DnnDDnnaDnDnnnnDDanDnnDDnnDD D D a a a -«™^ □ 8 g UNIVERSITY LIBRARY 9 H □ □ UNivERsrry of Massachusetts n D UBRARY 9 n AT D □ AMHERST g n D D ° g 8ia.OGICAl D □ p □ ft - Ti 1 ■- - - - Q 9 ArRi--*^._j n □ n ci D g SCIENCES LIBRARY B n □ □ D D p □ p a p □ ^— — ^-^■^— — — i^ p a □aDnnannnnnnnDnnnpnDDDnpnnnp Fruit Notes Prepared by the Depeirtment of Plant & Soil Sciences. University of Massachusetts Cooperative Extension System. United States Department of Agriculture, and Massachusetts Counties Cooperating. Editors: Wesley R. Autio and William J. Bramlage ISSN 0427-6906 Volume 58, Number 1 WINTER ISSUE, 1993 Table of Contents Peach Pests III: Diseases of Fruit and Foliage Peach Pests IV: Diseases of Peach Wood Apple Maggot Fly Behavior: Probability of Fly Capture on Red Sticky Spheres in Relation to Fly Age and Maturity Evaluation of Four Rootstocks and Two Mcintosh Strains Do Overwintering Red Mite Eggs Portend Summer Mite Troubles? Evaluation of Red Coloring Strains of Gala Apple Spiders in Second-level and First-level Apple IPM Blocks Apple Integrated Pest Management in 1992: Insects and Mites in Second-level Orchard Blocks Fruit Notes Publication Information: Fruit Notes (ISSN 0427-6906) is published the first day of January, April, July, and October by the Department of Plant & Soil Sciences, University of Massachusetts. The costs of subscriptions to Fruit Notes are $7.00 for United States addresses and $9.00 for foreign addresses. Each one-year subscription begins January 1 and ends December 3 1 . Some back issues are available for $2.00 (United States addresses) and $2.50 (foreign addresses). Payments must be in United States currency and should be made to the University of Massachusetts. 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The University of Massachusetts Cooperative Extension System t^ers equal opportunity in programs and employment. Peach Pests III: Diseases of Fruit and Foliage Karen I. Hauschild University of Massachusetts Cooperative Extension System In "Peach Pests I" and "II," I discussed insect and mite pests of peach finiit, foUage, and wood. In this article I will focus on the diseases of peach fiiiit and foUage. There are several frequently observed dis- ease problems of peach fruit in Massachusetts. The most common of these is brown rot; how- ever, peach scab and bacterial spot also can be troublesome. X-disease and peach leaf curl are the most frequently encountered foliar disease problems. Below is a brief description of each of these problems and basic information on non-chemi- cal control measures. Brown Rot Brown rot of peaches is caused primarily by Monilia fructicola (Wint. ) [There is another spe- cies oiMonilia, M. laxa (Aderh. & Rhul.) which normally is associated with almond, apricot, or tart cherry.] M. fructicola is a fungus that over- winters in mummified fruit, or in infected flow- ers or twigs. As frviit buds open in the spring, smaU apothecia (cup-shaped mushroom-like fruiting bodies) develop from mummied fruit. Development is favored by adequate moistin*e and temperatures between 63 and 68°F. Within each apothecium, asci bearing 8 ascospores each are produced. When moisture hits these asci, the ascospores are ejected and carried by wind to peach blossoms where they cause infections. The most susceptible flower part is the pistil. Brown rot infections also can occur when conidia arise either from cankers on the tree or from the surface of fruit mummies. Spores from these conidia are carried by wind or rain to susceptible peach flowers. (For conidia to form, relative humidity must be 85% or higher.) In- fected blossoms brown and wither but remain attached to twigs. During summer months, brown rot activity decreases, but increases again as fruit begins to mature. Conidia produced on infected blossoms or on green fruit usually are the source of infec- tion for fruit at harvest. Fruit infection can occvir directly through the fruit cuticle, through natu- ral openings on the fruit, or, most readily, through wounds. Warm, wet weather favors brown rot infections. Under optimum conditions for the fungus, mature fruit can decay in a matter of hours. Initial infections on fruit ap- pear as brown, dry blotches that spread rapidly over the finiit. Spores are produced 6x)m these blotches, resulting in grey fiizz. Handling in- fected fruit also can spread the disease to uninfected fruits. Removing infected and mummified firuits can reduce disease inoculum levels. Mowing in late fall also helps reduce inoculum. Removal of twigs infected with blossom blight helps control future brown rot infections. Fungicides apphed at bloom and before moistiire forms on the surface of maturing fruits help prevent brown rot infections. Peach Scab Peach scab is an occasional problem locally, but is more prevalent in warmer peach growing areas than here. Peach scab is caused by a fungus, Cladosporium carpophilum, that over- winters on twig lesions. Conidia are produced from these lesions in the spring and they infect peach fi-uit a few weeks after petal fall. Forty to 70 days after an infection has occurred small, greenish circular spots appear on fruit surfaces, especially near the stem end. As lesions age, they become velvety (like apple scab) and black. If infections are severe, the lesions coalesce. Fruit Notes, Winter, 1993 resulting in abnormal finiit growth and fixiit cracking. Pruning to facilitate good air circulation within trees helps to control peach scab. Fungi- cides applied to control brown rot usually also are efifective against peach scab. Peach scab generally is more prevalent when warm, wet weather occurs just after shuck split. Bacterial Spot Bacterial spot, caused by the bacterium Xanthomonas pruni, can infect leaves, shoots, and fruit of peaches, apricots, and nectarines. In the spring, bacteria oozing out of overwintering cankers are carried by water droplets to young fruit leaves or shoots. Moisture in fog or dew is sufficient to spread the bacteria. Heavy rain spreads the disease even further. Frequent rains accompanied by moderate temperatures and high winds also encourage infections, espe- cially during the months of June and July. Leaf lesions are small and angular, appear- ing first as water-soaked spots and then turning brown to black. Centers of these spots often fall out, leaving reddish colored margins. Lesions generally are more severe at the tips of leaves. Leaves that are severely infected turn yellow and drop. Early season infections on fruit de- velop into cracks. Lesions are not confined to the friait surface, but rather go deep into the frijit flesh. Non-chemical controls for bacterial spot in- clude the use of resistant cultivars such as Redhaven, Loring, Sunhaven, Jefferson, and Madison. Excessive use of nitrogen may aggra- vate bacterial spot problems. to leaf tissue and infection then can occur. Leaf curl is most severe during cool, wet weather, particularly at temperatures between 50 and 70°F. Peach trees are susceptible only during the short period of bud swell to bud opening. Symptoms appear about two weeks after leaf emergence. Small, reddish areas develop on small leaves. As the disease infection progresses, the leaf wrinkles and puckers in small areas or along the entire leaf. The m^'or- ity of infected leaves drop. The fungus produces ascospores which spend the summer on the peach tree, but then produce overwintering bud conidia. Where leaf curl is severe, maintain tree vigor by: 1) thinning fruit, 2) irrigating during periods of drought, and 3) fertilizing by mid-June. A dormant spray of a copper-containing fungicide after leaf drop or before bud swell usually will control leaf curl. A recent study conducted by L. Burkham ("Alternatives for ControlHng Peach Leaf Curl" appearing in Common Sense Pest Control Quar- terly) found that organic growers in California were able to control peach leaf curl by sprajdng a seaweed fertiUzer once a month. Speculation is that susceptibility to leaf curl may be related to magnesium deficiency. Seaweed contains a high level of this element. Also, numerous nectarine and peach culti- vars have been evaluated for susceptibility to leaf cin-1. (Scorza, R. 1992. Evaluation of foreign peach and nectarine introductions. Fruit Variet- ies Journal 46: 141-144). All of the North Ameri- can cultivars mentioned in this study (Harbelle, Elberta, Redhaven, ReUance, Loring, and Sun- Ught) showed varying degrees of susceptibility. Peach Leaf Curl Peach leaf curl is caused by the fungus Taphrina deformans. Spores of the leaf curl fungus are very resistant to adverse weather and can remain dormant on twig surfaces for two years or longer. Overwintering spores are washed to the surfaces of leaf buds by spring rains. These spores then multiply during wet weather until leaf bud scales open. Once bud scales become loose, spores are carried by water X-disease X-disease is caused by a virus-like organism known as a mycoplasma. Leafhoppers carry the disease from infected chokecherries or peaches to other peach, nectarine, or cherry trees. Once in the trees, mycoplasmas live in phloem cells, a type of vascular conducting cell. Symptoms of x-disease are leaf yellowing or reddening with shot-holing appearing during July and August. Affected leaves drop, leaving Fruit Notes, Winter, 1993 "tufts" of green leaves at ends of twigs. As the disease progresses through the tree, Umbs die back and each year more of the tree becomes infected. Fruit on infected trees at first appear normal, but they most often drop prematurely. Young trees infected with x-disease should be removed and destroyed. In older trees, re- moving infected Umbs may slow the spread of the mycoplasmas; but once x-disease has started, it is difficult to control. Antibiotic therapy may help also. Removing chokecherries near peach or- chards is essential. For additional information on any of these pests, please refer to: Jones, A.L. 1976. Diseases of Tree Fruits. (Cooperative Extension Services of the Northeast States. NE 96. LaRue, J.H. and RS. Johnson (eds.). 