Center in Belchertown, including Rogers Red Mcintosh on V. 1 , V.2, V.3, V.4, V.7, and M.26 EMLA. Trees were individually staked and generally maintained as slender spindles. Each year, trunk circumference was measured and total yield was assessed. After six growing seasons, dramatic differences in tree size existed. Trees on V.4 were more than twice as large as the next largest trees (Table 1). Under our conditions, these trees likely would be larger than Table 1 . Performance of Roge rs Red Mcintosh apple trees on several rootstocks planted in 1996 at the University of Massachusetts Cold Spring Orchard Research & Education Center. Yield efficiency Yield per tree (kg) (kg/cm- TCA) Fruit weight (g) T" 1 1 ruriK cross- sectional Cumulative Cumulative Average Rootstock area (cm^) 2001 (1998-2001) 2001 (1998-2001) 2001 (1998-2001) V.l 13.1 9 21 0.7 1.7 138 147 V.2 17.3 12 23 0.6 1.3 147 148 V.3 10.6 7 22 0.6 2.1 135 140 V.4 48.2 16 33 0.3 0.7 155 148 V.7 19.6 5 24 0.3 1.3 121 139 M.26 EMLA 18.0 12 25 0.7 1.5 148 154 1 18 Fruit Notes, Volume 67, Summer, 2002 comparable trees on M.7. Trees on V.2 and V.7 were similar in size to those on M.26 EMLA. Next smallest were trees on V. 1 . In another trial at the UMass Cold Spring Orchard, trees on V.l were somewhat larger thna trees on M.26 EMLA. The smallest trees were on V.3, likely similar in size to comparable trees on M.9. To date, cumulative yield (1998-2001) was highest from the largest trees (Table 1). However, when adjusted for tree size, the most yield efficient trees were on V.3, V.l, and M.26 EMLA (Table 1). The least yield efficient trees were on V.4. In 2001, V.4 resulted in significantly larger fruit than did V.7, but overall, there was no consistent effect of rootstock on fruit size These trees are too young to make a great number of conclusions, but these results along with those from three other trials at the UMass Cold Spring Orchard suggest that V.l and V.3 are promising, dwarfing rootstocks. Their hardiness, potential disease resistance, and yield efficiency make them worthy of continued trial. ic ic i: i: "k Fruit Notes, Volume 67, Summer, 2002 19 Fruit Notes University of Massachusetts Friilt Department of Plant & Soil Sciences lllllgj 205 Bowditch Hall ni^-i Amherst, MA 01003 Nonprofit Organization U.S. Postage Paid Permit No. 2 Amherst, MA 01 002 -1 SERIAL SECTION UMASS AMHERST, MA 01003 Account No. 2-22914 UM/Morr SB 35A F68 tit;^* Fpoit Notes ijewC'mlana Volume 67, Number 4 FALL ISSUE, 2002 Table of Contents Evaluation of Formulations and Release Rates of Benzaldehyde, an Attractive Fruit Odor for Plum Curculios Jaime Pihero, Sara Hoffmann, and Ronald Prokopy ^ Influence of Insecticide on the Ability of Traps to Capture Plum Curculios Jaime Pinero, Sara Hoffmann, Everardo Bigurra, and Ronald Prokopy ° Devising an Attractive Bait to Monitor the Seasonal Course of Plum Curculio Immigration into Apple Orchards using Traps Jaime Pinero, Sara Hoffman, Everardo Bigurra, and Ronald Prokopy ^^ Editors: Wesley R. Autio William J. Bramlage Publication Information: Fruit Notes (ISSN 0427-6906) is pub- lished each January, April, July, and October by the University of Massachu- setts in cooperation with the other New England state universities. The costs of subscriptions to Fruit Notes are $10.00 for United States ad- dresses and $12.00 for foreign ad- dresses. Each one-year subscription begins January 1 and ends December 31. Some back issues are available for $3.00 (United States addresses) and $3.50 (foreign addresses). Payments must be in United States currency and should be made to the University of Massachusetts, Correspondence should be sent to: Fruit Notes Department of Plant & Soil Sciences 205 Bowditch Hall University of Massachusetts Amherst, MA 01003 All chemical uses suggested in this publication are contingent upon continued registration. These chemicals should be used in accordance with federal and state laws and regulations. Growers are urged to be familiar with all current state regulations. Where trade names are used for identification, no company endorsement or product discrimination is intended. The University of Massachusetts makes no warranty or guarantee of any kind, expressed or implied, concerning the use of these products. USER ASSUMES ALL RISKS FOR PERSONAL INJURY OR PROPERTY DAMAGE. Issued by UMass Extension, Stephen Demski, Director, in furtherance of the acts of May 8 and June 30, 1914. UMass Extension offers equal opportunity in programs and employment. Evaluation of Formulations and Release Rates of Benzaldehyde, an Attractive Fruit Odor for Plum Curculios Jaime Pinero, Sara Hoffmann, and Ronald Prokopy Department of Entomology, University of Massachusetts In the 2000 Issue of Fruit Notes, we reported on a 2000 study showing that benzaldehyde in association with plum curculio (PC) pheromone (grandisoic acid) was the most attractive odor bait combination for PCs when compared with other odor baits affixed to panel and pyramid traps. In that study, we also found that although traps baited with benzaldehyde plus pheromone were very effective at determining the beginning, peak, and end of PC immigration into apple orchards from overwintering sites, benzaldehyde seemed to be less attractive to PCs after -10 days of exposure to sunlight. Subsequently, we found that the clear high-density polyethylene vials used in that study allowed UV-polymerization of about 10% of the benzaldehyde contained in the vials, which may have diminished or masked some of the attractiveness of benzaldehyde. We concluded from that study that research should be aimed at improving the formulation and longevity of benzaldehyde and optimizing the amount of benzaldehyde used as odor bait. Here, in an attempt to improve trap ability to capture PCs, we compared different formulations, release rates, and positions of benzaldehyde-releasing dispensers in tops of branch-mimicking cylinder traps placed on apple tree limbs. We also evaluated different amounts of benzaldehyde in association with PC pheromone in Circle traps, which are wrapped completely and tightly around apple tree trunks and are designed to intercept adults crawling up tree trunks. Materials & Methods We performed four different experiments. The first three were conducted in 200 1 and involved use of black cylinder traps. The fourth was carried out in 2002 and involved use of Circle traps. All evaluations were performed in unsprayed sections of apple orchards or in backyards containing unsprayed apple trees. Experiment 1. In this test, conducted from June 6 to July 3 (200 1 ) in Atkins orchard (Belchertown, MA), we evaluated (using cylinder traps) four different formulations of benzaldehyde alone (without pheromone) released from dispensers placed either inside or outside of the frap tops. Formulations tested were: (1) Great Lakes IPM (Vestaburg, MI), (2) IPM Technologies (Portland, OR), (3) four 400-'/4l high- density clear polyethylene vials (VWR Scientific Products; Boston, MA), each filled with 4OOV4I of benzaldehyde (as in 2000), and (4) one 1-ml low- density white polyethylene vial (Wheaton; Millville, NJ) filled with 1 ml of benzaldehyde. Unbaited traps served as a control treatment. For each formulation, the estimated release rate of benzaldehyde was about 1 0 mg per day except for the white vials, which released about 2.5 mg of benzaldehyde per day. Each treatment was replicated 4-5 times. Traps were deployed in perimeter-row apple frees and on apple frees located in rows 2, 3, and 4. Traps were inspected for PC captures 2 to 3 times per week. At each inspection session, trap tops were rotated (within a replicate) one position (clockwise). Experiment 2. This test, conducted from May 29 to July 3, 2001 in Atkins orchard, was aimed at evaluating different amounts of benzaldehyde released from 1-ml low-density white polyethylene vials in association with cylinder traps. Each white vial released about 2.5 mg of benzaldehyde per day. Treatments evaluated were: (1) one white vial (placed inside a frap top), (2) one white vial (placed outside a frap top), (3), five white vials (inside), (4) five white vials (outside), (5) 15 white vials (outside), and (6) unbaited traps as a confrol freatment. For treatments 2 and 4, vials were hung vertically from the periphery of the frap top using copper wire, about 2 Fruit Notes, Volume 67, Fall, 2002 inches away from the trap base. For treatment 5, the 15 vials were hung from a wooden stick (about 10 inches long) using wire. The stick holding benzaldehyde-releasing vials was then attached horizontally to apple tree branches using wire so that bases of vials were located about 4 inches above a cylinder trap top. In this test, benzaldehyde was evaluated in combination with grandisoic acid (PC pheromone) (ChemTica Intemacional, S.A., San Jose, Costa Rica). One pheromone dispenser, releasing about 1 mg of grandisoic acid per day, was placed inside each benzaldehyde-baited trap top. All vials containing benzaldehyde were replaced on June 15. Traps were deployed within a single row of apple trees and were inspected for PC captures 2-3 times per week. Trap tops were rotated one position (clockwise) at each inspection. Experiment 3. This evaluation was performed from May 25 to June 20, 2001, simultaneously at the UMASS Cold Spring Orchard Research & Education Center in Belchertown, Atkins orchard, and in backyard trees in Amherst, MA. The experiment was aimed at determining the longevity of four different formulations of benzaldehyde alone (without pheromone) using cylinder traps. The formulations evaluated were the same as those described in experiment 1. All benzaldehyde-releasing dispensers were positioned inside cylinder trap tops. Traps were inspected for PC captures 2 to 3 times per week, rotating the trap tops one position (clockwise) at each inspection. Experiment 4. This test was conducted from June 26 to July 2, 2002 in backyard trees in South Deerfield, MA, using Circle traps. The purpose was to determine the influence of different release rates of benzaldehyde, in association with PC pheromone, on PC captures. We evaluated three different release rates of benzaldehyde (10, 20, and 40 mg/day) together with a control treatment without benzaldehyde. Benzaldehyde was released from 15-ml low-density white polyethylene vials (Wheaton, Millville NJ). Each vial was filled with 15 ml of benzaldehyde to achieve a release rate of ~10 mg/day. Each vial was hung by its neck from a wire and placed inside an inverted, green 266-ml plastic cup to provide additional protection for this chemical against polymerization by UV light and rainfall. Cups were hung from tree trunks using wire in such a way that bases of cups were about 4 inches above Circle trap tops. Depending on the treatment, either no, one, two, or four cups were positioned above the Circle trap tops. In all, 32 Circle traps were deployed on unsprayed apple tree trunks. Each was baited with one of the abovementioned treatments and one dispenser releasing PC pheromone (release rate: 1 mg/day) placed inside the Circle trap top. Traps were inspected for PC captures one week after bait deployment. Results In the first experiment, no appreciable differences among odor-formulations were noticed when comparisons were made among vials placed outside of trap tops (Table 1 ). However, when vials were placed inside of trap tops, the '4 clear vials' formulation proved to be the most attractive formulation for PCs, followed by the '1 white vial' formulation. When PC captures by traps were compared according to position of vials Table 2. PC captures by cylinder traps baited with benzaldehyde (in combination with PC pheromone) according to the number and position | of 1-ml white vials. Amount of benzaldehyde Number of released per vials day (mg) Inside Outside Total PCs 1 2.5 2 4 6 5 12.5 2 11 13 15 37.5 — 3 3 unbailed traps 0.0 — — 1 TOTAL 4 18 23 1 Fruit Notes, Volume 67, Fall, 2002 Table 1. PC captures by black cylinder traps baited with formulations of benzaldehyde alone (without pheromone), posi outside of trap tops. four different tioned inside or Formulation Amount of benzaldehyde released per day (mg) Inside Outside Total PCs Great Lakes IPM IPM Technologies White vial 4 Clear vials Unbailed traps 10.0 10.0 2.5 10.0 0.00 2 2 5 8 7 9 6 7 9 11 11 15 2 TOTAL 17 29 48 1 within the same formulation, we found that traps baited with the 'Great Lakes IPM' and 'IPM Tech' formulations deployed outside the trap tops captured 3.5 and 4.5 times (respectively) more PCs than traps having the same type of formulation but placed inside the trap tops. For both clear and white vials, no differences in captures were noticed between vials placed inside or outside the trap top (Table 1). In the second experiment, traps having five white vials placed outside of trap tops captured the most PCs (Table 2). Traps having 15 vials (which released a total of -37.5 mg of benzaldehyde per day) captured the fewest PCs, only slighter more than unbaited traps. Overall, about four times more PCs were captured when vials were positioned outside of trap tops than inside. In the third experiment, wherein all formulations of benzaldehyde were placed inside of cylinder trap tops, results indicated that during the first 8 days of evaluation, traps baited with one white vial captured numerically more PCs than any other bait treatment (Table 3). From days 9-16, clear vials outperformed the other formulations. During this time Table 3. PC captures by black cylinder traps baited with different formulations of benzaldehyde (placed inside of trap tops and without pheromone) according to the number of days elapsed after bait deployment. Treatment Amount of benzaldehyde released per day (mg) 1-8 9-16 17-24 Total 25-32 PCs Great Lakes IPM IPM Technologies 1 White 1 -ml vial 4 Clear vials Unbaited traps 10.0 10.0 2.5 10.0 0.0 6 4 9 5 5 4 0 4 8 1 5 5 2 1 6 4 19 0 9 2 17 3 17 4 16 TOTAL 29 17 19 13 78 1 Fruit Notes, Volume 67, Fall, 2002 T3 Q) Q. CD O W O 0) E c ro .o 0 10 20 30 40 Amount of benzaldehyde released (mg/day) Figure 1. Relationship between total PC captures by Circle traps and amount of benzaldehyde released from 15-ml white polyethylene vials positioned ~4 inches above trap tops. Amounts of benzaldehyde released were 0, 10, 20, and 40 mg/day, each in association with PC pheromone (1 mg of grandisoic acid per day). period, traps baited with the 'IPM Technologies' formulation did not capture any PCs. However, 17-24 days after the initial baiting, the 'IPM Technologies' and the 'Great Lakes IPM' formulations performed better than the white vial and the clear vials but, nevertheless, did not perform better than unbailed traps. From 25-32 days, all traps captured similar numbers of PCs except traps baited with the 'IPM Technologies' formulation, which captured no PCs. Overall, the formulations '4 clear vials', '1 white vial', and the 'Great Lakes IPM' were about equally attractive to PCs, whereas the 'EPM Technologies' formulation was the least attractive. In the fourth experiment, wherein all dispensers of benzaldehyde were placed 4 inches above Circle trap tops, results show a strong linear relationship between the amount of benzaldehyde released (in association with PC pheromone) and the total number of PCs captured by Circle traps (Fig. 1 ). This suggests that, at least for Circle traps, the response of PCs to benzaldehyde in association with PC pheromone increases as the amount of benzaldehyde increases (up to the maximum release rate tested of about 40 mg per day). Conclusions Four conclusions can be drawTi from this series of experiments. First, white polyethylene vials releasing benzaldehyde performed as well as either the clear vials used in the 2000 field test or the other formulations of benzaldehyde evaluated (Great Lakes IPM and IPM Technologies). Therefore, white polyethylene vials (particularly the UV-light-protected 15-ml vials [see below]) can be used as devices to dispense benzaldehyde effectively in future tests. Second, results from the first and second experiments suggest, for the most part, that when dispensers are placed inside of cylinder trap tops, the odor of benzaldehyde may become repellent at close range, thus reducing the ability of cylinder traps to capture PCs. This was particularly true for both the 'Great Lakes IPM' and 'IPM Technologies' formulations but not for the ' 1 -white-vial' or '4-clear- vials' formulations (in experiment 1), and the '5 -white- vials' treatment (in experiment 2). Consequently, we believe that benzaldehyde-releasing dispensers should be placed outside of trap tops to avoid close-range Fruit Notes, Volume 67, Fall, 2002 negative effects while preserving (or even enhancing) attractiveness to PCs. Results from experiment 4 (involving Circle traps), in which vials were placed outside of trap tops, further support this conclusion. Third, 1-ml white vials releasing benzaldehyde were found to perform best during the first 8 days after deployment (experiment 3) and, after that time, their attractiveness decreased considerably. A close examination of the 1-ml white polyethylene vials revealed the formation of whitish/yellowish crystals m the area of necks of vials after 8 days of use. In contrast, the 15-ml white polyethylene vials used in experiment 4 showed no signs of such crystals on any parts of the vials after one week (experiment 4) or several weeks (data from other field studies) of use. This difference may be due largely to the type of screw cap used in association with the white vials in each year. In 2001, the 1-ml white polyethylene vials were enclosed by white polypropylene caps that lacked Teflon® liner as a sealant, and thus oxygen may have interacted with benzaldehyde altering its chemical composition. On the contrary, in 2002 the 1 5-ml white vials were enclosed by black phenolic Teflon®-lined caps, which apparently prevented oxygen from interacting with the benzaldehyde contained in the vials. Also, in 2002 the use of plastic cups provided extra protection against UV light and rainfall. Fourth, results from the fourth experiment strongly suggest that there was an increase in PC captures by Circle traps associated with an increase in the concentration of benzaldehyde. In this experiment, the maximum release rate of benzaldehyde tested was -40 mg per day. Hence, it is possible that even higher amounts of benzaldehyde may increase the attractiveness of benzaldehyde to PCs. This aspect is particularly important not only in relation to the determination of amount of benzaldehyde to be used to bait traps to monitor the onset, course, and end of PC immigration, but also to the determination of amount of benzaldehyde to be employed in perimeter- row odor-baited trap trees (see the 2002 winter issue of Fruit Notes) to follow accurately the course of plum curculio injury to fruit in commercial apple orchards in Massachusetts. Acknowledgments We thank Everardo Bigurra and Phillip McGowan for field assistance. This study was supported with funds provided by a USDA Northeast Regional IPM grant, a Hatch grant, a grant from USDA Crops at Risk program, and the New England Tree Fruit Research Committee. *1^ «1^ «£# ^f^ «1^ ^f% ^j^ #1^ ^^ «^ Fruit Notes, Volume 67, Fall, 2002 Influence of Insecticide on the Ability of Traps to Capture Plum Curcullos Jaime Pinero, Sara Hoffmann, Everardo Bigurra, and Ronald Prokopy Department of Entomology, University of Massachusetts Several factors may influence the effectiveness of different types of traps for capturing and monitoring plum curculios (PCs). We have determined, for example, that temperature is an important factor influencmg the ability of both Plexiglas panels (traps capturing flying PCs) and pyramid traps (traps capturing crawling PCs) to monitor extent and timing of PC immigration when traps are deployed at the edges of an orchard, in close proximity to woods. We found that panel traps are more effective than pyramid traps on warm days and, conversely, that pyramid traps outperform panel traps on cool days. For both branch-mimicking cylinder traps (which are positioned vertically on apple tree branches) and Circle traps (which are wrapped around orchard tree trunks), weather may have a lesser effect because the purpose of such traps is either to capture PCs already present within tree canopies (cylinder traps), or to intercept adults crawling up tree trunks into canopies (Circle traps). However, as indicated in the 2002 Winter issue of Fruit Notes, odor-baited cylinder traps have yet to demonstrate value for predicting extent of PC injury to fruit when deployed in commercial orchards. Similarly, odor-baited Circle traps, although able to capture numerous PCs under unsprayed orchard conditions, have not proven to be effective as a tool for predicting, in commercial orchards, the timing of PC injury to fruit based on extent of PC captures. The principal aim of this study was to determine the influence of insecticide presence (via orchard spray application) on surfaces of cylinder, pyramid, and Circle traps on trap performance. Materials & Methods Field studies. Studies were performed from May 16 to June 28 (2001) at the UMASS Cold Spring Orchard Research & Education Center, and from May 22 to June 6 (2002) at Atkin's Farm. Both orchards are located in Belchertown, MA. The UMASS orchard block consisted of Delicious/M.7 and Cortland/M.7. The Atkins' block consisted of Idared/M.7. 2001 Field study. In 2001, we evaluated two trap types: (1) a black cylinder trap (3 inches diameter x 12 inches tall) and (2) a reduced version of a pyramid trap (6.5 inches at base x 12 inches tall). Cylinders were made from PVC pipe. Pyramids were made from plywood. Both trap types were painted black using flat black latex paint. On May 16, just after petal fall, 14 traps of each type were deployed on branches of perimeter-row trees. Only one trap was used per tree. For every tree bearing a trap (central tree), there were two trees without traps (adjacent trees), one on either side (Figure 1). A few hours before an insecticide application was made (using a tractor-driven mist blower delivering 150 gallons of water per acre), seven traps of each type were covered with plastic bags. Traps were uncovered the morning after spray application. These traps will be referred as "unsprayed" traps. The remaining 14 traps, along with all tree canopies, received an application of Imidan® (70% WSB) at 3/4 pound per 100 gallons water. These traps will be referred as "sprayed" traps. This procedure (trap covering and uncovering) was repeated three times, once in association with each insecticide application against PC: May 16, May 25, and June 14. Each trap was baited with one 1-ml white, low- density polyethylene vial containing 1 ml of benzaldehyde (release rate: ~2.5 mg per day) and one dispenser releasing PC pheromone ( 1 mg of grandisoic acid per day). Both baits were placed inside the trap tops that capped cylinder traps. Benzaldehyde and pheromone dispensers were replaced once (on June 11). All traps were inspected twice per week (11 inspections in total) to determine PC captures. At every inspection, 20 fruit were sampled for PC injury in each trap-bearing tree and each of two adjacent trees (Figure 1). For presentation of results, we arranged data on Fruit Notes, Volume 67, Fall, 2002 Woods o • _Q "^^ O • O n o • O o • o • o O • o • o O • o o Figure 1. Schematic illustrat on of the plot used for the experiment. Trees were Cortland and Delicious in alternating row; .. For each row, the first three perimeter -row trees were used. A small pyramid or cylinder trap was placed in the central tree (black dot) Twenty fruit were inspected for PC damage in each trap- bearing ; tree and each adjacent non- trapped tree (white dots). captures and PC damage in the following manner: (1) 1-10 days after an application of insecticide, (2) 11 -20 days after application, and (3) more than 20 days after application. 2002 Field study. In 2002 we evaluated four trap types: (a) black cylinders, (b) small black pyramids, (c) Circle traps made of aluminum screen and wrapped entirely and tightly around tree trunks, and (d) Circle traps as above but made of plastic screen. On May 24, just after petal fall, eight traps of each type were deployed on apple trees located in a sprayed section of the orchard that received an application of Imidan® (as above). After application, all traps were removed and deployed, along with unsprayed traps, on branches (cylinders and small pyramids) or tree trunks (Circle traps) of perimeter-row trees located in an unsprayed section of the orchard. Traps were deployed in pairs (i.e., one sprayed trap of one type adjacent to one unsprayed trap of the same type). There were eight replicates for each trap type and insecticide regime. In 2002, all traps were baited with one 15 ml white low-density polyethylene vial containing 15 ml of benzaldehyde (release rate: ~10 mg per day) and one dispenser releasing PC pheromone (~1 mg of grandisoic acid per day). To protect benzaldehyde from sunlight and rainfall, each vial was hung by the neck using a wire and placed inside an inverted plastic cup. Each plastic cup was suspended from the tree trunk using wire in such a way that its base was -10 cm above each trap top. Each pheromone-releasing dispenser was placed inside the trap top. Benzaldehyde and pheromone dispensers were not replaced during the study. All traps were inspected on a daily basis for 12 days after application of insecticide. On June 10, all sprayed traps were removed and transported to the sprayed section of the orchard, where they received a second spray of Imidan®. Afterwards, traps were deployed again in the unsprayed section of the orchard but the position of each member of pair of sprayed and unsprayed traps was inverted. This study differed from the 2001 study in that 1) all traps were inspected on a daily basis for 12 days after application of insecticide, and 2) we did not inspect fruit to determine injury by PC. For presentation of results, we organized data on PC captures in the following manner: (1) 1-6 days after an application of insecticide, (2) 7-12 days after application. Laboratory observations. Behavioral observations were conducted in a laboratory during July 2000 and July 2001 to assess the effects of insecticide application Fruit Notes, Volume 67, Fall, 2002 on the propensity of PCs to crawl upon sprayed traps. For comparative purposes, in 2000 the insecticide evaluated was Guthion®, and in 2001, Imidan* was used (same dose as above). PC behavior was observed inside of Plexiglas cages with no top. Traps evaluated were as described above, but we also evaluated sprayed and unsprayed apple tree limbs (diameter: 2 inches; length: 12 inches). No attractive odors were used in these tests. In all instances, observations were performed 1 limbs (taken from trees in the application of insecticide. For Table 1. Total PC captures by sprayed (Imidan®) and unsprayed small pyramid and cylinder traps (field study, 2001). Data are presented according to the nimiber of days elapsed after an application of insecticide. Days after Pyramid spray unsprayed Pyramid sprayed Cylinder unsprayed Cylinder sprayed 0-10 5 11-20 3 >20 0 1 2 0 1 2 0 0 3 1 TOTAL 8 3 3 4 1 -3 days after traps or placed a PC on the floor facing one of the test traps orchard) received an and recorded, for a time period of up tolO minutes, the observations, we whether the PC was able to reach the top of the trap. UNSPRAYED SMALL PYRAMID TRAPS SPRAYED SMALL PYRAMID TRAPS 35 30 ~^ TRAP.eEARING TREE (r- 0-01) ■D. ADJACENTTREES |r= 0.28) ^•.^ TRAP-BEARING TREE (r= 0.56) D. ADJACENT TREES (1=0.06) 25 • 20 ■D 15 10 5 n • • D D D D n . n ^11:=::^:^:- ^ 0.0 0.2 0.4 0.6 0.8 1.0 1.2 o.O 0.2 0.4 0.6 0.8 1.0 1 2 *-* S5 40 35 30 UNSPRAYED CYLINDER TRAPS SPRAYED CYLINDER TRAPS "».. TRAP-BEARING TREE (r= -0.1 1 ) a._ ADJACENT TREES (r= 0.01) ^^ TRAP-BEARING TREE (r= 0) ~Ck ADJACENT TREES (r- 0) 25 20 • 15 • • 10 D • 5 0 D 0 □ 0.0 0.2 0.4 0.6 0.8 1.0 1.2 0.0 0.2 0.4 0.6 0.8 1.0 1 2 NUMBER OF PCs NUMBER OF PCs Figure 2. Degree of correlation between the total number of PCs captured by traps of each type and the percent fruit injured by PCs in trees bearing a trap and in adjacent trees. The higher the r value, the greater the extent of correlation. Fruit Notes, Volume 67, Fall, 2002 Results 2001 Field study. Table 1 shows that within the first 10 days after spraying, unsprayed traps (particularly pyramids) captured more PCs than sprayed traps. From 11 to 20 days after insecticide application, all traps captured similar numbers of PCs. Only one PC was captured after 20 days (by a sprayed cylinder trap). Overall, at least twice as many PCs were captured by unsprayed small pyramid traps than by any other trap type. Figure 2 depicts, for the first 10 days after insecticide application, the degree of correlation between the extent of PC captures by a trap and the 5 H 5 H 5 14 12 10 8 6 4 2 0 14 - 12 - 10 - 8 - 6 - 4 - 2 - 0 - 0-10 DAYS AFTER SPRAY - ■ Trap-bearing tree □ Adjacent trees ^^^H SPRAYED UNSPRAYED 11-20 DAYS AFTER SPRAY ■ Trap-bearing tree □ Adjacent trees SPRAYED UNSPRAYED > 21 DAYS AFTER SPRAY ■ Trap-bearing tree D Adjacent trees SPRAYED UNSPRAYED Figure 3. Amount of fruit injured by PCs on perimeter-row apple trees having a trap (i.e., trap-bearing tree) or on two adjacent non-trapped trees (adjacent trees). Data combined for pyramid and cylinder traps (2001 field study). Fruit Notes, Volume 67, Fall, 2002 amount of PC injury to fruit located in trees having a trap or in adjacent trees. A strong positive correlation (i.e., a value close to 1) would indicate that high PC captures reflect high damage to fruit by PC, and that low PC captures reflect low damage to fruit. If a strong correlation were found, we would be able to predict fruit injury based on trap captures. However, we found that all trap types (even the unsprayed ones) showed a poor ability to predict injury to fruit by PCs based on captures. Even though the strongest correlation (0.56) was found in the case of sprayed pyramid traps, the fact that few PCs were captured by traps of this type during the first 10 days does not allow us to consider such a correlation as convincing. Figure 3 shows that, in each one of the three time periods after insecticide application, fruit located in trees bearing both sprayed and unsprayed traps received consistently more damage than fruit located in adjacent trees. Such a pattern was especially pronounced after 20 days, when fruit injury was 2.4 times greater on trees bearing sprayed traps than on adjacent trees and about 1 .9 times greater on trees beanng unsprayed traps than on adjacent frees. 2002 Field study. Figure 4 reveals that regardless of the time period elapsed since insecticide spray, the application of Imidan® seems to have had little influence on the ability of any frap type to capture PCs. Both types of Circle fraps captured similar numbers of PCs, and these two trap types captured substantially more PCs than small pyramid or cylinder traps. 1-6 DAYS ■ sprayed D unsprayed Circle metallic Circle plastic Pyramid 12 n (A ^ 10 H i S c rs 0) 6- 4- 2- 7-12 DAYS Cylinder ■ sprayed D unsprayed Circle metallic Circle plastic Pyramid TRAP TYPE Cylinder Figure 4. PC captures by each type of odor-baited trap placed on perimeter-row trees (2002 field study). 10 Fruit Notes, Volume 67, Fall, 2002 Table 2. In laboratory tests, proportions of PCs that reached the top of unsprayed and sprayed tree limbs, small pyramid traps, and black cylinders. The insecticide evaluated in 2000 was Guthion®, and in 2001 was Imidan®. Trap type 2000 2001 No PCs % TOP tested No PCs % TOP tested Limb unsprayed Limb sprayed Pyramid unsprayed Pyramid sprayed Cylinder unsprayed Cylinder sprayed 91% 11 44% 16 67% 6 0% 12 75% 4 25% 4 100% 16 65% 20 100% 17 59% 22 94% 16 50% 22 1 Laboratory observations. Table 2 shows that in 2000 (when Guthion® was evaluated), 91, 67, and 75 % of total PCs reached the top of unsprayed limbs, pyramids, and cylinders, respectively, whereas for sprayed counterparts, only 44, 0, and 25%, respectively, reached the top. Table 2 also reveals that in 2001 (when Imidan® was evaluated), 100, 100, and 94% of total PCs reached the top of unsprayed limbs, pyramids, and cylinders, respectively, whereas for sprayed counterparts, only 65, 59, and 50%, respectively, reached the top. Comparatively, Guthion® exerted a greater negative effect than Imidan® on the propensity of PCs to crawl up the structures evaluated. Conclusions Results from the 200 1 field experiment suggest that when orchard trees are sprayed with Imidan® to protect against PC damage, PC captures by cylmder traps are strongly compromised during the first 10 days after application. This suggests that, particularly during this period of time, PC captures by cylinder traps would be very poor indicators of PC population levels in tree canopies, with a remarkably poor ability to forecast PC injury to fruit. In 2001, the negative effects of insecticide application were not apparent after 10 days following an application of Imidan®. Several of our studies have shown that odor-baited cylinder traps, when deployed in commercial orchards, offer little or no value for predicdng extent of PC injury to fruit, which we have attributed, in part, to the presence of insecticide on the trap surface. As found in the 2001 study, even unsprayed traps failed to reflect the amount of PC injury to fruit located in trap-bearing or adjacent trees. Such poor ability could have been due then to the possibility that very few PCs were present on sprayed trees. Even so, PC presence was sufficiently great to inflict damage to fruit. In both 2001 and 2002, unsprayed black pyramids captured numerically more PCs than unsprayed black cylinders, which suggests that small pyramids offer a stronger visual stimulus to PCs than cylinders. Results from the laboratory observations confirmed the negative effect of organophosphate insecticide application on trap performance found in the 200 1 field study. Here, there was strong evidence that, in the absence of any odor bait, PCs are reluctant to crawl upward on traps sprayed with Guthion® or Imidan®. Nonetheless, tree limbs sprayed with organophosphate insecticide proved considerably less deterrent to PCs, possibly because tree limbs possess positive contact stimuli that tend to override negative effects of insecticide. Results from the 2002 field study, however, failed to show an effect of insecticide application on trap captures even when the same insecticide (Imidan®) and dose (3/4 pound per 1 00 gallons water) was utilized as in the 2001 study. This may be due to the fact that the amount of benzaldehyde used to bait traps in 2002 was four times greater than in 2001 (2.5 mg/day vs. 10 mg/ day in 2001 and 2002, respectively). Therefore, in 2002 PCs may have been more strongly drawn to enter the trap tops, overcoming the negative effect of insecticide. Combined results suggest that, in the absence of any odor (as in our lab study), PCs are substanfially repelled from climbing up organophosphate-sprayed traps. However, such negative effect seems to be less pronounced as the amount of odor bait (i.e. Fruit Notes, Volume 67, Fall, 2002 11 benzaldehyde) is increased, as found in the field studies. As mentioned, the amount of benzaldehyde used in the field studies was increased from 2.5 mg/ day (in 2001) to 10 mg/day (in 2002), which seems to have overcome negative effects of the presence of insecticide on the trap surface. Based on our findings, we conclude that (1) unsprayed cylmder or small pyramid traps may be more effective in capturing PCs than sprayed cylinder or small pyramid traps, and (2) even though Circle traps may offer more promise for capturing PCs than unsprayed cylinders or small pyramids, other approaches to monitoring PC, such as an 'odor-baited trap tree' approach (see the 2002 winter issue of Fruit Notes), may be much more rewarding. A cknowledgm ents. We thank Joe Sincuk for aid in both the scheduling and execution of the insecticide applications and Phillip McGowan for technical aid. This study was supported with funds provided by a USDA Northeast Regional IPM grant, a Hatch grant, a grant from USDA Crops at Risk program, and the New England Tree Fruit Research Committee. %S^ %S^ %i^ «1^ %x^ #1^ #^ #^ #^ #Y* 12 Fruit Notes, Volume 67, Fall, 2002 Devising an Attractive Bait to IVIonitor the Seasonal Course of Plum Curculio Immigration into Apple Orchards using Traps Jaime Piiiero, Sara Hoffman, Everardo Bigurra, and Ronald Prokopy Department of Entomology, University of Massachusetts To reduce insecticide use against plum curculio (PC), management strategies should consider the time of first appearance of PCs on host trees after overwintering in woods, as well as the peak and the end of immigration. One approach to tracking the seasonal course of PC immigration is the use of a trap baited with a lure that is highly attractive to PCs. In the 2000 issue of Fruit Notes, we reported that both panel and pyramid traps baited with benzaldehyde (BEN) in combination with PC pheromone called grandisoic acid (GA) were very good indicators of the seasonal course of immigration into apple orchards when deployed in close proximity to woods. In that study, we also found that ethyl isovalerate (EIV) and limonene (LIM), in combination with GA, showed some degree of attractiveness to PCs, but to a lesser extent when compared to the high luring power of BEN+GA. Here, we report on two field studies performed in Massachusetts in 2001 and 2002 using panel and pyramid traps. The 2001 study was aimed at evaluating the three most attractive fruit odors (BEN, EFV, and LIM) found in our 2000 study to confirm the high attractiveness of the combination BEN+GA to PCs. The 2002 study was performed to evaluate PC response to four different amounts of BEN (the most attractive fruit odor found in the 2001 study) and two different amounts of GA to determine the amount of each odor needed to maximize the performance of monitoring traps. Materials & Methods Both studies were conducted in an unsprayed section of a commercial apple orchard at the UMASS Cold Spring Orchard Research & Education Center (Belchertown, MA). As in 2000, traps evaluated in 200 1 and 2002 were clear Plexiglas panels (2x2 feet, with the woods-facing side coated with Tangletrap) and black pyramid traps (24 inches wide at base x 48 inches tall) (Figure 1). Whereas panel traps capture mainly PCs in flight (particularly on warm days), pyramid traps capture primarily crawling PCs (mostly during cool days or at night). 2001 Study. This study was undertaken from April 30 to June 30, 2001. Host plant odors evaluated were benzaldehyde (BEN), ethyl isovalerate (EFV), and limonene (LIM), all purchased from Sigma-Aldrich Chemical Co. (Milwaukee, WI). Three different groups of odor treatments were arranged, each involving a single host volatile alone, GA alone, a combination of host volatile and GA, and a no-odor (control) treatment. By testing each fruit odor alone and in combination with GA, we sought to determine the extent to which each of the synthetic host plant volatiles tested enhanced PC responsiveness to GA. There were four replicates for each trap type and odor combination. BEN was released from 1-ml low-density white polyethylene vials in order to prevent polymerization of this chemical by UV light (as found in 2000 when using high-density clear polyethylene vials). Because this problem was not found for EFV and LIM, these two chemicals were tested (as in 2000) using 400 'Al high-density clear polyethylene vials. A white vial filled with 1 ml of BEN released -2.5 mg/day of BEN. Only one vial of this type was used per trap. Two vials containing LIM and three vials containing EIV were needed per trap to accomplish a release rate of ~10 mg/day of each chemical. Each pheromone dispenser released ~1 mg/day of GA. Fruit Notes, Volume 67, Fall, 2002 13 5.6 ft Pheroitione dispenser Clear Plexigla& sticky panel BEN-releasin* vial capped bv a CUD Black PV( sleeve Permanent bottom Figure 1. View of a panel and a pyramid trap used in the 2001 and 2002 studies to evaluate synthetic odors for attractiveness to PCs. Traps were deployed in pairs in close proximity (~lm) to woods to intercept immigrating PCs. Vials containing fruit volatiles were attached to the lower edge of a panel using binder clips, whereas one GA dispenser was attached to the upper edge of a panel. For pyramid traps, both fruit volatile- and GA- releasing dispensers were placed inside a boll weevil frap top. Vials containing BEN were replaced every 2 weeks to maintain a consistent release rate. Vials containing EFV and LEM, along with GA dispensers, were replaced twice (3 and 6 weeks after trap deployment). 2002 Study. In 2002, we evaluated four different amounts of BEN (0, 2.5, 10, and 40 mg/day), hereafter referred to as no-BEN, low, medium, and high release rates, respectively, and two amounts of GA ( 1 and 2 mg/day), hereafter referred to as low and high release rates, respectively. The low release rate of BEN (-2.5 mg/day) was achieved by filling 1-ml low-density white polyethylene vials with 1 ml of BEN (1 vial/trap), as in 2001. The medium release rate (~10 mg/day) was achieved by using one 15-ml low-density white polyethylene vial filled with 15 ml of BEN (1 vial/ frap). The high release rate (-40 mg/day) was achieved by using four such 15-ml vials per trap. Since each pheromone dispenser released -1 mg of GA per day, the high release rate of GA (2 mg/ day) was achieved by using two GA dispensers per trap. In total, eight treatments were evaluated. Each was replicated six times for each trap type. In 2002, besides using white vials to protect BEN from UV light, we employed green 266-ml plastic cups to provide additional protection against UV light and rainfall. Each vial containing BEN was hung by its neck from a wire and positioned inside a plastic cup. For use with pyramid traps, cups were hung in inverted position from the end of a wooden pole (buried in the ground at a 45° angle) in such a way that bases of cups were - 4 inches above pyramid frap tops (see Figure 1). Depending on the treatment, either one or four cups were attached to each pole. Cups holding BEN-dispensing vials were attached to the bottom edge of panels using wire and steel binder clips. GA dispensers were attached to the upper edge of panels using binder clips, or were placed inside the inverted screen funnel capping pyramid traps. All vials releasing BEN and all GA dispensers were replaced once (four weeks after initial trap deployment). Trap deployment. In both years, panel and pyramid traps were deployed in pairs (1 yard apart) along the periphery of the apple orchard, in close proximity (-1 yard) to woods. This approach allowed traps to intercept PC adults presumably immigrating into the orchard after overwintering in the woods. Each pair of traps was baited with the same odor combination and spaced 10 yards from other trap pairs on either side. Traps were inspected for PC captures on a daily basis. 14 Fruit Notes, Volume 67, Fall, 2002 although for the purposes of this article, results for each were baited during the tight cluster stage of apple tree year show PC captures by panel or pyramid traps across phenology (on April 29 in 2001 and on April 16 in the entire period of immigration. In both years, traps 2002). '^ 25 n OH Z) a. 20 H < o (A q! 15 u. O a: LU 10 m 5 - < LU UJ E E 8 a tu a: Z3 I- Q. < O (A O Q. u. o OH LU m < lU 25 1 20 15 10 B BC ■ I ' ' I ■ ' I ' 'I Ol LU _l > LU LU BEE + 8 B E E 8 B B B 1* 'I' ' I ' ' I ' 'I S LJJ LU _l - E E g 8 Figure 2. PC captures by A) panel traps and B) pyramid traps in the 2001 study. For each graph, bars in each group not superscribed by the same letter are significantly different at odds of 19:1. Fruit Notes, Volume 67, Fall, 2002 15 u u O d A 1 20 16 < u 1/1 17 u Cu b g O o Z 4 § a 0 -♦- 1 mg GA/day ^ - ■ - 2 mg GA/day .■-... A.-'' - - ' ' ab^^^^ - -ill^-J;- — — ""^ A ■ ■ -■ b 1 1 1 1 20 16 12 8 4 0 0 2.5 10 40 1 mg GA/day 2 mg GA/day ^ B AB 0 2.5 10 40 AMOUNT OF BENZALDEHYDE (mg/day) Figure 3. PC captures by A) panel traps and B) pyramid traps in the 2002 study as a function of amounts of BEN (benzaldehyde) and GA (grandisoic acid) used. For each graph, points in each Hne not superscribed by the same letter are significantly different at odds of 19:1. Results 2001 Study. Overall, 538 PCs were captured by traps (312 PCs by panels and 226 PCs by pyramids) over the period of 62 days that encompassed the PC season in 2001 (April 30-June 30). In 2001, BEN was the only host volatile that for both trap types significantly enhanced the response of PCs to GA. To illustrate, panel traps baited with BEN+GA captured 1 5 times more PCs than unbaited 16. Fruit Notes, Volume 67, Fall, 2002 traps of the same type, and captured twice as many PCs as traps baited with GA alone (Figure 2A). Panel traps baited with GA alone captured more PCs than panel traps baited with BEN alone or unbaited traps. Pyramid traps baited with BEN+GA captured 5 times more PCs than unbaited pyramid traps and 2.5 times more PCs than pyramid traps baited with GA alone. Pyramid traps baited with BEN alone or GA alone captured more PCs than unbaited pyramid traps (Figure 2B). For both trap types, the presence of EFV or LIM did not enhance the attractiveness of GA to PCs (Figure 2A and B). Also, for both trap types, consistently more PCs were captured by traps baited with GA alone than by traps baited with EfV alone, LIM alone, or unbaited traps. In no case did EIV or LIM alone significantly enhance adult response above that to control traps. 2002 Study. In all, 1,305 PCs were captured by traps (662 PCs by panels and 643 PCs by pyramids) over the period of 82 days that comprised the PC season in 2002 (April 17 -July 8). Figure 3A shows PC captures by panel traps according to amounts of BEN and GA evaluated. Overall, panel traps baited with the high release rate of GA captured about 35% more PCs than panel traps baited with the low release rate of GA. When we examined PC captures by panel traps baited with the low release rate of GA, we found a significant positive linear relationship between the amount of BEN and the extent of captures. As depicted in Figure 3A, increases in the amount of BEN released corresponded to increases in captures by panel traps, with the maximum number of PCs captured corresponding to the high release rate of BEN (40 mg/day). For panel traps baited with the high release rate of GA, we found that the most attractive release rate of BEN was again 40 mg/day, although differences among BEN treatments were only numerical. Figure 3B presents PC captures by pyramid traps according to amounts of BEN and GA used. Pyramid traps captured similar numbers of PCs regardless of the amount of GA used. For pyramid traps baited with the low release rate of GA, we found that the mere addition of BEN, regardless of the dose, enhanced PC captures relative to traps baited with GA alone (Figure 3B). For pyramid traps baited with the high release rate of GA, we found an increase in captures as the amount of BEN released increased but only up to a maximum of 10 mg/day. Beyond that amount, BEN did not enhance, but rather decreased the attractiveness ofGA. Conclusions Our results from the 2001 study indicate that, among all odor combinations evaluated, BEN in association with GA was the most attractive bait for PCs. Results from the 2002 study, as well as an assessment of cost of both BEN (as formulated by us) and GA (obtained from Great Lakes EPM), indicate that a high release rate of BEN (40 mg/day/trap) in association with a low release rate of GA (1 mg/day/ trap) seems to be the most cost-effective bait combination to be used for panel as well as pyramid traps. With our approach, BEN provided sustained attractiveness to PCs across the entire period of immigration (82 days in 2002). Placement of BEN- releasing vials outside of trap tops (for pyramid traps) appeared to preclude the kind of close-range repellency found in previous studies in which BEN-releasing vials had been positioned inside the tops of pyramid, Circle, or cylinder traps. We conclude that BEN (at 40 mg/day of release) in association with GA (at 1 mg/day of release) constitutes a powerful lure that may greatly improve the effectiveness of monitoring traps for PC. A cknowledgm ents We thank Phillip McGowan for assistance. This study was supported with funds provided by a USDA Northeast Regional IPM grant, a Hatch grant, the New England Tree Fruit Research Committee, and the UMass HRC Trust Fund. «1^ «1« %X^ %S^ «1^ ^* #1^ #1^ 'l^ ^s^ Fruit Notes, Volume 67, Fall, 2002 17 Fruit Notes University of Massachusetts ff lilt Department of Plant & Soil Sciences lilies 205 Bowditch Hall «^ Amherst, MA 01003 Nonprofit Organization U.S. Postage Paid Permit No. 2 Amherst, MA 01 002 -1 SERIAL SECTION UMASS AMHERST, MA 01003 A1 04911 B 68 Notes Volume 68, Number 1 ihwCn^LJ WINTER ISSUE, 2003 Table of Contents Comparison of Avaunt versus Guthion in Every-row versus Perimeter-row Sprays Against Key Apple Insect Pests: 2002 Results and Project Summary Ronald Prokopy, Matthew Harp, Andrew Hamilton, Bradley Chandler, and Isabel Jacome 1 Comparison of Traps and Trap Trees for Monitoring Plum Curculios: 2002 Results Ronald Prokopy, Bradley Chandler, Sara Dynok, Elisa Gray, Matthew Harp, Anne Talley, and Jaime Pifiero 5 Evaluation of Odor Combinations for Attractmg Plum Curculios to Trap Trees Ronald Prokopy, Bradley Chandler, Sara Dynok, Elisa Gray, Matthew Harp, Anne Talley, and Jaime Pinero 11 Can a Band of Tangletrap Around a Tree Trunk Suppress Plum Curculio Injury to Fruit? Ronald Prokopy 13 Helping Kids Do Farm Jobs Safely: Know Which Tasks Are Appropriate for Your Children George Cook 15 Visual Exposure: Farm Logos and Signs Tell Your Story Judith Powell 17 Editors: Wesley R. Autio William J. Bramlage Publication Information: Fruit Notes (ISSN 0427-6906) is pub- lished each January, April, July, and October by the University of MassachusettsAmherst in cooperation with the other New England state uni- versities. The costs of subscriptions to Fruit Notes are $10.00 for United States ad- dresses and $12.00 for foreign ad- dresses. Each one-year subscription begins January 1 and ends December 31. Some back issues are available for $3.00 (United States addresses) and $3.50 (foreign addresses). Payments must be in United States currency and should be made to the University of Massachusetts Amherst, Correspondence should be sent to: Fruit Notes Department of Plant & Soil Sciences 205 Bowditch Hall University of Massachusetts Amherst Amherst, MA 01003 All chemical uses suggested in this publication are contingent upon continued registration. These chemicals should be used in accordance with federal and state laws and regulations. Growers are urged to be familiar with all current state regulations. Where trade names are used for identification, no company endorsement or product discrimination is intended. The University of Massachusetts makes no warranty or guarantee of any kind, expressed or implied, concerning the use of these products. USER ASSUMES ALL RISKS FOR PERSONAL INJURY OR PROPERTY DAMAGE. Issued by UMass Extension, Stephen Demski, Director, in furtherance of the acts of May 8 and June 30, 1914. UMass Extension offers equal opportunity in programs and employment. Comparison of Avaunt versus Guthion in Every-row versus Perimeter-row Sprays Against Key Apple Insect Pests: 2002 Results and Project Summary Ronald Prokopy, Matthew Harp, Andrew Hamilton, Bradley Chandler, and Isabel Jacome Department of Entomology, University of Massachusetts In the 2001 issue oi Fruit Notes, we presented results from the first year of a planned two-year study comparing the effects of Avaunt versus Guthion in every-row versus perimeter-row sprays against plum curculio (PC), apple maggot (AM), summer leafrollers (LR) and internal Lepidoptera (a combination of codling moth, oriental fruit moth and lesser appleworm). Avaunt is a recently-labelled oxadiazine insecticide for use against these and other orchard pests. Guthion has been our standard organophosphorous material for general-purpose insect control for several decades, but its status for use in orchards beyond 2005 is uncertain. Conceivably, Avaunt might be an effective substitute for Guthion against key orchard insect pests. Avaunt and most other recently labelled insecticides are substantially more expensive than Guthion and other older insecticides. If the amount of Avaunt needed to achieve effective pest control could be reduced through modification of pattern of spray application (such as limiting application to only peripheral-row trees), then considerable cost savings could be achieved without sacrifice of fruit quality Here, we present results of our second and final year of research comparing effects of Avaunt versus Guthion in every-row versus perimeter-row sprays against PC, AM, LR, and internal Lepidoptera. We also present combined data from our two years of research on this subject. Materials & Methods In April of 2001, four plots were established in each of six commercial apple orchards in Massachussetts (24 plots in all). Rootstocks and cultivars varied among orchards, but all trees in a given orchard were on the same rootstock (either M.7, M.26, or M.9) and of the same cultivar (either Mcintosh, Empire, Cortland, Gala, or Delicious). Each plot was about 40 X 40 yards in size and consisted of seven rows of apple trees. The perimeter row bordered woods, hedgerow, or open field and was subjected to pressure ft-om immigrating PCs and AM. In 2002, one of the six orchards was so heavily damaged by firost that it could not be used in our 2002 research. In 2002, as in 2001, growers themselves sprayed all rows of all plots with azinphosmethyl or phosmet through petal fall. Thereafter, all sprays were applied by Andrew Hamilton using our own tractor-mounted mist blower. Plots in each orchard received four sprays after the petal fall spray: 10 days and again in 20 days after petal fall against PC, and on July 1 9-2 1 and again on August 9-11 against AM. Spray was delivered at the equivalent of 1 50 gallons of water per acre. Guthion (50 WP) was applied at the rate of 30 ounces of formulated material per acre against PC and 24 ounces of formulated material per acre against AM. Avaunt (30% WG) was applied at the rate of 6 ounces of formulated material per acre against both PC and AM. After the petal-fall spray, plots designated as "all row" plots received insecticide applied to both sides of trees on all seven rows, whereas plots designated as "perimeter-row" plots received insecticide sprays applied to both sides of trees of the perimeter (=first) and second rows but no insecticide applied to trees of the third through seventh rows (Figure 1). After the petal-fall spray, Andrew Hamilton applied Fruit Notes, Volume 68, Winter, 2003 azinphosmethyl or phosmet to trees in the eighth interior row and to orchard trees bordering plots on either side. Weekly from petal fall until harvest in September, 100 fruit m each of rows 1, 3, 5, and 7 of each plot were sampled for mjury by PC and AM. In addition, two unbaited sticky red sphere traps were hung toward the center of each row of each plot to monitor AM. Finally, at harvest, 100 fruit in each of rows 1,3, 5 and 7 of each plot were sampled for injury by summer LR and internal Lepidoptera. Results Incidence of each pest type, as averaged across all samples of fruit or traps in rows I, 3, 5, and 7 of each plot, is given in Table 1. As in 2001, results for 2002 show no significant differences among any of the four treatments (all-row versus perimeter-row sprays of Guthion versus Avaunt) in incidence of fruit injury by PC, trap captures of AM, Iruit injury by AM, fruit injury by summer LR, or fruit injury by internal Lepidoptera. Injury by PC in 2002 was sufficiently great to justify comparison of PC damage to fruit on perimeter- row trees with damage to fruit on interior trees. Combined date for all-row plus perimeter-row sprays of Guthion revealed that injury to fruit on perimeter- row trees (row 1) averaged about 10 times greater (1.275%) than the mean amount of injury to fruit on trees in row 3, 5, and 7 (0.125%). These data suggest that PCs which immigrate into orchards after a petal fall spray has been applied confine their activity to peripheral-row trees and infrequently penetrate into interior rows of orchards. Figure 2 displays combined data for each pest for 2001 and 2002. All-row sprays of Avaunt were approximately equal to all-row sprays of Guthion in protecting against PC, AM, summer LR and internal Lepidoptera. For both PC and AM, perimeter-row sprays of Guthion performed as well as all-row sprays of Guthion in providing plot-wide control. For PC and especially for AM, perimeter-row sprays of Avaunt were not as effective as all-row sprays of Avaunt in providing plot-wide control. For both summer LR and internal Lepidoptera, perimeter-row sprays were not as effective as all-row sprays in providing plot-wide control in the case of Guthion as well as Avaunt. Conclusions There were no statistical differences among any of the four treatments evaluated here in ability to control target pests in either 2001 or 2002. Indeed, combined data for both years indicate that all-row sprays of Avaunt were approximately as effective as all-rows sprays of Guthion in ability to confrol PC, Table 1 . Effectiveness of Guthion versus Avaunt against pest insects when applied to all rows versus the two perimeter rows of seven-row plots in five commercial apple orchards in Massachusetts in 2002. Values represent data averaged across all samples taken in rows 1, 3, 5 and 7 of plots. Incidence of pest Pest Plum curculio (% fhiit with injury)* Apple maggot (no. captured per sphere)* Apple maggot (% fruit with injury)* Summer leafrollers (% fruit with injury)* Internal Lepidoptera (% fruit with injiu^)* Guthion Avaunt All rows Perimeter All rows Perimeter sprayed rows sprayed sprayed rows sprayed 0.45 0.30 0.45 0.47 6.58 8.78 7.28 10.83 0.13 0.08 0.09 0.18 1. 00 1.70 0.90 1.60 0.05 0.15 0.00 0.15 "No statistically significant differences among treatments at odds of 19: 1 . Fruit Notes, Volume 68, Winter, 2003 Guthion Habitat Bordering Orchard Guthion Avaunt Avaunt Figure 1. Schematic illustration of pattern of spray application in four experimental plots of a commercial orchard. Plot treatments differed in location within each orchard block. = Trees sprayed by hired applicator. 0.5 I 0.4 i 0.3 5 0.2 ^ 0.1 1.5 li- 05 PLUM CURCULIO im GU ALL GU PER AV ALL AV PER SUMMER LEAFROLLERS GU ALL GU PB% AV ALL AV PER K 0.4 i 0.3 H 5 02 III. I APPLE MAGGOT GU PB? AV AV ALL PB? INTERNAL LEPIDOPTERA GU PER AV ALL AV PB? Figure 2. Two-year average (2001 and 2002) of data on effectiveness of Guthion (GU) versus Avaunt (AV) against pest insects when applied to all rows (ALL) versus the two perimeter rows (PER) of seven-row plots in commercial orchards in Massachusetts. Values represent data averaged across all samples taken each year in rows 1, 3, 5 and 7 of plots. Fruit Notes, Volume 68, Winter, 2003 AM, summer LR, and internal Lepidoptera. Further, combined data for both years indicate that applying Guthion only to perimeter-row trees from the first cover spray onward was just as effective in protecting interior rows agamst injury by PC and AM as applying Guthion to all trees in a block from the first cover spray onward. In the case of Avaunt, however, all-row sprays were numerically (though not statistically) superior to perimeter-row sprays in providing protection against injury by PC and AM on interior rows. We conclude that Avaunt can be an effective substitute for Guthion against PC, AM, summer LR, and internal Lepidoptera when applied to all trees in an orchard but may be less effective than Guthion in providing orchard-wide control of PC and AM if applied only to perimeter-row trees. A ckn o wledgem ents We thank the five cooperating growers: Gerry Beime, Aaron Clark, Don Green, Tony Lincoln, and Bob Tuttle. This work was supported by a grant from the USDA CSREES Crops at Risk Program and a grant from DuPont Corporation. it it it it it Fruit Notes, Volume 68, Winter, 2003 Comparison of Traps and Trap Trees for Monitoring Plum Curculios: 2002 Results Ronald Prokopy, Bradley Chandler, Sara Dynok, Elisa Gray, Matthew Harp, Anne Talley, and Jaime Pinero Department of Entomology, University of Massachusetts In the 2002 Winter issue of Fruit Notes, we reported on year 2001 tests in which we compared odor-baited with unbailed traps of three types (pyramid, cyhnder and Circle) for monitoring plum curculios (PCs) in several commercial apple orchards. All traps were placed beneath or within canopies of perimeter-row apple trees. Results indicated that Circle traps baited with benzaldehyde (BEN, a component of host plant odor) plus grandisoic acid (GA, male-produced aggregation pheromone) captured numerically more PCs than any other baited or unbaited traps. However, no trap type showed even a moderate positive relationship between the time of occurrence of PC captures by the trap (first, second, third, etc. week after petal fall) and time of occurrence of PC injury to fruit. Even for Circle traps baited with BEN plus GA, captures fell off dramatically soon after petal fall, whereas fruit injury rose steadily. Thus, low trap captures after petal fall could not be taken as indicative of a lack of need to spray against PC. In the 2002 Fall issue of Fruit Notes, we reported that pyramid traps and sticky-coated Plexiglas panel traps baited with BEN plus GA and placed at orchard border areas were effective in monitoring the seasonal course of immigration of overwintered PC adults into a small unsprayed orchard. This finding suggested that such traps placed in border areas might be useful for monitoring PCs in commercial orchards. Finally, in the 2002 Winter issue of Fruit Notes, we reported on a preliminary study in a single commercial apple orchard involving the establishment of odor-baited "trap trees" as a potentially new and effective approach to monitoring PCs. This approach involves baiting the branches of a few perimeter-row trees in an orchard with BEN plus GA and examining fruit solely on these few baited trees for signs of fresh PC injury, thereby eliminating the need to examine fruit or a large number of trees to gain an accurate estimate of the degree of current threat of PC injury to fruit. Moreover, a trap tree approach might overcome various shortcomings of odor-baited traps that have afflicted our ability to rely on extent of trap captures as indicative of extent of threat of PC injury to fruit. Here, we report results of a 2002 study in commercial apple orchards in which we compared the performance of odor-baited-sticky clear Plexiglas panels and black pyramids (both types of traps placed in orchard border areas) with the performance of odor- baited Circle traps (attached to trunks of perimeter- row apple trees) and the performance of odor-baited perimeter-row trap trees for monitoring the seasonal course of PC egglaying damage to developing apples. Materials & Methods The three types of traps were: (a) a clean Plexiglas panel (24 x 24 inches) attached vertically at head height to a wooden post, coated with Tangletrap on the side facing the orchard border area, (b) a black pyramid trap (24 inches wide at base x 48 inches tall), and (c) an aluminum-screen "Circle" trap, wrapped tightly around the base of a tree trunk so as to completely encircle the trunk. Each trap and trap tree were baited with four polyethylene-vial dispensers of BEN (Aldrich Chemical Company) that together released 40 mg of BEN per day plus 1 dispenser of GA (Great Lakes IPM) that released 1 mg of pheromone per day. Each vial of BEN was suspended inside of an inverted colored, plastic drinking cup to minimize the potential negative Fruit Notes, Volume 68, Winter, 2003 impact of ultraviolet light on the stability of BEN. Vials of BEN were not renewed during the course of our test but dispensers of GA were renewed once (after 5 weeks). Dispensers of BEN and GA were suspended from the bottom edge of panel traps and from the branches of trap trees. For pyramid and Circle traps, dispensers of BEN were suspended in such a way that the open bottoms of the protective drinking cups were 4 inches above the inverted screen funnel (that capped each trap) to reduce close- range repellency of BEN, and the dispenser of GA was placed inside of the screen funnel. Four plots were established along a continuous 132 yard section of a perimeter row of apple trees in each of 1 1 commercial orchards. Each plot was 33 yards long by 7 rows of trees deep and contained one of the four trap treatment types. Traps or trap trees were positioned midway along the 33 yard length of the perimeter row of a plot. Panel and pyramid traps were placed in orchard border areas, 7 yards from the near edge of the canopy of the central perimeter-row tree of a plot. Circle traps and trap trees were assigned to the central perimeter-row tree of a plot. Traps and trap trees were installed at the pink stage of bud development (April 22-24) and remained for 10 weeks (June 24-26). Weekly beginning at petal fall (May 13-15), we counted and removed all PCs from traps and examined 100 fruit per plot on perimeter trees for evidence of fresh PC egglaying scars. In all, 20 fruit were sampled on the central perimeter- row tree (directly opposite a panel or pyramid trap or containing a Circle trap or functioning as a trap tree) and 20 fruit were sampled on each of two evenly-spaced trees to the right and again to the left of the central tree. Fresh scars were those considered to have been made within the past 7 days. It is the appearance of fresh scars (not older scars) that ought to drive a grower's decision to spray against PC. Each grower applied three sprays of azinphosmethyl or phosmet to control PC in the plots. Results Across the entire season, panel traps captured significantly more PCs than either pyramid or Circle traps (Figure 1). Even so, for none of these three trap types was there a significant positive correlation between total captures of PCs per plot (across all weeks from petal fall through June) and mean percent of sampled perimeter-row fruit per plot exhibiting fresh egglaying scars (across all weeks from petal fall through June) (Figure 2). Furthermore, for none of the three traps types was there a significant positive correlation between sample- week trap captures per plot and sample-week percent of penmeter-row fruit per plot having fresh egglaying scars (Figure 3). A significant positive correlation would indicate that a week during which comparatively many trap captures occurred also was a week in which a comparatively large amount of fruit was injured by PC, whereas a week during which comparatively few T3 0) k_ 3 Q. u (/) O Q. c re D - a 4 - 3 - 2 - b c 1 - 0 - ' 1 ' Panel Pyramid Season-long captures Circle Figure 1. Season-long captures ot overwintered plum curculio adults by odor-baited panel, pyramid and Circle traps placed in association with plots of perimeter-row apple trees. Means superscribed by the same letter are not significantly different at odds of 19:1. Fruit Notes, Volume 68, Winter, 2003 . hich had internal browning. | Fruit from the first two harvest s were not cut to observe internal disorders. replaced in cold storage for another 60 days. Following the 150 days, fruit were again removed for obsenation, kept at room temperature for 7 days to approximate conditions to which they might be subjected prior to consumption, and then pressure tested and tasted. Table 1 shows the storage disorders observed on the fruit following cold storage, as well as the flesh firmness at the end of the 1 50 days of cold storage and week at room temperature. The only disorder which was significantly influenced by the delay of cold storage was soft scald. Delaying cold storage essentially eliminated soft scald; however, soft scald was not much of a problem. Only 4% of fruit de\ eloped the disorder even when cold storage was not delayed. Delaying storage would be recommended if soft scald were a problem, but it did not appear to be a problem for us (at least in 2002). Decay, internal browning, skin greasiness, and off fla\ or development were much greater problems, but treatments did not influence these problems differently. Delaying cold storage did not appear to have a significant negative effect on quality of stored Honeycrisp fruit. The storage problems that were evident were not made worse by delaying storage up to 4 days, so that if soft scald were a problem, this solution would not have a substantial down side, other than that of the inconvenience of moving the fruit an e.xtra time. This is not to suggest that it is not generally important to cool fruit as quickly as possible, but to suggest that in the case of Honeycrisp the benefit of delay may outweigh the risks. More important to us than soft scald have been decay and internal browning. Internal browning is especially problematic, since it is not visible on the packing line, and therefore seen first by the con- sumer. The browning tends to show up as a light brown sponginess of a large portion of the cortex of the apple. 0\erall. 25% of the fruit harvested Sep- tember 16 and 23, 2002 suffered from internal browning after 5 months of cold storage and I week at room temperature. Time of hanest had a powerful effect on internal browning as well as other qualities of stored fruit (Table 2). Decay was not affected by time of hanest, but internal browning, skin greasiness, and off flavors of fruit were significantly reduced less frequent in truit harvested on September 16 compared to those harvested on September 23. The earlier harvested trait were also fimier. In another experiment including two earlier harvest dates but no storage delay, the effect of time of harvest on post-storage frait quality was even more dramatic (Table 3). The only storage disorder that developed on fruit har\'ested on September 5 or 1 0 was decay, plus a trace of internal browning. It should be noted, too, that while superficial scald can be a post- storage problem on early-har\'ested fruit, it did not develop on these Honeycrisp. It is possible to use measurements of fruit ripening to assess a ban est date for Honeycrisp that will result in fewer storage problems (Table 4). A starch index of 5.5 to 6.0 has been recommended for Honeycrisp. In 2002, harvest of Honeycrisp fruit with starch index values in this range would have resulted in little development of storage disorders. Further, frait were significantly firmer at the earlier harvests. Lack of red color is the only negative aspect of early harvest. 'k i: :k ^ :k Fruit Notes, Volume 68, Spring, Summer, & Fall, 2003 Finding and Keeping the Right Employees: Ideas to Bait the Hook Judith M. Powell Whitefield, ME The right employees bring good fortune. How- ever, finding the right just doesn't happen right out of the blue. Having capable, eager and motivated people come a-knocking on your door, asking to do the kind of work you need done, happens in fair> tales. In real life, managing people is a big challenge that eats up precious time and can cause frustration. Not selecting the best candidate, or losing an enthusiastic worker, can signal that it's time to examine your human re- source approach. Tom Maloney, senior Extension associate in the Department of Applied Economics and Management at Cornell University, has spent the last 15 years of his career focusing on labor issues and policy. He's been visiting with farmers over the past three years at New England dairy seminars. Hiring, managing and suc- ceeding with farm employees are his specialties. "You need help, and you know the kind of person you wish you could find," Maloney begins his talk at the Maine Dairy Seminar held in Augusta. He asks the audience what counts. "A person who wants to work around animals," someone says. "Reliable— someone who will show up on time," is mentioned. Others say, "mechanical ability, can work independently, someone I can trust." Getting the per- son you want is within reach, Maloney says. So, where to begin? Finding the right person starts by getting a handle on the job. The first step is defin- ing what you expect to have done. What exactly will you assign the new person to do? What are the spe- cific tasks, and when must they be done? Must they be done in a certain way or at a certain time? Thinking through details makes it easier to determine what tal- ents and skills are needed for both the employer and employee to succeed. Farm-owner operators and family manage all kinds of jobs every day. They somehow leam them over time. But expectations must be realistic for a new hire on the fann. A person who is happily mucking out stalls may not efficiently pull reports out of the database or serve customers \\\\o drop by the fann stand. Employ- ees who are happy with what ihey are doing and are satisfied with their work environment are generally more productive. The first step in a systematic approach to success- ful human resource management is recruitment, Maloney says. "You want to develop the broadest pool of potential job candidates." He encourages using "traditional" sources like government job services agen- cies, farm internship programs, community bulletin board postings and advertisement in local and agricul- tural publications. However, he says, the best source is word-of-mouth. "Some of the best leads come from current employees. They know what the job is and have a vested interest in making sure their coworkers will be good," he explains. "Offer a bonus if the new person stays six months. A S50 or $200 bonus can make the grapevine or e-mail buzz!" "Don't be afraid to be creative by exploring "non- traditional" sources like homemakers, retirees, teach- ers with summers off Don't narrow the field and ex- clude people who might perform these very well and be happy doing it." Maloney says. Farms offer work variety, fiexible hours and the chance to work outside with animals. These are great benefits, which some people prefer over wages. "Not everybody wants to fry hamburgers for McDonald's, even though they might get $7 an hour. Farms should capitalize on their unique setting and mix of opportunities." The next step in the process is writing a "help Copyright©2003 by Moose River Publishing Company. Reprinted with permission from Fanning, The Journal of Northeast Agriculture. Volume 6, Number 1 (January), 2003. pp. 36-38. For subscription information, call Moose River Publishing Company at (800) 422-7147 or write to Farming, The Journal of Northeast Agriculture, P.O. Box 449, St. Johnshurv, VT 05819-9929. Fruit Notes, Volume 68, Spring, Summer, & Fall, 2003 wanted" ad that sells the position. There are many positive attributes that may draw people into your pro- spective applicant pool. Think of everyday "luxuries" your farm offers and draft some help wanted ads: "Looking or fresh air and exercise? Need variety and a challenge? Family business offers good work- ing conditions, flexible hours, done by 4 p.m." Choosing the best applicant out of those you inter- view can be tricky. Be prepared and keep an open mind, Maloney says. He suggests developing a short list of questions and asking all the questions each time, so the interviewer has a consistent means of compar- ing and evaluating candidates' responses. Asking what people like to do in their free time is one way to get at what tasks the person may excel at. Does the person prefer to work independently or with others? If your crew works as a team, it's important to select for this personality trait. One of the hardest areas in managing employees is keeping the right ones and getting rid of the others. The U.S. Department of Labor reports that respect— not money, nor benefits, but respect— is the number one thing employees say they want first and foremost. Workers need to know how important the boss thinks their roles are within the total scheme of the opera- tion. An open and friendly atriiosphere along with positive acknowledgement for good work will do won- ders. What can be easier than thanking people when they make special contributions, like stay late, work lunch, or go the extra mile when they could have got- ten by easier? Don't wait; make the acknowledgement immediately. "Positive reinforcement has to be earned. You cannot just give it away. Giving superfluous com- pliments is not respect," Maloney says. "If the em- ployee does something you did not like, tell him or her as quickly as you can. On the other hand, if he or she performs exceptionally well, tell that employee and everybody else too!" "Your goal is to build loyalty and an atmosphere of mutual respect," Maloney says, adding that the best way to accomplish this is keeping an open, friendly attitude. ".An employee is more apt to ask questions before she he acts on his own, when the boss' atiritude encourages it." Maloney advises. Assigning a title to positions is. an easy way lo ex- press the importance of the job and regard for how this role fits into tfae larger farm. The title a person carries tells the employee and others what you think of him. The title shouJd refer to the main job responsibility. Feedback is critical. Giving feedback becomes easier when performance is rated on a regular basis, such as quarterly or semiannually Using just three ratings — excellent, okay, unsatisfactory— will commu- nicate your regard for the person's performance. Evalu- ate the things that matter— such as timeliness, avoid- ing waste, safety, job skill, care of equipment, willing- ness, honesty, pride, use of time, reliability. Be can- did. Use the dme to go over problem issues and give praise, stressing performance rather than personal char- acteristics. Keeping dated notes provides documenta- tion for future reference. Finally, protect the investment you have made by developing your good workers who your needs. "No one is in busirBess just to make friends or because they like to work." Maloney says. Employees must feel ap- preciated and have opportunity to progress. If the fam- ily farm cannot increase wages and benefits or offer advancement, the best workers may mo\e on to greener pastures, unless they know that you want them to stay. Instead of a rajse, the employer and worker might dis- cuss together vahat else could be done to replace mtoney. Sometimes, options like flex time, job sharing, a:>.sign- ment of new casks, supervising or learning something new is reward enough. Keeping good workers satis- fied and at peaik performance is important. Otherwise, \ou may be filling vacancies again and starting all over The goal is to keep good workers who enjoy perfomi- ing in a friendly and open working environment and who know their roles are important within the whole operation. Feeling an important part of an organiza- tion contributes to everyone's success. 