1989. Peaches, Plums, and Nectarines: Growing and Handling for Fresh Market. Cooperative Extension, University of California. No. 331. Prokopy, R.J., P.J. Powers, D.R. Cooley, and J.W. Gamble. 1991. Peaches, Pears, Plums - Pest Control Guide for Commercial Growers in Southern New En- gland. University of Massachusetts Cooperative Ex- tension System Circular C-159 R 1991-2. ^% •10 •i^ ^L0 ^|V #J% rfi rf» •Y* •?• Peach Pests IV: Diseases of Peach Wood Karen I. Hauschild University of Massachusetts Cooperative Extension System This is the last in a series of four articles describing major insect and disease pests of peaches in Massachusetts. In this article I wiU describe diseases that attack peach wood, pri- marily canker diseases. In general canker diseases occur where peach trees are stressed due to drought, poor growing conditions, cold temperature, or poor pruning. Healthy, vigorous trees are less sus- ceptible to attack by canker diseases. Several disease organisms cause canker formation on peaches. Following are brief descriptions of the major causal agents of perennial cankers found on peaches and nectarines in Massachusetts orchards. Cytospora (Valsa) Canker Two species oiCytospora are associated with peach canker - C. leucostomia Saac. and C. cincta Saac. Cytospora overwinter in cankers or on dead peach wood. Bumps containing pyc- nidia with small conidia are produced under bark. These pycnidia grow through the bark and expose spores to rain. Splashing rain or rain driven by heavy winds spread conidia to other infection sites on damaged or injured bark. Canker growth is related to temperature and growth habit of the peach tree itself C. cincta is most active during spring and fall at tempera- tures between 60 and 75°F. C. leucostomia is more active at temperatures between 86 and 91°F, that is, during the summer months. Can- ker development can occur in one of three ways. First, cankers may extend down limbs toward tree trunks, with Umb death occiirring at the rate of one or two Umbs per year over a period of several years until the entire tree eventually is killed. This pattern is the classic "perennial Fruit Notes, Winter, 1993 canker syndrome." Second, cankers may de- velop in twigs, small branches, or around prun- ing cuts but remain localized. This type of canker generally results in only minor damage to the tree. Third, trees may leaf out normally, followed by sudden wilting and total tree death. In cases like this the tree usually is severely damaged by cold temperatures and the trunk and lower scaffold Umbs quickly are colonized by Cytospora. Again, tree health and environmen- tal factors play a major role in the severity of Cytospora. Since both species of Cytospora reqmre a wound or natural opening to infect peach trees, proper priming and pest management practices help prevent serious infections. Pruning in fall or early winter can contribute to Cytospora infections because pruning cuts made at these times do not heal as quickly as those made in the spring. For injured or weak trees, there are no chemical control measures for Cytospora that have proven completely successful, partly be- cause spores can be released throughout the year. If only a few cankers are present, remov- ing and destroying infected branches below any sign of disease can be helpful. Do not plant new pe ach orchards on poor si tes . Do not prune in the fall or early winter. Additional measures that will help prevent Cytospora canker infections include the following: 1. fertiUze trees early in the spring to avoid late growth spurts; 2. avoid mechanical injury to trees; 3. apply a fungicide spray after pruning, but before a rain; 4. avoid weak crotch angles; and 5. whitewash southwest sides of trees and lower limbs (this practice can help prevent injury due to cold temperatures). Brown Rot As mentioned in "Peach Pest III," brown rot, Monilia fructicola, can infect twigs. When the fungus moves into woody tissues it causes the development of small CEinkers. Cankers, as they grow, can girdle twigs eventually, resulting in withering and death of terminal growth. Gum- mosis often accompanies spur blight and canker formation. Cankers caused by brown rot may develop as a result of blossom blight or may move down from the finiit pedicel into a twig or larger branch. On twigs or small branches, brown rot cankers normally are eUiptical, well-defined, and brown. During wet weather, gummosis appears, followed or accompanied by tufts of grey spores. Cankers on larger branches caused by rotted fruit appear (similar to those described above, but likely to be much more severe and eventually kill the infected branch). In the year following severe canker development, leaves above the girdling cankers first appear normal then later turn yellow, wilt, and eventually die. Phytophthora Root and Crown Rot Crown rot does not appear to be a serious problem in Massachusetts peach orchards, but a brief description is given below. Waterlogged soil, air temperature, plant nutrient status, species of Phytophthora in- volved, and susceptibility of host tissue all play roles in the occurrence and severity of Phytophthora infections. Most infections occur during the spring, summer and fall months and are spread by infected plants, soil, or water. Infections that occur in crowns or larger roots (especially of yoimg trees) spread rapidly, oft^n killing trees in one or two seasons. Infected trees may appear healthy in the fall, leaf out normally in the spring, but then collapse when warmer temperatures occur. Symptoms of infection vary fi-om withered, bright rust-colored leaves on severely infected trees to decreased overall growth and smaller, yellow leaves on trees that show slower decline. Infected roots or crowns show reddish-brown necrosis of bark and outer wood with a distinct, layered margin; however, after some time roots decay and turn grey-black. Avoiding waterlogged soils, proper schedul- ing of irrigation, and proper planting practices help prevent Phytophthora infections from oc- curring and becoming severe. Bacterial Canker Bacterial canker, caused by either Pseudo- Fruit Notes, Winter, 1993 monas syrincae or P. morsprunorium, is thought to be an increasing problem in Massachusetts peach orchards. Damage by Pseudomonas var- ies among types of host fruit. On peaches, leaf and flower buds fail to open in the spring and are thought to have been infected during winter months. Or, in other instances, infected spurs show normal growth in the spring but collapse during sunmier months, turning into wilted leaves and dried-up fruit. If infection occurs annually, trees lose bearing surface. Bacteria overwinter in infected buds or can- kers. Spring rains wash bacteria to unfolding plant tissue. Frost-injvired leaves and blossoms are thought to be more susceptible to Pseudo- monas infection. Periods of cool, rainy weather foster early-season infections and disease spread. Disease spread also occurs under simi- lar weather conditions in the fall. Canker removal is the only known cultural control practice For additional information on any of these diseases, please refer to references listed in "Peach Pests III." %% ^% %% %% %% rj% •^ rj% rj* rj% Apple Maggot Fly Behavior: Probability of Fly Capture on Red Sticky Spheres in Relation to Fly Age and Fruit Maturity Max P. Prokopy, Jian Jun Duan, Gabriela G. Galarza, and Ronald J. Prokopy Department of Entomology^ University of Massachusetts To augment our current program of second- level apple IPM involving the use of baited sticky red spheres to intercept and capture apple maggot flies (AMF), we have been tracking foraging behavior patterns of female AMF. We want to know if the probability of a fly being captured on a sphere or of laying eggs in apples changes as flies age or apples mature. Methods Used In 1991, two potted apple trees were placed in screen cages on the campus of the University of Massachusetts. Each tree had approximately the same canopy size as a normal four-year-old dwarf (M.9) fruit-bearing tree. We placed either 50 green or 50 red evenly-spaced Gravenstein apples on a tree. The leaf-to-fruit ratio was about 20: 1 . The green fruit were picked on June 19 and had a diameter of about 3 cm. The red fruit were picked on August 1 and had a diam- eterofabout4.5cm. In all, 36 AMF of each of five ages were tested in the presence of only green finiit, and 30 of each of five ages in the presence of only red fruit. The flies were collected fix)m naturally infested fruit and were 3, 7, 11, 15, or 19 days old when tested. FUes seven days old or younger usually are not capable of lajdng eggs in fruit. A single fly was released onto a leaf at the lower center of the tree. A sticky red sphere, baited with one vial of the synthetic apple odor Fruit Notes, Winter, 1993 Table 1. Behavior of apple maggot females of different ages when released individually on a caged apple tree containing a sticky red sphere baited with butyl hexanoate and 50 green or 50 red Gravenstein apples.* Flies that Flies Number of laid one Fruit that captured fVuit visited or more eggs received an (%) ¥* per fly*** (%)*** egg(%) Fly age (days) Green Red Green Red Green Red Green Red 3 25 b 27 b 1.9 a 2.8 b 0 b 0 b Ob Ob 7 68 a 47 a 2.7 a 3.9 a 6 b 0 b 2 b lb 11 61 a 57 a 1.8 a 3.8 a 22 a 10 a 12 a 6 b 15 71 a 57 a 1.7 a 4.3 a 26 a 13 a 10 a 5 b 19 64 a 57 a 1.6 a 2.7 b 19 a 30 a 8 a 19 a ** Values in each column not followed by the same letter are significantly different at an odds ratio of 19:1. Represents flies captured on a sphere before leaving tree or before one hour had elapsed. *** Visits and egg laying before being captured on a sphere, before leaving the tree, or before one hour had elapsed. butyl hexanoate, was placed in the upper part of the tree canopy. After the fly was released, its movement was tracked during one hour of forag- ing within the tree. Tracking involved recording all leaves and fruit visited, all oviposition at- tempts and ovi}X)sitions, and whether or not the fly was captured on the sticky sphere. Any finiit iQ which the fly made an oviposition, or an attempt at it, was removed from the tree and dissected to see if eggs had been laid. Results Fly captures when either green or red fruit were on the tree increased significantly when the flies were more than three days old (Table 1 ). For flies seven or more days old, consistently more were captured when fruit were green than when they were red. Sixty-six percent of flies seven or more days old were captured when fruit were green; whereas, 55 percent were captured when finiit were red. Regardless of fly age, red fruit received more visits than green fruit (Table 1). Flies 1 1 or more days old were more hkely to oviposit in a frtiit than were younger ones. Interestingly, except for the oldest flies tested, a greater percentage of green fruit than red fruit received eggs. Conclusions Our results demonstrate that the age or maturity of a female AMF can strongly affect its fruit foraging and egg laying behavior and the probabihty of capture on a baited sticky red sphere. Once a female reached seven days of age, the chance that it would be captured on a sticky red sphere baited with butyl hexanoate hung in our test trees was 50% or better. As fly age increased above seven days, the probability of capture on a sphere did not increase, but the probabihty that it would lay eggs before being Fruit Notes, Winter, 1993 captured on a sphere did increase. This result indicates that for greatest effectiveness in con- troUing AMF, baited sticky red spheres should be hung very early in the fly season, before immigrating AMF have reached maturity. In addition, our findings suggest that while green apples may receive fewer visits by AMF than red apples, green apples may be more susceptible to oviposition by arriving AMF. This result again affirms the need to hang baited sticky red spheres early in the fly season for greatest effectiveness in avoiding finiit injury by immi- grating AMF. Acknowledgements This work was supported by the Science and Education Administration of the U.S.D.A, im- der grant 8900901 from the Cooperative Re- search Grants OfBce and by a USDA grant under the NE-156 Apple IPM project. ^% %% %% ^10 «^ rf* •^ rf% #J% rj% Evaluation of Four Rootstocks and Two Mcintosh Strains Wesley R. Autio and Franklin W. Southwick Department of Plant & Soil Sciences, University of Massachusetts Through the 1960's and 1970's, the trend in the New England apple industry was from seedling-rooted trees to trees on M.7 or similar sized rootstocks. In the latter part of the 1980's, the trend shifted toward smaller trees. In the 1990's, growers are planting significant num- bers of dwarf trees, mostly on M.9 and Mark rootstocks. In 1979, a planting was established at the University of Massachusetts Horticul- tural Research Center to assess rootstocks in the size range from M.7 to M.9. The planting included Rogers Red Mcin- tosh and Macspur Mcintosh on M.7A, M.26, M.9 (trained either to a post or on a 4- wire vertical trelhs, seven-feet tall), andM.9/MM. 111. Seven replications were planted, and each replication had four trees of each cultivar/rootstock combi- nation. Two trees of each group were used for data collection, and any Macspur that reverted to a nonspur habit was eliminated from the experiment. Normal fertilization and pest man- agement practices were used. All trees were maintained as central leaders. With the excep- tion of tjdng branches to the wires in the trellis treatment, very Uttle limb positioning was per- formed in the planting. After 10 growing seasons, trees on M.7A were the tallest, regardless of Mcintosh strain (Table 1). Trees on M.26 and M.9/MM.1 1 1 were similar in size and intermediate. Trees on M.9 were the shortest. Rogers trees were signifi- cantly taUer than Macspur trees. Tree spread followed a similar trend (Table 1); however, trees on M.9 trained to a trellis had a greater tree spread after 10 seasons than those trained to a post. Clearly, this difference related to the support provided to lateral branches by the trelhs wires. Tree spread was used to calculate poten- tial tree density (Table 1). It was assumed that trees could be planted 1 0 percent closer than the spread measured after 10 seasons. Seven feet Fruit Notes, Winter, 1993 Table 1. Tree size after 10 growing seasons and projected tree densities of Rogers Red Mcintosh and Macspur Mcintosh on different rootstocks. Tree height Tree spread Tree density (fl) (ft) (trees/acre)* Treatment Rogers Macspur Rogers Macspur Rogers Macspur M.7A 14.8 a* 14.9 15.8 a 14.5 145 c 172 M.26 12.0 b 9.9 13.2 be 11.5 202 b 254 M.9 (post) 8.8 c 8.4 10.2 d 9.3 297 a 363 M.9 (trellis) 9.3 c 9.0 12.9 c 10.6 295 a 363 M.9/MM.111 11.5 b 10.0 14.3 b 12.0 172 b 239 Average 11.3 ••• 10.4 13.3 - 11.5 222 - 278 Distance between trees within rows was projected to be 10% less than the natural tree spread, allowing for overlap of trees. The distance between rows was the distance between trees plus seven feet, with the exception of the trelhs, which was assumed to be spaced 13 feet between rows. For the three characteristics in this table, the relative differences between rootstock treatments were statistically similar for each strain. The letter presented between the Rogers and Macspur columns represents the differences among rootstock treatments only. For a particular characteristic, if not represented by the same letter, rootstock treatments are significantly different at odds of 19:1. Rogers and Macspur averages are different at odds of 999:1. were added to the distance between trees in a row to determine between-row spacing, with the exception of the trellis. Because of the shape of the trelUs, it was assixmed that all trellis combi- nations could be maintained at 13 feet. (This assumption is conservative, and it depends on the final width of the trellis rows.) Potential tree density ranged from over 360 trees per acre of Macspur/M.9 to 145 trees per acre for Rogers/ M.7A, Because of the difference in spread, Macspur could be planted at approximately a 20 percent higher density than Rogers, assuming no reversion. Figures 1 and 2 show the cumulative yield per tree for the rootstock treatments and the Mcintosh strains, respectively. (jeneraUy, larger trees )delded more per tree than smaller trees, that is, trees on M.7A yielded more than those on M.26, which yielded more than those on M.9. The exception is M.9/MM. 111. Trees on M.9/MM.111 yielded significantly less than the trees on M.26, which were of similar size. Trees on M.9 trained to a treUis yielded more than those trained to a post. This result may have occurred because the trellis maintains wood at a more desirable angle for continued Smiting and allows for upper branches to fill a larger portion of the canopy than when no additional support is provided. Additionally, the larger Rogers trees yielded more than the Macspur 8 Fruit Notes, Winter, 1993 20 Rootstocks: a _ -»-M.7A > ^15 -°-M.26 o> -^ M.9 (post) / b 1 i» ^ M.9 (trellis) Q. |io >> -•-M.9/MM.111 1 y Ztf:=C^ Cumulative ...>^^' 1982 1983 1984 1985 1986 1987 1988 Figiire 1. Cumulative yield per tree through the tenth growing season for each rootstock treatment (average of the two Mcintosh strains). 