'k :k i: ic 'k Fruit Notes, Volume 68, Spring, Summer, & Fall, 2003 Establishment and Biocontrol Potential of Released Typhlodromus pyri Predator Mites in Massachusetts Apple Orchards: 2000-2003 Ronald Prokopy, Starker Wright, Isabel Jacome, and William Coll Department of Entomology, University of Massachusetts Jan Nyrop, Karen Wentworth, and Carol Hering Department of Entomology, Cornell University, NYSAES, Geneva, New York In the 2000 issue of Fruit Notes, we reported the results of a 3-year project (1997-1999) aimed at establishing the predator mite Typhlodromus pyri in Massachusetts apple orchard blocks of different tree sizes. Results showed that following release in 1997, T. pyri became established in all eight blocks by the following year, spreading fastest from tree to tree among cultivars on M.9 rootstock and slowest from tree to tree among cultivars on M.7 rootstock. Result also showed that even in blocks on M.7 rootstock, by 1999 T. pyri had spread to the most distant trees in the 49-tree blocks and provided effective block-wide suppression of European red mites. Encouraged by results of this 1997-1999 project, in 2000 we launched a 4-year study to further characterize the establishment and spread of released T. pyri in commercial apple orchards in Massachusetts. We asked five questions. First, would the addition of pollen to trees in which T. pyri were released enhance the buildup of T. pyri'? This predator is known to feed on pollen when prey mites are low in abundance and previous research has shown that supplementary pollen could elevate predator numbers. Second, in which direction is T. pyri likely to spread fastest following release from trees on row 4 of a block: toward row 1 (the perimeter) or toward row 7 (the interior)? Third, would the establishment of American hazel trees opposite plots in which T. pyri were released contribute to the buildup of T. pyri and/or Amblyseius fallacis as predator mites? American hazel trees have been found b\ others to harbor substantial populations of predaiory mites. Fourth, what is the relationship between the abundance of T. pyri and the abundance of Amblyseius fallacis as predatory mites? Fifth, w ould the release of T. pyri in 2000 guarantee effectne biocontrol of European red mites in subsequent years? Here, we present data that address each of these questions. Materials & Methods Our experiment was conducted in 12 blocks of apple trees in ten commercial orchards. Each block was about 140 meters long by seven rows deep and was di\ ided into four equal-size plots. The perimeter row of each block was bordered by woods, hedgerow or open field. Trees were on M.9, M.26. or M.7 rootsiock and were principally Mc Intosh. Cortland, Gala, Empire, Jonagold or Fuji. There were four treatments at the outset in May of 2000 (one per plot): (1)7^ pyri released in the presence of fresh cattail pollen, which was applied to the tree canopy by a commercial pollen applicator (E-Z Power Duster, Firman Pollen Co, Yakima. WA) at the rate of one-seventh ounce of pollen (about 100,000 pollen grains) per tree, (2) T. pyri released in the absence of pollen amendment; (3) no release of T. pyri but, as with the first and second treatments, no insecticide applied after mid-June (apple maggot flies were controlled by Fruit Notes, Volume 68, Spring, Summer, & Fall, 2003 odor-baited red sphere traps), and (4) no release of T. pyri and organophosphate insecticide applied during July and August to control apple maggot. For the first and second treatments, T. pyri were released at bloom at the rate of about 100-200 individuals per tree on two trees in the fourth row of each plot, one tree to the right and one to the left of the center tree of the plot. Releases were made by wrapping a burlap band that contained T. pyri around the trunk of a release tree. In autumn of 1999, such bands had been placed around trunks of apple trees at Geneva, NY to collect T. pyri seeking overwintering sites. In 2000, we sampled 25 leaves per tree on each of two trees in rows 1, 4 and 7 in each plot. We did this twice during July and twice during August. One of the sampled trees was immediately to the right and the other immediately to the left of the center tree of the row (for rov\ 4, these were the same trees in which T. pyri were released). For 2001, 2002 and 2003, we no longer segregated samples according to plot and sampled five leaves on each often trees (50 in all) on each of rows 1, 4 and 7 in each block. We did this twice in 2001 (once in July and once in August), once in 2002 (in July) and twice in 2003 (once in July and once in August). In 2000, in four of the blocks we planted 20 seedling trees of American hazel in hedgerows opposite and about 5 meters away from plots in which T. pyri were released. Our intent was to sample leaves from these seedlings for abundance of predatory mites as soon as the seedlings achie\ ed reasonable growth (reached 1 meter height). Hence, in 2002 and 2003, we sampled five leaves from each often American hazel seedlings (50 leaves in all) once during August in each of the four blocks. All sampled leaves were sent by overnight mail to Geneva. New York for the identification and counting of pest and predatory mites. From 2000-2003, none of the sampled plots received pyrethroid or carbamate insecticide (except carban. 1 as thinner), none received EBDC fungicide after mid-June, and none received miticide (except prebloom oil). The only exception was orchard F, which received a spot-treatment of Acramite in August of 2003 against European red mite. Results With respect to our first question, data for 2000 presented in Figure 1 show that addition of cattail pollen had no detectable effect on the buildup of T. pyri in trees in which these predators were released. Peak populations of T. pyri in 2000 were just as great in trees not receiving cattail pollen as in those that did receive pollen, and were roughly twice as great (on sampled center trees in row 4) in plots where T. pyri were released as in plots where no T. pyri were released. Conversely, peak populations of European red mites on sampled trees averaged about twice as great in plots where no T. pyri were released and which received insecticide during July and August as in plots where T. pyri were released and received no insecticide after mid-June. Peak populations of A. fallacis averaged roughK the same in all plots. For each of the four plot types. A- fallacis was less abundant than T. pyri. In regard to our second question, there was no statistical evidence that spread of T. pyri differed among the rows of trees, although data for 2001 shown in Fig. 2 hint that T. pyri released in 2000 on trees in row 4 may ha\ e spread faster to trees in row 7 than to trees 2 S 1.5 TP Figure 1. For 2000, peak abundance of 7! /J'>T/(TP),/4./a//acK (AF) and European red mites (ERM) in two trees in row 4 of each of four plots in each of 12 orchard blocks: trees in which TP were released and cattail pollen was added (TPP), trees in which TP were released but no pollen was added (TPNP), trees in which no TP were released, no pollen was added and apple maggot was controlled by baited red sphere traps (NTP) and same as preceding except apple maggot was controlled by grower-applied insecticide (GC). Fruit Notes, Volume 68, Spring, Summer, & Fall, 2003 2001 02, '" 02, *' 2, ERM S0.15- JO'S- |005. ^^B ^^M ^^M ^^^^^^1 ^^^^^H ^^^^^H ; 1 5 - o ,, |0.5, _ 0 J — ^ ^ ^ 1 4 7 14 7 14 7 2002 02, '" AF ERM 0.1, ^H ^H ^H |1.5 g 1- _ |0 5- 0 J— ^ Q 1 4 7 14 7 14 7 2003 TP I"''- !0.15. 1°" ^ IH ^ 1 °^ oJ-^ ^ ^™- 1 4 7 AF 1 15 |05 ERM 1 4 7 1 4 7 Figure 2. For 2001, 2002 and 2003, average abundance (across all sampling dates) of T. pyh (TP), A. fallacis \ (AF) and European red mites (ERM) in rows 1 , 4 and 7 of 1 2 orchard blocks in which TP were released in row 4 in 2000. in row 1. By 2002 and 2003, however, T. pyh were equally abundant in rows 1 , 4 and 7. A. fallacis showed no clear pattern in abundance according to row across 2001, 2002 and 2003 . The same was true for European red mites. Our third question focused on the potential value of establishing American hazel trees in border areas as a way of promoting buildup of predatory mites and enhancing populations of predators in adjacent blocks of orchard trees. However, as shown in Fig. 3 for the four orchard blocks involved in this evaluation, the abundance of T. pyri and especially A. fallacis was low on leaves of American hazel trees in border areas. Moreover, neither of these predators was more abundant in row 1 trees than in row 4 or row 7 trees, which could have been expected if substantial numbers of predators were moving from American hazel trees toward orchard blocks. Our fourth question concerned the relationship between T. pyri and A. fallacis. Data from our study of Fruit Notes, Volume 68, Spring, Summer, & Fall, 2003 2002 0.2 1 S 0-15 H TP 0.2 S 0.15 AF 0.1 - > 0.05 < 2003 0.2 TP 0.2 -I AF Row Row Figure 3. For 2002 and 2003, average abundance (across all sampling dates) of T. pyri (TP) and A.fallacis (AF) in American hazel trees (H) in border areas adjacent to four orchard blocks and in rows 1. 4, and 7 of these four blocks (in which TP were released in row 4 in 2000). 0.2 ™ 0.15 AF 0.05 02 03 Figure 4. For 2001, 2002 and 2003, average abundance (across rows 1, 4 and 7 and across all sampling dates) of T. pyri (TP), and A.fallacis (AF) across 12 orchard blocks in which TP were released in 2000. Fruit Notes, Volume 68, Spring, Summer, & Fall. 2003 oTyphlodromus pyn +Amblyseius fallacis o "O 0) c - -S>- o —rr- ■ 0 0 0 1 0 2 0 3 T pyn density 0.4 Q 6 n 1 r "T I I I I 1 I r Orchard Figure 5. A) Proportions of piiytoseiid mites identified as either T. pyri or A. fallacis in each of 12 orchard blocks over three years. Within a year there are 12 sets of circles denoting the T. pyn proportions and 12 + symbols denoting the A. fallacis proportions. At some sites, no phytoseiids were collected and these are denoted by a circle enclosing a + symbol. B) Maximum densities of European red mites in relation to the average density of T. pyri. Each circle represents data collected from a block in one of the years 2001, 2002 or 2003. The dashed line was fit by eye. C) Average densities of T. pyri in orchards over the years 2001, 2002 and 2003. Each set of three connected circles represents three years of data from an orchard block, arranged in sequence (left to right) for 2001, 2002 and 2003. Circles with a + symbol indicate no T. pyri were collected in the samples. 10 Fruit Notes, Volume 68, Spring, Summer, & Fall, 2003 1997-1999 reported in the 2000 issue of Fruit Notes suggested that increasing abundance of T. pyri was correlated with decreasing abundance of A. fallacis. This pattern has been observed elsewhere and occurs because establishment of T. pyri usually leads to low levels of European red mites. A. fallacis are only abundant in apple trees when there is a ready supply of pest mites for food. In this study, nearly all the orchards had populations of T. pyri prior to their release in 2000. Therefore, we would expect low numbers of A fallacis. Our resuls are in accord with this expectation. As shown in Fig. 4, data for 2001, 2002 and 2003 averaged across all 12 orchard blocks indicate that overall, T. pyri was about ten times more abundant than A. fallacis on sampled leaves. Another way of looking at this relationship is to compare the proportions of T. pyri and A. fallacis found in each orchard (Fig. 5A). In 2001 A. fallacis were found in only four orchards and these were sites where some European red mites were also found. In 2002 there was but one orchard \\ here A. fallacis was collected and in 2003 this number increased to two. Note that in 2003 there were four orchards where no phytoseiids were collected and five orchards where no T. pyri were collected. At present, we have no explanation for this. Our final question asked whether establishment and conservation of T. pyri would assure effective biocontrol of European red mites. Previous research has shown that T. pyri. when sufficiently abundant, can keep European red mites at non-damaging densities. Recalll that T. pyri were present in most orchards prior to their release and by 2001, T. pyri were recoverd in all the orchards (Fig. 5A). Shown in Fig. 5B a is the relationship between the maximum density of European red mites observed and the average density of T. pyri . The dashed line was fitted by eye to the data points that reflect the highest European red mite numbers in relation to predator density. This graph shows that when T. pyri numbers are low (< 0.15 per leaf), there is a possibility that European red mite will become problematic. Note that even when T. pyri densities are low, pest mites do not always reach high densities, but the potential is there. On the other hand, when T. pyri were more numerous, European red mites never reached high numbers. It is also helpful to examine changes in the abundance of T. pyri over time because our experience has been that once established in an orchard, these predators usually persist in relatively high numbers. As shown in Fig. 5C, this was not the case, as in 2r»03 we did not collect any T. pyri in five of the 12 orchards studied. At present, we can offere no explanation for this decline in predator numbers Conclusions Across the four years of our study (2000-2003), we gained much useful information on the ecology and biocontrol potential of T. pyri in Massachusetts. Our findings lead us to the following conclusions. First, addition of a substantial amount of cattail pollen (as a food supplerr»ent) to trees in which T. pyri were released in 2000 had no detectable effect on buildup of T. pyri. Thus, there is sufficient alternate food to allow for establishment of T. pyri provided no pesticides harmful to this predator are used. Second, by 2002 T. pyri were equally abundant in plots where they were released or not released, with the exception of two sites where they were only found in plots where they were released, and they were equally abundant among the sampled rows (1, 4, 7). This likely reflects that T. pyri were present in most blocks prior to release. Third, establishment of American hazel trees (known to harbor mite predators) in border areas adjacent to plots of orchard trees did not substantially enhance populations of either T. pyri or A. fallacis in such plots. Fourth, commencing in 200 1 , T. pyri predominated in the study blocks, with A. fallacis absent or at very low levels in most blocks. Only where European red mites were moderately to very abundant were A. fallacis found. Finally, in a majority of orchard blocks T. pyri were sufficiently abundant by 2001 to provide what appeared to be consistently effective biocontrol of European red mites. In some orchard blocks, however, T. pyri did not build to appreciable levels or declined in abundance (for reasons unknown, but apparently not associated with use of offensive pesticides). In some of these blocks in some years, European red mites reached threatening levels. Overall, as in our 1 997- 1 999 study, T. pyri showed much promise as an effective biocontrol agent of European red mites in most of the blocks in which it is established and conserved. Fruit Notes, Volume 68, Spring, Summer, & Fall, 2003 11 A ckn o H'ledgm en ts We are grateful to the ten growers participating in Broderick, Dave Chandler, Tom Clark, Don Green, this study. Each made a special effort to refrain from Tony Lincoln. Joe Sincuk, Mo Tougas and Steve Ware, applying pesticides potentially detrimental to T. pyri. This work was supported by a grant from the Northeast The> were Keith Arsenault, Gerry Beirne, Bill Sustainable Agncultural Res. & Education Program. :k ic ic it 'k 12 Fruit Notes, Volume 68, Spring, Summer, & Fall, 2003 Real Buzz Words: Beekeeping Sites for All Levels Diane Baedeker Petit Massachusetts Department of Agricultural Resources It's no surprise that beekeeping is a traditional farming activity. Bees provide a much-needed service by pollinating crops, and the honey they produce is a great product to offer at farmstands and farmers' markets. Whether you're just thinking about getting into beekeeping, or if you're an experienced apiarist looking for new ideas or suppliers, the Internet is swamiing with information on the subject. The following are several good general reference Web sites, but these will, in turn, lead you to more specific resources on beekeeping and honey sites around the world. BeeSource.com (www.beesource.com) is a nicely designed site that provides new sources of bees, books, supplies, plans for constructing beehives, information on beekeeping laws, equipment and issuer; there's also a page of links to other beekeeping Web sites. If you're looking to share infomiation with other beekeepers, this site provides its own bulletin board for discussion on various beekeeping topics, as well as links to other beekeeping discussion groups, news groups and more. The Mid-Atlantic Apiculture Research and Extension Consortium Beekeeping Information Index (http://maarec. cas.psu. edu/Beeinfoindex. html) is a simple Web site that provides all the basics of apiculture. This site is organized and reads more like a manual. It provides everything you need to know about beekeeping from honeybee biology to beekeeping equipment, and colony management to diseases, pests and parasites and pollination. The Colony Management section includes infomiation on managing for honey production and managing for pollination. Other management topics are organized by season. There's even advice on contracting with growers for pollination services. The design of this site is not fancy, but links and information are presented in an easy to navigate format. Only a small amount of the infomiation here is specific to the Mid-Atlantic region. Most of it is applicable to beekeeping anywhere. There's a page of additional resources, which provides names, addresses and phone numbers of organizations, industry journals and experts. The page is dated 1996 so you have to wonder if some of the infomiation is out of date. The glossary of beekeeping terms is quite extensive. The Beehive {www.xensei.com/users/alwine/), based in Massachusetts, is an electric mix of useful beekeeping information and games. In addition to practical resources such as bee anatomy, how to start beekeeping and how to store and use honey, there is also fun stuff here as well, such as a beehive crossword puzzle, a trivia quiz and a game called "Sting Me." There are articles on how bees were used as weapons of war and city beekeeping, as wells as frequently asked questions about bees. The programs that you can download from this site also reflect the mix of serious information and fun. Included in the download section are an e-book on Beginning Beekeeping, and a beehive jigsaw puzzle program that is fun and easy to complete. This light-hearted site would be a good resource for young people just getting into beekeeping. National Honey Board (www.nhb.org) is a broad resource for honey producers including national news, business information, marketing resources, quality control infomiation and statistics on national honey production and consumption. There are also numerous articles here on honey research, legislation, organic standards and the like. All of these sites are great resources worth bookmarking, but don't stop there. Be sure to follow the many links to more resources that these sites provide to round out your research in apiculture. 'k ic ic 'k :k Fruit Notes, Volume 68, Spring, Summer, & Fall, 2003 13 SJP84 Winter Hardy Dwarf Apple Rootstock Series from Agriculture and Agri-Food Canada National High Value Crop Breeding Program Shahrokh Khanizadeh, Yvon Groleau, Audrey Levasseur, Raymond Granger, and Gilles Rousselle Agriculture and Agri-Food Canada Research Station, St-Jean-sur-Richelieu, Quebec Campbell Davidson Agriculture and Agri-Food Canada Cereal Research Centre, Morden, Manitoba Apple production potential in Quebec is between 5.5 and 7 million bushels per annum. In 1 986 and 1 987, there were severe low temperature injuries, and yields were reduced to 2.8 million bushels and 4.0 million bushels, respectively. This loss represents approximately SI 8 million in 1986 and $12 million in 1987, and a concomitant increase in the volume of apples imported to the province. In 1 993-1 994. similar damage was reported by Quebec apple growers (Khanizadeh et al., 2000a). Cold winter temperatures is one of the most limiting factor in many apple-growing regions, especially in Northern Central Canada when the winter temperature dropped below -30°C (Granger, 1981; Asnong, 1 982; Khanizadeh et al., 200021. Cold tolerance of many plant species has been extensively reviewed and studied (Chen and Li. 1980; Gustaetal., 1982; Li, 1987; Sakai and Larcher. 1987 Khanizadeh et al., 1989a; Khanizadeh et al.. 1989b Khanizadeh, 1991; Khanizadeh et al., 1992a Khanizadeh et al., 1992b; Khanizadeh et al.. 1994). Our previous studies have compared the concentration of amino acids, protein, sugars, starch, sorbitol, N, P, and K of cropped and non-cropped trees in relation to cold hardiness (Khanizadeh et al., 1989b; Khanizadeh et al., 1992a; Khanizadeh et al., 1994). It has been shown that cropped trees that progress into the winter with lower nutrient levels in their buds are more vulnerable to low temperatures than those on non- cropped trees (Khanizadeh et al., 1989b; 19923). There have been many studies of: 1 )cold resistance and metabolic changes in apple woody tissue, (Brown, 19^8; Li, 1987; Sakai and Larcher, 1987; Khanizadeh etaJ., 1989a; 1989b; 1992a; 1994), 2) types of freezing injury ( Weiser, 1 970; Granger, 1 98 1 ); 3 ) breeding hardy varieties or using hardy intermediate framestocks (Soishnoff, 1972; Spangeloetal., 1974; Granger etal., 19*91; 1992; 1993); 4) inactivating icenucleating bacteria (Lindow and Connell, 1984; Lindow et al., 19SI9); 5) use of chemical cryoprotectants (Ketchie and Munren, 1976); 6) cultural manipulation to slow growth and induce wood matunty in early autumn (Collins et al.. 1978; Stang et al., 1978); and 7) autumn sprays of grov^lh regulators to delay bud break. The use of winter hardy rootstocks and \arieties, hovve\er, seems to be the most desirable approach to avoid winter injury and are used in international trials to screen this specific trajit(Marinietal., 2001a; 2001b). Many reports have been published on the winter hardiness and survival of selected rootstocks (Granger et al., 1993; Doroshenko et al., 1995; Skrivele et al., 19*95; Fisher & Fisher, 1996; Yang etal., 1995; Witney, 19*96; Khanizadeh et al., 2000a; Khanizadeh et al., 20<00b; Marini et al., 2001a; Marini et al., 2001b; Webster, 2003). Alnarp 2 (A2) was reported to have the highest survival rate when exposed to low soil temperatures, followed by MM.104, Antonovka, M.26, MM. Ill, M.4, MM. 106, M.9, and M.7, respectively (Zagaza, 1977). 0.3 and 0.8 were reported to be 14 Fruit Notes, Volume 68. Spring, Summer, & Fall, 2003 hardier than M.26 and MM. 106 (Heeney, 1981), and Bugadovsky was reported to be as hardy as M.26 (Czynczyk, 1979). A part of the Agriculuire and .Agri-Food Canada (AAFC) National High \alue Crop (NHVC) breeding program is devoted to de\elopment of adapted, dwarf and semidwarf, winter-hardy, and disease-resistant apple rootstocks. The original rootsiock-breeding program began in early 1950 in Ottawa. Ottawa 3 (0.3) was the first commercialK released clonal rootstock, released in 1974 from this National program, and the rest was send to Quebec for further testing along with others developed in Ottax'.a and in Manitoba. The identification of new, well adapted, winter- hardy, disease-resistant apple rootstocks that propagate easily will have a direct impact on the apple industry in the northern U.S. and in Canada by reducing production fluctuation caused by cold-temperature tree damage. Materials & Methods Several crosses were made in 1975 including Mains robiista R-5 with M.26 or with Budagovsky 579490, and also some seeds was collected from open pollinated 0.3. Seeds were germinated under greenhouse conditions and planted in a nursery in 1980. Budding to Spartan was conducted in Ii982, and trees with bud failure were cleft-ijrafted in 1983. All trees were planted in 1984 (5.5 x 3.0m) at the experimental farm of AAFC in Frelighsburg, Quebec. Standard orchard management practices were applied each year (Anon., 1976). Of the 908 trees started in 1984, only 499 were used for evaluation and the rest eliminated from the program due to their lack of winter hardiness, disease susceptibility, or other undesirable characters, like extreme difficulty to propagate in stool bed. Data are shown only for those nine superior rootstocks (Table 1 ) which have not shown any w inter injury since 1984 and were not eliminated for other reasons. Trunk circumference was measured at 25 cm abo\ e the graft union and used to calculate trunk cross- sectional area in 1990. Yield and incidence of root suckers were recorded annually from 1988-1990. Tree height and spread were measured as the maximum vertical extension of the tree and the maximum horizontal extension of the canopy, respectively (Table 1). Two other sites were also established to examine the ease of propagation and suitabilit> of the rootstocks for commercial grafting compare to M26, M9, and 0.3 (data not shown). "Summerland Mcintosh' was used as scion for the nine superior rootstocks (Table 2). They were planted in four selected locations including L'Acadie (AAFC, Experimental site) and also tested under controlled conditions at two commercial grower sites Dunham and Mont St-Gregoire (Verger Dupuis Inc., 587 Hudon, Table 1. Performance of se.ec ted nine superior rootstocks with Spanan as the scion. ^elected from 908 seedl ings planted in 19S'4 in Frelighsburg, Quebec Canopy size TCA' Cumulative Yield YE^ 1990 Cumulative Height Spread no of Test Code Selectior. Parentage (cm') (kgl (kg/cm') (m) (m) Root suckers SJP84-5218 75-13-0?: R5xM.26 13.2 22.95 1.73 2.6 2.6 5.3 SJP84-5217 75-13-065 R5xB 574*0 9.7 10.05 1.04 2.1 2.6 7.3 SJP84-5230 75-13-r9 R5.\M.26 23.0 28.65 1.25 2.9 2.5 0.0 SJP84-5198 75-13-lSi:i R5xM.26 13.0 17.25 1.32 2.2 3.1 0.6 SJP84-5162 75-13-lS.- R5xM.26 14.2 25.5 1.81 2.9 2,4 13.0 SJP84-5231 75-13-209 R5xM.26 6.7 6.15 0.91 1.6 0.9 9.0 SJP84-5174 75-13-219 R5xM.26 18.9 20.70 1.10 3.4 3.5 7.0 SJP84-5189 75-13-246 R5xM.26 13.0 22.35 1.71 1.6 2.8 8.3 SJP84-5180 75-13-296 R5xM.2& 17.7 19.S 1.12 2.9 2.6 6.3 ' TCA = trunk cross-sectional area. - YE = yield e fficiency (cumu lative yicldTCA) Fruit Notes,"Volume 68, Spring, Summer, & Fall, 2003 15 Table 2 Performance of nine sl perior rootslocks an AO.^h with 5 ummcrland Mcl" osh as the i;;^on compared to M.26, M.9. M :-. MM.UIand | 0.3 pijiiiied in 1995 in Mont St- Grego re, Verg er Yvan Due lesne ( avera jeof3 tree; ?er repl caie Yiei; kg) O _0 c o 1 in > E o "e < O f- a. ON o o o § r". li o as ti. s .1 ~C0 - c — 2 SJP84-5:i8 75-13-032 44 175 24 2.5 3.5 1.2 14.3 29 .- 58.1 lo:- } 4.2 724 116 0 1.5 SJP8-l-5:i7 75-13-065 ."6 213 36 }_2 3.5 2.3 12.6 15 46.6 "6-i ; 1 544 126 : 5 05 SJP8-1-5230 75-13-179 ■i;9 107 9 2 3 2.2 0.5 3.1 13.^ 18.8 35 i 3.9 293 106 ; 2 0.0 SJP84-5198 75-13-180 ;:8 155 19 2.7 3.0 0.1 2.9 13: 36.1 52 7 2.8 403 124 ;.8 0.0 SJP84-5162 75-13-183 ;:3 149 18 2.8 2.7 0.6 6.3 12: 28.8 4^2 2.8 359 119 ! 8 3.0 SJP84-5231 75-13-209 "^9 120 11 19 2.3 0.0 3.1 9i: 18.5 3( - 27 249 112 2 5 0.0 SJP84-5174 75-13-219 ;54 187 28 2.9 3.2 0.1 4.9 15 > 42.6 63 :■ 2.3 461 132 2.0 0.0 SJP84-5189 75-13-246 ;36 165 22 2.9 3.0 0.2 5.8 7> 35.3 49:- 2.0 368 136 1.5 0.0 SJP84-5I80 75-13-296 ;34 162 21 3.0 3.3 0.0 5.7 18 30.9 54 ^ 2,6 323 172 3,5 4.0 0.3A :i6 141 16 2.7 2.8 0.9 8.7 18 V 30.8 59 : 3.7 420 125 1.3 1.7 M.26 -.51 183 27 3.3 3.2 0.6 3.9 12 32.1 4S- 1.8 292 163 30 0.0 M.9 100 121 12 2.4 2.5 0.5 6.7 10: 25.5 43 2 3.7 306 133 2.8 2.7 MM. Ill 230 280 62 4 1 2.9 00 0.9 3 f 19.9 T^ "i 0 4 179 133 : 0 0.3 M.27 "9 96 7 19 2.1 0.2 3.2 6S 9.2 19-1 2.6 136 133 1.5 0.0 0.3 132 160 20 2.7 3.1 0.1 5.1 17.: 32.1 54 ~ 2.8 398 128 0.3 2.7 LSD' 28 34 10 54 84 1.2 5.4 8.^ 19.8 20 i 1.1 207 30 1.9 3.8 ' Vigour: Trunk circumference a } a percent of M.9. -' Fruit weiL t (g) was talin usmg 25 randomly selected fru;t5 Truni circumference and crosi-sectional area (TCA) 25 cm above ' Burrknoi - -ting: 0 = de5;r3 ble. 10 = undesirable. graft union. Average r .mber o f sutlers ciounled during the 2002 season. ' 1999-2002 = cumulative yield from 999-2002. ' If differerce between r--o means exceeds LSD, then it ^ sign ficant at ' Efficiency: (cumulative yield TCA) odds of 1^ Dunham. Qc, Canada; Verger Ivan Duchesne Inc., 1 1 8 oh. Sous-Bois, Mont St-Gregoire, Qc, Canada ) in 1997 using three trees per sites/replicates. Several commercially grown cultivars (Gala, Spartan, Mcintosh, Lobo) were also grafted onto these rootstocks to assess graft compatibility. During the multiplication and evaluation of the rootstocks, we discovered a clone of 0.3 (0.3A) to be different from original 0.3 developed earlier by Spangelo et. al. (1974). 0.3A appears to produce wider branch angle and have a better rooting efficiency in stool beds compared to the original 0.3. This rootstock (0.3A) was also tested along with advanced SJM rootstocks in all sites. M.27 was planted only at one commercial site due to the insufficient number rootstocks. Results & Discussion The majority of the superior rootstocks came from R.5 X M.26 crosses, and only one (75-13-065) came from R5 x B57490. The superior rootstocks showed no incompatibilit]. with tested commercial scion culti\ ars. All rootstcucks produced trees that were dwarf or semi-dwarf and were easier to propagate and numencally more efficient than trees on M.26 (Table 2). Generally the trees were more vigorous in Dunham (Table 3) than in Mont St-Gregoire (Table 2) based on the trunk circumference. SJP84-5230. M.9, and M.27 were the least \ igorous rootstocks in Dunham (Table 3) and Mont St-Gregoire (Table 2); how ever, there was not a significant difference between M.2'', SJP84-5230. SJP8--5231, and M.9 in Mont St-Gregoire. MM.lll was the most vigonous at both sites. S.iP84-5218 and SJP84-5217 were the most precocious rooistocks at both sites. M.Mlll was the least precocious. In Dunham, SJP84-5 1 98, SJP84-5 1 89, SJP84-5162, and SJIP84-5217 had higher cumulative yield than did .M.26, SJP84-523 1 , MM. ill, M.9, and SJP84-5230 (Table 3). In Mont St-Gregoire, SJP84- 52 1 8. SJP84-52 1 7. SJP84-5 1 74, SJP84-5 1 80, 0.3, and 0.3 A had higher aumulative yield than did MM.lll 16 Fruit Notes, Volume 68, Spring, Summer. & Fall, 2003 Table ." Performance of nine superior rootstocks ar J 0.. ?A with Sum merlan d Mclr tosh as the sc on compared to M.26, M.9 M.26, MM.llI and 0.3 planted in 1995 in Dunham Vergei Dupu is Inc. (average of 2 -3 trees per /replicate^ 1 'J 1 > E _E <-* O "e < o '^ M ? -o a. 00 Yield (kg) i-E 3 it £ 2 c ^ 6 S Z - 00 5 -S u. S o f^i o o o o o o SJPS4-5:iS 75-13-032 173 150 18 1.9 2.4 2.3 S.9 5.2 15.2 31.8 1.8 263 118 3.8 SJP84-5:i7 75-13-065 172 149 18 1.9 2.3 2.7 9.0 4.0 18.1 33. S 1.9 279 114 2.2 SJPS4-5:30 75-13-179 108 93 7 1.4 1.3 0.8 3.9 0.8 4.0 9.4 1.5 78 126 1.5 SJP84-5I98 75-13-180 153 132 14 M 2.3 4.0 10.1 5.5 17.1 36.7 2.6 294 114 2.5 SJP84-5I62 75-13-183 169 146 17 1.7 2.7 3.3 S.7 7.5 14.4 33.8 2.0 260 118 3.5 SJP84-523I 75-13-209 122 105 9 1.7 1.3 3.2 -;.7 2.9 9.2 20.1 2.1 171 126 2.8 SJP84-5I74 75-13-219 205 177 25 1.9 2.2 0.5 - - 9.3 15.4 33.0 1.3 296 96 1.0 SJP84-5189 75-13-246 182 157 20 2.8 2.8 2.1 "4 6.6 19.9 36.0 1.9 319 100 1.8 SJP84-5180 75-13-296 - - - - - - - - - 0.3A 160 139 15 1.9 2.2 3.2 S.3 6.7 13.1 31.2 2.0 270 102 0.7 M.26 173 149 18 1.8 2.7 1.6 5 7 2.4 12.6 22.2 1.3 185 119 3.3 M.9 100 86 6 1.8 1.6 0.8 2 5 1.7 5.3 10.3 1.8 94 116 3.0 MM. Ill 224 194 30 3.2 2.1 0.0 ■; -> 3.4 9.0 15.6 0.6 119 130 2.2 0.3 156 135 15 1.9 2.7 1.9 ~,5 8.1 11.8 29.2 2.1 242 104 1.7 LSD* 38 33 8 64 56 2.0 --' 5.6 6.0 10.8 0.9 75 19 1.9 ' Vigour; Trunk circumfereni. e as a percent of M.9. ^F ruit weight (g was taken us: -1% 25 randomly selected fruits ^ Trunk circumference and cross-sectional area i :CA) 25 cm *■ Buni^not rating 0 = desirable 10 = undesirable abo\e era ft union. ^A verace number of sue kers cc anted d jring the 2002 season ' l999-:002 = cumulative >ield from 1999-2002. * If difference between lu o means exceeds LSD, then it IS ^ Efficiency: (cumulative yield ATCA). significant at odds of 1 9: 1 . and M.27 (Table 2). The most efficient rootstocks were SJP84-5198 in Dunham (Table 3) and SJP84-5218 in Mont St- Gregoire (Table 2). MM. Ill resulted in the lowest efficiency at both sites. Few differences existed in burrknot rating (Tables 2 and 3) or root suckering (Table 2). Based on the observation made since 1984 in six orchards, nine of the SJP84 series are being released for commercial testing and evaluation. All the retained SJP84 senes are winter hardy, easier to propagate in stool bed than 0.3, and produce a thick and vertical growing sucker in stool bed. No mildew, scab, or woolly aphid was observed on these rootstocks. To date, no graft incompatibility has been observed. SJP84-5218 and SJP84-5198 stand out from the superior group, based on the visual tree observation (height, spread, branch angle, fruit distribution, tree form, graft union, root suckers, and burr knots) in five locations and also on their performance in stool beds. A patent is pending for all of the SJP84 series rootstocks. A limited number of rootstocks are available for research purposes from the author (SK). Non- exclusive multiplication licences can be obtained from Agriculture and Agri-Food Canada. European nurseries can obtain a multiplication licence from Meiosis Ltd. (Bradboume House, Siable Block, East Mailing, Kent ME19 6DZ). Literature Cited Anon. 1976. Pommier-culture. Agdex 211/20. Publication 333. Conseils des productions vegetales du Quebec (production Guide). Asnong, J. 1982. L'industrie de la pomme au Quebec: Etat de la situation. Conference socioeconomique sur l'industrie de la pomme. Min. Agr. Pecheres et alimentation du Quebec. Brown, G.N. 1978. Protein synthesis mechanisms relative to cold hardiness, in Plant cold hardiness Fruit Notes, Volume 68, Spring, Summer. & Fall, 2003 17 and freezing stress, (P. H. Li and A. Sakai, eds.), pp. 153-163. Academic Press, New York. NY. Chen, H.H, and RH. Li. 1980. Characteristics of cold acclimation and deacclimation in tuber bearing solanum species. Plant Physiol. 65:1 146-1 148. Collins, M.D., P.B. Lombard, and J.W. Wolfe. 1978. Effects of evaporative cooling for bloom delay on Bartlett and Bosc pear tree performance. J. Amer. Soc. Hort. Sci. 103:185-187. Czynczyk. A. 1979. Effect of M.9, B.9, and M.26 rootstocks on fruiting and frost resistance of apple tree cultivars. Fruit Sci. Reports 4:144-152. Doroshenko, T.N., E.V. Makarova, and G.N. Nikulin. 1 995. .A. rapid selection of winterhardy stock-scion combinations in fruit crops. Sadovodstvo i Vinogradarstvo 5:5-6 (abstract). Fisher, C. and M. Fisher. 1996. Results in apple breeding at Dresden-Pillnitz: review. Gartenbauwissenschaft 6 1 : 1 39- 1 46. Granger, R.L. 1981. Notes concerning the harsh winter of 1 980/ 1 98 1 . Fruit Notes. 46: 1 4- 1 6. Granger, R.L., G.L. Rousselle, M. Meheriuk. and A.H. Quamme. 1991. Promising winter hardy apple roostock from a breeding program at Morden, Manitoba. Fruit Var. J. 45(3): 185- 186. Granger, R.L., G.L. Rousselle, M. Meheriuk. and S. Khanizadeh. 1992. Performance of 'Cortland' and 'Mcintosh' on fourteen rootstocks in Quebec. Fruit Var. J. 46(2): 114-1 15. Granger, R.L., M. Meheriuk, S. Khanizadeh. and Y. Groleau. 1993. Performance of 'StarkspurSuperm Delicious' on 25 rootstocks in Quebec. Fruit Var. J. 47(4):226-229. Gusta,A.L., D.B. Fowler, and N.J. Tyler. 1982. Factors influencing hardening and survival in winter wheat. //; Plant cold hardiness and freezing stress, (P. H. Li & A. Sakai, eds.), pp. 23-40. Academic Press, New \'ork, NY. Heeney, H.B. 1981. Apple rootstock studies at Smithfield Experiment Farm, 51 p. Technical Bulletin No. 3. Ketchie. D.O. and C. Murren. 1976. Use of cryoprotectants on apple and pear trees. J. Amer. Soc. Hort. Sci. 101:57-59. Khanizadeh, S., D. Buszard, and C.G. Zarkadas. 1989a. Seasonal variation of proteins and amino acids in apple flower buds (Malus pumila Mill. Mcintosh/ M7). J. Agr Food Chem. 37:1 246- 1 252. Khanizadeh, S., D. Buszard, and C.G Zarkadas. 1989b. Effect of crop load on seasonal variation in chemical composition and spring frost hardiness of apple flower buds. Can. J. Plant Sci. 69:1277- 1284. Khanizadeh, S. 1991. Controlling temperature by microcomputer. HortScience 26(5):607. Khanizadeh, S., D. Buszard, and C.G Zarkadas. 1992a. Effect of crop load on hardiness, protein and amino acid content of apple flower buds at several stages of development. J. Plant Nutrition 15(11):2441- 2455. Khanizadeh, S., D. Buszard, and C.G Zarkadas. 1992b. Comparison of three methods for calculating protein content in developing apple flower buds. J. Assoc. Off Anal. Chem. 75(4):734-737. Khanizadeh, S., D. Buszard, and C.G Zarkadas. 1994. Seasonal variation of hydrophilic, hydrophobic, and charged amino acids in developing apple flower buds. Journal of Plant Nutrition 17(ll):2025-2030. Khanizadeh, S., C. Brodeur, R. Granger, and D. Buszard. 2000a. Factors associated with winter injury to apple trees. Acta. Hort. 514:179-192. Khanizadeh, S., Y. Groleau, R. Granger, J. Cousineau, and G. L. Rousselle. 2000b. New hardy rootstocks from the Quebec apple breeding program Acta Hort. 538:719-721. Li. P.H. 1987. Plant cold hardiness. Alan R. Liss, Inc., New York, NY. Lindow, S.E. and J.H. Connell. 1 984. Reduction of frost injury to almond by control of ice nucleation active bacteria. J. Amer Soc. Hort. Sci. 109:48-53. Lkidow, S.E., N.J. Panopoulos, and B.L. McFarland. 1989. Genetic engineering of bacteria from managed and natural habitats. Science 244:1300- 1302. Marini R.P, B.H. Barritt, J. A. Barden, J. Cline, R.L. Granger, M.M. Kushad, M. Parker, R.L. Perry, T. Robinson, S. Khanizadeh, and C.R. Unrath. 2001 a.Perfomiance of "Gala" apple on eight dwarf rootstocks: ten-year summary of the 1 990 NC- 1 40 rootstock trial. Journal American Pomological Society. 55(4): 197-204. Marini R.P, B.H. Barritt, J. A. Barden, J. Cline, E.E. Hoover, R.L. Granger, M.M. Kushad, M. Parker, R.L. Perry, T. Robinson, S. Khanizadeh, and C.R. Unrath. 2001b. Performance often apple orchard systems: ten year summary of the 1990 NC-180 systems trial. Journal American Pomological 18 Fruit Notes, Volume 68, Spring, Summer, & Fall, 2003 Society. 55(4):222-238. Sakai, A. and W. Larcher. 1987. Frost survival of plants. Responses and adaptation to freezing stress. SpringerVerlag, New York, NY. Skrivele. M., M. Bluknianis, L. Ikase, E. Kaufmane, S. Ruisa, and S. Strautina. 1995. Fruit breeding in Latvia: current problems. Proc. Larvian Acad. Sci. Section b, NaiL Sci. 5-6: 109-1 1 3. Spangelo. L.RS., S.O. Fejer, S.J. Leuty. and R.L. Granger. 1974. Ottawa 3 colonal apple rootstock. Can. J. Plant Sci. 54(3):601-603. Stang, E. J., D.C. Ferree, RR. Hall, and R.A. Spotts. 1 97S. Overtree misting for bloom delay in Golden Delicious apple. J. Amer. Soc. Hort. Sci. 103:82- 87. StushnotT, C. 1972. Breeding and selection methods for cold hardmess in deciduous fruit crops-. HortScience 7:10-13. Webster, A. D. 2003. Breeding and selections of apple and pear rootstocks. Acta Hort. 622(499-512) Weiser, C. J. 1970. Cold resistance and acclimation in woody plants (A review). HortScience 5:403-40S. Witney, G. 1996. Tree condition and cold tolerance. Good Fruit Grower 47:24-26. Yang, J. M., Y Z. .Xiu, Z. H. Zhang, and D. W. Zhu. 1995. Breeding of Green Delicious, a tolerant to drought and cold resistant apple variety. Acta Horticulturae 403:78-80. Zagaza, S.W. 1977. Transmission of disease resistance and winter hardiness from selected fruit of Asiatic and East European. PI. 480 Res. Inst. Sac. Pomology, Skiemiewice, p. 5-16. %i^ %i^ «1^ %i^ %S^ ^T% #T» ^T% ^T% *T^ Fruit Notes, Volume 68, Spring, Summer, & Fall, 2003 19 Summertime Heat & Health: Prevention Is the Best Medicine George Cook Extension Maple Specialist, University of Vermont Folks boast of their dark tan; many think a dark tan looks healthy, but in reality, skin cancer is the most common of all cancers. The main cause of skin cancer is overexposure to the sun, even here in the Northeast. We may even be more susceptible. Much of our weather is a combination of sun and clouds, so when the sun does shine, we peel off the clothes to take full advantage of it. Our body's natural defense against damaging ultraviolet radiation from the sun is a pigment called melanin; however, even the darkest skin does not contain enough melanin to prevent damage resulting from exposure to the sun. Farmers have an increased risk of skin cancer, due to the hours spent working in the sun. Remember, the sun's rays are brightest between 10 AM and 3 PM. There are a few preventive steps you can tbllow to protect your skin from skin cancer. A wide-rimmed hat is recommended over the ever- popular "baseball" cap that many of us wear. They provide a sun shield for not only your eyes, but also for your ears, neck, and shoulders. These are all common locations of skin cancer outbreaks. Fabric provides an excellent source of protection against the sun. Darker colors, though warmer, tend to block more sun. Some clothing manufacturers are beginning to put Sun Protection Factor (SPF) ratings on their clothes. You should look for a rating of 1 5 or higher. Generally, a tighter weave of fabric gives more protection. For example, denim jeans have an SPF of 1 ,700. A hat should have a 4-inch rim all around, or a broad bill and flap to cover your ears. Sunscreen is the best way to protect any exposed skin. It is important that you use the right SPF for you. There are two factors to consider. First, how many minutes can your unprotected skin be in the midday sun before it begins to redden and bum? Second, how many minutes will you be working in the sun? You can then figure the minimum SPF rating suncreen you need to apply (SPF = Minutes to be spent in the sun divided by .Minutes before skm reddens). Always use a sunscreen with a minimum rating of 15. They are available at 30, 45, and higher. If you sweat heavily, use a waterproof or sports sunscreen. You should apply sunscreen 20 to 30 minutes before going outside to give it time to penetrate your skin and protect your cells. It does not last all day, check the label to see how often you should repeat the application. Also, the sun's rays can reach through thin clouds, so apply sunscreen even on a cloudy day. Your lips are also at risk, so use an SPF lip balm to provide protection for them. Finally, when \ou purchase farm equipment, consider the benefits of features such as enclosed cabs or sun shades. Your skin's health is vitally important to your overall health. It was 9:30, I had been working for three hours already, the humidity was high, the air hot and close. I had a headache, and I began to pant and feel nauseated. My skin felt hot and dry; I was near collapse. I had only had a small sip of water all morning. My friends called the emergency medical service. The emergency personnel came and immediately administered first aid. Later, they said 1 nearly died. Heat stroke is a serious illness caused by erheating. It if life threatening, and must be treated as an emergency. S> mptoms include dry, hot, red or ov Copyright's 2002 by Moose River Publishing Company. Reprinted with permission from Fanning, The Journal of Northeast Agriculture, Volume 5, Number 7 (July), 2002. pp. 28-29. For subscription information, call Moose River Publishing Company at (SOD) 422-7147 or write to Farming, The Journal of Northeast Agriculture. P.O. Box 449, St. Johnshun: IT 05819-9929. 