20 — 15 o> Q. •55 10 > E 3 o Strains: ^*" Rogers ^ Macspur /L^^^^'o 1982 1983 1984 1985 1986 1987 1988 Figure 2. Cumulative jdeld per tree through the tenth growing season for each Mcintosh strain (average of the five rootstock treatments). Truit Notes, Winter, 1993 4 o o o Rootstocks: -•-M.7A a. k 33 -^M.26 -^ M.9 (post) 0C ^ r 1 • 2 0 ^M.9 (trellis) / X^y^° 1.2 ♦M.9/MM.111 y ///^ ^ > « >> y1^^^^:^y^ ? 3 E 3 u .^^'^ 1982 1983 1984 1985 1986 1987 1988 Figure 3. Cumulative yield per acre through the tenth growing season for each roots tock treatment (average of the two Mcintosh strains). 4 Strains: 0 0 0 ^ Rogers ^3 "H- Macspur a 1 y^ ^ £ u y^^^b // •0 » >> ^^^:^ 0 > 3 E 3 0 1 ^^---^ 1982 1983 1984 1985 1986 1987 1988 Figure 4. Cumulative yield per acre through the tenth growing season for each Mcintosh strain (average of the five rootstock treatments). 10 Fruit Notes, Winter, 1993 Table 2. Economic comparison of the five rootstock treatments (average of both strains of Mcintosh). Establishment costs were modified fi-om those presented in Fruit Notes 55(4): 1-5. Growing and harvesting costs were modified from those presented in Fruit Notes 53(l):4-7. Item M.7A M.26 M.9 (post) M.9 (treUis) M.9/ MM.lll Costs: Establishment Growing Harvesting $920 $6,660 $4,780 $2,030 $6,540 $5,040 $2,980 $7,010 $5,170 $3,900 $7,190 $6,170 $1,730 $6,540 $3,730 Total yield (bu)* 2780 b 2930 b 3010 b 3590 a 2170 c U.S. Extra Fancy, 1987 + 1988 (%)• 37 d 62 be 64 b 51 c 80 a Fruit count per 42 lbs, 1988* 140 a 125 b 120 c 119 c 144 a Estimated crop value $25,890 $36,210 $39,310 $42,650 $25,370 Net returns $13,530 $22,610 $24,150 $25,390 $13,370 Within a row, means 19:1. not followed by the same letter are significantly different at odds of trees. Obviously, the amount of fi*\iit obtained fix)m individual trees is of little importance when the trees are at different densities. Fig- ures 3 and 4 show the cumulative yield per acre for the rootstock treatments and the Mcintosh strains, respectively. M.9 trained to a trelHs resulted in the highest jdelds per acre. M.9 trained to a post, M.26, and M.7 were statisti- cally similar in cumulative yield, and M.9/ MM.lll resulted in the poorest yield per acre, yielding only 60 percent of trees on M.9 trained to a trelUs. Macspur trees outyielded Rogers trees on a per-acre basis. Factors other than yield must be consid- ered before selecting the most desirable root- stock or training system. Establishment, grow- ing, and harvesting costs vary fi-om treatment to treatment. Estimates of these differences are presented in Table 2. Also, packout is an impor- tant consideration. Table 2 presents the percent of a whole-canopy random sample which made the U.S. Extra Fancy grade in 1987 and 1988. Trees on M.9/MM.111 produced the most high grade fruit; whereas, trees on M.7A produced the least. Of the M.9-rooted trees, those on posts produced more U.S. Extra Fancy finiit than those on trellises. These numbers were used to approximate the grade distribution of fi-uit. It was assimaed that one half of the fi-uit not making U.S. Extra Fancy were Number 1 and the other half were used for cider. These esti- Fruit Notes, Winter, 1993 11 $30 o" Rootstocks: 1 $25 -fr^M.TA A f x^ 2^ $20 u 10 -0-M.26 -^ M.9 (post) 0/ ] |$15 M -A-M.9 (trellis) ♦ M.9/MM.111 1/ y > 1 $10 yi'/ -^ ^Z c ji^ Cumulative U1 o y^^^6^ ^^ -$10 19 79 1980 1982 1982 1983 1984 1985 1986 1987 1988 Figure 5. Cumulative net returns per acre for the ten years 1979 through 1988. mates are conservative, since the sample for grading was random. Multiple pickings would have resulted in greater percents in the highest grade. Additionally, no summer pruning was performed in our trellis treatment, and fruit quahty clearly would have benefitted greatly fi*om summer pruning. Fruit size also varied significantly among the treatments (Table 2). The average fruit from trees on M.7 or M.9/MM.111 were 140-count or smaller. Fruit from trees on M.9 averaged nearly 120-count in size, and those from trees on M.26 were somewhat smaller than 120-count. When size and grade are considered, along with yield, crop value can be estimated (Table 2). Accomiting for crop value and costs, Table 2 presents the net returns possible from these treatments. The two M.9 and the M.26 treatments produced similar returns, with the M.9 trellis treatment giving approximately five percent more, and the M.26 treatment giving approximately six percent less than the M.9 post. The M.7A treatment netted only 53 per- cent of what the M. 9 trellis netted. M. 9/MM. Ill was slightly less profitable than M.7A. When evaluating different rootstocks and training systems, it is necessary to assess many different characteristics. Costs of estab- hshment, training characteristics, jrield poten- tial, fruit grade, fruit size, and costs of manage- ment must all be considered before selecting an appropriate combination. The best system is the one that can be managed within the con- straints of a particular grower and that provides the best net returns to the orchard. In this study, trees on M.9 and on M.26 were the most profitable over the first ten years, and clearly would be better choices than trees on either M.7AorM.9/MM.lll. ^f^ %f^ %{« «£# %t« 0^ rj% rj% •Y* •Y* 12 Fruit Notes, Winter, 1993 Do Overwintering Red Mite Eggs Portend Summer Mite Troubles? Jennifer Mason, Margaret Christie, and Ronald Prokopy Department of Entomology^ University of Massachusetts Among foliar pests, European red mites (ERM) remain a major problem for apple trees. They can be particvdarly difGcvdt in second- level IPM blocks, where growers are dependent on predator mites to control summer ERM popula- tions. In these blocks, current non-biological control measures consist of one or two dormant oil sprays in the spring prior to egg hatch. To maintain control of ERM, predators build up to levels capable of controlling the mites that hatch. Unfortunately, it is difiicult to balance spring oil control of ERM and encouragement of a healthy population of predator mites. This leads to the question: Can prebloom oil alone effectively control summer ERM populations? During January of 1992, we collected 200 buds per orchard from 11 orchards that partici- pate in the second-level IPM project. Six of these were full second-level IPM blocks, and five were transitional second-level blocks. The percentage of buds with ERM eggs present was recorded for each block, and orchards were placed into three categories: low (0-33%), medium (34-66%), and high (67-100% of buds with mite eggs). During late spring and summer months, mite populations in each block were recorded as part of normal IPM scouting procedures. ERM presence or absence was counted on 200 fruit cluster leaves beginning in May and continuing through September. Examination of peak ERM populations in the second-level IPM blocks in May showed little or no apparent relationship between winter ERM egg percentages and spring mite numbers. Peak ERM populations in June, however, were related to winter egg per- centages (Table 1). The low and medium ERM egg groups both had very low June ERM popula- tions, but all orchards in the high ERM egg group had substantial numbers of Jxine mites. In first-level blocks there appeared to be no consistent relationship between overwintering egg numbers and June mites, which were low in all of these orchard blocks (Table 1). Of the second-level blocks, all received at least one dormant oil spray prior to egg hatch in the spring (Table 1). In the high group, two blocks had received two sprays. In the low and medium orchards, it appears that dormant oil sprays were sufficient to control mite popula- tions through June. In the orchards in the high group, however, even those receiving two appli- cations had thriving ERM populations by the endof Jvme. Further work needs to be done on the rela- tionship between dormant oil sprays, overwin- tering ERM eggs and resulting early summer ERM populations before any firm conclusions can be drawn. If these results are estabhshed as fact, then oil spray recommendations may need to be revised for blocks where high numbers of overwintering ERM eggs are foxuid in winter coimts. Without a strong predator population, these orchards may be subjected to large sum- mer ERM populations if they depend on normal amoimts of prebloom oil to be effective. Higher rates of oil (e.g., three gallons of oil per 100 gallons of water) at green tip or half -inch green may be necessary, with a second oil treatment at a lower rate at tight cluster. It is p>ossible, however, that the higher mite numbers in the high blocks may be "attractive" to predator populations, and that these orchards may even- tually become areas of good biological control. Fruit Notes, Winter, 1993 13 Table 1. Overwintering egg and peak mite levels in eleven second-level and eleven first-level IPM blocks. Number of Number of dosage Twigs with Leaves with prebloom oil equivalents overwintering ERMin Orchard sprays of oil eggs (%) June (peak %) Second-level IPM blocks A 3 1.8 4.5 2.5 B 2 0.9 8.5 0.0 C 1 1.0 16.0 0.5 D 2 1.5 35.0 0.0 E 2 44.5 0.0 F 2 1.3 56.0 0.5 G 2 1.5 58.0 1.5 H 1 0.8 81.0 13.0 I 1 0.3 90.0 19.5 J 2 1.0 90.0 13.0 K 2 1.5 92.0 19.5 First-level IPM blocks A 3 1.8 4.5 2.5 B 2 1.3 31.0 1.5 E 2 37.5 2.0 F 2 1.3 40.0 2.5 G 2 1.5 44.0 0.5 C 1 1.0 63.0 0.5 J 2 0.8 75.5 6.5 I 2 0.8 78.5 0.0 D 2 1.5 81.0 0.0 K 2 1.5 81.5 0.0 H 1 1.0 87.0 4.0 1 Acknowledgements We are grateful to the Massachusetts Soci- ety for Promoting Agriculture, the USDA North- east Regional IPM Competitive Grant Program, and State/Federal IPM fimds for funding this project. %% %% ^t^ %% %f^ ry% •^ ry% ry% rj% 14 Fruit Notes, Winter, 1993 Evaluation of Red Coloring Strains of Gala Apple Duane W. Greene And Wesley R. Autio Department of Plant & Soil Sciences, University of Massachusetts Gala is an apple that has experienced a recent and rapid rise in popularity throughout the world. It is being planted heavily in Europe, South America, New Zealand, and the United States. Gala represented 25% of all apple trees sold by Washington State nurseries in 1990. Gala has many desirable characteristics, including very high flesh quahty, attractive appearance, precocity, and high productivity. The original strain of Gala is not a red apple, but rather, a cream-yellow one with an orange-red cheek. Mutations in fruit skin coloring occur readily. There is a general preference among nurserymen and growers for red coloring strains of a cultivar because there is the perception that these strEuns are preferred by the consumer. It is commonly accepted that the red coloring strains of Delicious that are being sold today, although very attractive, have decidedly infe- rior quality compared with the original Deli- cious strain. Further, production from some strains of Delicious may be only one third of more productive strains. There has been no comprehensive evalua- tion of the commonly- available strains of Gala. A Gala strain trial con- taining Kidd's D-8 (stan- dard). Royal, Regal (Fulford), Imperial, and Scarlet Gala was planted at the University of Mas- sachusetts Horticultural Research Center in Belchertown in 1988. This report summarizes growth, flowering, fruit characteristics, and fi*uit quahty of these five strains of Gala. lyees Kidd's D-8 and Royal Gala were obtained fi-om Stark Bros. Nursery, Louisiana, Missouri, and Imperial and Regal Gala were obtained fi-om Newark Nursery, Hartford, Michigan. All trees were on M.26 roots tock and were similar in caHper at planting. Propagating wood of Scarlet Gala was obtained fix)m Txu-key Hollow Nursery (Cumberland, Kentucky) in the spring of 1987, bench grafted on M.26 rootstock and then lined out in the nxirsery. In the spring of 1988, trees were planted in a randomized complete block design with eight rephcations. Each tree was supported by a one-inch x 10-foot metal conduit post set three feet in the ground. The first data on these trees were collected in 1990. Table 1. Growth in 1990 of five strains of Gala planted in 1988. Strain Kidd's Royal Scarlet Imperial Regal Trunk cross- Final sectional trunk area cross- Tree Tree increase in sectional height (ft) spread (ft) 1990 (in=^ area (in^) 9.6 a 7.9 a 1.4 a 5.3 a 9.9 a 7.6 a 1.5 a 5.6 a 8.9 a 5.0 b 1.4 a 4.0 b 10.2 a 7.6 a 1.7 a 5.2 a 9.2 a 6.9 a 1.6 a 4.9 a Means within columns not followed by the same letter are significantly diff'erent at odds of 19:1. Fruit Notes, Winter, 1993 15 Growth Prior to bud break in 1990, a line was painted 20 inches above the soil surface and the trunk circumference was measured. After leaf fall, height, spread, and trunk circumference were measured. At the end of the third leaf. Gala strains differed little in vegetative growth. The height of all Gala strains was comparable, while the spread of Scarlet was smaller than that of the others (Table 1). The trunk circumference in- crease of all Gala strains in 1990 was similar, but the total cross-sectional area of Scarlet was less. Scarlet Gala trees were smaller at planting because they were bench grailed and grown for only one year; the other strains were budded on roots that were in the ground for one growing season and grew an additional year after bud- ding. Therefore, the small spread and trunk cross-sectional area of Scarlet Gala trees is probably a reflection of the tree size at planting rather than inherent vigor of the strain. Bloom, and Fruit Set Two limbs per tree were selected at the pink stage of flower development and the circumfer- ences were measured. The numbers of blossom clusters on one-year-old and two-year-old wood were counted. In 1991, fi-uit set also was as- sessed on these two hmbs in July by determining separately the fruit persisting on one-year-old and on older wood. Spur bloom density was lowest on Scarlet Gala and highest on Royal Gala in 1990, but there were no differences in 1991 (Table 2). Fruit set on all strains of Gala was comparable Table 2. Flower bud formation and fruit set of five strains of (Jala.* Bloom density Fruit set (blossom clusters/in Mimb (firuit/in" limb Strain cross .-sectional ar ea) cross-sectional area) Spur One-yr-old Total Spur One-yr-old Total 1990 Kidd's 52 ab 124 a 176 ab .. Royal 63 a 123 a 186 a ~ ~ ~ Scarlet 16 c 128 a 144 be — ~ ~ Imperial 34 be 103 a 137 c ~ ~ ~ Regal 46 ab 102 a 148 be 1991 Kidd's 67 a 147 a 214 a 35 a 85 a 121 a Royal 66 a 127 a 193 ab 44 a 77 a 121 a Scarlet 61 a 132 a 192 ab 30 a 77 a 108 a Imperial 48 a 117 a 164 b 25 a 67 a 92 a Regal 52 a 134 a 185 ab 23 a 68 a 92 a * Means within columns and years not followed by the same letter are significantly different at odds of 19:1. 16 Fruit Notes, Winter, 1993 and very heavy. In general, the bloom density of Imperial Gala was lower than that of the other strains. Bloom on all trees was considered 'snowball* and excessive when compared to most other cultivars. Although the lower bloom den- sity of Imperial may have been real, it is of Uttle practical significance because of the excessive bloom that occurred on all strains in this trial. All strains of Gala bloomed extensively and comparably on one-year-old wood, accounting for over two-thirds of the bloom. Following June-drop, over two- thirds of the fruit that per- sisted originated from one-year-old wood. Fruit produced from bloom on one-year-old wood gen- erally was small and the quality was inferior. Since fruit size of Gala is normally small, and lateral fi^dt are even smaller, it is important to develop a thinning strategy for all strains of Gala to remove fiiiit developing from lateral bloom selectively. Fruit Characteristics and Quality At normal harvest, 15 fruit per tree were sampled. Fruit were weighed, flesh firmness and soluble soUds measured, ground color and starch pattern were rated, and p>ercent red color on each fi-uit was estimated to the nearest 10%. In 1991, finit were harvested September 3, 12, and 19. Additionally, stem-end cracking was evaluated and the length-to-diameter ratio was determined. Table 3. Fruit characteristics of five strains of Gala at harvest.* Fruit size Flesh Soluble Red Ground 1 i'edicel-end (count/ firiimess solids color color Starch L/D cracking Strain 42-lb box) (lbs) (%) (%) index** index*** ratio (%)**** 1990 Kidd's 111 a 19.2 ab 14.2 b 74 b 7.1 b 5.6 a __ __ Royal 114 a 19.9 a 14.6 b 88 a 7.1 b 5.0 a ~ ~ Scarlet 119 a 19.7 a 15.0 ab 80 ab 7.2 b 5.4 a — — Imperial 110 a 20.0 a 14.5 b 86 a 7.2 b 4.7 a — — Regal 107 a 18.3 b 15.7 a 84 ab 1991 8.1 a 6.8 a Kidd's 135 b 18.3 b 13.0 c 70 c 6.7 b 5.4 a 0.86 a 2.2 b Royal 131 b 18.0 ab 13.2 b 77 b 6.8 b 5.2 a 0.87 a 1.1 b Scarlet 126 b 19.6 a 14.2 a 78 b 6.9 b 5.1 a 0.86 a 4.6 b Imperial 126 b 18.6 b 13.3 b 87 a 6.9 b 5.3 a 0.87 a 6.7 b Regal 112 a 18.7 ab 14.4 a 89 a 7.5 a 5.9 a 0.86 a 21.1 a * Means within col umns and years not followed by the same letter are significantly different at odds of 19:1. ** Adapted from a New Zealand Gala ground color chart provided by Dr. Ian Warrington, 1 = green; 10 = orange. *** Starch chart developed by W. R. Autio, 1 = immature; 9 = oveiinature. 