20 Fruit Notes, Volume 68, Spring, Summer, & Fall, 2003 spotted skin. The victim becomes extremely weak and may lose consciousness, but with rapid, strong pulse. If not treated immediately, it can lead to convulsions, brain damage, and death. First Aid Put the person in a cool or shady area, and fan them to promote cooling. An air conditioned tractor cab may be just what the doctor ordered. Remove the victim's clothing, and sponge the skin with cool water. Call an ambulance immediately. Prevention Is the Best Medicine WTio is a prime target'!* Overweight and elderly persons, small children, diabetics, alcoholics and drug users, people with high blood pressure, and people taking certain medications. Precautions should be taken when working in hot. humid environments such as in the field or in hot, confined spaces with poor ventilation. Heat stroke can be largely avoided by following basic health and safety practices. Get enough sleep every night. Your body needs adequate rest, and this is especially true for farm-workers and others who do manual labor. Eat a good breakfast before going to work. Like a tractor, our bodies need fuel to function properly. Dress appropriately for the warm \v eather. A long- sleeved shirt, long pants, and wide bnmmed hat give the best protection from the sun. Clothes made of cotton are cool and allow air to circulate on the skin's surface. Drink plenty of water during the cay. Our bodies lose water from sweating, and the w ater lost must be replaced constantly. Provide an adequate water supply in the field, and take breaks often to ge; a drink. If you are feeling thirsty, you have waited too long. It is best to carry a water bonle with you. Do not drink beer or other alcoholic beverages; the alcohol actually dehydrates your body. Take breaks to cool off and rest. This will extend your energy and will actually increase the amount of work done each day. If you feel dizzy, weak, or overheated, stop working and go to a cool place. Sit or lie down, drink water, and wash your face with cool water. If you do not feel better soon, notify your boss or supervisor so you can be treated properly. We can always find excuses for failing to take all these preventive measures. But remember, it is as much your responsibility to protect >ourself, as it is your employer's. Everyone should be aware of the conditions that cause heat stress and do what is necessary to prevent it, and know ho\'. to deal with its symptoms. As farm workers, we need strong, healthy bodies to v\ork. We should strive to keep them in top shape. *1^ *1^ ^1* ^1^ *1^ ^j^ ^J^ ^j^ #y* #^ Fruit Notes, Volume 68, Spring, Summer, & Fall, 2003 21 A Comparison of Six Strains of M.9 Over 1 0 Years Wesley Autio, James Krupa, and Jon Clements Department of Plant & Soil Sciences, University' of Massachusetts Serious interest in the use of clonal, dwarfing rootstocks for apples developed in the United States only in the latter half of the 1900's. The use of dwarf apple trees, however, dates back more than 2,000 years, and the identification of potentially useful materia] for rootstocks likely began about 500 years ago. L"p through the 1800's, these rootstocks were categorized as either Doucin (semidwarf) or Paradise (full dwarf). The variety of clones within these two categories and the misidentification of clones led the researchers at the East Mailing Research Station in Kent, England to collect, name, and properly describe 24 different apple rootstocks. They were given the names East Mailing I through East Mailing XXIV. One of these rootstocks, EM. IX (later changed to M.9) was originally found in France in 1 879. It originated as a chance seedling and was given the name Jaune de Metz. Subsequently, it became known as the fully dwarf rootstock of choice, and now is the most widely planted apple root- stock in the world. All living organ- isms are subject to occasional mutation in their genetic code. Apples are no excep- tion. Obvious ex- amples of random mutations (or sports) are seen in some varieties more than others. Delicious, Gala, and Jonagold, for example, are prone to obvious skin-color mutations. Marshall Mcintosh is a random mutation of Rogers Red Mcintosh found at Marshall Farms in Fitchburg, MA. Rootstocks also express mutations from time to time. Since much of the plant is belov^ ground, however, most mutations are not obvious, and even ones that may be beneficial are lost. Even so. several genetically different strains of M.9 have been characterized over the years. Until relatively recently. U.S. growers have had access only to M.9 and M.9 EMLA. In the last 1 0 or more years, other strains have entered the U.S. market, most notably M.9 NAKBT337. These strains offer some variation in the grafted tree. Likely, the most obvious difference is in the degree of dwarfing, but other characteristics may change with mutations. It is important for nurseries and growers to understand strain differences, so that the best possible rootstocks and management systems are used. In 1994, the NC-140 Multistate Research 100 _ 90 80 E a 70 - 60 - c o ■^ 50 0) tf) in V) o c 3 40 30 - 20 10 0 be cd cd M.26 EMLA M.9 Pajam 2 M.9 M.9 M.9 M.9 M.9 M.27 RN29 Pajam 1 EMLA T337 Fleuren EMLA 56 Figure 1. Trunk cross-sectional area of Gala apple trees on various strains of M.9 and on M.26 EMLA and M.27 EMLA, after 10 growing seasons. Bars topped by different letters are signficantly different at odds of 19: 1 . 22 Fruit Notes, Volume 68, Spring, Summer, & Fall, 2003 400 - a 350 - ■g- 300 - S 250 - D) ab ab ab b b b "-■•#■■■ ^ 200- ,t 150 - - i i c 100 - i i 50 - ■1 M.26 M.9 M.9 M.9 M.9 M.9 Ml.9 M.27 EMLA Pajam 2 RN29 Pajam 1 EMLA T337 Fleuren EMLA S6 Figure 2. Height of Gala apple trees on various strains of M.9 aad om M.26 EMLA | and M.27 EMLA, after 10 growing seasons. Bars topped b> different letters are signficantly different at odds of 1 9: 1 . Committee established a trial including 17 rootstocks with Gala as the scion cultivar at 25 locations. Six of the rootstocks were different strains of M.9. In this article, we report the results gathered from one location after 10 years of trial, concentrating on the M.9 strains. M.26 EMLA and M.27 EMLA are in- cluded in this article for comparison (they also were part of this trial). Trees were planted in April of 1 994 at the University of Massachusetts Cold Spring Orchard Re- search & Education Center in Belchertown. MA in a randomized-com- plete-block design with 10 replications. All trees were staked and maintained roughly as vertical axes. Pest and fertil- ity management was per local recommen- dations. Root suckers were counted and cut annually. Yield per tree and fruit size were assessed each year from I99»6 to 2003. Trunk cross-sectional area (20" abo\ e the graft union), canopy spread, and tree height were measured at the end of the 2003 growing season. Materials & Met hods Gala trees were budded on various rootstocks during 1992 growing season and grown in the nursery through the 1993 sea- son. Trees were dug in the fall, stored, and shipped to cooperators in the Spring of 1994. The rootstocks of in- terest in this article are M.9 EMLA, M.9 Fleuren 56, M.9 Pajam 1, M.9 Pajam 2, M.9 RN29, and M.9 NAKBT337. Data for 350 - ^ ab ^^1 ^^1 at)c 300 E o -250- ^1 ^H ^H ■■ ^H ^^ a. 200 (A o 150 - c ra " 100 - ^H ^H ^H ^H ^H ^H ^H 50 - III 1 1 1 1 1 0 - ^1 , H , ^1 . Hi , H , ^1 ,^H , ^1 M.26 M.9 M.9 M.9 M.9 M.9 M.9 M.27 EMLA Pajam 2 RN29 Pajam 1 EMLA T337 Fleuren EMLA 56 Figure 3. Canopy spread of Gala apple trees on various strains of M.9 and on M.26 EMLA and M.27 EMLA. after 10 grovring seasons. Bars topped by different letters are signficantly different at odds of 19:11. Fruit Notes, Volume 68, Spring, Summer, & Fall. 2003 23 CO a o ^^^^^^H S 40 ^^H T» ^^^^^1 » ^^^1 ® 35 S 30 ^^H abc ^^1 ^^H abc ^^^ ^^H 125- ^H ^H ^H ^H m ^^^^^1 ^^^^^1 ^^^^^H ^^HHiia ^^^^^^ a 20 ^^1 ^H ^^1 ^H ^^M u 5 15 ^H ^H ^H ^^^ ^H ^H o ^^H ^^H ^^H gmgn ^^1 ^^1 e 10 ^1 H ^M ^M H ^1 de o > 1 5 e ■■■■■■■ 3 i oJ ■MH , IIMi ^.■■^■■_^AB_M9_HK_^H_ *J M.26 M.9 M.9 M.9 M.9 M.9 M.9 M.27 EMLA Pajam 2 RN29 Pajam 1 EMLA T337 Fleuren EI\^LA 56 Figure 4. Cumulative root suckering of Gala apple trees on various strains of M.9 and on M.26 EMLA and M.27 EMLA, over 10 growing seasons. Bars topped by different letters are signficantly different at odds of 1 9: 1 . (Figure 4). Cumula- ti\ ely, trees on Pajam 2 produced 42 suck- ers on average; whereas, those on EMLA produced only 14. The differences in suckering were not strictly related to tree vigor, since trees on Fleuren 56 were the least vigorous but produced the second most root suckers. As a comparison, trees on M.26 EMLA pro- duced only nvo suck- ers on average in the 10 years of this trial. Cumulative yield per tree (Figure 5) was closely related to Results tree size. The more vigorous the M.9 strain, the greater the yield. When the yield was adjusted for tree size. After 10 growing seasons, differences among the that is was assessed as yield efficiency, the strains of six M.9 strains were striking, particularly related to M.9 were similar (Figure 6). It is mteresting to note tree size. Of the six, the largest trees were on Pajam 2, that trees on all strains of M.9 were significantly more and the smallest were on Fleuren 56 (Figures 1, 2. and 3). Trees on Pajam 2 were nearly VC/o larger than those on Flueren 56. The order of tree size from largest to smallest was Pajam 2, RN29, Pajam I, EMLA, NAKBT337, and Fleuren 56. Trees on Pajam 2 were some- what smaller than those on M.26 EMLA, and trees on Fleuren 56 were substantially larger than those on M.27 EMLA. Root suckering varied greatly over the 10 years of the trial Af\n * a S 350- o S 300- S 250 - «u du abc :cd bed rd \j\j d ^ 200 - •a ■I 150 1 100- i 50- e O n M.26 M.9 M.9 U.9 M.9 M.9 M.9 M.27 EMLA Pajam 2 RN29 Pajam 1 EMLA T337 Fleuren EMLA 56 Figure 5. Cumulative yield of Gala ayple Irees on various strains of M.9 and on M.26 EMLA and M.27 EML.\, over eight finuiting seasons. Bars topped by differeinit letters are signficantly different at odds of 19: 1 . 24 Fruit Notes. Volume 68, Spring, Summer, & FalU 2003 yield efficient than trees on M.26 EMLA. Fmit size averaged over the fruiting life of the trial, like yield effi- ciency, was not affected by M.9 strain ( Figure 7). Interestingly, fruit from trees on M.26 EMLA were larger than those from trees on three of the M.9 strains, and fruit trom trees on M.27 EMLA were signifi- cantly smaller than those from trees on any of the .\1.9 strains. Conclusions Dramatic differ- ences in tree size and relatively similar differ- ences in per-tree yield resulted from the six different M.9 strains. Differences in yield effi- ciency and fruit size did not result from the different strains. So, the important M.9 qualities of high yield and large fruit did not vary among the strains evaluated here. The degree of dwarfing, however, did \ary. Growers must therefore be careful not so much in the choice of M.9 strain but in the planting system and tree spacings utilized with the particular M.9 strain. M.26 EMLA M.9 Pajam 1 M.9 EMLA M.9 T337 M.9 M.27 Fleuren EMLA 56 Figure 6. Cumulative yield efficiency of Gala apple trees on various strains of M.9 and on M.26 EMLA and M.27 EMLA, over eight fruiting seasons. Bars topped by different letters are signficantly different at odds of 19:1. « 150- o o CM a % 145- en ab ab 1 1 ab S 140 - a) N b b h ^ 135- "5 S, 130- c < 125 - 120 - M.26 M.9 M.9 M.9 M.9 M.9 M.9 M.27 EMLA Pajam 2 RN29 Pajam 1 EMLA T337 Fleuren EMLA 56 Figure 7. Average size of fruit harvested from Gala apple trees on various strains of M.9 and on M.26 EMLA and M.27 EMLA, over eight fruiting seasons. Bars topped by different letters are signficantly different at odds of 1 9: 1 . %1« %X^ %1^ %i^ %1^ ^f* ^J^ ^^ #y% *^ Fruit Notes, Volume 68, Spring, Summer, & Fall, 2003 25 Be Aware: Protection During Lightning Storms George Cook Extension Maple Specialist, University of Vermont Lightning is a random and unpredictable event. Lightning strikes may generate electrical current levels that exceed 400 kA, temperauires that reach 50,000°F and hit at speeds approaching one-third the speed of light. Globally, some 2,000 ongoing thunderstorms cause about 100 lightning strikes to earth each second. Lightning causes more than 26,000 fires annually in the United States with damage to property in excess of $5 to 6 billion, according to the National Lightning Safety Institute. Thunderstorms and lightning are most likely to develop on hot, humid days. Lightning is a frequent weather hazard impacting outdoor recreation and farm-work situations. If lightning is seen or heard, take protective action immediately. Being prepared can reduce the risk of the lightning hazard and raise safet>' levels. Lightning Safety for Outdoor Workers If you can see lightning or hear thunder, activate your safety plan. Resume activities only when lightning and thunder have not been observed for 30 minutes. Advance planning is the single most important means to lightning safety. The following steps may help avoid injury. Designate a responsible person to monitor weather conditions. An inexpensive portable weather radio will provide regular weather condition updates. An emergency procedure should include: suspending activities, moving people to safety, monitoring conditions, then resuming activities. Identify safe locations beforehand. These include fully enclosed metal vehicles with windows up or substantial and pemianent buildings. Unsafe areas include small structures, including huts and rain shelters, and nearby metallic objects like fences, gates, instrumentation, electrical equipment, wires and power poles. Also avoid trees, water, open fields, and using the (hard wired) telephone and headsets. If outdoors, avoid water, high ground, and open spaces, get off farm machinery, get out of the water if you are swimming or boating, and avoid all metal objects including electric wires, fences, motors, power tools, clotheslines, metal pipes, rails, etc. Unsafe places include underneath canopies, small picnic or rain shelters, or near trees. However, standing under a group of trees, shorter than others in the area, is better than being in the open. Put down any object that might conduct electricity, such as a rake, hoe, or shovel. Seek low ground, preferably a ditch or gully. If you are outside with no protection, get to a low spot. Make your body low to the ground, but do not lie flat on the earth. Learn the Lightning Safety Crouch. If hopelessly isolated from shelter during close-in lightning, adopt a low crouching position with feel together and hands on ears. If lightning is striking nearby when you are outside, you should assume the Lightning Safety Crouch. Avoid proximity (minimum of 15 feet) to other people. If there is a group of people, spread out. If someone feels his or her hair stand on end, it may mean lightning is about to strike. Stay calm and keep low. This will help reduce your chances of being struck by lightning. If indoors, avoid water, stay away from doors and windows, do not use the telephone, and take off Copynght©2002 by Moose River Publishing Company. Reprinted with permission from Fanning, The Journal of Northeast Agriculture, Volume 5. Number 9 (September). 2002, p. 15. For subscription information, call Moose River Publishing Company at (800) 422-7147 or write to Farming, The Journal of Northeast Agriculture, P.O. Box 449. St. Johnsbury. VT 05819-9929. 26 Fruit Notes, Volume 68, Spring, Summer, & Fall, 2003 headsets. Postpone baths, showers, and doing dishes until the storm passes. Turn off, unplug, and stay away from appliances, computers, power tools, and TV sets. Lightning may strike exterior electric and phone lines, inducing shocks to inside equipment. Computers should be surge protected. Suspend activities for 30 minutes after the last observed lightning or thunder. Lightning-caused Hazards Do not touch fallen wires. Report them to police or local utility immediately. If an appliance or tool catches fire, try to unplug it or turn off the current at the fuse box. Donot pour water on the fire. Use a Class C fire extinguisher, or throw baking soda on the fire. Before it gets out of control, call the local fire department and get everyone outside. First Aid for Lightning Victims People who have been struck by lightning do not carry an electrical charge and are safe to handle. Apply first aid immediately, if you are qualified to do so. Call 911, or send for help immediately. Besides bums, lightning can also cause ner\ous system damage, broken bones, and loss of hearing or eyesight. Victims may experience confusion and memory loss. First aid for lightning victims needs to be carried out immediately. After the lightning strikes, get to the victim as quickly as possible. Check breathing and pulse, if the victim is unconscious. If the victim has a pulse, but is not breathing, begin mouth- to-mouth resuscitation. If there is no pulse, begin cardiopulmonary resuscitation (CPR). Check for other injuries, such as possible fractures. Do not move a suspected spinal-injury victim. Cover the electrical bum with a dry, sterile dressing, but do not cool the bum. There may be more than one bum area, one where the current entered the body and another where it left. Keep the victim from getting chilled until help arrives. If a person stmck by lightning appears only stunned or otherwise unhurt, medical attention may still be needed. Check for bums, especially at fingers and toes, and areas next to buckles and jewelry. Make sure all lightning victims have a medical examination, even if they do not seem to need it. Two helpful Web sites are http:// lightninijsafetv.com/nlsi, which is the site for the National Lightning Safety Institute, and www. cdc.gov/ nasd/, the National Ag Safety Database. ^t^ «1^ %i^ %i^ VL^ ^T^ ^1% ^T* #J% *^ Fruit Notes, Volume 68, Spring, Summer, & Fall, 2003 27 An Early Look at a Few of the Geneva Series Apple Rootstocks In Massachusetts Wesley Autio, James Krupa, and Jon Clements Department of Plant & Soil Sciences, University of Massachusetts The Cornell-Geneva Rootstock Breeding Program began in earnest in 1 968 by Dr. Jim Cummins. Its goal was to produce rootstocks which resulted in a high degree of precocity, high productivity, size control, and resistance to pests. A particular focus of the program was to breed fireblight resistance into dwarfing rootstocks. Recent years have brought the release of a number of rootstocks from this program, but we have had very little experience with them in Massachusetts. The first significant trial including one of the recent releases was planted in 1 998, and the next two were planted in 1999. This article will provide early results from these three trials. Please note that the first part of the rootstock name is "G" for those Cornell-Geneva rootstocks that have been commercially released. The names of those under trial but not yet released begin with "CG." 1998 NC-140 Apple Rootstock Trial As part of the 1998 NC-140 Apple Rootstock Trial, a planting was established at the University of Massachusetts Cold Spring Orchard Research & Education Center, including Gala on M.9, M.9 EMLA, and G.16. Trees were staked and maintained as vertical axes. Trunk cross-sectional area, root suckering, yield, and fruit size were assessed annually. After six growing seasons, trees on G.16 were larger than those on M.9 or M.9 EMLA (Table 1). Suckering has been low and comparable among the three rootstocks. Trees on G.16 yielded more cumulatively (1999-2003) than either strain of M.9, but yield efficiencies were similar. Average fruit size from 1999 through 2003 was smaller from trees on G.16 than from either M.9 strain. Table 1. Trunk cross-sectional area, suckering, yiel± yield efficiency, and fruit weight in 2003 of Gala trees on various rootstocks in the Massachusetts planting of the 1998 NC-140 Apple Rootstock TriaJ.' Trunk cross- sectional Rootstock area (cm^) Root suckers (no. /tree, 1998-2003) Yield per tree (kg) Yield efficiency (kg/cm^ TCA) Fruit weight (g) Cumulative 2003 (1999-2003) Cumulative 2003 (1999-2003) Average 2003 (1999-2003) G.16 17.8 a M.9 11.7 b M.9 EMLA 10.6 b 0.4 a 0.3 a 0.3 a 15.7 a 40 a 6.5 a 24 b 5.3 a 20 b 0.97 a 2.26 a 0.56 a 2.05 a 0.48 a 1.89 a 131a 104 b 162 a 132 a 143 a 125 a ' Means within columns not followed by the same letter are significant at odds of 19: 1. 28 Fruit Notes, Volume 68, Spring, Summer, & Fall, 2003 Table 2. Trunk cross-sectional area, suckering. yield, yield effici ency, and fruit weight in 2003 of Mcintosh trees on several rootstocks in the Massachusetts planting of the 1999 NC -140 Dwarf Apple Rootstock Trial. Root Yield efficiency Trunk suckers Yield pe - tree (kg) (kg/cm -TCA) Fruit w eight (g) (no./tree, 1999- sectional Cumulative Cumulative Average Rootstock area (cm") 2003) 2003 (2001-03) 2003 (2001-03) 2003 (2001-03) CG.3041 16.4 cd 1.2 a 23.4 bed 35 bed 1 .42 ab 2.14 ab 162 a 155 ab CG.4013 29.9 a 1.2 a 42.0 a 66 a 1.41 ab 2.19a 164 a 160ab CG.5179 21.9 be 0.7 a 30.5 ab 49 ab 1 .40 ab 2.25 a 165 a 158 ab CG.5202 25.2 ab 0.0 a 31.3 ab 49 ab 1.29 ab 2.01 ab 161 a 160ab G.16N 13.3 d 0.0 a 16.0 bed 26 bed 1.12 ab 1.82 ab 154 a 147 ab G.16T 14.6 cd 0.2 a 17.6 bed 28 bed 1.22 ab 1.95 ab 145 a 144 ab M.26 EMLA 16.5 cd 0.0 a 15.0 cd 20 cd 0.88 b 1.19b 162 a 158 ab M.9NAKBT337 9.2 d 0.0 a 11.4d 17d 1.25 ab 1.89 ab 173 a 169 a Supporter 1 ll.Sd 0.0 a 19.5 bed 30 bed 1.63 a 2.42 a 145 a 139 ab Supporter 2 15.3 cd 0.6 a 25.2 bed 37 bed 1.66 a 2.50 a 141 a 134 b Supporter 3 16.3 cd 0.0 a 25.3 be 41 be 1.56 a 2.53 a 145 a 146 ab ^ Means \\ ithin columns not followed by the same etter are signi ficant at oddsof 19:1. Table 3. Trunk cross-sectional area, suckering. yield, yield efficiency, and fruit weight in 2003 of Mcintosh trees on several rootstocks in the Massachusetts planting of the 1999 NC-140 Semidwarf Apple Rootstock Trial. Trujik Root Yield per tree (kg) Yield efficiency (kg/cm^ TCA) Fruit weight (g) suckers (no./tree, 1999-2003) Rootstock sectional area (cm^) 2003 Cumulative (2001-03) 2003 Cumulative (2001-03) 2003 Average (2001-03) CG.4814 13.1 c 11.2ab 24.3 ab 37 ab 1.87 a 2.82 a 175 a 154 a CG.7707 16.8 c 3.5 be 20.3 b 29 be 1.20 ab 1.73 b 175 a 168 a G.30N 31.5 a 0.5 be 37.9 a 53 a 1.25 ab 1.71 b 175 a 169 a M.26 EMLA 15.3 c 0.0 c 13.7b 19c 0.88 b 1.23 b 177 a 168 a M.7 EMLA 30.6 ab 15.2 a 23.2 b 30 be 0.75 b 0.96 b 153 a 163 a Supporter 4 29.7 b 1.2 be 22.6 b 32 be 0.79 b 1.12b 164 a 169 a ^ Means within columns not followed by the same letter are signi ficant at oddsof 19:1. Fruit Notes, Volume 68, Spring, Summer, & Fail, 2003 29 1999 NC-140 Dwarf Apple Rootstock Trial As part of the 1999 NC-140 Dwarf Apple Rootstock Trial, a planting was established at the University of Massachusetts Cold Spring Orchard Research & Education Center, including Mcintosh on CG.3041, CG.4013, CG.5179, CG.5202, G.16 (both tissue cultured and stool bedded), M.26 EMLA, M.9 NAKBT337. Supporter 1. Supporter 2, and Supporter 3. Trees were individually staied and maintained as vertical axes. Trunk cross-sectional area, root suckering, yield, and fruit size were assessed annually. After fi\e growing seasons, trees on CG.4013 were the largest, followed by those on CG.5202 and CG.5179 (Table 2). The rest had statistically similar trunk cross-sectional areas. Cumulative yield (2001- 03) was greatest for trees on CG.4013. Across all rootstocks, however, yield was roughly related to tree size. Cumulative yield efficiency (adjusting yield for tree size) was similar for all but trees on M.26 EMLA. Those trees were significantly less efficient than trees on CG.4013. CG.5179, or any of the Supporter rootstocks. Fruit size was not dramatically affected by rootstock. The only statistically significant difference was that fruit from trees on M.9 NAKBT337 were larger than those from trees on Supporter 2. 1999 NC-140 Semidwarf Apple Rootstock Trial As part of the 1999 NC-140 Semidwarf Apple Rootstock Tnal, a planting was established at the University of Massachusetts Cold Spring Orchard Research & Education Center, including Mcintosh on CG.4814, CG.7707, G.30. M.26 EMLA, M.7 EMLA, and Supporter 4. Trees were maintained as free- standing central leaders. Trunk cross-sectional area, root suckering, yield, and fruit size were assessed annually. After five growing seasons, trees on G.30 were significantly larger than all other except those on M.7 EMLA (Table 3). The smallest tree was on CG.4814, which was obviously misplaced in the semidwarf group. Its trunk cross-sectional area, yield, and yield efficiency were similar to the dwarf trees in the trial reported above. G.30 resulted in many fewer root suckers than did M.7 EMLA, and had significantly greater yield per tree (2001-03). Although the difference was not statistically significant, trees on G.30 were 75% more efficient than those on M.7 EMLA. Fruit size was apparently unaffected by rootstock. Conclusions It is much too early to make conclusions based on the data reported here. The variability that exists now will dissipate over the next few years and expose more statistically significant differences. That said, G.16 apjjears to be producing a tree somewhat larger than does M.9 but one that is comparably yield efficient. Fruit size from trees on G.16, however, bears watching. Trees on G.30 have performed very well for semidwarf trees, similar in size to those on M.7 EMLA, but without many root suckers and with app>arently greater yield. The other Cornell- Geneva rootstocks in these trials (CG.3041, CG.4013, CG.4814, CG.5179, CG.5202, and CG-7707) all appear to be performing well but vary considerably in size, from full dwarf to semidwarf %X^ %i^ %i^ %i^ *A^ #T* #T* #T^ *T* #T* 30 Fruit Notes, Volume 68, Spring, Summer, & Fall, 2003 How Does B.9 Stack Up Compared to M.9? Wesley Autio Department of Plant & Soil Sciences, University of Massachusetts In a previous article (pp. 22-25 in this issue), the various M.9 apple rootstock strains were compared. These were part of the 1994 NC-140 Apple Rootstock Trial, with Gala as the scion. Budagovsky 9 (B.9) was also part of that trial, planted in 1994 and maintained for 10 years. In this brief article, the data for B.9, M.9 Fleuren 56 (the smallest M.9 strain in the trial), and M.9 Pajam 2 (the largest M.9 strain in the trial) are presented (Figure 1). After 10 growing seasons, trees on B.9 were comparable in size to those on M.9 Fleuren 56 but significantly smaller than those on M.9 Pajam 2. Root suckering from B.9 was lower than from M.9 Pajam 2. Yield of trees on B.9 was comparable to trees on M.9 Fleuren 56 and lower than trees on M.9 Pajam 2. B.9 resulted in yield efficiency and fruit size similar to the two M.9 strains. Over the 10 years of this trial, B.9 performed well, producing a small M.9-sized tree with similar yield characteristics. We now have 20 years experience with B.9 and have no negative aspects of the rootstock to report. 96 -S4- 45 36 27 18 9 - -aso- iH 300 ■ 240 180 - 120 - 60 - 5 - 2 - -4«e- 150 - 120 90 60 30 - !#:: Trunk cross-sect, area (cm2) Cumulative suckers per tree Cumulative yield per tree (kg) Yield efficiency (kg/cm2 TCA) Average fruit size (g) Figure 1 . Trunk cross-sectional area, root suckering, yield, yield efficiency, and fruit size of Gala apple trees on B.9, M.9 Fleuren 56, and M.9 Pajam 2, after 10 growing seasons. Bars with different letters are significantly different at odds of 1 9: 1 . Fruit Notes, Volume 68, Spring, Summer, & Fall, 2003 31 Fruit Notes Unisersity of Massachusetts fPIIJt Department of Plant & Soil Sciences jjgtgS 205 Bowditch Hall >l£L Amherst, MA 01003 Nonprofit Organization U.S. Postage Paid Permit No. 2 Amherst, MA 01002 -1 SERIAL SECTION UMASS AMHERST, MA 01003 104911 Per SB F68 Volume 69, Number 1 WINTER ISSUE, 2004 Table of Contents rleu/Cnaland Effectiveness of Peripheral-row vs. All-row Sprays against Plum Curculio Ronald Prokopy Are Adult Plum Curculios Capable of Overwintering Within Apple Orchards? Jaime Pineru, Everardo Bigurra, Isabel Jdcome, Guadalupe Trujillo, and Ronald Prokopy . Extent of Early-season Plum Curculio Penetration into Commercial Apple Orchards Jaime Pinero, Isabel Jdcome, Everardo Bigurra, Guadalupe Trujillo, and Ronald Prokopy .... Establishing Characteristics of Odor-baited Trap Trees for Monitoring Plum Curculio Ronald Prokopy, Isabel Jdcome, Eliza Gray, Guadalupe Trujillo, Mareana Ricci, and Jaime Pinero. A Threshold for Spraying Against Plum Curculio Using Odor-baited Trap Trees Ronald Prokopy, Isabel Jdcome, and Jaime Pinero What Size of Apple is the Most Prone to Plum Curculio Attack Early in the Season? Jaime Pinero, Everardo Bigurra, Sara Hoffmann, and Ronald Prokopy Photographs of Fresh and Older Egglaying Scars of Plum Curculio on Apples Jon Clements, Jaime Pinero, and Ronald Prokopy 14 16 18 f leu/Unaland Editors: Wesley R. Autio William J. Bramlage Publication Information: Fruit Notes (ISSN 0427-6906) is pub- lished each January, April, July, and October by the University of MassachusettsAmherst in cooperation with the other New England state uni- versities. The cost of subscriptions to Fruit Notes is $20.00 per year. Each one-year subscription begins January 1 and ends December 31. Some back issues are available for $5.00. Payments must be in United States currency and should be made to the University of Massachusetts Amherst. Correspondence should be sent to: Fruit Notes Department of Plant & Soil Sciences 205 Bowditch Hall University of Massachusetts Amherst Amherst, MA 01003 All chemical uses suggested in this publication are contingent upon continued registration. These chemicals should be used in accordance with federal and state laws and regulations. Growers are urged to be familiar with all current state regulations. Where trade names are used for identification, no company endorsement or product discrimination is intended. The University of Massachusetts makes no warranty or guarantee of any kind, expressed or implied, concerning the use of these products. USER ASSUMES ALL RISKS FOR PERSONAL INJURY OR PROPERTY DAMAGE. Issued by UMass Extension, Stephen Demski, Director, in furtherance of the act.': of May S and June JO, 1914. UMass Extension offers equal opportunity in programs and employment. Effectiveness of Peripheral-row vs. All-row Sprays against Plum Curculio Ronald Prokopy Department of Entomology, University of Massachusetts Studies by Chouinard et al. (1992) and Vincent et al. (1997) suggest that spraying only peripheral rows of trees as opposed to all rows of trees can be an effective approach to plum curculio (PC) control in many Quebec apple orchards. This approach is rooted m the presumption that most PCs overwinter in woods or hedgerows outside of orchards and when entering orchards in spring do not move beyond peripheral rows of apple trees before settling down to feed and lay eggs. The proportion of overwintering PCs that satisfies this presumption under New England conditions is uncertain. Such uncertainty invites evaluation of peripheral-row vs. all-row sprays against PC in New England orchards. Here, in 2003 in one orchard in Vermont and two orchards in New Hampshire, we compared three different approaches to spraying PC that differed m location of trees (peripheral vs. interior rows) designated to receive sprays. Materials & Methods There were three experimental plots in each orchard. Each plot contained seven rows of apple trees. The perimeter row of each plot bordered woods. All rows within a plot were of the same length (80- 1 20 yards). All plots in the same orchard received the same insecticide at each spray event against PC: Avaunt in orchard X and Guthion in orchards Y and Z (each at label-recommended rate). Treatment protocols in each orchard were as follows: Plot Petal fall spray P' & 2"'' cover spray A B C All rows All rows Rows 1 and 2 All rows Rows 1 and 2 Rows 1 and 2 The petal fall spray was applied within 5 days after 90% petal fall (June 1, June 4, and June 8, respectively, for orchards X, Y, and Z). The first cover spray was applied when fruit on odor-baited trap trees reached a pre-determined threshold of two fresh egglaying scars out of 100 fruit sampled beginning 7 days after the last insecticide spray. A trap tree baited with one dispenser of attractive pheromone (grandisoic acid) plus four dispensers of attractive fruit odor (benzaldehyde) was located at the center of the perimeter row of each plot. In all, 33 or 34 fruit were sampled twice per week on each trap tree, giving a total of 100 fruit per sampling date across all three trap trees in an orchard. In response to sampling information, the first cover spray was applied on June 1 5 in each orchard. Sampling fruit on trap trees indicated no need to apply a second cover spray in orchards X and Y, whereas orchard Z received a second cover spray on Table 1. Effectiveness of different spray treatment protocols for controlling plum curculio (PC) in three commercial apple orchards. Fruit with PC injury (%) Orchard Plot A** PlotB** PlotC** X Y Z Average 1.7 0.9 0.3 1.0a 1.9 0.3 1.0 1.1a 2.0 1.1 6.5 3.2a * Average values followed by the same letter are not significantly different at odds of 19: 1 . ** Plot A: all rows sprayed at petal fall and first and second cover. Plot B: all rows sprayed at petal fall; only rows 1 and 2 sprayed at first/second cover. Plot C: only rows 1 and 2 sprayed at petal fall and first and second cover. Fruit Notes, Volume 69, Winter, 2004 June 23. For spray applications only to rows 1 and 2, the tractor was driven outside of row 1 and between rows 1 and 2. On June 26, we sampled 100 fruit in each of the seven rows in each plot for signs of any PC injury. Results Data in Table 1 show that across all three orchards, plot-wide injury to fruit by PC averaged 1.0, 1.1, and 3.2% for plots A, B, and C, respectively. Although these values did not differ significantly from one another, injury trends were similar for each orchard, with plot C always showing the greatest injury. Conclusions Results from this experiment indicate that applying a petal fall spray against PC only to peripheral rows 1 and 2 (as in plot C) is unlikely to provide effective orchard-wide control. However, applying a petal fall spray to all rows followed by subsequent sprays only to rows 1 an 2 (as in plot B) appears to be just as effective as applying a petal fall spray and subsequent sprays to all rows (as in plot A). Our data from 2003, therefore, suggest the PC behavior and ecology might be slightly different in New England compared with Quebec, possibly due to the colder climate of Quebec. It seems that either more PCs overwinter within orchards in New England than in Quebec or that, prior to petal fall, more PCs move deeper into orchards in New England than Quebec after emerging from overwintering sites in woods (see the next two articles in this issue of Fruil Notes for further information on these two questions). Whichever, based on results here, we tentatively recommend that growers apply insecticide against PC to the entire orchard at or shortly after petal fall and spray only peripheral rows 1 and 2 in subsequent treatments against PC. We recognize that data from trials in only three orchards provide a somewhat thin foundation for the above recommendation. We therefore plan to repeat this experiment in these same orchards in 2004. Ackno wledgem ents Many thanks to Zeke Goodband, Erick Leadbeater, and Steve Wood for participating in this experiment and to Lupita Trujillo and Mareana Ricci for assistance in sampling. This study was supported by a grant from the USDA Crops at Risk Program. References Chouinard, G, S. B. Hill, C. Vincent and N. N. Bartakur. 1992. Border row sprays for control of plum curculio in apple orchards. Journal of Economic Entomology S5: 1307-1317. Vincent, C, G Chouinard, N. J. Bostanian and Y. Monn. 1997. Peripheral zone treatments for plum curculio management: validation in commercial apple orchards. Entomologia Experimentalis Applicata 84: 1-8. %1^ «1^ «1> %1^ %1> #Y* ^1^ *Y* ^y* ^y* Fruit Notes, Volume 69, Winter, 2004 Are Adult Plum Curculios Capable of Overwintering Within Apple Orchards? Jaime Piiiero, Everardo Bigurra, Isabel Jacome, Guadalupe Trujillo, and Ronald Prokopy Department of Entomology, University of Massachusetts In the preceding article on the effectiveness of peripheral-row vs. all-row sprays against plum curculio (PC), results indicated that spraying only peripheral rows of apple trees beginning at petal fall was insufficient for adequate orchard-wide control of PC. Two reasons, alone or in combination, were put forward to explain this insufficiency: ( 1 ) enough PCs overwintered within the intenor of commercial orchards (inside of peripheral rows) to cause excessive fruit injury on interior trees that were left untreated against PC, and (2) excessive fruit injury on interior trees was caused by PCs that overwintered in woods and hedgerows and penetrated into interior rows before a petal fall spray was applied to peripheral rows. Here, we report results of an experiment conducted in 2003 aimed at addressing the first explanation. We asked whether PCs were able to overwinter successfully inside of two blocks of a commercial orchard in Massachusetts that differed primarily with respect to type of management (weed control). PLOT A (managed) PLOT B (unmanaged) n 5 WOODS m A ii 3 ALLEYWAY 1^ ^y ( ) :( ) ( r% ) :)CMK) :() : ) ( ) ( I:( u ). Figure 1. Representation of trap deployment in Plot A (subjected to weed management) and Plot B (not subjected to weed management) to determine distribution of PC overwintering in 2003. For each plot, 60 emergence traps were arranged in 12 transects (only one transect is shown). Each transect consisted of five emergence traps located at different sites (denoted as 1-5) along each transect. Fruit Notes, Volume 69, Winter, 2004 Materials & Methods Study site. This study was performed during April-June of 2003 in two unsprayed plots of a commercial apple orchard (University of Massachusetts Cold Spring Orchard Research & Education Center, Belchertown, MA) that differed in level of management. For each plot, the perimeter row selected for our expenment had a similar length (about 150 yards) and orientation (west). For each plot there was an alleyway (about 20 yards width) separating penmeter-row trees from woods (which were composed primarily of deciduous trees) (Figure 1). These two alleyways were mowed in August, 2002. In the first plot (Plot A), fungicides, insecticides, and herbicides were applied throughout 2002. Thus, area beneath tree canopies was devoid of vegetation. At the time of trap deployment in plot A (see below), approximately 120 fruit (from the previous year) were present beneath each tree. The second plot (Plot B) was not managed, with no insecticide, herbicide, or fungicide applied for at least 6 years. Thus, there were tall grass and other vegetation growing beneath tree canopies. In this plot, there were fewer fruit present beneath each tree (approximately 30) than in Plot A due to low fruit load the previous year (2002). Trap deployment. For our study, we used pyramidal emergence traps (depicted in Figure 2) that were 1 . 