1 *♦** Cracking on the third harvest, September 19, 1991. Fruit Notes, Winter, 1993 17 There were no differences in fi-uit weight among strains in 1990, but in 1991, Regal Gala stood alone as the strain with the largest finiit (Table 3). Strains differed in flesh firmness and soluble solids but the differences were not con- sistent in the two years evaluated. All strains of Gala colored well, although red coloring selec- tions generally had more red color. Quantitative differences in red color among red coloring sports were not consistent. Regal had the high- est ground color rating, indicating a greater loss of chlorophyll. Strains did not differ in either starch index or length-to-diameter ratio. Sig- nificant stem-end cracking did not occur vmtil the last harvest in 1991 and then it occurred only on Regal Gala. There were clear indications that Regal Gala was an early maturing strain. As Gala ripen, ground color index, starch index, red color, soluble sohds and finiit cracking increase. Regal Gala differed consistently from the other strains in each of these characteristics in a way that indicated advanced ripening. Cracking at harvest has been cited as a problem with Gala in some areas, and that problem may be associated with uneven ripen- ing. If trees are thinned properly and pruned to allow good light penetration, we have observed that Gala can be picked injust two harvests. No significant cracking occurred until the last har- vest, and even then, it was restricted to Regal Gala. All strains could have been harvested before September 19, 1991, and Regal Gala a week earlier, when cracking was minimal. Therefore, we feel that cracking is not a problem with Gala if finiit are harvested at the proper time. When cracking does become a problem, fi-uit maturity has advanced to a point where fi-uit feel 'greasy*, and the postharvest life has been diminished significantly. Sensory and Visual Evaluation In 1991, sensory and visued evaluation of strains (Table 4) was done by 17 judges includ- ing pomology faculty, pomology graduate stu- dents, technical assistants, and students in an orchard management class. Each panelist evaluated three repUcations. A replication in- cluded one fi-uit of each of the five strains and one Table 4. Visual and sensory evaluation of five strains of Gala at harvest* Skin Flesh Strain Aroma toughness crispness Juiciness ! Sweetness Acidity Starchiness Flavor Kidd'8 -0.1 a 0.2 a 0.1 b 0.2 a 0.2 a -0.3 c 0.0 a 0.1c Royal -0.3 a 0.5 a 0.8 a 0.4 a 0.5 a 0.6 ab -0.2 a 0.9 a Scarlet 0.0 a 0.5 a 0.8 a 0.3 a 0.4 a 0.8 a -0.1 a 0.7 ab Imperial -0.6 a 0.5 a 0.2 b 0.3 a 0.1 a 0.3 b -0.2 a 0.4 be Regal -0.1 a Color 0.6 a 0.4 Color b 0.4 a 0.7 a Overall 0.5 ab 0.0 a 1.1 a Kidd'8 brightness uniformity Attractiveness desirability 0.1c -0.1 c 0.1 b 0.2 b Royal 0.8 b 0.9 b 0.7 b 0.8 a Scarlet 0.7 b 0.6 be 0.5 b 0.7 a Imperial 0.7 b 0.8 b 0.8 b 0.5 ab Regal 1.7 a 1.7 a 1.6 a 1.0 a •Means within columns not followed by the same letter are significantly different at odds of 19:1. 18 Fruit Notes, Winter, 1993 reference fruit to which all of the strains were compared. The reference fruit was Kidd's D-8, and this fact was not divulged to the panehsts. Judges scored each fi*uit on a horizontal scale with opposite descriptive terms at each end of the line and the center represented by the refer- ence fruit. The intensity of the deviation of each fi-uit from the reference fruit was recorded by a pencil mark either to the right or left of the reference fruit. Taste pgmeUsts were able to distinguish dif- ferences in quality and appearance among the Gala strains. Royal, Scarlet, and Regal Gala all were judged to have better flavor than Kidd's D- 8. Royal and Scarlet had the crispiest flesh. The flesh of £dl red-coloring strains was more acid than Kidd's D-8. There were no differences eunong strains in aroma, skin toughness, juici- ness, sweetness, or starchiness. Regal Gala was judged to be the most attractive Gala strain. It also had the brightest red color and the most uniform color. There are legitimate concerns that the Gala strains selected solely on the basis of red skin color may not have the same high quality char- acteristics of the original Kidd's D-8 strain. Not only were all strains judged to be equal to Kidd's D-8, but when panelists considered all factors and rated overall desirability, Royal, Scarlet, and Regal Gala were selected as being better than Kidd's D-8. Conclusions Growth Emd bloom characteristics of Gala strains appeared to be similar; however, all strains bloomed heavily on one-year-old wood. Because of the lower value of fruit borne on this wood, thinning strategies should target these fruit. Regal is an early maturing strain of Gala, and was selected by paneUsts as the most attrac- tive strain. Royal, Scarlet, and Regal were judged to have better flavor and to be, overall, more desirable than Kidd's D-8 Gala. %|# %% %% ^f^ ^% rj* #1% rj% #1% •Y* Fruit Notes, Winter, 1993 19 Spiders in Second-level and First-level Apple IPM Blocks Joanna Wlsniewska, Yanghe Yang, and Ronald Prokopy Department of Entomology^ University of Massachusetts One of the principal practices of full second- level IPM is to control key summer fruit pests by a combination of behavioral and ecological tech- niques, thus allowing beneficial predators and parasitoids to increase enough to control sum- mer foUar pests. Spiders may be an important group of such predators. Insecticides can reduce numbers and diversity of spiders in apple or- chards. Therefore, full second-level IPM, which eliminates insecticide use Eifter early June, may allow spiders to prohferate in apple orchards. In 1992, we assessed spider populations in blocks of apple trees under full second- level IPM compared with first-level IPM practices. Addi- tionally, we conducted a laboratory test of the effects of Guthion™, Thiodan™, and Omite™ on the most common spider species found in second- level IPM blocks. Besides these evaluations, we also were in- terested in the effects of herbicides on spider populations in these orchards. Frequently, veg- etation growing under apple trees is controlled in commercial orchards with herbicides applied early in the growing season, v/hile vegetation between the tree rows is mowed throughout the season. These practices reduce competition for nutrients, lower humidity (which may contrib- ute to higher disease pressure), and eliminate alternative sources of food and shelter for many orchard pests. Herbicides can decrease spider numbers in vegetable production systems (Riechert and Bishop, 1990), but their effects have not been examined in an orchard system. Hence, in 1992, we examined the effects of herbicide treatments on the number of spiders on apple trees in second-level IPM blocks. Spider Numbers in Full Second-level and First-level IPM Blocks Spiders were sampled in six apple orchards. Each orchard contained a six- to nine-acre block imder full second-level IPM and a nearby six- to nine-acre block under grower-supervised first- level IPM. Guthion and Thiodan were used in both types of blocks through early or mid-June to control early-season insect pests. After mid- June, second-level blocks received no insecti- cides while first-level blocks received an average of 2 sprays of Guthion or Imidan (once in July and once in August). All blocks were sprayed with carbaryl in early June to thin finiit. Beginning in early July, spiders were sampled on twenty randomly chosen trees every two to three weeks in both tjT)es of blocks in each orchard by tapping tree branches with a rubber mallet over a two-by-two-foot tray. Spiders were preserved in 70% alcohol and returned to the laboratory for identification, a process not yet complete. Figure 1 summarizes the results obtained over the entire season. The mean number of spiders collected per tree at the beginning of the sampUng period (July 2) was very low and W£is the same in both second-level and first-level IPM blocks. As the season progressed, however, these numbers increased to 1.5 spiders per tree by late September in the second-level blocks compared with 1.0 spiders per tree in the first- level blocks. Data trends were similar for each orchard considered, except for one orchard where there seemed to be no difference between the two types of blocks. The low numbers of spiders per tree in early July in all blocks may have been due to spraying for plum curculio, which extended through early to mid-June in all blocks. Beyond mid-June, growers continued to use insecticides in the first- level blocks but not in the second-level blocks. This difference probably accounted for the greater abundance of spiders in the second-level 20 Fruit Notes, Winter, 1993 1.8 1.6 - O 2nd level IPM • 1st level IPM a P 1) t) V a. 1.4 1.2 - / / - V •g 'q. in o 1.0 0.8 _ / / /•: c o l> 2 0.6 0.4 - c / / V / b 0.2 _a -4==^::^ » b 0.0 7/2 7/17 7/30 B/23 9/10 Collection period 9/24 Figure 1. Numbers of spiders collected per tree ia full second- level and first-level IPM blocks during 1992. Means within each date accompanied by a different letter are significantly different at odds of 19:1. blocks during August and September, a conclu- sion reinforced by laboratory findings (next sec- tion). Insecticide and Miticide Effects on Spiders To test the effects of insecticides and miti- cides on spiders directly, a laboratory test was conducted on the most common spider species found in all six orchards: Araniella displicatta (Araneidae). All individuals tested were imma- ture, averaging 2 mm in size (the size found in early September in the field). All were collected at the same time in the same orchard. Spiders ity to pesticides. cation). Ten additional jars were coated with water as controls. After 9 hours all 10 spiders in the Thiodan jars were dead, as were 9 of the 10 in Guthion jars. None died in the Omite or control jars, although one spider died in the Omite jar after 45 hours. These results indi- cate that these insecti- cides were highly toxic to spiders, or at least to this particular found species. Omite, on the other hand, was not very toxic to this species of spider. It would be inappropriate, how- ever, to apply these find- ings to all orchard pesti- cide-use situations, in that pesticide