1 x 1.1 yards at base and were made of PVC and steel screen. Traps were purchased from Pest Management Innovations (Harpers Ferry, WV). A plastic device topping each trap permitted the capture of PCs that, upon emergence from hibernation, walked upward on the interior surface of the trap. For each plot, 60 emergence traps were deployed in 12 transects. Each transect consisted of five emergence traps arranged in the following manner: ( 1 ) a trap placed next to the trunk of a perimeter-row tree (denoted perimeter-row trap), (2) a trap placed in the alleyway, in close proximity to the edge of the canopy of a penmeter-row tree (denoted canopy-edge trap). Figure 2. Depiction of a pyramidal emergence trap used for the detemiination of PC overwintering within two orchard plots in Massachusetts. Trap dimensions: 1.1 x 1.1 yards at base. Traps were purchased from Pest Management Innovations (Harpers Ferry, WV). (3) a trap placed in the alleyway, midway between perimeter-row trees and woods (denoted alleyway trap), (4) a trap placed at the edge of woods (denoted woods- edge trap), and (5) a trap placed 6-8 yards inside the woods (denoted woods-interior trap) (see Figure I). Traps were deployed in such a way that no PCs emerging in the area covered by a trap could exit, and no PCs could enter a trap from the outside. Traps were deployed on April 15 (at the silver tip stage). Each trap was baited with one PC pheromone dispenser (releasing 1 mg of grandisoic acid per day) to draw PCs towards the capturing device. All traps were inspected for PCs two to three times per week until late June. Results Figure 3 reveals that for the plot subjected to weed management (plot A), 50% of the total number of PCs was captured by perimeter-row traps, whereas 36% of the total was captured by woods-interior traps. For the unmanaged plot (plot B), 62% of the total number of PCs was captured by perimeter-row traps, whereas 25%) of the total was captured by woods-interior traps. For both plots, canopy-edge and woods-edge traps Fruit Notes, Volume 69, Winter, 2004 80 n 60 % '0 PCs 40 CAPTURED 20 0 H Plot A (managed) N= 14 D Plot B (unmanaged) N= 56 Perimeter- row (1) canopy- edge (2) Alleyway Woods- edge Woods- interior (3) (4) (5) Figure 3. Distribution of PC overwintering that took place within two apple orchard plots in Massachusetts that differed in type of weed management. For each plot, "N" refers to the total number of PCs captured across all (60) emergence traps. caught low percentages of PCs (5-7%) relative to the total number of PCs captured across all traps. For both plots, no PCs were found in traps located in the alleyways. Conclusions Based on our results, we conclude that (1) PCs are able to overwinter inside apple orchards in Massachusetts, and (2) extent of overwintering seems to be influenced by type of weed management. Our findings, when combined with those reported by researchers in Quebec (e.g., LaFleur et al., 1987), suggest that geographical zone along with weather conditions prevalent in a given year, in particular during late summer and early autumn when PCs seek overwintenng sites, might also influence the distribution of overwintering PCs. We plan to repeat this study in 2004 to determine if results presented here are consistent over a two-year period. A ckn a wledgm ents This study was supported with funds provided by a USDA Northeast Regional IPM grant, a Hatch grant, a grant from USDA Crops at Risk program, and the New England Tree Fruit Research Committee. Literature Cited Lafleur, G, Hill, S.B., and Vincent, C. 1987. Fall migration, hibernation site selection, and associated winter mortality of plum curculio (Coleoptera: Curculionidae) in a Quebec apple orchard. Journal of Economic Entomology 80: 1 152-1 1 72. %X^ %1^ %1^ «1> «1^ ^1^ ^^ ^{^ #^ ^1^ Fruit Notes, Volume 69, Winter, 2004 Extent of Early-season Plum Curculio Penetration into Commercial Apple Orchards Jaime Pinero, Isabel Jacome, Everardo Bigurra, Guadalupe Trujillo, and Ronald Prokopy Department of Entomology, University of Massachusetts In the first article in this issue oi Fruit Notes, we evaluated the effectiveness of peripheral-row vs. all- row sprays in controlling plum curculios in New England apple orchards. We proposed two possibilities to explain why confining sprays exclusively to peripheral rows led to unacceptable PC control. In the preceding article, we provided information supporting the first possibility: some PCs are able to overwinter inside of orchards, and thereby they may escape sprays applied only to peripheral rows against immigrant adults. We suggested that one of the main factors influencing the amount of ovei-wintenng inside orchards might be type of orchard management, such as presence of vegetation beneath orchard trees, particularly during the period of time at which adult PCs seek overwintering sites in the autumn. Here, we report results of a study conducted in 2003 aimed at addressing the second possibility. We asked whether PCs overwintering in woods or hedgerows outside of orchards move into interior rows of orchards before petal fall and thereby escape effects of petal fall and subsequent sprays when they are confined only to peripheral rows. Materials & Methods This study was performed during April/May of 2003 in eight commercial apple orchards in Massachusetts. Within each orchard, blocks selected had similar length (about 200 yards of perimeter-row trees) and depth (at least 80 yards). For each block, trees used were of a particular size: either large (M.7 rootstock), medium (M.26 rootstock), or small (M.9 rootstock). For this study we used Circle traps (originally developed by Edmund Circle, a pecan grower in Oklahoma), which are made of either aluminum or vinyl- coated polyester screen with a PC-capturing device integrated on top. Traps are wrapped around the base of tree trunks so as to completely encircle the trunk, thereby intercepting adults walking upward. For each selected block, 20 Circle traps were deployed on April 24 (at the green-tip tree stage) on trees located in the central part (about 60-70 yards in length) of each orchard to minimize potential penetration of PCs from the lateral or back sides (Figure 1). For each block, traps were arranged in four transects of five traps each, starting on perimeter-row trees. Because there were different inter-row distances and tree densities due to the different tree sizes, blocks having large trees received traps deployed in consecutive rows (1-5), blocks having medium-sized trees received traps deployed in rows 1,3,5, 7, and 9, and blocks having small trees received traps deployed in rows 1,4,7, 10, and 1 3 . Under this approach, traps were deployed at similar distances mside a block: on perimeter-row trees (A), and on trees about 12, 22, 32 and 42 yards inside of perimeter-row trees (B-E) (Figure 1). On May 8 (at mid-pink), traps corresponding to two of the four transects in each block were baited with one dispenser of PC pheromone (grandisoic acid, releasing 1 mg per day) (GA) in association with one dispenser releasing the attractive host plant odor benzaldehyde (BEN) at a very low release rate (2.5 mg/day). Traps for the two remaining transects per block were left unbailed (Figure 1). Results show combined captures (baited + unbailed traps) because no differences in captures by either baited or unbailed traps were found. All traps were inspected for PCs on Fruit Notes, Volume 69, Winter, 2004 WOODS OR HEDGEROW ~70 yards -► |»00«0000@00€ 00«0000@00€ 00«0000©00€ 00«0000©00€ ■oo«ooooQooe -42 yards -80 yards -200 yards Large (M.7) WOODS OR HEDGEROW -70 yards »oo*ooooeooe 30000000000C •oo*ooooeooe DOOOOOOOOOOC •00*0000@00€ DOOOOOOOOOOC •oo«ooooeoo€ DOOOOOOOOOOC A B c D E -42 yards -80 yards -200 yards Medium (M.26) WOODS OR HEDGEROW -70 yards DOO DOO •oo DOO 300 •oo 300 DOO •oo DOO DOO • OO ooooo ooooo •oooo ooooo ooooo •oooo ooooo ooooo oooo ooooo ooooo • oooo oooc oooc ©OO0 oooc oooc ©00€ oooc oooc ©ooe oooc oooc eoo€ D Ei -42 yards -80 yards -200 yards Small (M.9) Figure 1 . Layout of trap deployment in eight blocks of commercial apple orchard trees in Massachusetts, according to tree size. For each block, 20 Circle traps were deployed, arranged in four transects each having five traps (shown as A-E). Of the 20 traps used per block, ten were baited (denoted as closed circles) and 10 remained unbaited (denoted as hatched circles). Fruit Notes, Volume 69, Winter, 2004 100 n % PCs CAPTURED 80 60 40 20-1 0 ■ small (M.9) n medium (M. 26) D large (M.7) ■ nl^^ Perimeter row 12 22 32 42 DISTANCE (in yards) Figure 2. Distribution of overwintered PCs that penetrated into commercial orchard blocks according to tree size and distance (from perimeter-row trees) at which Circle traps were deployed (20 traps per orchard block). May 23-24, just after the petal fall spray of insecticide against PC. Thus, results show captures that occurred during a two-week period. Results Figure 2 reveals that extent of PC penetration into commercial orchard blocks varied considerably according to tree size. For blocks having large and medium trees, most PCs were captured by Circle traps located on perimeter-row trees (about 70 and 67%, respectively). For blocks having small trees, most PCs (about 78%) penetrated into interior rows. Conclusions Based on our findings, we conclude that by petal fall: (1) most PCs were congregated on perimeter-row trees in blocks of large or medium-sized trees (M.7 or M.26 rootstock), and (2) a substantial number of PCs was able to penetrate inside blocks (at least up to 42 yards in our study) where trees were small (M.9 rootstock). An alternative explanation is that PCs may have overwintered within rather than penetrated into interiors of some blocks. Our results here, when combined with findings reported in the preceding article, may explain why growers who might limit all insecticide application against PC exclusively to peripheral-row trees would attain unacceptable PC control. We aim to repeat this study in 2004 to corroborate our findings here. A ckn o wledgm en ts We are grateful to Keith Arsenault, Gerry Beime, Bill Broderick, Aaron Clark, Don Green, Tony Lincoln, Joe Sincuk, and Steve Ware for permitting use of orchards for this study. This work was supported by funds from a USDA Northeast Regional IPM grant, a USDA Northeast Regional SARE grant, a Hatch grant, and a USDA Crops at Risk grant. %X^ %1> %1> «i^ vi# ^j^ ^j^ ^j^ #^ #Y* Fruit Notes, Volume 69, Winter, 2004 Establishing Characteristics of Odor-baited Trap Trees for IVIonitoring PlumCurculio Ronald Prokopy, Isabel Jacome, Eliza Gray, Guadalupe Trujillo, Mareana Ricci, and Jaime Pinero Department of Entomology, University of Massachusetts In the three preceding articles in this issue of Fruit Notes, evidence was presented that enough plum curculio (PC) adults are present on interior rows of apple trees at petal fall to justify a petal fall application of insecticide to all rows of an orchard block rather than just peripheral rows. In the first article, evidence was also presented to suggest that following a petal fall application of insecticide, subsequent insecticide applications against PC (first/second cover sprays) can provide effective block-wide control if confined only to perimeter rows 1 and 2. The question now arises as to which blocks in an orchard require cover-sprays for perimeter rows and what is the best timing for such perimeter-row sprays. In the 2003 Winter issue of Fruit Notes, we reported that penmeter-row apple trees baited with a combination of synthetic attractive pheromone (grandisoic acid) plus synthetic attractive fruit odor (benzaldehyde) could function as "trap trees" that aggregated PC injury. We suggested that sampling for PC injury to ascertain where and when to apply perimeter-row sprays could be restricted to trap trees rather than spread out among many different trees in a block. Here, we present results of 2003 experiments addressing five questions relevant to practical implementation of an odor-baited trap tree approach to monitoring PC: (1) what are optimum amounts of grandisoic acid (GA) and benzaldehyde (BEN) to deploy per trap tree; (2) over what distances do trap trees act to aggregate injury to fruit by PCs; (3) does a trap tree at the intersection of two perimeter rows (i.e., at a comer) outperform one midway along a perimeter row; (4) within a trap tree, is fruit injury likely to be greatest in the vicinity of the odor source; and (5) within a trap tree, where should a grower or consultant examine fruit to gain a representative sample of injury? Materials & Methods For all experiments, odor-baited trap trees were located on perimeter rows of blocks of commercial- orchard apple trees in Massachusetts. Tree size, spacing, and cultivar composition were the same for all treatments within a replicate, but these characteristics varied among replicates and experiments. Perimeter- row trees received three or four grower-applied sprays of Guthion or Imidan at label-recommended rate for PC control. Applications commenced in late May, shortly after petal fall and ended in mid or late June. BEN was introduced into 1 5 ml capped polyethylene vials in the amount of 8 ml of liquid per vial: 9 parts BEN plus 1 part of 1 , 2, 4-trichlorobenzene as stabilizing agent. Each vial was suspended by wire inside of an inverted red plastic drinking cup to minimize potential negative impact of ultraviolet light on the stability of BEN. Both cup and vial were suspended by wire protruding through the bottom of the inverted cup. Vials deployed in this manner were found to release about 10 mg per day of BEN per vial. Each dispenser of pheromone was designed by the manufacturer to release about 1 mg per day of GA. All dispensers of attractive odor were deployed during bloom of apple trees (mid-May) and remained (unrenewed) for 7 weeks (through late June), when all experiments ended. Unless indicated otherwise, each trap tree received four dispensers of BEN plus one dispenser of GA hung at head height near the tree trunk. In all experiments, PC response to treatments was assessed by examining fruit for signs of ovipositional injury, which comprises 90% or more of all injury to apples by PC. Sampling in each experiment occurred Fruit Notes, Volume 69, Winter, 2004 once during each of 4 weeks in June, beginning when fruit averaged 9 mm diameter and ending when fruit averaged 3 1 mm diameter. Unless indicated otherwise, samphng was accomplished by selecting haphazardly (at approximately head height and m an evenly-spaced manner as possible) 20 fruit from the outer half of the canopy and 20 fruit from the inner half of the canopy of each designated tree. Unless indicated otherwise, a fruit was classified as injured if an ovipositional scar was fresh. Fresh scars were those considered to have been made within the past 7 days (see pictures in the last article m this issue of Fruit Notes). We chose to record only fresh scars because it is the appearance of fresh scars (not older scars) that ought to drive a grower's decision to apply insecticide for PC control. Experiment 1 : Amount of Odor. In 1 3 blocks of orchard trees, each having a perimeter row at least 225 yards long bordered by continuous woods or hedgerow, we selected nine treatment trees spaced 33 yards apart for evaluation of optimum amount of odor to deploy in a trap tree. Four of the trees received one dispenser of GA plus one, two, four or eight dispensers of BEN. Four other trees received two dispensers of GA plus one, two, four or eight dispensers of BEN. One tree remained unbaited. Within each block, treatments were randomized in position. Experiment 2: Distance of Response. In 18 blocks of orchard trees, each having a perimeter row at least 90 yards long bordered by continuous woods or hedgerow, we chose one tree at the approximate center of the perimeter row to be the odor-baited trap tree (no other tree received odor bait). The degree to which ovipositional injury on perimeter-row trees was aggregated on the trap tree was determined by comparing the proportion of sampled fruit injured on the trap tree with that injured on each of four perimeter- row trees to the right and each of four perimeter-row trees to the left of the trap tree. Such trees were 7-9, 15-17, 25-27, or 34-36 yards the right or left of the trap tree. Experiment 3: Trap Tree Location along Perimeter Row. In 10 square blocks of orchard trees, each having three perimeter rows about 90 yards long bordered by continuous woods or hedgerow, we chose as odor-baited trap trees two comer trees and two other perimeter-row frees midway between and about 45 yards from comer frees. We compared incidence of fresh ovipositional injury on comer trees vs. midway trees. Experiment 4: Nearness of Injury to Odor Source. In eight blocks of large orchard trees (M.7 rootstock), each having a perimeter row bordered by continuous woods or hedgerow, we chose four perimeter-row trees as trap trees. For each of the 32 trees, we randomly assigned one quadrant to receive BEN plus GA and the opposite quadrant to remain E 5-1 Q Pi z z < 4 - 3 - 2 - 1 - 0 A AB B A B I I 1 GA 1 GA 1 GA 1 GA 2 GA 2 GA 2 GA 2 GA 10 BEN 20 BEN 40 BEN 80 BEN 10 BEN 20 BEN 40 BEN 80 BEN CON RELEASE RATE (mg/day) Figure 1. Mean percent of sampled fruit on perimeter-row trap trees baited with different amounts of grandisoic acid (GA) and benzaldehyde (BEN) or unbaited (CON) that received fresh ovipositional injury by plum curculio. Means superscribed by the same letter are not significantly different at odds of 19:1. 10 Fruit Notes, Volume 69, Winter, 2004 OS b Q z < u 8 - 7 - 6 5 4 3 2 - 1 - 0 B B B B B B 34-36 25-27 15-17 7-9 TT 7-9 15-17 25-27 DISTANCE (YARDS) FROM TRAP TREE 34-36 Figure 2. Mean percent of sampled fruit on a perimeter-row trap tree (TT) baited with grandisoic acid (1 mg/day) plus benzaldehyde (40 mg/day) and on perimeter-row unbaited trees at varying distances from the trap tree that received fresh ovipositional injury by plum curculio. Means superscribed by the same letter are not significantly different at odds of 19:1. unbaited. Within a quadrant, lures were positioned at head height withm an imaginary circle about 1 yard from the outennost canopy foliage and 4-5 yards distant from a corresponding imaginary circle on the opposite H as o QC 5 n 4 - 3 - S 2- 6^ z < 1 - A CORNER MIDWAY LOCATION side of the tree. To assess incidence of ovipositional injury near and far from the source of odor, we examined 20 apples in each of the two imaginary circles. Experiment 5: Representative Sample of Injured Fruit within Trap Trees. In each of eight blocks of 1 8 large- size (M.7 rootstock) apple frees, we chose three perimeter-row trap frees. We examined 20 fhiit at head height in the outer half of the canopy, 20 fruit at head height in the inner half of the canopy, and 20 fruit in the upper central part of the canopy in each tree for evidence of ovipositional injury. Sampling was confined to the last week of June. For this experiment, fruit with fresh as well as older damage was counted as injured. Figure 3. Mean percent of sampled fruit on perimeter-row trap trees baited with grandisoic acid (1 mg/day) plus benzaldehyde (40 mg/day) located at comers of orchard blocks (intersection of two perimeter rows) vs. midway between and at least 45 yards distant from comer trees that received fresh ovipositional injury by plum curculio. Means superscribed by the same letter are not sigmficantly different at odds of 19:1. Results In the first experiment, there were no significant differences in amounts of fresh injury among trap frees baited with one dispenser of GA plus four or eight dispensers of BEN and frap frees baited with two Fruit Notes, Volume 69, Winter, 2004 11 4 - 3 - 5 5n b Q Z 2 < S 0 T 1 0-1 M FROM ODOR 4-5 M FROM ODOR LOCATION Figure 4. Mean percent of sampled fruit on penmeter-row trap trees that received fresh ovipositional injury by plum curculio when sampled fruit were within an imaginary circle (1 yard diameter) containing grandisoic acid (1 mg/day) plus benzaldehyde (40 mg/day) or within an imaginary circle (1 yard diameter) lacking odor bait on opposite side of the tree (4- 5 yards from odor source). Means superscribed by the same letter are not significantly different at odds of 19: 1 . E 1 ■^ b O S 0.4 H 0.8 0.6 - < 0.2 - A ■P OUTER HALF INNER HALF UPPER PART LOCATION Figure 5. Mean percent of sampled fruit on penmeter-row trap trees baited with grandisoic acid (1 mg/day) plus benzaldehyde (40 mg/day) (both positioned near the center of the tree) that received ovipositional injury (fresh and older injury combined) to fruit at head height in the outer half of the canopy, at head height in the inner half of the canopy and in the upper central part of the canopy in samples taken during the last week of June. Means superscribed by the same letter are not significantly different at odds of 19:1. dispensers of GA plus one, two, four, or eight dispensers of BEN (Figure 1). All six of these treatments received significantly more fresh injury than trap trees baited with one dispenser of GA plus one dispenser of BEN and than unbailed trees. Numerically, just as much fresh injury occurred on trap trees baited with one dispenser of GA (releasing 1 mg/day) plus four dispensers of BEN (releasing a total of 40 mg/day) as on trees of any other treatment, with injury on trees receiving this treatment about eight-fold greater than on unbailed trees. In the second experiment, the amount of fresh injury on trap trees was significantly greater (about eight-fold greater) than on unbailed trees 34-36 or 25-27 yards distant from trap trees, and was likewise significantly greater (about seven- fold and five-fold greater, respectively) than on unbailed trees 1 5 - 1 7 or 7-9 yards distant from trap trees (Figure 2). In the third experiment, perimeter-row trap trees located at comers of orchard blocks received an almost identical amount of injury (no significant difference) as perimeter-row trap trees located midway between corner trees (Figure 3). In the fourth experiment, there was only a slight (and insignificant) tendency for within-canopy injury on trap trees to be greater in the vicinity (within 1 yard) of the source of attractive odor compared with 4-5 yards distant from the odor source (Figure 4). In the fifth experiment, a nearly identical amount of injury on trap trees was found among fruit sampled at head height at the outer 12 Fruit Notes, Volume 69, Winter, 2004 half of the canopy as among fruit sampled at head height at the inner half of the canopy, with injury among fruit sampled in the upper part of the canopy (above head height) bemg slightly though not significantly less (Figure 5). In this experiment, odor sources were positioned at head height and near the tree trunk. Conclusions Our findings indicate that perimeter-row trap trees baited with one dispenser of GA plus four dispensers of BEN performed as well as or better than trap trees baited with greater or lesser amounts of these attractants. They also indicate that the distance over which a trap tree baited with such an amount of odor is effective in luring PCs extended to at least 34-36 yards along a perimeter row of apple trees and that trap trees at comers of orchard blocks were equally as alluring to PCs as perimeter-row trap trees midway between comer trees. Further, our findings suggest that within the canopy of a trap tree, PC injury to fruit tended only slightly (and not significantly) to be concentrated near the source of attractive odor when such odor was positioned at the periphery of the canopy. When attractive odor was positioned near the center of the canopy, fruit injury tended to be rather evenly distnbuted among various sectors of the canopy. Together, these findings set the stage for an experiment to determine a threshold of injury to fruit on a trap tree that would justify spray applied to perimeter rows 1 and 2 to control PC following application of a petal fall spray to all rows. A ckn o H'ledgeni en ts This work was supported by funds from a USDA Northeast Regional IPM grant, a USDA Northeast Regional SARE grant, a USDA Crop at Risk grant, a USDA Specialty Crops Research grant, the Massachusetts Society for Promoting Agriculture, and the New England Tree Fruit Research Committee. %i^ %1> %1^ «1> %1^ ^j^ #Y^ ^f^ ^]^ *T^ Fruit Notes, Volume 69, Winter, 2004 13 A Threshold for Spraying Against Plum Curculio Using Odor-baited Trap Trees Ronald Prokopy, Isabel Jacome, and Jaime Pinero Department of Entomology, University of Massachusetts In the preceding article, we established several characteristics that an odor-baited trap tree ought to have in order to qualify as a site for monitoring fruit injury by plum curculio (PC). Here, we present results of a 2003 experiment aimed at determining a tentative threshold of PC injury to fruit on a trap tree that would justify insecticide application to rows 1 and 2 of an orchard block following a whole-block spray at petal full. Materials & Methods We selected 12 blocks of frees in commercial orchards in Massachusetts. Each block was comprised of at least eight rows of trees and was bordered along its entire 200 yard perimeter by continuous woods or hedgerow. Each block was located in a different orchard and was divided into three equal-size plots. A trap tree baited with 1 dispenser ofgrandisoic acid plus four dispensers of benzaldehyde (see preceding article) was established at the center of the perimeter row of each plot, 33 yards from either edge. Each of the three plots per block was pre-assigned at random a threshold of either 1, 2 or 4 freshly injured fruit out of 50 fruit sampled on the trap tree. Each trap tree was sampled for freshly injured fruit three times per week (Monday, Wednesday, Friday), beginning 7 days after a petal fall spray of insecticide. We presumed that residual activity of insecticide extended at least 7 days after application. Sampling involved examining 50 haphazardly chosen fruit per tree at head height; 25 in the outer half of the canopy, 25 in the inner half. Sampling was tenninated on June 30, when no fresh injury was detected in samples on any trap tree for two consecutive sampling periods. All 36 plots received a grower-applied treatment of Guthion or Imidan across the entire plot within 4 days after petal fall. Thereafter, only the first (= perimeter) and second rows of a plot received insecticide as applied by growers, who sprayed both sides of first-row trees and the perimeter-facing side of second-row trees. In all cases, such treatments were made within 24 hours of our sampling a trap tree and our determination that the proportion of sampled fruit showing injury had reached the pre-established threshold of 1 , 2, or 4 freshly injured fruit. Once a plot had received an insecticide treatment to rows 1 and 2, we allowed 6-7 days before resuming examination of fruit on trap trees for injury. Then, for each plot, we waited until fresh injury to sampled fruit on a trap tree again reached the pre-established threshold for that plot before calling for the next insecticide application to rows I and 2. To guard against invasion of PCs into plots from an exposed lateral side or from rows deeper than the seventh row, growers applied insecticide at 7-to- 1 0-day intervals to orchard trees abutting trees in test plots. To evaluate the plot-wide outcome of insecticide application against PC as driven by varying thresholds of allowable injury on trap trees, during the first week of July we examined 20 fruit at head height in the outer half of the canopy on each of five trees in each of rows I, 2, 3, 5, and 7 of each plot for evidence of any injury caused by PC (total of 100 fruit per row per plot). Fruit on the trap tree were excluded from consideration, because such fruit would normally comprise a very low percentage of all fruit in an orchard block. For example, for a 2.5 acre square block of medium-size trees on M.26 rootstock, fruit from a trap tree at the center of a 110 yard perimeter row would constitute less than 0.2% of the total amount of fruit in the block. Results The mean number of insecticide applications made by glowers to trees in rows 1 and 2 declined successively (though not significantly) from 1.56 to 1.44 and 0.89 sprays as the pre-assigned threshold calling for spray application increased successively from I to 2 and 4 freshly injured fruit out of 50 fruit sampled on trap trees (Table 1). Conversely, the mean proportion of fruit injured by PC in samples taken during the first week of July (i.e., at the conclusion of the injury season) on 14 Fruit Notes, Volume 69, Winter, 2004 Table 1 . For apple orchard plots that received insecticide application on rows 1 and 2 whenever a pre-set threshold of 1, ,2 or 4 freshly injured fruit out of 50 fruit sampled on a trap tree was reached 7 days or more after the preceding application, mean number of insecticide applications and mean percent fruit injured by plum curculio in samples of 100 fruit per row taken during the first week of July. Mean no. insecticide applications Mean % fruit inj ured* Pre-set injury threshold on trap tree Rows 1+2 Rows 3-7 Rows 1-7 1 2 4 1.56a 1.44 a 0.89 a 1.61 a 2.33 a 2.39 a 0.43 a 0.71 a 0.82 a 0.77a 1.17a 1.27a *Means in each column followed by the same letter are not significantly different at odds of 19:1. rows 1 and 2 combined increased successively (though not significantly) from 1.61 to 2.33 and 2.39% as the pre-assigned threshold calling for spray application increased successively from 1 to 2 and 4 freshly-injured fruit out of 50 fruit sampled on trap trees (Table 1 ). The same was true for fruit sampled from rows 3-7 combined (Table 1), where injury increased successively from 0.43 to 0.71 and 0.82% with increasing pre-assigned threshold. Combined injury fi"om all rows in a plot shows that whole-plot injury averaged 0.77, 1.17, and 1.27%, respectively, for plots having pre-assigned thresholds of 1 , 2, or 4 injured fruit out of 50 fruit sampled on a trap tree. Conclusions Findings from the first article in this issue indicate that a whole-block spray against PC is needed at petal fall to control PCs that many have overwintered within or immigrated into interior rows. Findings from that article also suggest that effective control of PC after a whole-block petal fall spray can be attained by applying insecticide only to perimeter rows 1 and 2. There appears to be no need to continue spray all rows m a block against PC after an all-row spray shortly after petal fall. To know where and when to apply post- petal-fall spray to control PC, findings here suggest that a threshold of 1 freshly injured fruit per 50 fruit sampled on an odor-baited perimeter-row trap tree may be used provisionally as an indicator of the need to apply an insecticide spray to all trees on rows 1 and 2 to prevent block- wide damage from exceeding an injury level of 1%. Further, our data suggest that a spray-driven threshold of 2 or more freshly injured fruit per 50 fruit sampled on a trap tree may be too great to prevent block-wide damage from exceeding \%. Further studies are needed to confirm the provisional threshold suggested fi"om results here. Special attention should be paid to assessing effects of orchard architecture (size of blocks, spacing of trees, arrangement of cultivars, size, and pruning of trees, etc.) on candidate thresholds. A ckn o H'ledgm ents We are sincerely grateful to the growers who allowed use of orchards blocks for this experiment and who responded rapidly when sampling indicated the need for insecticide treatment: Keith Arsenault, Gerry Beime, Bill Broderick, Dave Chandler, Bob Davis, Don and Chris Green, Tony Lincoln, Mo Tougas, Bob Tuttle, and Steve Ware. This work was supported by funds from a USDA Northeast Regional IPM grant, a USDA Northeast Regional SARE grant, and Massachusetts Society for Promoting Agriculture. %1> *JU %Sl0 *JU *JU ^j^ #^ ^1^ #^ ^1^ Fruit Notes, Volume 69, Winter, 2004 15 What Size of Apple is the Most Prone to Plum Curculio Attack Early in the Season? Jaime Pifiero, Everardo Bigurra, Sara Hoffmann, and Ronald Prokopy Department of Entomology, University of Massachusetts In the 2000 Issue of Fruit Notes, we reported on the distribution of fruit injury by plum curculios (PC) within the canopies of large, medium, and small trees that were not baited with attractive odor. Our findings indicated that, for large trees, early-season damage to fruit by PC was greatest at tree tops, which was the area in the canopy that also had the largest truit. For medium and small trees, however, damage to fruit by PC was distributed similarly among different sectors of tree canopies, a result that coincided with the distribution of fruit size. Here, we aimed at assessing the relationship between fruit size and early-season damage to fruit by PC in large, medium, and small unbailed trees located in unsprayed blocks of commercial orchards in Massachusetts. Materials & Methods This study was performed at Atkins Farm and University of Massachusetts Cold Spring Orchard Research & Education Center (Belchertown, MA) in 2000. In all, 760 fruit were sampled haphazardly (about 30 fruit per tree on each sampling date) from six large (Cortland/M.7), four medium (Priscilla/M.26), and six small (Mclntosh/M.9) trees. Sampling began 2 weeks after petal fall, which occurred by May 18 in 2000. Sampling was performed on June 2 for large trees. May E INJURED D UNINJURED Small Small Medium Medium (May 24) (May 31) (May 23) (May 30) TREE SIZE (AND SAMPLING DATE) Large (June 2) Figure 1. Association between fruit size (expressed as diameter in mm) and early-season injury by PC. Fruit were sampled from small, medium, and large unsprayed apple trees in MassachuseUs in 2000. For each doublet of bars, means not superscribed by the same letter are significantly different at odds of 19:1. 16 Fruit Notes, Volume 69, Winter, 2004 23 and May 30 for medium trees, and May 24 and May 31 for small trees. Each mdividual fruit was categorized as injured or uninjured based on the presence or absence of PC egglaying scars (fresh or old), and its diameter was recorded. To assess the relationship between fruit size and occurrence of injury to fruit by PC, comparisons of the diameter (in mm) of fruit having or lacking PC scars were performed. Results Figure 1 clearly shows that, regardless of tree size, fruit sampled early in the season that showed PC injury were significantly larger than uninjured fruit. The smallest size of a fruit having a PC scar was 4.8 mm in diameter, which corresponded to the first sampling date in small Mcintosh trees. Conclusions trees where fruit are larger (e.g., upper part of the canopy of large trees, exterior zone of branches). As the season progresses, however, it is likely that smaller fruit may be more likely to be attacked by PC, possibly because, as suggested by Levine and Hall ( 1 977), late- season mortality of PC larvae is greater in large fruit due to the higher internal pressure of the growing cells. None of the trees in our study was baited with attractive odor. Results on the distribution of PC injury among fruit in various tree sectors could be different for odor- baited trap trees. A cknowledgnients This study was supported with funds provided by a USDA Northeast Regional IPM grant, a Hatch grant, a grant from USDA Crops at Risk program, and the New England Tree Fruit Research Committee. Our findings lead us to conclude that, early in the season, larger fruit are much more prone to attack by PC than are smaller fruit, probably because abscission of fruit damaged by PC is more likely to occur when fruit are small. Thus, early-season sampling of unbailed trees should be conducted preferentially in areas of the Literature Cited Levine, E., and Hall, F.R. 1977. Effect of feeding and oviposition by the plum curculio on apple and plum fruit abscission. Journal of Economic Entomology 70: 603- 607. %1^ vl# *i* Vtf %£f ^j^ ^J^ ^f% #Y^ ^i* Fruit Notes, Volume 69, Winter, 2004 17 Photographs of Fresh and Older Egglaying Scars of Plum Curculio on Apples Jon Clements Department of Plant and Soil Sciences, University of Massachusetts Amherst Jaime Pinero and Ronald Prokopy Department of Entomology, University of Massachusetts Amherst The use of odor-baited trap trees to aggregate plum curculio (PC) adults should simplify monitoring for PC by confining sampling to just a few odor-baited trees in an entire orchard. Under this approach, sampling would involve examination of about 50 fruit on a trap tree for signs of fresh PC egglaying scars. As discussed in a previous article in this issue, application of a perimeter- row spray would occur when one fruit out of 50 sampled fruit shows fresh injury. The question then becomes: how to tell a fresh injury from an older injury. Here, we present photographs of fresh and older PC injury from a study conducted m 2003. Materials & Methods At petal fall, cloth bags were placed over several terminals of unsprayed Mcintosh and Delicious trees at the University of Massachusetts Cold Spring Orchard Research & Education Center in Belchertown. Each Monday beginning when king fruit averaged 6 mm diameter, two mated PC females were introduced into each bag and allowed to remain until Tuesday, when they were removed. On Wednesday, Friday, and the following Monday, a digital camera (Nikon CoolPix 990) was used to photograph some of the egglaying scars. Each scar shown here was therefore 1 , 3, or 6 days old when photographed. Results Figures 1 -4 show, respectively, egglaying scars that were photographed over 6-day periods for the weeks of May 28, June 4, June 1 1 and June 1 8. For Mcintosh, fruit size averaged 6, 8, 14, and 19 mm diameter, respectively, when injury was initiated, whereas for Delicious fruit size averaged 6, 7, 10, and 14 mm diameter, respectively. Regardless of the week when injury was initiated, photographs show that 1 -day-old scars appear as narrow crescents (from top to bottom) similar to an eighth moon. Reflecting fruit growth, 3-day-old scars appear as somewhat broader crescents, with 6-day- old scars appearing as crescents that are broader still (much like a half moon) or as scars that have begun to lose their crescent shape. Scars initiated on 6 mm fruit (week of May 28) show little sign of a stem and have little resemblance to a mushroom (Figure 1). Scars initiated on 10-14 mm fruit (week of June 1 1 ) show a distinct stem and strongly resemble a mushroom (or the cloud of an atomic bomb) (Figure 3). By 6 days after egglaying, even the most pronounced mushroom shape of a 1 -day-old scar (as m Figure 3) has begun to fade. It should be noted that the change in appearance from fresh to older PC egg-laying scars as described above is most accurate for Mcintosh. With Delicious, the change in appearance is not quite as distinct - some caution is advised when looking at different cultivars as the age of PC egg-laying scars may be more difficult to judge than it is on Mcintosh. More observations of other cultivars (such as Gala) are needed. Conclusions Once a grower or consultant has firmly in mind the image of a fresh (e.g., 1-day) versus an older (e.g., 6- day) scar, that mental image can be carried to the field to aid in interpretation of the age of PC scars on odor- baited trap trees. Ackno wledgem en ts This study was supported by USDA Hatch funds. 18 Fruit Notes, Volume 69, Winter, 2004 "W ' ^ '4C1 ipun iLt-" r t ^ik Delicious -3 days 6 days Figure 1 . Appearance of PC eggla\ ing scars on Mcintosh (6 nun) and Red Delicious (6 nun) apples (left to right) that were initiated on Max 27 and photographed w hen 1. 3 and 6 days old (top to bottom) Fruit Notes. Volume 69, Winter, 2004 19 V Mcintosh' 3 days ^ -^£sa?a ^sasi^'S- Delicious 6 days Figure 2 Appearance of PC eggla\ mg scars on Mcintosh (S mm) and Red Delicious (7 nun) apples (left lo right) that were initiated on June 3 and photographed when I. o and 6 da>s old (top to bottom) 20 Fruit Notes, Volume 69, Winter, 2004 Mcintosh 1 day IP fe. Delicious 1 day Mcintosh 6 days Figure 3 Appearance of PC eggla> ing scars on Mcintosh ( 14 nun) and Red Delicious ( 10 nun) apples (left to right) tliat were initiated on June 10 and photographed when 1. 3 and 6 da\ s old (top to bottom). Fruit Notes. Volume 69, Winter, 2004 21 ■^ I [ H 1 1 1 < • \~:A 1 day ^ cintosh days Figure 4. Appearance of PC egglaMiig scars on Mcintosh (19 mm) and Red Delicious ( 14 mm) apples (left to right) that were initiated on June 17 and photograpiied \^hen 1. 3 and 6 da> s old (top to bottom) 22 Fruit Notes, Volume 69, Winter, 2004 Stockbridge Schoo . at the University of Massachusetts Amherst 15 Stockbridge Hall • Campus Center Way • Amherst, MA 1 reparefor a Career in. i*^ Fruit & Vegetable Crops Stand Out in the Crowd... We offer other Career Opportunities in: ^ Arboriculture & Community Forest Management ^ Equine Industries ► Horticulture |QQo/^ Q^gg^ Placement - Floriculture Crop Production - General Horticulture - Management of Woody Plants - Retail Floral Design ^ Landscape Contracting ^ Turfgrass Management Two-Year Degrees Internships The Small School with BIG Opportunities (413)545-2222 • www.umass.edu/stockbridge Fruit Notes, Volume 69, Winter, 2004 23 Fruit Notes University of Massachusetts fruit IJcparlment of Plant & Soil Sciences Uglgj 205 Bowditch Hall ni^ Amherst, MA 01003 ^^^^\ C/ass Ma;7 01003 us Postage PAID SmartMa;/ 30297 - 1 SERIAL SECTION UMASS AMHERST, MA 01003 104911 Volume 69, Number 2 SPRING ISSUE, 2004 Table of Contents rIewCnaiand A Fruit Notes Issue in Honor of Ronald J. Prokopy Wesley Autio Remembering Ron William Coli Ron's Papers Daniel Cooley . Optimizing Distances Between Odor-baited Spheres on Perimeter Apple Tree Ronald Prokopy, Isabel Jdcome, and Everardo Bigurra Ideal Within-canopy Positioning of Odor-baited Red Spheres for Monitoring Sara Hoffman, Isabel Jdcome, Everardo Bigurra, and Ronald Prokopy Evaluation of Pesticide-treated Spheres for Control of Apple Maggot Flies in Ronald Prokopy, Isabel Jdcome, Everardo Bigurra, and Marina Blanco gland 10 .. 15 .. 21 A Tribute to Ronald J. Prokopy (1935-2004) Editors: flewCnaland Wesley R.Autio William J. Bramlage Publication Infonnation: Fruit Notes (ISSN 0427-6906) is published each January, April, July, and October by the University of Massachusetts Amherst in coop- eration with the other New England state universities. The cost of subscriptions to Fruit Notes is $20.00 per year. Each one-year subscription begins January 1 and ends December 3 1 . Some back issues are available for $5.00. Payments must be in United States cun-ency and should be made to the University of Massachusetts Amherst. Correspondence should be sent to: Fruit Notes Department ofPlant, Soil, & Insect Sciences 205 Bowditch Hall University of Massachusetts Amherst Amherst, MA 01 003 All chemical uses suggested in this publication are contingent upon continued registration. These chemicals should be used in accordance with federal and state laws and regulations. Growers are urged to be familiar with all cirrrent state regulations. Where trade names are used for identification, no company endorsement or product discrimination is intended. The University of Massachusetts makes no warranty or guarantee of any kind, expressed or implied, concerning the use of these products. USER ASSUMES ALL RISKS FOR PERSONAL INJURY OR PROPERTY DAMAGE. Issued by UMass Extension, Robert Schroder, Acting Director, in furtherance of the acts of May 8 and June 30, 1914. UMass Extension offers equal opportunity in programs and employment. A Fruit Notes Issue in Honor of Ronald J. Prokopy Wesley R. Autio Department of Plant, Soil, & Insect Sciences, University of Massachusetts I still have a hard time believing that we have lost our friend and colleague Ron Prokopy in May, 2004. His contribution to the science and practice of apple pest management will never be forgotten. Ron Prokopy was the entomological side of the UMass Fruit Program. He contributed regularly to Fruit Notes, Healthy Fruit, and the New England Apple Pest Management Guide. He wrote twenty- six Annual March Messages, an update on the state of tree-fruit insect control for fruit growers, and he spoke at all but three or four of the nearly 60 Twilight Grower Meetings since I joined the faculty 19 years ago. Further, he was always available to assist grow- ers with their problems. This tally, however, does not adequately capture how Ron extended the research of UMass to the fruit industry. His outreach efforts were borne from a deep-seated concern for the well being of the tree-fruit industry and the growers as individuals and from an unquenchable enthusiasm for the details of insect pest management. He understood the con- straints imposed on farmers both by the natural world and by society. This understanding helped Ron mold Fruit Notes, Volume 69, Spring, 2004 his outreach to guide our tree-fruit industry to a level which put them among the most progressive pest man- agers in the World. This extremely effective outreach effort was sup- ported by one of the most productive research pro- grams in the University. With hundreds of research articles to his credit, Ron Prokopy was one of the most respected entomological scientists in the World. He helped mold the concepts which are the foundation of current and future integrated pest management (IPM). It was both remarkable and inspirational how his re- search spanned the spectrum from basic to applied. All his research, even the most fundamental, was clearly focused on solving a practical problem. There are many examples of how Ron brought his research and outreach together, but I particularly en- joyed his talk at one of our twilight meetings a few years ago. Plum curculio is one of the most difficult pests for orchardists and scientists alike. Ron focused much of the last 10 years on this troublesome insect. He spent much time watching and recording curculio movement into and around apple trees. At a mid-June twilight meeting, Ron spent a good portion of his 20 minutes (which usually lasted at least 40 minutes) de- scribing how curculios found an apple tree. This talk was given mostly from the orchard floor, that is Ron was lying down and crawling along the ground (and speaking) showing the growers how the curculio saw the world. This enthusiasm for the actions of plum curculio, and also for apple maggot tlies, gave Ron the ability make great strides in research, interpret those results, and develop and transfer the knowledge nec- essary to help growers. Members of the Fruit Program cooperate on a num- ber of fronts, from research to educational programs, but we are always together at nine twilight grower meetings per year (three series of three meetings each). For at least one of each of these series over the last several years, three or four of us would travel together. This tnp usually was to Plymouth County, Bnstol County, or Rhode Island and was as much as a two-hour ride from Amherst. We always had to study the weather forecast before heading that way with Ron. If it was going to be hot (and Ron loved hot, humid weather), we tried to get the largest vehicle available, usually a van. Most of us enjoy the benefits of automotive air conditioning in hot weather, but not Ron. The large vehicle allowed us to make him ride in the far back, away from the air conditioning and near his own open window. Some of Ron's other eccentricities included power naps, eating a head of lettuce for supper, re- viewing papers while driving, and his numerous pillows, sweaters, and bags that always traveled with him. These "quirks" punctuated his honest and unwavering con- cern for people. He cared about all of us, growers, students, colleagues, and friends. This issue of Fruit Notes is dedicated to Ron's memory. It begins with a few memories of Ron and ends with the last three articles that he wrote for Fruit Notes (in the few weeks before his death, thanks to Isabel Jacome for typing these articles). Ron Prokopy was an amazing individual. He was among the best scientists, the best extension educa- tors, and the best people that we will ever know. ^{^ %1^ %1^ «1^ *x* ^j% ^^ #Y* *T* *T* Fruit Notes, Volume 69, Spring, 2004 Remembering Ron William M. Coli Department of Plant, Soil, & Insect Sciences, University of Massachusetts By now, orcharding and University communities all over the world have learned that we have all lost a rare and unique individual: Dr. Ron Prokopy. As Wes Autio put it so well in a recent email, "Ron's boundless support of the apple industry will be sorely missed, and his extensive research contributions will never be for- gotten." As Ron would have wanted, and in spite of the depth of our feelings of loss, I hope we can all focus on how he lived his life rather than on this untimely loss. I'm sure there will be a lot of sharing of stories at the memorial ser- vice planned for May 22 at his beloved farm in Conway. For those who can not attend, I'd like to offer just a few recollec- tions about the 29 years I have known Ron. The first time I ever met him, I knew right away that Ron was not your typical University faculty mem- ber. I don't know if it was the longer than normal hair style, the South American knit bag that he always car- ried with him (and which inevitably contained bags of neatly sliced, home grown carrots), or his propensity to take his little "rests" (cat naps that he would always take while we were on route to some place or another). When he first arrived at UMass Amherst in 1975, he was already well known in Entomology circles for his ground-breaking and innovative work developing ef- fective, multi-colored, sticky sphere traps for monitor- ing fruit flies. The story goes that when another fac- ulty member (Dr. John Stoffolano) was introducing Ron to the clerical staff in Femald Hall, he was ob- viously excited to have this new high-powered behavioral ecologist in the department . John, assuming perhaps that the clencal staff was familiar with Ron's earlier re- search said: "This is Ron Prokopy, our new faculty Ex- tension Ento- mologist. You know, he's the guy with the red and yellow sticky balls!!" Once all present stopped laugh- ing, John told them what he really meant to say. While working on a special research project on traps for the blueberry maggot fly with Ron, I continued to gain a better perspective on this unique guy. I learned that he was about the hardest working person I'd ever known. There was never a single field day that Ron wouldn't be out there counting flies with me. When the data were finally analyzed, he was insistent that we write the results up for a paper to submit to an Ento- Fruit Notes, Volume 69, Spring, 2004 mological journal. Those researchers who know him well are probably saying "What? Only one paper?" since Ron, in addition to arguably knowing more than anyone else in the world about the Family Tephritidae (fruit flies), was also incredibly productive in his publication record. In spite of his brilliant intellect, Ron was very down to earth, very easy to talk with, and incredibly commit- ted to extension work: once again not typical of Uni- versity Faculty in general. He loved his days in the field. There was literally nothing he preferred more than sit- ting in the orchard observing his beloved insect sub- jects. Ron always joked that when he died, he wanted to be reincarnated as an apple maggot fly. I hope for all our sakes that he does not get his wish, because I envision apple maggot becoming A LOT BIGGER prob- lem if the species has Ron's incredible knowledge and energies to draw upon. Ron Prokopy was truly deserving of the 'one-of- a-kind' label. While it is comforting to know that Ron was following his passions right to the last, and that his passing was peaceful, the fruit industry, the science of Entomology, the University of Massachusetts, his many graduate students, and all his many friends and col- leagues will miss him dearly. %1^ *A^ %1^ *1^ «1^ ^r% ^r% ^f% ^r* ^r% Fruit Notes, Volume 69, Spring, 2004 Ron's Papers Daniel R. Cooley Department of Plant, Soil, & Insect Sciences, University of Massachusetts There was no doubt in my mind that Ron Prokopy would hve until he was at least 90. I also knew he wouldn't stop his life's work, ever. And now that only one of those certamties has proven true, I can't yet see how our world of New England apple growers and researchers, the world of insect ecologists, our univer- sity, or my own world will function in quite the same way. Half the time I forget that he isn't home in Conway, isn't at his Femald Hall office, and isn't check- ing curculio traps. Maybe as a way to make my mind adjust, I've been focusing on just one facet of his life. I've been wondering how Ron Prokopy ever managed to write all those papers, over 450 publications, an almost in- comprehensible number. As the main form of academic research currency, the number of publications a per- son writes gives other academics a quick read on the stature and impact a scientist carries. It's a career batting average, and Ron was a Ted Williams when it comes to writing. Very good scientists would be happy to write one or two hundred articles, chapters and other pieces over a career. And just as every hit Williams got represented hundreds of swings and hours of prac- tice, every article a scientist writes represents hours of grant writing, lab and field experiments, data analysis and finally, the actual writing. Naturally, some scientists cook the books a bit, ac- cepting partial credit for papers to which they may have made little or no real contribution. It's like Enron re- porting millions in imaginary earnings so that the com- pany will look much more substantial. In science, this sort of "pub padding" can make author lists that read like an Old Testament genealogy. Ron never indulged in this sort of publication inflation, and he contributed a meaningful part in any research that carried his name, making his accomplishment all the more remarkable. So I wonder, how did he do it? Perhaps it was because he frequently had trouble sleeping, and would not so much complain as comment on the fact that he had gotten only 4 hours of sleep the previous night. Getting along on a sleep regimen that could crack hard- ened spies certainly could explain some of Ron's pro- ductivity. He did need an occasional recharge. When we were out on the road, between orchards he might say that he really needed a little rest, if I didn't mind, and he would doze off for 10 or 15 minutes. He revived, dragging his palm from forehead to chin as if it would wipe away the last vestiges of his nap, and emerging from his pupae-like slumber he'd launch full flight into an intense discussion concerning how we might arrange tests in the next orchard to serve multiple research tasks. Couldn't we use Broderick's old Mac block for the curculio work, and the maggot work, and the fly- speck work, making data collection visits even more productive? Ron lived with a New England farmer's kind of efficiency, carrying lettuce and carrot lunches in washed and re-used plastic bags, sporting an eclec- tic wardrobe of Goodwill clothes, and always trying to squeeze every bit of data possible from an experiment. While Ron always got the most from a dollar, I'm not sure his Yankee frugality always contributed to re- search efficiency. He grew up on a Connecticut farm, and eeking a living from rocky New England soils means a lot of getting by and making do. For better or worse, he carried those habits into his research projects. And since the sort of research and teaching he did extended beyond brick and ivy to the orchards of New England, Ron and his lab group drove hours to and from research sites every day. The several vehicles needed for this were much like his clothes, a sort of Goodwill collec- tion, including such classics as a vintage Korean War surplus MASH ambulance, a banana yellow Ford Torino with vestigial brakes, and cabin-cruiser like sta- tion wagons with rotted floors, all vehicles that had been rescued from the scrap-heap. They had far outlived their usefulness in polite society but could still carry people, tools and various objects covered with sticky goop around the state. I don't think Ron could fully conceive of buying a new car, or even a late-model used car, not when the same money could be used for an extra summer assistant. In fact, I think the rusty roof of a 10 year old LTD appealed to Ron not only because it was cheap, but because it said to growers Fruit Notes, Volume 69, Spring, 2004 that Ron didn't care what things looked Hke, that we were not some well-funded, effete research institute, but rather people who got by and could be trusted. On the other hand, whether these crates would start reli- ably or keep chugging through sparsely populated parts of the state was another issue. Some days, I think Ron's powerful will to understand the orchard ecosys- tem was the only thing that kept those cars going. Ron used time much the way he used research dollars, squeezing the minutes. When he drove one of the old heaps himself, he wasn't content to just think or listen to the radio. He had to read, review and, some say, even write papers while navigating the notonously narrow, rock- and tree-lined roads between New En- gland orchards. His approach to driving pretty much insured that if someone else was joining him, they vol- unteered to get behind the wheel. Ron could then re- treat to the back seat to fully devote attention to his papers without the distraction of an on-coming cement truck. For longer trips, every plane ride, every hotel room served as an office and study for the constant, nearly undecipherable pencil scribbling on page after page of yellow lined paper. That single-minded atten- tion to filling in what might otherwise be downtime with writing undoubtedly helped Ron's publication record. Technology didn't. Ron never allowed computers to make his writing and research more efficient. He tried a laptop computer once, thinking it might save ev- erybody time if they didn't have to download his email, then read and type his responses, not to mention typing up the pages of pencil scrawled manuscripts. And with a laptop, Ron could still write as he traveled, or when he sat in an orchard. It was a good theory, but Ron's mind never adapted to the keys and electronic screen. Within a few weeks, his son Josh had inherited the un- used computer for his own use. Ron stayed with the yellow lined paper. Naturally, rather than a PDA, Ron had a unique Fruit Notes, Volume 69, Spring, 2004 paper organizational system. For day-to-day opera- tions, he would penodically pull a small pile of recycled scraps from his pocket, consult 2 or 3 of them, and then make a phone call, ask a student to copy a re- search paper, or do whatever else the notes remmded him needed to be done. To my knowledge, Ron never had a date book or notebook; he had stacks of recycled paper scraps filled with his cryptic scrawl. He did have a relatively inflexible organization to his year that probably contributed to efficiency; he could more easily plan ahead. His field experiments would be, for the most part, planned by the time we started the twilight grower meetings in the spring. Ron looked forward to those drafty bam sessions, talking with grow- ers about the latest way to deal with tarnished plant bug or leaf miner. He remembered going to them as a kid with his uncle and seeing scientists from the Con- necticut Expenment Station. Then, after getting his Ph. D. in entomology at Cornell, he went back to the Con- necticut Agricultural Experiment Station to take on the position working with insects and mites in apples. The happy homecoming only lasted a little while, and the stories are vague. Evidently, Ron got involved in late 60 's radical politics in New Haven. Ron left the sta- tion, traveling Europe with Linda, his wife, in a VW microbus. Being Ron, traveling Europe meant going behind the Iron Curtain rather than to the Riviera. On his return, he tried starting his own research station in Wisconsin and spent time in Texas working with semi- nal figures in the IPM movement just as it was start- ing. Then in 1975, he landed in Massachusetts. But I'm digressing. As I said, Ron's year began with twilight meetings and grower visits, and it contin- ued with 1 6 hour or longer days filled with field experi- ments, circus-like tents over apple trees, and all man- ner of contraptions designed to figure out why apple insects behaved the way they did. Ron digested data as it came in, on a daily basis, but by the end of the summer, he would already be putting it together into a bigger picture. The fall meetings would start in late October with a gathering of apple IPM researchers and advisors in Vermont, where the very latest results from that year would be presented and shared. A little later, more polished presentations would be made at the national entomology meetings and as the New Year began to growers at the New England Fruit Meetings. At Amherst, Ron would teach his IPM course each fall. In January, he would disappear to the library each day, reading articles that would be assimilated into grants or papers, as well as the March Message. The March Message included all the latest apple pest man- agement information a grower could want, and Ron created it because the standard pest management ma- terial couldn't or wouldn't keep up with the pace he wanted to set. Delivered just before the growing sea- son started, Ron would joke that it was good bathroom material. Wherever they read it, growers would make sure that they had. By the time the March Message was ready for press, Ron would be leaving for his an- nual trip to Hawaii. Of course his New England heri- tage wouldn't let himjust go and enjoy Hawaii though he loved the place, so Ron had a long-running grant to study fruit flies there. Anyone he took with him soon discovered that the research agenda was just as 24-7 in Hawaii as it was in Amherst. As soon as he got back to Amherst, the twilight meetings and grower vis- its would start again. Woven into this annual fabric were daily meetings with grad students, lab assistants and technicians, post-docs, other faculty and visiting scientists. And all this was punctuated by special meet- ings and talks in which any successful scientist engages, talks in China or Washington, or meetings in Europe and Australia. Around this schedule Ron wrote the huge number of grant proposals and publications that mystifies me. I know that it made a few people feel better to write-off Ron's publication record as the results of a monomaniacal workaholic. It wasn't that, and Ron, while he worked hard, didn't eliminate family, friends, recreation or the arts from his life. Some of the other parts of Ron's life seem totally at odds with his image as hard-working, salt-of-the-earth academic. For ex- ample, Ron played golf When I went a round with him, he showed up carrying a battered, ancient set of clubs, wearing his Larry Bird short shorts and a T-shirt. It occurred to me that golf must be some concession Ron had reluctantly made to recreation, that someone had told him he needed a hobby, so he'd looked around a thrift store, seen golf clubs and determined that he would go play a round every week for Recreation. About the 6h hole, I began to see a pattern that sug- gested a different story. Short, but straight drives on the fairway, uncannily accurate approaches to the best part of the green, and consistent putting had Ron at par or better, while everyone else in the group was at least 5 strokes over. Ron was playing winning golf, and thor- oughly enjoying it. In fact, he had several athletic hobbies, done in Fruit Notes, Volume 69, Spring, 2004 less-than-conventional ways that fit his schedule. He probably swam in every orchard pond in the state, fol- lowing a day counting insects in apple trees, and maybe a short jog. On his own farm, he kept a muddy pond that doubled as a hockey rink. I remember one game when Ron had magnanimously taken a few of the weaker skaters, among them my wife, on his team. Because we had a shortage of real hockey sticks, Ron volunteered to use a broom. Not surprisingly, Ron's team quickly slipped behind. Ron's frustration grew more visible as the debacle played out, and as one of his sons threatened to score against Ron's group yet again, Ron swooped over to my wife, grabbed her stick, stole the puck from his 10-year-old, and skated the length of the ice to score himself He followed that with enough goals to satisfy himself that he would not be humiliated. I suspect Ron's competitive nature also had a significant effect on his research record as well. I can't fit his love of opera into an explanation of his publishing record, except that it was probably one of those releases any intense person needs to keep from imploding. Not being an opera aficionado, I failed, on several levels, to understand Ron's trips to New York to see Carmen or some lesser-known production. I do like non-musical theater, and music without theater, and Ron, knowing this, would be the one who organized evenings to see a summer play at Smith or a jazz per- formance in Northampton. Releases though these may have been, I still wonder how a man doing the grant writing, experiments, analysis and publication work necessary for 15 or so publications a year could have time for any of this? Or the baseball trips to Fenway Park. Or the hikes. Or the dinners with students, col- leagues and friends. Or singing with the local chorus. Teaching a course sets limits on research, and many successful scientists consider teaching a burden. Most have no idea what it means to work with people outside the university, people like New England apple growers. For many of the most successful scientists, their exclusive priority is the production of research papers. In contrast, Ron reveled in his role as advisor and colleague to the apple growers of New England, and devoted himself to teaching IPM to university stu- dents. He never considered ignoring the growers or students so that he might focus on more on research. Ron loved apples, the people that grow them, the places they grow, the insects that feed on them, all of it. Just as important, and less obvious, he knew that his work in the orchards led to better research and teaching. He knew that teaching growers how to manage apple pests taught him how to develop ecological theories that worked in the real world. It made his classroom more relevant and real to his university-based students. The time it takes to do all this, of course, makes those 450 papers even more astounding. Ron uniquely bridged the space between academ- ics and apple growers. I think it's difficult for purists in either group to appreciate how well he did it. For ex- ample, he and a colleague discovered that Rhagoletis pominella (the apple maggot fly) had moved from its native American host, the hawthorn (Crataegus sp.), to an imported host, the domestic apple (Malus domestica). They held this up as an exciting example of sympatric speciation (one species diverges into two separate species in a single geographic location) by publishing in the world's best scientific journals and speaking at major academic meetings. It's still a clas- sic example in ecology. At the same time Ron showed that the apple maggot's predilection for round, red ob- jects could be useful to growers, telling them when the damaging flies were present in their orchards, and just as importantly, when they were not. For a few years, I'm sure Ron totally disrupted the market for croquet and bocce balls, buying them up, painting them red, covenng them in sticky goo, and hanging them in apple trees to determine whether growers needed to apply an insecticide. I'm still not sure how Ron sold LPM to apple grow- ers. He came into the job with some pressure, as the previous two apple entomologists at UMass had been fired. When he started his Extension work, Ron still had most of his long hair from the 60's and carried his ever-present paperwork and field equipment in a wo- ven Guatemalan shoulder bag. It's hard to remember now, but at that time EPM ran counter to standard pest management dogma. For years. Extension and pesti- cide salesmen had been telling orchardists that they needed to spray chemicals weekly, sometimes more, to eliminate any possibility of pests and disease in apples. Along came Ron, asking them to hang colored sheets of sticky cardboard and bocce balls in their trees, count bugs, and above all, not to spray pesticides until the pests actually started their invasion. I know many growers, looking at Ron and the colored bocce balls, were worried that this ivory tower hippie from the University was trying to lead them into disaster. But Ron, having grown up on a fruit farm, was not an ivory tower scientist. He may have been an idealist 8 Fruit Notes, Volume 69, Spring, 2004 but he understood growing apples. And after talking with him, a few influential growers recognized that. Perhaps more importantly. Bill Pearse, probably the most influential quality control man working for the larg- est apple wholesaler in Massachusetts, saw the prom- ise of better pest management with fewer pesticides. Ron was a little different and intense, but I know Bill liked and respected him, and the feelings were mutual. I'm sure BUI quietly suggested that growers give some of this IPM stuff a try, and at the same time, set Ron straight as to how far growers might actually be willing to go. In the next decades, even after Bill's death. New England apple growers would be leaders in using IPM, because Ron wanted to do more than just hide in the University and write papers. But of course he did write all those papers too. I probably never will really understand how, but I'm glad that he did it, that he managed to get down on paper so much of the knowledge he gained. Ron collected knowledge, from growers and other scientists, from everyone he met, from his experiments, he gathered it in, processed it in his own inimitable way, and wrote so much of it down. What a tremendous legacy. While no one will ever touch each of us the way Ron did, I re- main hopeful that some of his students, or perhaps his students' students, will be able to bridge that widening gap between academics and our agricultural resources, and carry on Ron's dream of a truly ecological, sus- tainable orchard. *1^ %l0 %i^ %t^ %i^ ^^ ^f% ^^ ^f% #^ Fruit Notes, Volume 69, Spring, 2004 Optimizing Distances Between Odor- baited Spheres on Perimeter Apple Trees for Control of Apple Maggot Flies Ronald Prokopy, Isabel Jacome, and Everardo Bigurra Department of Plant, Soil, & Insect Science, University of Massachusetts For several decades, spraying apple trees with insecticide in July and August has been the standard approach to apple maggot fly (AMF) control. While this approach is likely to continue to be the standard in most orchards for decades to come, some growers would like an alternative approach that eliminates the need for insecticide application during summer months. One alternative that we have been studying for more than a decade is the surrounding of orchard blocks with odor-baited spheres on perimeter apple trees to intercept immigrating AMF before they can penetrate into interior rows. hi the Spring 2002 issue oi Fruit Notes, we reported that the most effective odor bait to use in conjunction with perimeter spheres for maximizing AMF control under a broad range of orchard conditions is a five- component blend of synthetic attractive apple volatiles developed at Cornell University. In other issues of Fivil Notes preceding 2002, we presented data suggesting that odor-baited spheres deployed on perimeter trees may be more effective (a) in orchards comprised of small or medium trees than in orchards of large trees, (b) in orchards having particular arrangements of susceptible versus tolerant cultivars, and (c) in orchards bordered by open space than by hedgerow or woods. In addition, we suspected that sphere effectiveness might be greater in well-pruned than poorly-pruned perimeter trees. To qualify as a viable alternative to spraying an orchard for AMF control, use of odor-baited spheres on perimeter trees must be cost-competitive; the fewer the number of spheres needed, the less the cost. Until now, distances between perimeter spheres in apple orchards have been assigned largely on an arbitrary basis (devoid of established guiding principles), varying from 2 to 45 yards apart. Here, we developed an approach to assigning distances between odor-baited spheres or perimeter trees of apple orchards. It employs an index incorporating characteristics of four environmental variables: size of orchard trees, quality of pruning, cultivar composition and nature of bordering habitat. Materials & Methods Block layout. Our experiment was conducted in 12 blocks of apple trees in ten commercial orchards in Massachusetts. Each block consisted of seven rows of apple trees, was about 120 yards long, and averaged 35 yards deep in extension from a perimeter row that bordered open field, hedgerow, or woods to the seventh interior row. Each block was divided into two plots: one plot about 90 yards long, the other about 30 yards long. Blocks consisted of either small (M.9 rooted), medium (M.26 rooted), or large (M.7 rooted) trees that were either well, moderately, or poorly pruned in 2003. Each row of a block was comprised of the same cultivar, which was considered as being of relatively low susceptibility to AMF if Mcintosh or Empire, moderate susceptibility if Cortland or Delicious, and high susceptibility if Fuji, Gala, or Jonagold. Each of the four sides of a block was bordered by grower-sprayed orchard trees, open field, hedgerow, or woods. Pesticide sprays. Each plot in each block was sprayed by cooperating growers with insecticide and fungicide in April, May, and June to control a variety of insects and diseases. Thereafter, the smaller (30 x 35 yards) plot received two or three grower-applied sprays of insecticide in July and August to control AMF; whereas, the larger (90 x 35 yards) plot received no insecticide after June but received odor-baited spheres to control AMF. Spheres. Each sphere trap was 3.5 inches in diameter, red in color, and coated with Tangletrap to 10 Fruit Notes, Volume 69, Spring, 2004 Table 1. Values ascribed to characteristics of four environmental variables as components of an index for assigning distances between odor-baited spheres on perimeter apple trees. Value Tree size Quality of pruning Cultivar susceptibility Bordering habitat 1 2 3 Large Medium Small Poor Fair Good High Moderate Low Woods Hedgerow Open* *Also applies to bordering habitat consisting of grower-sprayed orchard trees. capture alighting AMF. Spheres placed on perimeter trees to intercept immigrating adults were accompanied by a blend of five synthetic attractive fruit volatiles contained in a polyethylene vial. Spheres placed on interior trees to monitor adults that penetrated into plots were not baited. All spheres were deployed during the last week of June (before arrival of adults) and remained through harvest (in September). Deployment was at mid-canopy height in a way that maximized visual conspicuousness and attractiveness. Index for assigning distances between spheres. The index used for assigning distances between odor-baited spheres on each side of each targeted plot was created by first prescribing a value of 1, 2, or 3 for each of tree size, quality of pruning, cultivar susceptibility, and bordering habitat for that side (Table 1) and then using the sum of the four values to determine distance between spheres (Table 2). Based on previous studies conducted in Massachusetts and Quebec, we chose 6 yards as a minimum distance between spheres and 1 8 yards as maximum distance. Given that this was the first year of using such an index and given that all test blocks were in commercial orchards where valuable fruit was at risk, we were reluctant to deploy spheres at distances greater than 18 yards apart. In some cases, the structure of a block (spacing of trees within and among rows) did not allow us to position spheres precisely according to assigned distances. In such cases, we compromised in favor of an assigned distance closest to the original. Assessment of treatment performance. We used two methods of assessing treatment performance. First, every other week from trap deployment until harvest we counted and removed all AMF captured by eight unbaited spheres placed on interior trees of row 4 of baited-sphere plots and by four similarly-positioned unbaited spheres in grower-sprayed plots. Captures by such spheres were used as an indicator of relative numbers of adults that penetrated into interiors of plots. At the same time, we counted and removed all AMF captured by odor-baited spheres on perimeter trees and cleaned all baited and unbaited spheres of insects and debris, re-coating spheres with Tangletrap if necessary. Second, at harvest we sampled 20 fruit on each of five trees on each of the four sides of each baited-sphere and each grower-sprayed plot plus ten fruit on each of Table 2. Index for assigning distances between odor-baited spheres on perimeter apple trees. Sum of values is derived from qualities of four environmental variables as given in Table 1 . Distance between Sum of values spheres (yards) 4 6 5 7.5 6 9 7 10.5 8 12 9 13.5 10 15 11 16.5 12 18 1 Fruit Notes, Volume 69, Spring, 2004 11 five interior trees in each of rows 3 and 5 of each plot (total of 500 fruit per plot). All sampled fruit were picked and kept in a greenhouse for one month before examination for ovipositional punctures, confirmed by dissection of punctured fruit for signs of larval growth. Treatment comparisons and data analysis. In both 2001 and 2002, the same 12 baited-sphere plots used here received odor-baited spheres on each side of each plot at arbitrarily prescribed distances of 6 or 1 1 yards apart. Also, m both 2001 and 2002, the same 12 grower-sprayed plots used here received similar pesticide treatments as here. Use of unbaited spheres on interior trees to monitor penefration of adults into plots and sampling of fruit for AMF damage m 2001 and 2002 were equivalent to procedures used here. To compare outcomes of the index -based approach of 2003 with the arbitrary approach of 2001 and 2002 for assigning distances between spheres, we subjected each year's data on number of baited spheres used on perimeter trees, number of AMF captured per unbaited monitoring sphere, and percent sampled fruit injured by AMF to analysis of variance. For 2003 data, we used correlation analysis to determine the relationship between percent injured fruit on each of the four sides of each of the 12 baited- sphere plots and the value (1 , 2, or 3) ascribed to that side for each of the following: tree size, quality of pruning, cultivar susceptibility, and bordering habitat. In addition, we used correlation analysis to determine relationships between mean numbers of AMF captured by interior unbaited monitoring traps in baited-sphere plots or percent fruit injured on interior frees of baited- sphere plots (100 fruit per plot) and tree size or quality of pruning for that plot. Whereas, in every case, tree size and quality of pruning were the same for all perimeter trees in a plot, thus permitting such analysis, cultivar susceptibility and border habitat differed among perimeter trees of the same plot and thus were excluded. Results Compared with the mean number of odor-baited spheres deployed on perimeter trees per plot in 2001 and 2002, the mean number deployed in 2003 was significantly fewer (33-39% fewer) (Figure I). Even so, mean values in Figure 2 show that captures of AMF on unbaited monitoring fraps at interiors of plots 45. 