effects may not be confined to pure contact toxicity. Also, many different spider species exist and some may differ from A. displicatta in susceptibil- Effects of Herbicides on Spiders on Apple Trees To determine if herbicide treatment of ground cover affects the number of spiders on trees, some trees in five second-level IPM blocks were not treated with herbicide while a herbi- cide treatment was apphed in May beneath other trees. Two additional blocks (likewise under full second-level IPM) at the University of Massachusetts Horticultural Research Center (HRC) in Belchertown also were employed in this experiment. Herbicides vised included para- were placed individually in glass jars coated quat and simizine in the HRC blocks, and these with the substance to be tested. Ten jars were herbicides as well as Post™, amate, and coated with Guthion, 10 with Thiodan, and 10 Fusilade™ in the five second-level IPM blocks, with Omite (each at standard field rate of appli- The two HRC blocks consisted of dwarf trees Fruit Notes, Winter, 1993 21 3.5 3.0 " 2.5 « a m \- «) ■o ■q. 2.0 -s 1-5 o u 2 1.0 0.5 - 0.0 O herbicides • no herbicides 7/16 8/19 Collection period 8/31 9/15 Figure 2. Effects of herbicide treatment of ground cover on the mean number of spiders per tree at different times of the season. This portion of the study was conducted in two blocks at the University of Massachusetts Horticultural Research Center which were under second-level IPM. Means within each date accompanied by a different letter are significantly different at odds of 19:1. (seven feet tall). On each sampling occasion (five in all, starting Jvdy 1), spiders were collected from 40 trees of each treatment. The five sec- ond-level IPM blocks contained larger trees (10 to 13 feet tall). Forty to 65 of these in each treatment were sampled on four different occa- sions from each orchard. Sampling was carried out by tapping the branches as described above. In the five full second- level IPM blocks, her- bicide treatments did not have any effect on the number of spiders on trees. Mean numbers of spiders per tree show the same seasonal trend for herbicide as well as non-herbicide treat- ments. In the two HRC blocks (Figure 2), herbicide-treated trees contained significantly more spiders in August than non-herbicide- treated trees. There were no significant differences earlier and later in the season. Lack of any difference between herbicide- and non-herbicide-treated trees in the five second- level IPM blocks might have been due to the fact that trees in these blocks werematiire. Their cano- pies reached well into the vegetative region between rows, diminishing the con- trast between herbicide and non-herbicide treat- ments. In general, it can be concluded that no nega- tive effect of herbicide treatment on numbers of spiders per tree has been demonstrated by these data. Among smaller trees there may be a slight positive effect. Perhaps when an understory cover exists directly beneath the trees, spiders may forage there for prey and be di- verted away from the trees. They may move back into the tree cano- pies when there are more insect prey to be foimd there than in the ground cover. Conclusions Spiders were found to be significantly more abundant in second-level than in first-level IPM blocks. This result suggests that elimination of insecticide use after early or mid-June allows an increase in population of at least one group of natural enemies. High toxicity of broad-spec- trum insecticides to spiders, as revealed in our laboratory tests, supports this suggestion, £is do findings of Mansour et al. (1980), Madsen and 22 Fruit Notes, Winter, 1993 Madsen (1982), and Bostonian et al. (1984) and other authors. The decreased number of spiders in first- level IPM blocks may have been due not only to direct contact toxicity of insecticide but also to insecticide acting as a repellant to spiders, tox- icity to spiders of prey feeding on insecticide- treated plant material, lack of prey insects (as a result of prey being killed or driven away by pesticide), destruction of webs by turbulence created by spraying, or a combination of these and other factors. Several questions stiU remain to be an- swered. One of them is whether or not the increased number of spiders in second-level IPM blocks is great enough to contribute signifi- cantly to the control of foliar pests. Can spiders prey effectively on leafminers, leafhoppers, and mites? Will they eat enough of such pests to make a difference? We plan to address these questions in the near futiu-e. Acknowledgements This project was funded by the Massachu- setts Society for Promoting Agriculture, the USDA Northeast Regional IPM Competitive Grants Program, and State/Federal IPM funds. We gratefully acknowledge this funding. We are grateful to the following growers for their par- ticipation and support: Dana Clark, Dave Chan- dler, Dick Gilmore, Tony Lincoln, Wayne Rice, and Joe Sincuk. Literature Cited Bostonian, N.J., CD. Dondale, M.R. Binns, D. Pitre. 1984. Effects of pesticide use on spiders (Araneae) in Quebec apple orchards. Canadian Entomologist 116:663-675. Madsen, H.F. and B.J. Madsen. 1982. Popula- tions of beneficial and pest arthropods in an organic and a pesticide treated apple orchard in British Columbia. Canadian Entomologist 114:1083-1088. Mansour, F., D. Rosen, and A. Sulov. 1980. A survey of spider populations (Araneae) in sprayed and unsprayed apple orchards in Israel and their ability to feed on larvae of Spodoptera littoralis (Boisd.). Acta Oecologica: Oecol. Applic. 1:189-197. Riechert,S.E. and L. Bishop. 1990. Prey control by an assemblage of generalist predators: spi- ders in garden test systems. Ecology 71:1441- 1450. •^ ^JV •t» ^JV ^{f ^ ^ rfi rf» #Y* Fruit Notes, Winter, 1993 23 Apple Integrated Pest Management in 1992: Insects and Mites in Second-level Orchard Blocks Margaret Christie, Ronald Prokopy, Kathleen Leahy, Jennifer Mason, Andrea Pelosi, and L. Kate White Department of Entomology, University of Massachusetts Last spring, in Fruit Notes [57(2):5-13], we reported results of oiir first year of second-level IPM trials in Massachusetts apple orchards. Under second-level IPM, orchard management is integrated across all classes of pests: insects, mites, diseases, weeds, and vertebrates, rather than focusing on a single type of pest. Here, we report results of the second year of second- level IPM trials on insects and mites in commercial Massachusetts orchards. Insect and mite management under second- level IPM practices requires appUcation of three to four selective insecticide sprays fi-om April to early June to manage tarnished plant bug (TPB), European apple sawfly (EAS), plum curculio (PC), green fruitworm (GFW), the first generations of codling moth (CM), lesser appleworm (LAW), leafminer (LM), and leaf- hopper (LH). Insecticide application to the inte- rior of the block ceases after the final plum ctu"cuho spray in early June, allowing natural populations of predatory insects and parasitoids to increase to levels we hope will be sufficient to provide control of summer populations of foliar pests. In full second-level IPM blocks, apple maggot flies (AMF) are controlled by perimeter interception traps. In transitional second-level blocks, use of AMF interception traps is replaced by perimeter row spraying with Guthion"™ or Imidan"™ every three weeks beginning in early Table 1. Average percent injury by early-season insect pests in second-level eind first-level IPM blocks in 1992.* Type of block TPB PC EAS GFW Total Full second-level 1.5 a 0.1 a 0.1a 0.0 a 1.7 a First-level 2.3 a 0.1 a 0.1 a <0.1 a 2.5 a Transitional second-level 1.1 a 0.5 a 0.1 a 0.2 a 1.9 a First-level 0.7 a 0.1 a 0.1 a 0.1 a 1.0 a * Means in each couplet in each column followed by a different letter are significantly different at odds of 19:1. Two hundred fruit of each of three cultivars (Mcintosh, Cortland, and Delicious) were sampled at harvest. TPB = tarnished plant bug; PC = plum curculio; EAS = European apple sawfly; GFW = green fruitworm. 24 Fruit Notes, Winter, 1993 July. In both typ>es of blocks, removal of unmanaged apple and pear trees within 100 yards of each block reduces immigration of CM and LAW. Removal of drops after harvest dis- courages buildup of within-orchard populations ofAMF, CM, andLAW. In early April of 1 99 1 , we selected six full and six transitional second-level IPM test blocks of six to nine acres each. In 1992, we replaced one of the transitional blocks (which had been sold and was no longer available to us) with a new block on another farm. Each second-level block was matched with a nearby control block which weis managed by the grower, using first-level IPM methods. Early-season Fruit-injuring Pests For control of arthropod pests active up to early June, second-level IPM reUes on early- season pesticide treatment based on monitor- ing. We monitored each orchard weekly begin- ning in mid-April, then biweekly from mid-Jime through September. Five each of four types of sticky traps were hung in each block to monitor for TPB, LM, and EAS. We examined 100 or 200 leaves or terminals per block for LM, LH, aphids, mites, and mite predators. Fruit were examined both by IPM scouts and growers for fresh PC injury. Based on this monitoring, recommendations were made to the grower for treatment of the experimental block. In second-level IPM blocks (both fiill and transitional) in 1992, combined injuries from early-season fruit pests were simUsu" to those in nearby first-level IPM (grower control) blocks. In both first- and second-level IPM blocks, TPB caused the greatest amount of injiuy, followed by PC, EAS, and GFW (Table 1). Early season insecticide use was similar in both types of blocks, probably because both types were man- aged through identical first-level IPM tech- niques (Table 2). Injury by these early-season pests was lower in 1992 than in 1991. Table 2. Dosage equivalent s (spray events in parentheses) of insecticides and acaricides used in second-level and first-level IPM blocks in 1992.