1 a ^ 1 1 no. baited spheres deployed o b S 15 - 0) n - U 1 1 . 1 . ■ 1 2001 2002 2003 Figure 1 . Mean number of odor-baited spheres deployed on perimeter apple trees in the same 1 2 plots in commercial orchards in 2001, 2002 and 2003. Means superscribed by the same letter are not significantly different at odds of 1 9; 1 . 12 Fruit Notes, Volume 69, Spring, 2004 15 1 2001 c a» o L. 17 ■ u. Q. < at: 9 ■ o B Z u o 6 ■ e C O E 3 ■ I Baited sphere plots n Grower-sprayed plots Captures 15 1 2002 (/I o u 1? - Q. < (/I 9 ■ o B Z O 6- B ■♦-* 1 B O E 3 ■ A . ■ Baited sphere plots n Grower-sprayed plots A Captures 15 T 2003 ■ Baited sphere plots D Grower-sprayed plots Captures 3 C s 'a c 01 ■ Baited sphere plots D Grower-sprayed plots Injury ■ Baited sphere plots D Grower-sprayed plots Injury 0.6 1 c s 0.5 - E *' 0.4 - =g n.3 - s? B 0.2 • w 0.1 - 0 • ■ Baited sphere plots n Grower-sprayed plots Injury Figure 2. Mean number of AMF captured on interior unbailed monitoring spheres and mean percent injured fruit in baited sphere and grower- sprayed plots in 2001, 2002, and 2003. For each comparison, means superscribed by the same letter are not significantly different at odds of 19: 1 . and plot-wide percent fruit injury were not significantly greater in baited-sphere plots (relative to sprayed plots) m any of the three years (2001, 2002, or 2003). For 2003, percent fruit injured on perimeter trees comprising the four sides of baited spheres plots was significantly negatively correlated (at odds of 15 to 1) with values prescribed for quality of pruning but not significantly correlated with values prescribed for tree size, cultivar susceptibility or border habitat. For 2003, captures of adults by unbailed monitoring traps on interiors of baited sphere plots were significantly negatively correlated (at odds of 10 to 1) with values prescribed for tree size and quality of pruning but not with values prescribed for cultivar susceptibility or Fruit Notes, Volume 69, Spring, 2004 13 border habitat. Percent fruit injured on interior trees of baited-sphere plots was not correlated with values prescribed for tree size or quality of pruning. Conclusions Our findings for 2003 indicate that assigning distances between odor-baited spheres (on perimeter trees of plots in commercial apple orchards) according to an index incorporating characteristics of four environmental variables (tree size, quality of pruning, cultivar susceptibility, and border habitat) resulted in a level of AMF control no different from that achieved by sprays of insecticide in 2003 and no different from that of arbitrary assignment of distances between odor- baited perimeter spheres in the same plots in 2001 and 2002. Only 61-67% as many spheres were used under our new index system for determining distances between spheres in 2003 as under the arbitrary system used in 2001 and 2002. Correlation analyses suggested that the index used here for assigning distances between odor-baited spheres on perimeter trees was reliable with respect to values prescribed for cultivar susceptibility and border habitat, but for future use it may require adjustment with respect to tree size and quality of pruning. Some of the analyses showed a significant negative correlation between tree size or quality of pruning and fruit injury by AMF or captures of AMF by interior monitoring traps, suggesting that distances between spheres prescribed by the index used here may have been too great to ensure high performance in plots of large and/or poorly pruned trees. One potential solution to this possible shortcoming would be to prescribe a value of less than 1 (rather than the value of 1 used here) for perimeter trees of large size and poor pruning. Doing so could, in some cases, require that spheres be placed closer than 6 yards apart. Conversely, for small- size perimeter trees that are pruned well, it may prove possible to assign a value 4 or more (rather than the value of 3 used here) and achieve acceptable control of AMF using odor-baited spheres positioned greater than 18 yards apart (the maximum distance apart allowed here). On average, each of the 12 plots in this study received 24 odor-baited sticky spheres 1 2 yards apart on perimeter trees that encompassed about 1 acre of orchard. We estimate that it cost about $10 per sticky sphere for all materials and labor ($1.50 tor sphere, Tangletrap, and odor plus $8.50 for labor to apply sticky, deploy spheres, periodically clean spheres of insects and debris, and replenish sticky). The estimated cost per plot of controlling AMF using odor-baited sticky spheres was therefore $240, compared with an estimated cost of about $45 per plot for control using insecticide (materials, spray equipment, and labor). If odor-baited sticky spheres were used to encompass a block of 10 acres rather than a 1 acre plot of apple trees, then 72 spheres (at 12 yards apart) would have been needed, costing a total of $720, or $72 per acre. This still IS substantially greater than the cost of applying insecticide to control AMF ($45 per acre) and calls into question the economic wisdom of using sticky spheres for this purpose. Ultimately, a replacement for sticky spheres is needed that is both less expensive and less messy to deploy and maintain. Such a replacement is on the horizon in the form of a red sphere topped by a disc comprised of spinosad (as insecticide), sugar (as feeding stimulant) and paraffin wax (as binder) (see a following article in this issue). Under high humidity, morning dew, or rainfall, spinosad and sugar seep from the disc onto the sphere surface, where they are ingested by alighting AMF, which then die. The total annual cost per odor-baited sphere of this type, amortized over a 10-year period, is estimated by its manufacturer (Pest Management Innovations, Harpers Ferry, West Virginia) to be about $3. Following initial deployment, such disc- capped spheres would require no further attention through harvest. Deploying odor-baited, disc-capped spheres on penmeter apple trees at distances prescribed by an index such as that put forward here could render behavioral control of AMF as effective and affordable as insecticide sprays, especially for large blocks of apple trees that are on dwarfing rootstock and well pruned. Acknowledgements We thank Eliza Gray, Guadalupe Trujillo and Mareanna Ricci for technical assistance and Jaime Pifiero for statistical analyses. This study was supported by a USDA Northeast region SARE grant, a USDA Northeast Region IPM grant, a USDA Crops at Risk grant, and the Massachusetts Society for Promoting Agriculture. «1^ %1^ %£# ^X* *X^ ^j^ #Y* ^y* *T* *T* 14 Fruit Notes, Volume 69, Spring, 2004 Ideal Within-canopy Positioning of Odor-baited Red Spheres for IVIonitoring or Control of Apple Maggot Flies Sara Hoffmann, Isabel Jacome, Everardo Bigurra, and Ronald J. Prokopy Department of Plant, Soil, & Insect Science, University of Massachusetts About 20 years ago, we conducted tests aimed at establishing favorable positions within canopies of apple trees for deploying unbaited sticky red spheres to capture apple maggot flies (AMF). We found that removal of all foliage and fruit within 10 to 20 inches of a red sphere resulted m greater AMF captures than allowmg foliage and fruit to encroach within 3 mches of a sphere or removing all foliage and fruit within 40 inches of a sphere. Since the time of this initial study, researchers at the New York Agricultural Experiment Station in Geneva have developed a blend of synthetic, attractive apple volatiles that draws AMF toward blend- baited trees and enhances captures of AMF by red spheres deployed in blend-baited trees. Here, we report on expenments conducted in 2002 and 2003 aimed at defining favorable positions within apple trees for deployment of blend-baited red spheres for capturing AMF. We asked three questions. First, we asked which distance between a baited red sphere trap and the nearest foliage and fruit gave rise to the greatest AMF captures. Second, we asked which part of the tree canopy (outer half or inner half) was the more favorable for positioning a baited red sphere trap to maximize captures. Finally, we asked whether the distance to which foliage and fruit were cleared away from a red sphere trap was of greater consequence to trap performance when traps were baited or when traps were not baited. For each question, we examined effects of season on the pattern of AMF response to traps. Materials & Methods All experiments were conducted in a city-ov^ned apple orchard in Leominster, Massachusetts dedicated to honor Johnny Appleseed (a.k.a. John Chapman, who was bom in Leominster). We used Jersey Mac trees on M.26 rootstock, which had a moderate amount of fruit each year. We also used Golden Delicious trees on M.7 rootstock, which also had a moderate amount of fruit each year. All trees involved in our trials were moderately well pruned and received periodic season- long treatments of fungicide to protect against apple diseases. They received insecticide treatments through May to protect fruit against early-season insect pests but none thereafter. Each year, we conducted two experiments: one using Golden Delicious trees, the other using Jersey Mac trees. There were not enough trees of either cultivar to conduct both experiments each year using the same cultivar. Spheres used as traps were wooden, 3.5 inches in diameter, and coated with Tangletrap to capture alighting AMF. When baited, a sphere received a single polyethylene vial containing a five -component blend of synthetic attractive apple volatiles positioned about 6 inches to the side of the sphere. Each year, spheres were deployed in mid-July and remained in place until rmd-September. Each tree received ^ single sphere hung at head height. Our first question was addressed in 2002 using Golden Delicious trees. Foliage and fruit were cleared to one of five distances (in a radius) around spheres: 0, 10, 20, 30, or 40 inches. For the 0-inch treatment, clearance was just enough to prevent foliage and fruit from touching the sphere. All spheres were odor-baited and hung in the outer half of the tree canopy. There were six replicates of each treatment. Our second question was addressed in 2002 using Jersey Mac trees. Odor-baited spheres were deployed Fruit Notes, Volume 69, Spring, 2004 15 either in the outer or inner half of the tree canopy, with foHage and fruit cleared to a distance of either 1 0 or 20 inches. There were six replicates of each treatment. Our third question was addressed in 2003 using both Jersey Mac and Golden Delicious trees. Spheres were either odor-baited or not baited. Spheres in Jersey Mac trees were deployed either in the outer half of the canopy with foliage and fruit cleared to a distance of 20 inches or in the inner half of the canopy with foliage and fruit cleared to a distance of 10 inches. Spheres m Golden Delicious trees were deployed in the outer half of the canopy with foliage and fruit cleared to a distance of either 20 or 40 inches. Once per week, captured AMF, other insects of similar or larger size and debris were removed from spheres. If necessary, Tangletrap was renewed, new growth of foliage was pared back, and enlarging fruit that encroached upon prescribed clearance distances were removed. The sex of captured AMF was not recorded in 2002 but was recorded in 2003. For each experiment, captured adults were separated into three groups according to season of capture. For captures in Jersey Mac trees, groups were mid-season (mid July to early August), late-season (early to late August), and post-harvest (late August to mid September). For captures in Golden Delicious trees, groups were early-season (mid July to early August), mid-season (early to late August) and late season (late August to mid-September). Results For our first question, data reveal that over the entire season in Golden Delicious trees, baited spheres with foliage and fruit cleared to 10 or 20 inches captured significantly more AMF than equivalent spheres having foliage and fruit cleared to 0 or 40 inches (Figure 1). Captures on spheres having foliage and fruit cleared to 30 inches were not significantly different from either group. This pattern characterized adult response to sphere treatments during early, mid and late season (Figure 1). For our second question, results show that across the entire season in Jersey Mac trees, baited spheres 200 ElO inches DIG inches ■ 20 inches 0 30 inches ^40 inches Early Mid Late Entire Figure 1. Mean number apple maggot flies captured per odor-baited sphere in Golden Delicious trees with foliage and fruit cleared to a radius of either, 0, 10, 20, 30, or 40 inches around a sphere. Captures were evaluated for early, mid, and late season and across the entire season. For the entire season, mean values superscribed by the same letter are not significantly different at odds of 19: 1. 16 Fruit Notes, Volume 69, Spring, 2004 300 250 SI 200 Q. (A I- a 150 o c c 100 010 inches Out 0 20 inches Out ■ 10 inches In 0 20 inches In B Mid Late Post Entire Figure 2. Mean number AMF captured per odor-baited sphere \n Jersey Mac tiees when spheres were either in the outer or inner half of the canopy and fohage and fruit were cleared to either 10 or 20 inches in a radius around the sphere. Captures were evaluated for mid, late, and post season and across the entire season. For the entire season, mean values superscribed by the same letter are not significantly different at odds of 19:1. in the outer half of the canopy with foliage and fruit cleared to 20 inches captured significantly more AMF than equivalent spheres in the inner half of the canopy with foliage and truit cleared to 1 0 or 20 inches (Figure 2). Captures on spheres placed in the outer half of the canopy with foliage and fruit cleared to 10 inches were not significantly different from the other treatments. This pattern characterized adult response to sphere treatments during mid, late and post season (Figure 2). For our third question, data show that across the entire season in Jersey Mac trees, baited spheres placed in the outer half of the canopy with foliage and fruit cleared to 20 inches caught significantly more female AMF than baited spheres in the inner half of the canopy with foliage and fruit cleared to 10 inches (Figure 3). The same was true for males. On the other hand, there was no significant difference in response of either female or male adults to these two position treatments when spheres were unbaited. For each sex and each position, baited spheres captured significantly more adults than unbaited spheres. These patterns characterized the response of each sex to each position treatment during mid, late, and post season (Figure 3 ). For our third question, data also reveal that across the entire season in Golden Delicious trees, baited spheres placed in the outer half of the canopy with foliage and fruit cleared to 20 inches caught significantly more female AMF than baited spheres m outer half of the canopy with foliage and fruit cleared to 40 inches (Figuire 4). Again, the same was true for males, again there was no significant difference in response of either sex to position treatments when spheres were unbaited, and again baited spheres in each position captured significantly more adults of each sex than unbaited spheres. These patterns held during early, rnid and late season (Figure 4). Conclusions Combined findings show that AMF responded maximally to odor-baited red sphere traps when traps were hung in the outer half of the tree canopy and all Fruit Notes, Volume 69, Spring, 2004 17 Females B 20 inches out baited ■ 20 inches out unbaited ^ 10 inches in baited D 10 inches in unabited 80 n 0) /o - Q. 60 - (/) 0) 50 - a 40 - o c 30 - c ro 20 - 0) 10 - 0 - Mid Late Post SEASON Males Entire ra 20 inches out baited ■ 20 inches out unbaited ^ 10 inches in baited D 10 inches in unbaited A Mid Late Post Entire SEASON Figure 3. Mean number female and male AMF captured per odor-baited and unbaited sphere in Jersey Mac trees when spheres were either in the outer or inner half of the canopy and foliage and fruit were cleared to either 20 or 10 inches in a radius around the sphere. Captures were evaluated for mid, late, and post season and across the entire season. For the entire season, mean values superscribed by the same letter are not significantly different at odds of 19:1. 18 Fruit Notes, Volume 69, Spring, 2004 0) 0) a (/) ^ t- 0 TO O o c o 00 CD O) CO 0) o Q) Q. 100- 90- 80- 70- 1997 PFF^ ^^;Cj^— — r 60- /[ 50- /J 40- PFE^ /y^ 30- y 20- x7 10- n 'rK 'A U 1 iir 1 ^ \ 1 1 26-Apr 10-May 24-May Date 7-Jun 21-Jun Figure 1 . Percent thyriothecia on blackberry canes that matured during each year, 1997, 1998, and 1999, in five Massachusetts orchards: Aslifield (B), Belchertowii (J), Briinfield (H), Shelbume (F), and Sterling (E). Times of bloom (B) and petal fall (PF) of Mcintosh m 1998 and 1999 are shown, ±3 days depending on the orchard, while in 1997 the phenological stages are indicated for each site. the orchard sites for those periods when relative humidity was 95% or greater. Five of the nine data sets had hourly humidity data sufficient to calculate Fruit Notes, Volume 69, Summer, 2004 I I r 500 1000 1500 2000 Accumulated Degree Days Base 0°C from Green Tip 2500 Figure 2. Percent of the season's thyriothecia matxired in five Massachusetts orchard sites during 1997, 1998, and 1999 as a function of the degree days (base 0''C) accumulated from green tip for the apple cultivar Mcintosh. degree days. The mean of these observations was 106 degree days, not significantly different from the 125 degree days observed in the laboratory. So, it appears that both high humidity and accumulation heat are required to get the maturation process started. Surprisingly, humidity did nOt seem to play a role in spore development once it started. When we looked at high humidity degree days throughout the whole maturation process, from green tip to the end of spore development, then they were poorer predictors of what percentage of thyriothecia would mature than using total degree days. Would a second generation of thyriothecia develop ascospores in the same growing season? Thyriothecia start to form on blackben-y in mid to late summer and continue to form until late fall. The rate at which the number of thyriothecia increased depended on location (Figure 4). At two locations in the eastern Berkshires, thyriothecia counts dropped slightly in September and October, while counts increased linearly at two locations in south-central Massachusetts. The increase in the number of thyriothecia in the southwest was more rapid than that in the northwest. Examinations of these thyriothecia from July through November never found any that matured and produced new ascospores. We feel that is because thyriothecia need to go through a winter, some sort of chilling dormancy perhaps, before they can produce ascospores. When we collected thyriothecia over the winter, they differed in their potential to mature, depending on the date they were collected and on the site where they grew. Thyriothecia collected from three sites in Massachusetts during December 1996 failed to develop after one week of incubation in high humidity at 70° (Figure 3). Of thyriothecia collected in January 1 997, 4 to 1 3% developed mature asci after incubation, and the percent that matured in subsequent months generally increased through April, when sampling ended, hi other words, with more exposure to winter temperatures, the fungus is increasingly ready to produce spores when it gets warm. Therefore, it appears S. poini has a disease cycle similar to that of V. iimequalis, in that ascospores get ready to grow during the winter and early spring, and then are matured and released when environmental conditions are favorable in the growing season. There is little evidence that conidia or mycelia serve as primary inoculum. While thyriothecia have been found on apple Uvigs and fallen fruit in orchards, it is unlikely that these serve as important sources of primary inoculum in commercial orchards where fungicides are commonly used. Like V. inaequalis, S. pomi produces the season's generation of ascospores over a discrete period generally corresponding to phenological development 8 Fruit Notes, Volume 69, Summer, 2004 ^ r\r\ 1 uu Asci (°A 00 CD o o 1 1 B ^ 0) a 70-1 CO ^ 60- i 50- "O 2 40- Q. ^^ B ■n 30- £ 20- /^^^-""^l^ 1^ 10- (- n n ■^^'^- "^"" n ■LI 1 1 1 U 1 Dec Jan Feb Mar Apr Montli Figure 3. Percent of thyiiothecia that had produced mature asci after one week incubation at 2rC. Collections from blackbeiTy canes at tluee sites in Massachusetts, Amherst (B), Wilbraham (J), and Shelburne (H), during 1996- 1997. Lines indicate linear regressions for each site. temperature. In our study orchards, the first flyspeck infections on fruit occurred at the earhest on July 16, nearly 30 days after the production of ascospores had stopped, and as late as September 21, 90 days after the end of ascospore production. While fruit infections first appeared by mid- July at the earliest in Massachusetts, they appear earlier in warmer climates: near the end of June in West Virgmia (5), by late May or early June in North Carolina (3), and by the beginning of May in Alabama (6). Again, this is not surprising given that both tree development and fungal development are in apples. In New England, the period when S pomi produces mature asci generally starts at late pink to bloom, and contmues for 4 to 6 wks, when fruit are 0.75 to 1.75 inches in diameter. While the beginning and end of ascospore production coincided with apple growth stage, dates varied fi-om year to year just as a growth stage such as bloom varies. For example, depending on the orchard and year, flyspeck ascospores began to mature as early as May 5 and as late as May 25, as would be expected when a process is highly dependent on c:n OU 45- a- 40- ^^ o 35- ^^^ .--^^ O 30- i— H y^^ --'^ Q.25- ■g 20- ^^ ^- - % 15- |io- ^^::^^^^^ ' ^^ 5- n H I-" 1 1 1 1 1 1 1 19-Jul 2-Aug 16-Aug 30-Aug 13-Sep 27-Sep 11-Oct Date Figure 4. Thyriothecia counts per cane from blackbeny canes growing in border areas of four apple orchards during 1999 in Massachusetts, Brimfield (H), Belchertown (J), Shelburne (F), and Ashfield (B). Ten canes located in a flagged area of the orchard border were counted on each date. Lines represent the linear regressions for each location. Fruit Notes, Volume 69, Summer, 2004 largely temperature driven. In our study during 1999, while apple infections first appeared between September 15 and 21, the first new thyriothecia (infections) appeared on blackberry canes m the borders of four orchards by August 1 7-24, about 4 weeks earlier. This may indicate that the environment in orchard hedgerows is more conducive to S. pomi growth, or that the infections on these canes occuiTed before those on adjacent apple trees. The latter possibility would support the hypothesis that epidemics originate on alternate hosts in orchard borders and spread to the orchard from there via conidia. A significant number of thyriothecia never mature. Over the three years, from 33% to 69% of thyriothecia did not contain any signs of spores at the end of the maturation cycle. Such thyriothecia might have actually been fertile, but when examined, they had released their spores and the spore tissue had disintegrated. Possibly some thyriothecia are damaged over the winter by cold temperatures or desiccation. It takes two different mating types of the S. pomi fungus to produce ascospores, and perhaps some thyriothecia never come in contact with a different mating type of the fungus, so no spores can develop. We have answered a couple of the key questions. S. pomi does not produce ascospores throughout the year, but only at one time, and that time is between pink and early fruit set. Unfortunately, we still have not answered the question of where these ascospores cause their infections. We do have some suggestions. A 30-day period between the appearance of inoculum and the first flyspeck symptoms in the field is typical of flyspeck (9). In one of three years in this study (1998) the end of ascospore production was 30 to 40 days before first infections were detected. Apples inoculated with ascospores from several wild hosts can cause flyspeck symptoms (1; 2). However, conidia of Z. jamaicensis commonly infect apple and cause tlyspeck (1; 4; 8). Spore trapping and the timing of symptom development also indicated that conidia are a significant portion of the inoculum that causes flyspeck on apple (10). Conidia are common during the period of most rapid symptom development. In 2 of 3 years the latency period between the end of ascospore release and the first appearance of flyspeck on apple was 60 to 90 days, and it is unlikely that ascospores do any more than start the epidemic. As we said at the beginning of this paper, if the initial inoculum of flyspeck epidemics is primanly ascospores, it might be possible to manage the disease by preventing these primary infections, much as apple scab is managed by targeting primary ascosporic infections. However, if most or all of the infections that blemish apples are secondary infections caused by conidia that arise on reservoir hosts in orchard borders, primary infections would have to be stopped in those borders. Given legal constraints on fungicide use off site, and the expense involved in owning and clearing borderareas, such an approach is problematic. Before such treatments could be recommended, it would be necessary to know that the registration changes and expense of these approaches would be justified in terms of SBFS disease reductions. At present we have a better understanding of when primary infections occur. A ckn o wledgem en ts The authors wish to acknowledge the support of USDA Federal Integrated Pest Management funds, Massachusetts Department of Agricultural Resources Integrated Pest Management Funds, and USDA Sustainable Agriculture Research and Education funds. We also wish to thank Dr. Bernard Roitberg, Simon Frasier University, for assistance on the degree-day model. References 1. Barnes, R.C. 1940. Pathogenicity and hosts of the fly-speck fungus of apple. Phytopathology 30:2. 2. Baker, K. F., L. H. Davis, R. D. Durbin, and W. C. Snyder. 1977. Greasy blotch of carnation and flyspeck of apple - diseases caused by zygophiala-jamaicensis. Phytopathology 67 (5):580-588. 3. Brown, E. M., and T. B. Sutton. 1993. Time of infection of gloeodes-pomigena and schizothyrium-pomi on apple in north-carolina and potential control by an eradicant spray program. Plant Disease 11 (5):45 1-455. 4. Durbin, R. D., L. H. Davis, W. C. Snyder, and K. F. Baker. 1953. The imperfect stage of microthyriella-rubi, cause of flyspeck of apple. Phytopathology 43 (9):470-47 1 . 5. Hickey, K. D., F. H. Lewis, and C. F. Taylor. 1958. 10 Fruit Notes, Volume 69, Summer, 2004 Time of apple fruit infection by gloeodes pomigena and microthyriella-rubi. Phytopathology 48 (8):462-462. 6. Latham, A.J. ; HoUingsworth.M.H. 1973. Incidence and control of sooty blotch and flyspeck on apples m alabama. Auburn Univ. Agric. Expt. St?!. Circ. 208. 7. Lemer, S. M., T. Klioriana, and D. R. Cooley. 1997. What part do tlyspeck ascospores play m disease development? Fruit Notes 62 (3):4-6. 8. Ocamb-basu, C. M., andT. B. Sutton. 1988. Effects of temperature and relative-humidity on germination, growth, and sporulation of zygophiala-jamaicensis. Phytopathology 78 (1):100-103. 9. Sutton, T. B. 1990. Sooty blotch and flyspeck. hi Compendium of apple and pear diseases, edited by A. L. Jones and H. S. Aldwinkle. St. Paul: APS Press. 10. . 1990. Dispersal of conidia of zygophiala- jamaicensis in apple orchards. Plant Disease 74 (9):643-646. *J* vl* *£» *i» *i» *j^ #^ *^ ^f% #y» Fruit Notes, Volume 69, Summer, 2004 11 SmartFresh™ Maintains Firmness and Delays the Onset of Senescent Breakdown in IVIacoun Apples Renae E. Moran and Patricia McManus Highmoor Farm Agricultural Experiment Station, University of Maine Macoun, a high-value apple cultivar in New England, has high consumer appeal because of its flavor, but loses its appeal within a few months of harvest because of rapid softening, hi addition to softening, Macoun is prone to senescent breakdown, typically succumbing after two to three months in regular air storage. As a result, production remains less than 10% of the total m New England. We tested SmartFresh effectiveness in maintaining fiminess of Macoun harvested at different maturities and stored in regular air. Materials & Methods Macoun apples were harvested at two different dates in three years: September 24 and October 4 in 200 1 , October 7 and 1 5 m 2002, and October 1 and 8 in 2003. Fruit were harvested from frees on various dwarf rootstocks. Flesh fmnness and starch index were measured on ten fruit at each date. The Cornell Starch Chart was used where 1 = all starch remainmg and 8 = no starch. Internal ethylene concentration at harvest was measured in ten fruit in 2002 and 2003. Apples were exposed to 1 ppm of SmartFresh within 24 hours of harvest. Fruit were stored at 37°F in regular afr for 100 days in 2001. hi 2002 and 2003, fruit were stored at 34°F in regular air for 50 and 90 days. Following storage, fruit were kept at 68°F for one and seven days when firmness and disorders were measured. Results \n 2001, starch index was 3.0 at the first harvest and 5.6 at the second. Following four months storage and seven days at 68°F, SmartFresh maintained fiminess in fruit from the first harvest (12 lbs.) above the firmness of untreated fruit (1 1 lbs.). This did not occur with the second harvest when fiminess was 10 lbs. in both treated and unfreated fruit. Fruit from the second harvest were too mature for SmartFresh to be effective for as long as 100 days in regular air. The effect of SmartFresh is temporaiy, becoming undetectable after several months in regular air storage, hi this study, the effect on firmness did not last 100 days in overmature fruit. hi 2002, starch index was 3.1 at the first harvest and 4.9 at the second. hitemal ethylene was undetectable at the first harvest and 29 ppm at the second. An apple is considered too mature for long- temi storage when the internal ethylene rises above 1 ppm. hi 2002, SmartFresh maintained firmness above that of untreated fruit after 50 and 90 days, but was more effective in fruit from the first harvest (Figure 1 ). After 50 days, fiminess was gi'eater by 4 lbs. in first- harvest fruit, but only by 2 lbs in second-harvest fruit. After 90 days, fiminess of first harvest fmit was greater by 3 lbs., but only by 1 lbs. in second harvest fmit. hi 2003, starch index was 2.7 at the first harvest and 3.5 at the second. Ethylene was 4 ppm at the first harvest and 1 ppm at the second. Finmiess in 2003 followed a similar pattern as in 2002. Fiminess was maintained 4-5 lbs. above untreated fruit with the first harvest and 2-3 lbs. with the second. Minimum acceptable fiminess by consumers is considered to be about 12 lbs. and optimum firmness about 15 lbs. SmartFresh maintained fiminess near 12 Fruit Notes, Volume 69, Summer, 2004 18 15 ^ 12 '& 9 o c 0 18 15 5 12 o c E 0 2002 2003 fm 1st Harvest I I Control -50 days |~~| SmartFresh - 50 days ^ Control -90 days ^ SmartFresh - 90 days 2nd Harvest Figure 1 . Macoun apple firmness was maintained by SmartFresh after 50 and 90 days regular air storage and seven days at room temperature. Fruit Notes, Volume 69, Summer, 2004 13 40 ^30 8 o (0 Q) c CO 20 10 0 40 -.30 o o c CO 20 10 I I Control - 50 days [ I SmartFresh - 50 days ^ Control - 90 days SmartFresh - 90 days 2002 p7//m 2003 1st Harvest T 2nd Harvest Figure 2. SmartFresh delayed the development of senescent breakdown after 90 days regular air storage and seven days at room temperature. 14 Fruit Notes, Volume 69, Summer, 2004 optimum for 50 days and near the minimum acceptability for 90 days when fruit were picked before starch index reached 4.0. When fruit were picked after a starch index of 4.0, SmartFresh maintained finnness near minimum acceptabihty for 50 days, hi untreated fruit, firmness fell below 1 2 lbs. by 50 days with little difference between the two harvest dates. Senescent breakdown was not affected by SmartFresh in 2001 when incidence was approximately 10%. Occurrence of senes- cent breakdown in 2002 was slight in fruit from the first harvest, so SmartFresh had no effect on its occurrence (Figure 2). hi fruit from the second harvest, senescent break- down was more prevalent, and was reduced by SmartFresh after both 50 and 90 days storage. In 2003, there was almost no senescent breakdown in either treatment after 50 days, so SmartFresh had no effect on its occuiTence. After 90 days, senescent breakdown was more prevalent, and SmartFresh reduced its occurrence. Macoun is very prone to senescent breakdown, which occurred in each year of the study, but was most severe in 2002. It began to develop in untreated fruit as early as 50 days in storage. SmartFresh reduced the occurrence of senescent breakdown, but did not completely prevent it, since SmartFresh-treated fruit eventually developed it, as well. SmartFresh increased the occurrence of coreline browning in 2001, but this was slight and insignificant in fruit from the first harvest (Figure 3). In fruit that were very mature at harvest, SmartFresh increased the incidence of coreline browning. Incidence of coreline browning was highly variable from year to year, being veiy prevalent in 2002 and almost nonexistent in 2003. In these two years, SmartFresh reduced the incidence of coreline browning. It is not clear why 40 I 30 5 o CO! « 20 o o 10 0 40 I 30 2 g 20 o o 10 0 40 .| 30 o QG o c 20 10 I I Control I I SmartFresh 2001 2002 ^_J ^ 2003 1st Harvest f 2nd Harvest Figure 3. Coreline browning in Macoun after 100 days regular air storage in 2001, and 50 days in 2002 and 2003. Fruit Notes, Volume 69, Summer, 2004 15 corelme browning was increased by SmartFresh in 2001, but could have been due to the advanced maturity with the second harvest since these fruit were harvested more mature than in later years. hi 2002, stem-end brownmg did not occur until 90 days when SmartFresh reduced its occurrence from 7% to less than 1% with the first harvest, and from 4% to 2% with the second harvest, fri 2003, stem-end browning did not occur. Conclusions For Macoun, SmartFresh has the potential to maintain optimum firmness during the normal two- month marketing window. SmartFresh did not completely prevent senescent breakdown or coreline browning, but in most instances these disorders were reduced to a very low level. vt« •!« vi« %X* *A* #^ *y» •y* #^ *y% 16 Fruit Notes, Volume 69, Summer, 2004 The James Underwood Crockett Agricultural Technology Growth Fund James E. Mulcahy Clerk and 1960 Stockbridge School of Agriculture Graduate James Underwood Crockett was a student at the Stockbridge School of Agriculture in the class of 1935. The James Underwood Crockett Agricultural Teclinology Growth Fund (aka the Jim Crockett ATG Fund) was established in his honor and memory after his untimely 1979 death. The non-profit public- charity status as an IRS 501(c)(3) tax-exempt entity was achieved in 1982. The ERS account number is 04-2754324. The first contributions arrived promptly, and the first grant was made in 1983. The fund continues to solicit annual donations as well as asking for bequest in the wills of supporters. The donations have been received and invested by the Personal Trust Department of the State Street Bank & Trust Co. in Boston. In December 2003, the Personal Trust Department became a part of the U.S. Trust Co., with the same trust officers, headed by Francis M. Barrett Assistant Vice President, and with the same mailing address at 225 Franklin Street, Boston, Massachusetts 02110. The trust account number is 52- 010157. All donations become the principal or corpus of the trust for perpetual investment to generate principal growth as well as producing earnings of interest and dividends for distribution. The trustees meet twice a year and vote to grant about 5% of the value of the fund from the earnings to non-profit organizations, schools, etc. that are in the northeast U.S. and that are involved in some phase of agriculture. See the web site at www.jimcrockett.org. Since 1983, $120,600.00 has been distributed by the trustees in mini-grants to 34 gi'antees in 96 grants, usually m the $500 to $2,000 range. Over half have been given to various parts of the UMass College of Natural Resources & the Environment, both on the Amherst campus as well as to UMass research sites in Belchertown, Waltham, and Wareham. Editors 'Note: The Jim Crockett ATG Fund has been a generous contributor to fruit activities at the University of Massachusetts, including contributions to purchase equipment for teaching, to establish new plantings for educational purposes, to erect a new 1-181 sign, and to help build the Massachusetts Fruit Growers ' Association endowment in support of the UMass Cold Spring Orchard Research & Education Center. We are very grateful for this long-term support. vl# ^i» *1^ «1« *1^ #T» *T» *T» #T» #^ Fruit Notes, Volume 69, Summer, 2004 17 Fruit Notes University of Massachusetts fPllit Department of Plant & Soil Sciences Unfpo 205 Bowditch Hall nl,U Amherst, MA 01003 Nonprofit Organization U.S. Postage Paid Permit No. 2 Amherst, MA01002 -1 SERIAL SECTION UMASS AMHERST, MA 01003 104911 Table of Contents Predicting Plum Curculio Immigration into Apple Orchards in Massachusetts: Degree Days versus Tree Phenology Jaime Pihero and Ronald Prokopy 1 Immigrants or Re-colonizers? Studying Plum Curculio Movement Using Odor-baited Traps Jaime Pihero and Ronald Prokopy 9 Is More Than One Trap Tree Required on Perimeter Rows to Monitor the Course of Plum Curculio Injury to Fruit? Jaime Pihero, Isabel Jdcome, Paul Appleton, Marina B. Blanco, and Ronald Prokopy 12 Notes rleu/Cnaland Editors: Wesley R.Autio William J. Bramlage Publication Infonnation: Fruit Notes (ISSN 0427-6906) is published each January, April, July, and October by the University of Massachusetts Amherst in coop- eration with the other New England state universities. yn The cost of subscriptions to Fruit Notes is Of^^ A g $20.00 per year. Each one-year subscription begins January 1 and ends December 3 1 . Some back issues are available for $5.00. Payments must be in United States cuixency and should be made to the University of Massachusetts Amherst. Correspondence should be sent to: Fruit Notes Department of Plant, Soil, & Insect Sciences 205 Bowditch Hall University of Massachusetts Amherst Amherst, MA 01 003 All chemical uses suggested in this pubhcation are contingent upon continued registration. These chemicals should be used in accordance with federal and state laws and regulations. Growers are urged to be familiar with all current state regulations. Where trade names are used for identification, no company endorsement or product discrimination is intended. The University of Massachusetts makes no warranty or guarantee of any kind, expressed or implied, concerning the use of these products. USER ASSUMES ALL RISKS FOR PERSONAL INJURY OR PROPERTY DAMAGE. Issued by UMass Extension, Robert Schroder, Acting Director, in furtherance of the acts of May 8 and June 30, 1914. UMass Extension offers equal opportunity in programs and employment. J Predicting Plum Curculio Immigration into Apple Orchards in Massachusetts: Degree Days versus Tree Phenology Jaime Pinero and Ronald Prokopy Department of Plant, Soil, and Insect Sciences, University of Massachusetts Determining need for and timing of insecticide applications that will protect fruit from injury by plum curculio (PC) based on presence of adults on host trees has been a critical aspect for managing populations. In concept, a reduction in amount of insecticide used against PC, from the current norm in Massachusetts of three spray applications during May and June to an amount that is precise according to need should be accompanied with an effective approach to monitoring the course of PC immigration into apple orchards. Limb jarring, an approach that involves tapping tree limbs using a pole to dislodge PCs onto an underlying ground cloth is one of the methods traditionally used to determine the time of first appearance, location, and relative abundance of PCs within an orchard. However, limb jarring has several shortcomings: (1) it is labor intensive; (2) it is not very accurate (its effectiveness is highly dependent upon tree size, weather, and other factors); (3) it carmot be used to study immigration, because PCs that are able to overwinter beneath perimeter-row trees will be confounded with true immigrants that overwintered in the woods; and (4) it cannot be performed at night, the time of day when PCs are most active on trees. In the 2000 combined issue of Fruit Notes we reported that panel and pyramid traps baited with attractive odor and deployed in close proximity to the forested areas that are the main overwintering sites of adult PCs offered great potential for monitoring the onset and extent of PC immigration into apple orchards. Here, we investigated, over a five-year period, temporal dynamics of PC immigration into an unsprayed section of a commercial apple orchard using odor-baited traps. In particular, our objectives were: (1) characterizing the overall pattern of PC immigration; (2) determining the relationships among trap captures, tree phenology, and weather; (3) estimating thermal constants, expressed in Degree Days, for different stages (onset, 50* and SO"" percentiles of cumulative captures) of PC immigration; and (4) determining the relative predictability of different stages of PC immigration by comparing tree phenology versus thermal constants. Materials & Methods Study site and trap deployment. We conducted this study over a period of five years (2000-2004) at the University of Massachusetts Cold Spring Orchard Research & Education Center (Belchertown, MA) utilizing a 1 .4-acre unsprayed block comprised of a secfion having 2 1 6 small (M.9 rootstock) Mcintosh and Delicious trees located on the eastern side, and two smaller sections having 145 medium-sized (M.26 rootstock) trees of various disease-resistant varieties located on the western side (Figure 1). The perimeter of the entire block, bordered almost entirely by mixed deciduous forest, was about 500 yards. Traps utilized for the study were of two different types: (a) clear sticky Plexiglas panels (2x2 feet), which capture PCs in flight, and (b) a trunk-mimicking black pyramid ti-aps, which capture PCs approaching host trees primarily by crawling. The woods-facing side of each panel was coated with Tangletrap glue to capture PCs that were presumably immigrating from the woods into the orchard block. For each of the five years, traps were deployed in pairs along the periphery of the orchard, in close proximity to the woods. Each pair of traps was spaced 10 yards from other trap pairs on either side except in 2004, when the distance between each trap pair was 35 yards. For each of the five years, trap captures were pooled across all traps of the same type deployed m Fruit Notes, Volume 69, Fall, 2004 tmQ m Nr^fr^ ;«*»"- s.*J- »t!^-'"fl ctOt'^^"^ t * Figure 1. Unsprayed section of the apple orchard used for this study (UMass Cold Spring Orchard; Belchertovvn, MA). Panel and pyramid traps were deployed in pairs along the periphery of the orchard block, in close proximity to woods, the main overwintering sites of adult PCs. The perimeter of the block was about 500 yards. Picture: courtesy of Jon Clements (UMass Extension). the orchard. The predominant bait used for luring PCs to traps was composed of benzaldehyde (attractive, synthetic, host-plant odor) in association with and grandisoic acid (PC aggregation pheromone). For each trapping year, trap deployment and baiting took place approximately during the silver-tip stage of bud development. Traps were inspected for PC captures on a daily basis (7:30-10:00 AM) from the moment of trap deployment until fruit reached 1 .2 inches in diameter (by late June/early July). All adult PCs captured were brought to the laboratory, where they were sexed. All females captured were dissected under a stereomicroscope to determine the sexual maturity stage (presence of mature eggs) and mating status (presence of sperm in the spermatheca). Characterizing PC immigration. The process of PC immigration into the apple orchard was characterized beginning with the day of first captures by traps. The next important stages of PC immigration were the 50"" and 80* percentiles of cumulative captures. The latter occurred around petal fall, the stage of tree phenology at which PCs have shown the highest activity and dispersal and the time at which the first insecticide is commonly applied against PC. We ended the studies by late June/early July, when no captures occurred for 3-4 consecutive days with relatively high temperatures. Classification of tree phenology. We monitored and characterized, on a daily basis, the different stages of bud and fruit development on the Mcintosh trees using the following numerical code: (1) silver tip, (2) green tip, (3) half-inch tip, (4) tight cluster, (5) first pink, (6) full pmk, (7) first bloom, (8) full bloom, (9) petal fall, (10) within a week after petal fall, and (11) Fruit Notes, Volume 69, Fall, 2004 2-6 wks after petal fall (depending on the year). Stages 1-9 were considered as pre-petal fall, whereas stages 10-11 were post-petal fall. Calculating Thermal Constants. Thermal constants for the initiation of PC iiTiinigration (START), and the 50* and 80* percentiles of cumulative captures were estimated using a temperature threshold of 43°F for the resumption of adult PC activity after overwintering. On each trapping year. Degree Days started to accumulate on January 1 . Relative Predictability of PC Immigration: Tree Phenology versus Thermal Constants. To determine whether the onset of immigiation was better explained by accumulation of Degree Days or by tree phenology, two coefficients of variation (CV) were constructed. A coefficient of variation is a relative measure of variability (it uses the standard deviation [SD]) around a mean value, therefore a low CV (relative to the other CV estimated) suggested greater reliability of the particular method used to predict onset of PC immigration. Our first CV involved mean thermal constants (using the mean DD and SD obtained across the five trapping years), whereas the second CV involved the particular phenological tree stage at which PCs started immigrating into the orchard block (using the mean and SD of the numerical codes used on each year). Results Overall pattern of PC immigration, hi all, 4,279 PCs were captured by traps across all five trapping years (Table 1). On average, the entire period of PC immigration lasted 63 days, with the shortest and longest periods encompassing 5 1 days in 2000 and 85 days in 2002, respectively. The earliest start of PC immigration occurred in 2002 (on 14 April), whereas the latest start of immigration took place in 2001 (on 2 May). PCs started immigrating when trees were either at the silver tip stage (stage 1) (in 2004), at the tight cluster tree stage (stage 4) (m 2000, 2002, and 2003) or at the first pink tree stage (stage 5) (in 2001). Fifty percent cumulative captures occurred when trees were either in full bloom (stage 8) in 2000 and 2001, by petal fall (stage 9) in 2003 and 2004, or during the first week of fruit development (stage 10) in 2002. Eighty percent cumulative captures took place during stage 10 (i.e., first week of fruit development) in four of the five years (2000-2003) or during stage 11 (i.e. after one week of fruit development) in 2004. Table 1 shows that of the total number of PC immigrants captured by traps (potentially colonizing host trees), on average, 59% have already done so by petal fall, with the remaining 41% being captured by traps after petal fall. A statistical test revealed that numbers of PCs being captured by traps before and after petal fall differed significantly across years. The period of time required from the last day of petal fall to achieve 80% cumulative PC captures was one week in 2000 and 2004, two weeks in 2003, and three weeks in 2001 and 2002. Relationships among trap captures, tree Table 1 . For each of the five trapping years, PC occurring before petal fall (PF) (phenological tree stages 10-11). captures (by panel and pyramid traps stages 1-9) and after petal fall (pheno combined) logical tree EVENT 2000 2001 2002 2003 2004 Average Total PCs captured 430 Last day PF 05/24 Cum. captures last day PF 307 544 05/16 303 1,354 05/17 575 485 05/22 289 1,366 05/14 877 Percent of total 71.4 55.7 42.5 59.6 64.2 58.7 ±4.8 Fruit Notes, Volume 69, Fall, 2004 2.0 1.8 1.6 1.4 1.2 1.0 2000 N^,PANEL;R '-0.19; F-OM '■q. PVRAMID: R '-0.08; F-O.U 10 12 14 16 18 20 MEAN AIR TEMPERATURE ("Q ^ PANEL: R ^-0.«; f- 0.003 ""a. PVRAMID: R "-0.J7; /'-0.09 8 10 12 14 16 18 20 22 24 26 28 MEAN AIR TEMPERATURE (°0 "^ PANEL: R '- 0.51; P« 0,001 'a PYRAMID: R ■-0.54;P< 0.001 8 10 12 14 16 18 20 22 24 26 28 MEAN AIR TEMPERATURE ("Q 2 1. a 1- S 0 z 5 0 B 2000 ^ PANEL: R '-0.0I; /'-0.48 "n.. PYRAMID: R '-0.03; F'HAO Cbr 00 aj'^ q: 'a ^er°5 — g S'^u fe 14 16 18 20 22 MEAN AIR TEMPERATURE ("tT) 2001 ^PANEL:R '-OM; F-0.21 ■"D,PVRAMID:R '-O.0I; /'-0.61 ^,ggp°^S^n....g.6.,.^gg..|^ 12 14 16 18 20 MEAN AIR TEMPERATURE (»Q 2.0- 1.8 1.6 1.4 1.2 1.0 0.8 0.6 0.4 0.2 0.0 ^PANEL:R '-0.01; P-OM ■■a,PYRAMID:R '-0.01; /"-O.?* a *1 10 12 14 16 18 20 22 24 26 28 MEAN AIR TEMPERATURE (°C) Figure 2. For each of the five trapping years, relationships between daily PC captures by panel and pyramid traps and mean air temperature either (A) before or (B) after petal fall. The number of days before/after petal fall was 23/52 in 2000, 17/43 m 2001, 33/51 m 2002, 24/30 in 2003, and 29/37 m 2004, respectively R' values denote, on a scale of 0 to 1 , the amount of common variation between the two variables. An R^= 1 indicates a perfect correlation. Fruit Notes, Volume 69, Fall, 2004 B 2003 ^ PANEL: F? = 0.32; P-= 0.001 'n, PYRAMID: Ff -0,07;P= 0.15 8 10 12 14 16 18 20 MEAN AIR TEMPERATURE (°Q 2004 8 10 12 14 16 18 20 MEAN AIR TEMPERATURE CQ 2004 >■ 5 < e o a 4 % 2 e u S 0 V^PANEL: F?- 0.56: P< 0.001 □ "-Q. PYRAMID: Ff = 0.52; P <: 0.001 S 4 < U 3 12 ^ PANEL: f* = 0.01 ; P = 0.62 ■•D. PYRAMID: F* = 0.04; P= 0 J2 a°, \s^-. "^-^^ a 10 12 14 16 18 20 22 24 26 28 MEAN AIR TEMPERATURE ("Q 8 10 12 14 16 18 20 22 24 MEAN AIR TEMPERATURE ("Q Figure 2. Continued. phenology, and weather. Correlation analyses revealed a strong positive influence of mean daily air temperature on PC captures by panel traps before petal fall for each of the five trapping years. Captures by pyramid traps were less influenced by temperature than panel traps (Figure 2A). hi contrast, the relationship between mean air temperature and captures by either panel or pyramid traps after petal fall was rather weak, except in 2003 for panel traps (Figure 2B). The proclivity of adults to either fly or crawl was independent of sex. Thermal constants for different stages of PC immigration. Table 2 shows the thermal constants (base 43°F) for different stages of PC immigration. On average, PC immigration started when 235 DD had accumulated since January 1. The number of DD accumulated since January 1 to attain 50% and 80% cumulative captures was 480 and 775, respectively. Relative predictability of PC immigration: Tree phenology versus thermal constants. Using CV's, we detemiined that initiation of PC immigration was better explained by accumulation of Degree Days (CV= 13.2) than by tree phenology (CV= 42.2). Female sexual maturity stage and mating status. Fruit Notes, Volume 69, Fall, 2004 Table 2. For each of the five trapping years, date and sta ge of tree phenology for die first captures, and thermal constants (expressed in Degree Day s [DD]) estimated for different stages of PC immigration 1 (START, 50* and 80* percentiles of cumulative capUires). See Materials and Methods for a description of numerical ranks used to characterize phenologic al tree stage. EVENT 2000 2001 2002 2003 2004 Mean ± SE START (date) 05/02 04/30 04/15 04/29 04/17 START (rank of tree phenology) (4) (5) (4) (4) (1) 3.6 ±0.7 START (DD43»f) 283 212 209 248 222 235 ±14 50* percentile (date) 05/07 05/11 05/24 05/19 05/12 50* percentile (DD43"f) 404 450 556 462 526 480 ± 27 80* percentile (date) 06/01 06/08 06/05 06/08 05/21 80* percentile (DD43«f) 785 853 789 732 713 775 ±25 1 Figure 3 (A-E) reveals that, except for 2003, all females captured by traps were already sexually mature and/or had been mated by the end of the petal-fall period. These findings will be discussed in the next article of Fruit Notes . Conclusions \n this study we focused on the relative importance of weather factors and tree phenology on the timing of PC immigration into an apple orchard as determined by trap captures. Because odor-baited traps were deployed along the periphery of the orchard block and inspected on a daily basis for the entire period of PC immigration, we believe this study examined timing and extent of PC immigration from overwintering sites (which primarily are woods) more accurately than previous studies that have relied on branch-tapping. Based on our combined data, we propose the occurrence of a pre- and a post-petal-fall period of PC immigration, each of which is influenced to a different extent by temperatures prevailing in spring. The relative influence of temperature on patterns of PC immigration was very strong during the pre-petal-fall period of immigration, whereas immigration taking place during the post-petal-fall period depended to a lesser extent on temperature. In almost all cases, captures by panel traps were more strongly influenced by air temperature than captures by pyramid traps. Historically, the timing of PC immigration was related to either soil and air temperatures or to host- plant phenology, but the relative influence of these two environmental factors had not been quantified in detail before. Here, we determined that the onset of immigration was better explained by accumulation of DD (base 43°C) than by tree phenology. This finding means that examination of the stages of bud development in spring is a poor tool for forecasting onset of PC immigration. Our trap-capture patterns obtained over a five-year period allow us to characterize PC immigration as follows. First, stretches of hot weather occurring during the pre-petal-fall period (as in our 2000 season) are conducive to concentrated PC emergence and immigration. Under these conditions, most adults may be present within orchards before the end of the pre- petal-fall period and thus a petal-fall spray covering the entire orchard block is recommended and should yield excellent control of the majority of the population. Second, during the post-petal-fall period, PC immigiation continues but with a lesser influence of weather, unless cool temperatures (such as in our 2002 season) have prevailed during the pre-petal-fall period, which would lead to an extended period of PC emergence and immigration. We recommend that, depending on the type of weather (primarily temperature) prevalent during the pre-petal-fall period of PC immigration, the first spray Fruit Notes, Volume 69, Fall, 2004 2000 2001 1.00 - Vi UJ < 0.80 - Ul S 0.60 1 0.40 § 0.20 Q. 0.00 1 1 / » P.F. i °' s " S 0.4. g CI. 0 ■ / • • / p.p. — < — % maftjfe ■ % mated — • — %m3luce •■ •/.mated May May May May May May May May May May May May May May Jun 2-5 6-7 8-9 10- 12- 14- 16- 18- 20- 22- 24- 26- 28- 30- 1-2 11 13 15 17 19 21 23 25 27 29 31 May May May May May May May May May May May May May May Jun 1-3 4-5 6-7 8-9 10- 12- 14- 17- 19- 21- 24- 26- 28- 30- 1-2 11 13 16 16 20 23 25 27 29 31 2002 2003 1 - ' ♦ • • >■ < • "" — » — %m3ture ■ % mated 0.4 P.P. 0.2 ■ 0- ■ Apr May May May May May May May May May May May Jun 22- 1-4 5-6 7-8 9-12 13- 17- 22- 24- 26- 28- 30- 1-3 30 16 21 23 25 27 29 31 1 Hi u. O 2 Q % a. O tc a. / P.P. 1 1 0.8 0.6 ■ 0.4 0.2 / \ * / / — • — %mature ■■ %mated Apr May May May May May May May May May 30- 3-4 5-6 7-8 9-10 11- 13- 15- 19- 21- May 12 14 18 20 29 2 May 30- 31 Jun Jun Jun Jun 1-2 3-4 5-6 7-8 2004 / 0,8 - ■ 1 r — • — %malijfe ' • %maEd 0.4 - I m P.F. 0.2 ■ n ■ 9 Apr May May May May May May May May May May Jun Jun Jun 26- 1-3 4-6 7-9 10- 13- 16- 19- 22- 25- 29- 1-3 4-5 6-8 30 12 15 18 21 24 28 31 Figure 3. For each of the five trapping years, proportions of PC females captured by traps that were either sexually mature or mated, according to date. For each year, a box with diagonal lines indicates the petal-fall period. L of insecticide (commonly applied by the time of petal fall) be delayed either (1) by one week if the pre-petal- fall period is characterized by high temperatures (as in our 2002 season), or (2) by 10-14 days if cool, rainy weather prevails during the pre-petal-fall period. By doing this, a grower can maximize PC control as a higher proportion of immigrants may be killed, while costs and exposure to insecticide would be minimized given the fewer applications that might be needed. This is analogous to the temperature model developed at Cornell University by Reissig et al. (1998) to control PC, which involves use of cumulative heat unit models to predict, in particular, termination of PC oviposition activity. Acknowledgments We are grateful to Paul Appleton, Katie Bednaz, Fruit Notes, Volume 69, Fall, 2004 Everardo Bigurra, Brad Chandler, Sara Hoffmann, Maria Teresa Fernandez, Isabel Jacome, Phillip McGowan, Amanda Ross, Guadalupe Trujillo, and Starker Wright for assistance. We also thank Arthur Tuttle for providing the weather data. This study was supported with funds provided by a USDA Northeast Regional IPM grant, a Hatch grant, a grant from USDA Crops at Risk program, the Horticultural Research Fund (Massachusetts Fruit Grower's Association), and the New England Tree Fruit Research Cominittee. Literature Cited Lafleur, G. and Hill, S.B. 1987. Spring migration, within-orchard dispersal, and apple-tree preference of plum curculio in Southern Quebec. Journal of Economic Entomology 80: 1173-1187. Reissig, W. H., J. R Nyrop, and R. Straub. 1998. Oviposition model for timing insecticide sprays against plum curculio (Coleoptera: Curculionidae) in New York State. Environ. Entomol. 27: 1053-1061. «£* «1^ vi« «|> %^ *^ •T» #T» #T» •T* 8 Fruit Notes, Volume 69, Fall, 2004 immigrants or Re-coionizers? Studying Pium Curcuiio IVIovement Using Odor-baited Traps Jaime Pinero and Ronald Prokopy Department of Plant, Soil, and Insect Sciences, University of Massachusetts In the preceding article of Fruit Notes, we presented results of a 5-year study aimed at establishing the relationships between timing of plum curcuiio (PC) immigration, weather factors, and phenological tree stage. One of our findings was that most PCs (59% on average) were captured by traps by the end of the petal- fall period, with the remaining 4 1 % being captured after petal fall. Therefore, an important aspect to consider because of its implications for management is whether those PCs captured after petal fall are either immigrants or re-colonizers. One way of addressing this and other questions concerning PC immigration and movement Figure 1. Unsprayed section of the commercial orchard used for tliis study (UMass Cold Spring Orchard Research & Education Center, Belchertown, MA). Hollow circles represent the 12 release points of color-marked PCs beneath perimeter-row trees. Dashed circles represent the 48 points at which color-marked PCs were released (at 3, 6, 13, and 24 yards inside the woods) in 2002. Picture courtesy of Jon Clements (UMass Extension). Fruit Notes, Volume 69, Fall, 2004 18- • § 15 - • t 12 - < U 9- O PL, 6 - 3- fi - •^^^^ 0 • U T 1 1 1 1 1 3 6 12 24 DISTANCE (in yards) Figure 2. For the 2002 study, percentages of color-marked adult PCs captured by panel and pyramid traps at different distances (3, 6, 12, and 24 yards) from the woods edge. For each distance, solid circles denote PC captures occurring at each of the three release areas (N, W, and S). Hollow circles represent the mean percent value. is by means of mark-capture studies using odor-baited traps. Here, our objectives were to detemiine (1) the distance from which odor-baited traps are attractive to overwintered PCs immigrating into an apple orchard block from forested areas; (2) the relative attractiveness of odor-baited traps to PCs immigrating from woods versus PCs already present on orchard trees; and (3) the extent of back-and-forth PC movement between orchard trees and woods as determined by trap captures. In this article, we also discuss the findings presented in the preceding Fruit Notes article, in relation to the female maturity stage and mating status of the PC females captured by odor-baited traps over a 5-year period. Materials & Methods This study was conducted during 2002 and 2004 at the University of Massachusetts Cold Spring Orchard Research & Education Center located in Belchertown, MA. The first two questions were addressed in 2002. For the 2002 study we used adult PCs that were raised from infested fruit collected in Amherst area in the summer of 2001 and kept over the winter in plastic containers with a layer of soil (5 inches), overlaid by 5 inches of maple leaves. Containers were then buried into the gi'ound outdoors and protected from rainfall. Before being overwintered, adult PCs were separated by sex and marked on the elytra with different color combinations using acrylic paint. Of the 938 color-marked PCs that were recovered in the spring of 2002 after overwintering, 168 were released beneath 12 perimeter-row trees (14 PCs per tree) next to the tree trunks, and 770 PCs were released in the woods, at 3, 6, 12, and 24 yards from the woods edge (Figure 1). Color-marked PCs were released in the woods in the northern, southern, and western areas of the orchard block. Within each release area, 16 different release points of about 48 color-marked PCs each were established (Figure 1). Overwintered PCs were not fed prior to release. For the releases, each group of PCs was placed on the ground after removing some leaves and then were covered with a boll weevil trap top that was slightly buried into the ground. This 10 Fruit Notes, Volume 69, Fall, 2004 protected PCs from potential predators and at the same time allowed them to exit from the open end of the funnel whenever they chose to do so. To assess the extent of response of wood-released versus orchard- released PCs to synthetic odors, 48 panel and 48 pyramid traps were baited with benzaldehyde (attractive synthetic host plant odor) in association with grandisoic acid (attractive PC pheromone). Traps were deployed at the periphery of the orchard block and were inspected for PC captures on a -daily basis for a 8- week period starting on May 16 (at bloom). Our third question, concerning the extent to which PCs exhibit some sort of back-and-forth movement between orchard trees and woods, was addressed in 2004 in a straightforward way by putting sticky on both sides of 14 panel traps deployed along the periphery of the orchard block. We then contrasted numbers of wild PCs captured on a daily basis in the wood-facing side or in the orchard-facing side of the panels. Results For the first question. Figure 2 shows that the greater capture rates (13.4%) of color-marked PCs occurred for PCs released 3 yards from the traps (which also correspond to the wood's edge). Fewer PCs were captured as the distance from traps (i.e., woods edge) progressed. A capture rate of 5.1% was achieved for PCs released 24 yards inside the woods. For the second question, Figure 3 reveals that, without taking into account the distance at which color- marked PCs were released inside the woods, substantially more PCs (almost seven times more) were captured by panel and pyramid traps when they were released from the woods (7.9%) on average) than from orchard trees (1 .2%o). For the third question, Figure 4 shows that before petal fall, most wild PCs were captured by the woods- facing side of panel traps and very few PCs were captured in the back of panels. However, during and about 2 weeks after petal fall, PC captures in the back of panels increased substantially, suggesting that during this period there were high rates of back-and-forth movement between woods and orchard trees. PC captures beyond the 2-week period after petal fall period were in general low. ORCHARD TREES 1 7.9% WOODS Figure 3. For the 2002 study, overall capture rates (in %, shown inside the arrows) of color-marked PCs released in the woods (n= 770) and beneath perimeter-row trees (n= 168). Fruit Notes, Volume 69, Fall, 2004 11 c rs ■a a a u d s a 2.7- 2.4 - 2.1 ■ 1.8 - 1.5- 1.2 - 0.9- 0.6- 0.3 - iP.F Males-back Males-front Females-back Females-front I I I I'l I'l I'l I I I'l I I I'l I'l I I r>'r«f«**r-l i i i I'l i i i i I'l i i I'l i i i I'l ri'i n r I'l I'i'i i riT i r i a. < c < a. < c. < a. < a r^ ir> 00 ^H ^H rH ^H (M (M 00 « C -H -H .- 3 c c e s s DATE Figure 4. For the 2004 study, mean number of male and female PCs captured per trap (only panel traps) according to date. Panel traps were coated with Tangletrap in the woods-facing side (i.e., front) as well as in the orchard-facing side (i.e., back). The area delimited by a dashed line and filled with diagonal lines represents the duration of the petal-fall period in 2004. Conclusions From the 2002 study, we learned that adult PCs are attracted to the odor emitted by traps baited with benzaldehyde and grandisoic acid from at least 24 yards inside the woods. The maxiinum distance considered for this study represents the area more likely to be serving as overwintering sites for PCs (Lafleur and Hill 1987). From the 2002 study, we also determined that, once PCs are present on orchard trees, their degree of responsiveness to odor-baited traps decreases substantially, compared to PCs released in the woods that had not been exposed to stimuli provided by a host tree. Similarly, Leskey and Wright (2004) also determined that the responsiveness of southern-race PCs to traps baited with benzaldehyde and grandisoic acid decreased significantly in the presence of apple trees. From the 2004 study we determined that, before petal fall, nearly all overwintered PCs trapped were captured in the woods-facing side of panel traps. This supports the notion that, early in the season, overwintered PCs moving into the orchard by means of flight are, most likely, immigrants. We also determined that, during and about two weeks after petal fall, there seem to be high rates of movement by PCs from host trees to woods and vice versa. This finding suggests that some PCs may be moving from orchard trees to woods (and vice versa) by the time of petal fall onwards. However, the exact proportion of PCs that may exhibit this behavior has yet to be determined. In the preceding Fruit Notes article we reported that nearly all females captured by traps by the end of petal fall were already mated and ready to lay eggs. If PCs captured by traps after petal fall were actually immigrants that had just emerged from overwintering sites and were moving into the orchard block, then we would expect some of those trapped females to be sexually immature or unmated. Results from another study that involved use of pyramidal emergence traps in the same orchard block showed no emergence of PCs beyond two weeks after petal fall. Altogether, the evidence presented above, gathered under unsprayed conditions, lead us to the conclusion that some of the PCs potentially found inside orchard blocks immediately after petal fall may be re-colonizers rather than true immigrants, although the exact proportion is still unknown. Under this scenario, some 12 Fruit Notes, Volume 69, Fall, 2004 of the damage by PC to fruit sampled at harvest may be as a consequence of re-mfestations that occurred after the petal-fall spray of insecticide. It would be very important to detemiine, under sprayed conditions, the extent to which PCs show this type of back-and-forth movement after the petal-fall application of insecticide. More research is also needed to determine what type of factors (e.g., weatherand tree size) influence this behavior. was supported with funds provided by a Hatch grant, a grant from USDA Crops at Risk program, and the New England Tree Fruit Research Committee. Literature Cited Lafleur, G. and Hill, S.B. 1987. Spring migration, within-orchard dispersal, and apple-tree preference of plum curculio m Southern Quebec. Journal of Economic Entomology 80: 1173-1187. A ckitowledgm en ts We thank Paul Appleton, Everardo Bigurra, Sara Hofifmann, and Isabel Jacome for assistance. This study Leskey, T.C. and Wright, S.W. 2004. hfluence of host tree proximity on adult plum curculio (Coleoptera: Curculionidae) responses to monitoring traps. Environmental Entomology 33: 389-396. vl« *3^ %i^ *A* *A^ •T» *T* *j» *Y* 'J* Fruit Notes, Volume 69, Fall, 2004 13 Is More Than One Trap Tree Required on Perimeter Rows to IVIonitor the Course of Plum Curculio Injury to Fruit? Jaime Pinero, Isabel Jacome, Paul Appleton, Marina B. Blanco, and Ronald Prokopy Department of Plant, Soil, and Insect Sciences, University of Massachusetts The concept of a trap tree as a practical approach to determine need and timing of insecticide applications against overwintered plum curculios (PCs), based on the occurrence of fresh egglaying injury, was put forward by Ron Prokopy in the 2002 Winter Issue of Fruit Notes. Based on research conducted during 2003, the following guidelines were proposed: (1) use of four vials dispensing benzaldehyde (BEN), the attractive host plant odor at a rate of -40 mg/day (= 4 BEN), in association with one dispenser releasing the attractive PC pheronione grandisoic acid (GA) at a rate of ~1 mg/day (= 1 GA); (2) use of a threshold of one fruit showing fresh PC injury out of 25 fruit sampled on a trap tree; and (3) use of a single perimeter-row odor-baited tree located mid-way of a perimeter row encompassing 60-70 yards. Because in our 2003 evaluations the greatest distance tested on a perimeter row was 30 yards to either side of a trap tree, it was not possible to determine whether trap trees would be attractive to PCs over distances longer than 30 yards. Whether or not the amount of attractive odor being emitted by a trap tree could draw PCs into an orchard from a distance greater than they would normally travel to find an orchard, which could potentially result in a greater-than-normal amount of PC injury to fruit on perimeter-row trees having trap trees, was another question that came out from the 2003 evaluations. Here, our objectives were to detennme (1) the maximum distance over which the combination of 4 BEN + 1 GA is able to congregate PCs and (2) whether an increase in the number of odor-baited trees on a perimeter row is associated with increasing amount of damage to perimeter-row fruit. = Trap tree Figure 1 . Representation of an apple orchard block having on each of its four sides either 0, 1 , 2, or 4 trap trees spaced equidistantly. Each trap tree was baited with 4 BEN and 1 GA. Each of the four sides of the blocks used for this study comprised at least 120 yards. 14 Fruit Notes, Volume 69, Fall, 2004 15 §12 "■ 9 LLi zi 6 -5 o:: Q UJ q: 3 3 - June 1-2,2004 n small trees D large trees S=^ TT 2-8 10-16 18-24 26-32 34-40 42-48 50-56 DISTANCE FROM TRAP TREE (in yards) 15 12 June 15-16,2004 n small trees ^ D large trees T ' — hr" — ' 1 I — n 1 1 TT 2-8 10-16 18-24 26-32 3440 42-48 50-56 DISTANCE FROM TRAP TREE (in yards) Figure 2. For the side of orchard blocks having only one trap tree located at the center of the perimeter row, amount of injury to perimeter-row fmit by PC on either (A) the first sampling date or (B) the second sampling date, as a function of distance from a trap tree. Trap trees were baited with 4 BEN and 1 GA on May 25-26, 2004. Materials & Methods This evaluation was conducted during May and June, 2004, in 12 sprayed sections of eight commercial orchards located in Massachusetts. Six of the orchard blocks used had small (M.9 rootstock) trees, whereas the remaining six blocks had large (M.7 rootstock) trees. Each block was composed of one or more of the cultivars Mcintosh, Gala, Delicious, Cortland, and Empire, among others. Each of the four sides of the blocks used for this study was at least 120 yards long. All trees within a block were sprayed with insecticide against PC in a similar fashion. On May 25-26 (i.e., about 10 days after petal fall), either, 1, 2, or 4 perimeter-row trap trees, each baited with 4 BEN and 1 GA, were set up on each side of a block; the remaining side of a each block had no trap trees (Figure 1). The sides of the blocks to which a Fruit Notes, Volume 69, Fall, 2004 15 B First sampling (June 1-2) D Trap trees D Non-trap trees A A a — I a ■a "E, First sampling G Trap trees 10 1 (June 1-2) n Non-trap trees a. [a 8 • 6 ■ '5 4 ■ 2 - n ■ b B 1 b B b rH^ No. trap trees IS 1 Second sampling n Trap trees 15 ■ (June 15-16) A n Non-trap trees 12 ■ A A 6 - 3 - n - a a a a 18 ■o "= 15 B^ .2,12 e = 2 Z 9 •^ i 6 3 0 I 2 No. trap trees Second sampling (June 15-16) D Trap trees n Non-trap trees A^ 'n o. trap trees No. trap trees Figure 3. For each of the four sides of orchard blocks composed of either (A) small or (B) large trees, amount of injury by PC that occurred on trap trees or on other perimeter-row trees (= non-trap trees), according to the number of trap trees deployed. particular treatment were assigned (i.e., 0, 1, 2, or 4 trap trees) were randomized to minimize variation in results due to the nature of habitat (woods, hedgerow, orchard trees) bordermg the different sides of a block. We addressed the first question by sampling 25 fruit per tree on the side of blocks having only one trap tree. This showed incidence of PC injury on perimeter- row trees located up to 60 yards on either side of the trap tree. The second question was addressed by comparing PC injury occurring on trap trees, as well as on perimeter-row non-trap trees, on each of the four sides of each block. This showed what effect trap trees exerted on total amount of injury by PC to fruit in perimeter-row trees. Amount of injury by PC to fruit was quantified twice: on June 1-2 (i.e., one week after odor-baiting) and on June 15-16 (i.e., three weeks after odor-baiting). For blocks having large trees, all perimeter-row trees were sampled for PC injury (25 fruit per tree). For blocks having small trees, either every other tree or every-two trees were sampled for PC injury (including all trap trees) because of the tree density in these blocks was much higher than in blocks having large trees. Results Combining both sampling dates, almost 63,000 fruit were sampled on the 1 2 orchard blocks used for this study. For the first objective. Figure 2 reveals that one week after deploying 4 BEN and 1 GA (i.e., on June 1- 2), the maximum distance over which PCs were congregated to a trap tree was 50-56 yards for blocks having small trees, and 42-48 yards for blocks having large trees. Three weeks after deploying the synthetic lures (June 15-16), the maximum distance over which PCs were congregated to a trap tree was 34-40 yards, regardless of tree size. For the second objective. Figure 3 A shows that, for both sampling dates and for blocks having small trees, amount of injury to fruit by PC on the trap trees was similar in the sides of blocks having either 1 , 2, or 4 trap trees, hnportantly, for both sampling dates, an almost identical amount of injury to fruit by PC occurred on non-trap trees in each of the four sides regardless of the number of trap trees deployed. Figure 3B reveals that, for large trees, initial amount of injury 16 Fruit Notes, Volume 69, Fall, 2004 to fruit by PC (i.e., first sampling) was greater in the sides of blocks having 4 trap trees than either 1 or 2 trap trees. The same result was found for amount of injury by PC in non-trap trees. For the second sampling, the amount of injury produced by PC to fruit on the trap trees was similar on the different sides of blocks, regardless of the number of trap trees deployed. The amount of injury by PC in non-trap trees was very low in general and was not associated with the number of trap trees deployed on the different sides of a block. Overall, three weeks after deploying 4 BEN and 1 GA (i.e., by June 15-16) trap ti"ees were, on average, 28 tunes more likely to retlect injury by PC than all perimeter-row non-trap trees sampled in blocks having small trees, and were 15 times more likely to reflect injury by PC than all perimeter-row non-trap trees sampled m blocks having large trees. Conclusions From the first study, we learned that the effective distance over which trap trees seemed to aggregate PC injury was at least 50-56 yards for the first sampling date and 34-40 yards for the second sampling date. We also determined that trap trees were less able to concentrate injury by PC by the first sampling than by the second sampling, in particular if blocks had large trees. We believe this result is largely due to the cool and rainy weather that prevailed from the moment in which we baited the trap trees (on May 25-26) until the first sampling (on June 1-2). Because during that period of time the release rates of the synthetic lures were presumably low, it is conceivable that PCs may have not been strongly attracted to trap trees and, as a consequence, injury to fruit by PC was more spread fi-om the trap tree for the first sampling date than for the second sampling date. After three weeks, most injury by PC occurred on the trap trees and on the most adjacent trees. Our results from the second study show that, except for blocks having large trees in the first sampling date, the amount of injuiy by PC to trap trees was similar on perimeter rows having 1 , 2, or 4 trap trees, regardless of the size of trees in a block. This finding indicates that a single trap tree deployed mid-way of a perimeter row of about 120 yards will be sufficient to monitor accurately the seasonal course of injury by PC to fruit. Remarkably, the amount of injury by PC to perimeter- row ixuit located in the side of blocks having no ti-ap trees was as low as the amount of injury that occun-ed in all perimeter-row fruit when we excluded injuiy on the trap trees. Thus, we should not expect greater-than- normal amounts of injury by PC to perimeter-row fruit by having odor-baited trap trees (regardless of the number). Whether the attractiveness of a trap tree could be enhanced by adding other types of stimuli so as to increase its ability to congregate PCs is a question that remains to be investigated. Finding a way of enhancing the attractiveness of trap trees could be very valuable, for instance, in the context of potential direct control of PC by confining insecticide sprays to trap trees only (after a whole-block spray). In the context of monitoring of PC injury, an enhanced trap tree might decrease the extent to which PCs penetrate into orchard blocks (especially in blocks having small trees) by holding PCs on perimeter-row trees, thereby making perimeter-row sprays more efficient. A ckn o wiedgm en ts We thank Bruce Carlson, Aaron Clark, Dave Chandler, Don Green, Andy Martin, Mo Tougas, and Steve Ware, for allowing us to work on their orchards. Funds for this study were provided by the New England Tree Fruit Research Committee. %i« «1> «1* «1« *1^ •^ #^ •y* •^ *y» Fruit Notes, Volume 69, Fall, 2004 17 Fruit Notes University of Massachusetts fruit Department of Plant & Soil Sciences Ugigj 205 Bowditch Hall tt^ Amherst, MA 01003 Nonprofit Organization U.S. Postage Paid Permit No. 2 Amherst, IV! A 01 002 --1 SERIAL SECTION UMASS AMHERST, MA 01003 ^■'Z^h^ 104911 ACME MAR 0 0 2005 too CAMtiKiwMfe SJ f^tfft