* Fruit pests Mites Before After mid- mid- Other Type of block June June Oil miticides LH ABLM Total Full second-level 2.4 0.0 0.9 0.0 0.2 1.1 4.6 (4.0) (0.0) (1.8) (0.0) (0.2) (1.0) (7.0) First-level 2.8 2.0 1.1 0.1 0.0 0.4 6.4 (3.8) (2.2) (1.8) (0.2) (0.0) (0.5) (8.5) Transitional second-level 2.7 0.7 1.2 0.3 0.0 1.0 5.9 (3.4) (2.6) (2.0) (0.2) (0.0) (1.0) (9.2) First-level 3.3 3.1 1.3 1.1 0.0 0.5 9.3 (3.6) (3.2) (2.0) (1.0) (0.0) (0.6) (10.4) * LH = leafhopper; ABLM = apple blotch leafminer. Fruit Notes, Winter, 1993 25 Table 3. Season-long apple maggot fly (AMF) injury and trap captures in second-level IPM blocks and first-level IPM blocks in 1992.* Interior Perimeter % AMF monitoring monitoring Interception injury trap trap trap to finiit captures captures captures Type of block at harvest per trap per trap per block Full second-level 0.4 a 9.0 a 16.2 a 2430 First-level 0.1 a 6.9 a 14.4 a - Transitional second-level 0.2 a 3.5 a 5.9 a „ First-level 0.1 a 3.7 a 5.6 a — * Means in each couplet in each column followed by a different letter are significantly different at odds of 19:1. Two hundred finiit of each of three cultivars (Mcintosh, Cortland, and Delicious) and two hundred border row fruit of mixed cultivars were sampled at harvest. Table 4. Fruit injury by codling moth (CM), leafrollers (LR), lesser appleworms (LAW), and San Jose scale (SJS) in second-level and first- level IPM blocks in 1992.* Type of block CM LR LAW SJS Full second-level First-level Transitional second-level First-level <0.1 a 0.2 a 0.0 a 0.0 a <0.1 a 0.1 a 0.0 a 0.0 a 0.0 a 0.2 a 0.0 a 0.0 a 0.0 a <0.1 a 0.0 a 0.0 a * Means in each couplet in each column followed by a different letter are significantly different at odds of 19:1. Two hundred fniit of each of three cultivars (Mcintosh, Cortland, and Delicious) were sampled at harvest, and for CM and LR and additional two hundred border- row fruit of mixed cultivars were sampled at harvest. 26 Fruit Notes, Winter, 1993 Summer Fruit-injuring Pests: Full Second-level IPM Odor-baited sticky red spheres were hung every five yards on perimeter apple trees of each full second-level experimental block to intercept immigrating AMF. These were baited with both butyl hexanoate, a synthetic fi-uit odor deployed in polyethylene vials, and ammonivun acetate, a sjTithetic food odor released through a Consep™ membrane. Interception trap captures averaged 2430 in the six full second-level blocks, indicating that AMF pressure was moderate in 1992. In 1991, trap captures averaged 3562 in three blocks in which traps were baited with both food and firuit odor. Captures ofAMF on four interior unbEii ted monitoring traps (indicative of AMF penetra- tion into the block interior) were statistically similar in second-level blocks and in nearby first-level blocks. AMF injury to firuit at harvest in second-level blocks was similar to that in nearby first-level blocks (Table 3). One second- level block, however, had 8% injury to Cortlands in mid-September. The nearby first-level block had no Cortlands , and all the Mcintosh had been picked, so no comparison was available. The second year of use of both butyl hexanoate and ammonivim acetate (or carbon- ate) to bait the AMF interception traps indicates that this double-odor strategy may be very effec- tive in large blocks. We ehminated the problem of quick loss of ammonia by replacing polyethyl- ene vials with slow release membranes. Tests performed in our laboratory showed that flies continue to be attracted to these membranes even afler they have been in the field for several months. Tests also indicated, however, that fewer flies approached the trap if the membrane flapped loosely in the wind. In addition, traps may require more fi-equent cleaning than we had previously thought, especially if the double- odor trapping procedure results in the capture of additional non-target insects. In 1992, we cleaned our traps once a month, but in one orchard, trap captures during a one-month pe- riod were 271% higher on traps which were cleaned of all insects than on those which were not cleaned thoroughly, indicating that as in- sects build up on the traps, trap captures de- crease. In high-pressure situations, more fre- quent trap cleaning may be necessary if AMF are to be captured effectively. Fruit injury by CM averaged less than 0.1% in both block types for the second year. LeafroUer (LR) injury averaged 0.2% in fuU second-level blocks for the second year, and was 0.1% in nearby first-level blocks (Table 4). We will continue to monitor carefiilly for leafrollers because of concern that leafi-oller populations may grow in blocks in which the interior is not sprayed afler early or mid-June. No LAW or San Jose scale (SJS) injury was found (Table 4). No insecticides were apphed in second-level blocks after mid-Jime. In the companion first- level blocks, growers applied an average of 2.0 dosage equivalents of pesticide after mid-June, and sprayed the block an average of 2.2 times (Table 2). Summer Fruit-injuring Pests: Transitional Second-level IPM Every three weeks after early June, i)erim- eter row apple trees in transitional second-level blocks were treated with insecticide to control AMF. The block interior remained firee of insec- ticide after early June. AMF injury averaged 0.2% in transitional second-level blocks and 0.1% in the nearby first-level blocks, slightly lower in both cases than in 1991. On average, 3.5 AMF were captured on unbaited interior monitoring traps in transitional second-level blocks and 3.7 in first-level blocks, indicating that in most cases relatively few AMF pen- etrated into the orchard interior (Table 3). In- secticide use after mid- June was reduced signifi- cantly in transitional second-level blocks com- pared to first-level blocks because apphcations were made only to the block perimeter. Total dosage equivalents of insecticide applied against fi-uit pests afler mid-June averaged 0.7 in transitional second-level blocks and 3.1 in first-level blocks. Growers also sprayed transi- tional second-level blocks slightly less fre- quently (Table 2). Unmanaged apple and pear trees were re- moved fi"om within 100 yards of the six transi- Fruit Notes, Winter, 1993 27 Table 5. Peak levels of mites and mite predators in second-level and first- level IPM blocks in 1992.* Mite presence (% of leaves) Type of block ERM+TSM Af YM Ratio of ERM+TSM to Af Full second-level 43.2 a First-level 42.5 a Transitional second-level 25.7 a First-level 20.3 a 1.5 a 2.7 a 0.5 a 1.0 a 3.7 a 0.9 a 0.4 a 0.7 a 29:1 16:1 51:1 20:1 * Means in each couplet in each column followed by a different letter are significantly different at odds of 19:1. ERM = European red mite; TSM = two-spotted mite; Af = Amblysieus fallacis; YM = yellow mite. Table 6. Foliar insect pest peak population and injury levels in second-level and first-level blocks in 1992.* Type of PLH WALK block PLH injury WALK injury ABLM GAA GAAP WAA Full second-level 11.2 a 15.0 a 13.8 a 0.3 a 10.8 a 68.7 a 54.5 a 6.2 a First-level 2.3 b 6.3 a 10.6 a 3.4 a 13.6 a 69.5 a 44.3 a 3.3 a Transitional second-level 7.2 a 4.5 a 6.1 a 9.3 a 10.8 a 77.3 a 55.3 a 8.2 a First-level 0.5 b 0.5 a 1.1 a 0.4 a 11.8 a 65.3 a 57.0 a 11.0 a * Means in each couplet in each column followed by a different letter are significantly different at odds of 19:1. PLH = potato leafhopper, WALH = white apple leaftiopper; ABLM = apple blotch leafminer; WAA = wooly apple aphid; GAA = green apple aphid; GAAP = green apple aphid predators: cecidomyiids and syrphids. Data for PLH, PLH injury, and WALH is in terms of percent of terminals examined. Data for WALH is in terms of percent of fruit examined at harvest. Data for ABLM is in terms of the average number of mines per 100 leaves. Data for GAA, GAAP, and WAA is in terms of the percent of watersprouts examined. 28 Fruit Notes, Winter, 1993 tional second-level blocks. No CM injury was seen in the transitional second-level blocks or their companion first-level blocks. LR injury was sUghtly, but not significantly higher in the transitional second-level blocks than in the first- level blocks. LR injury in transitional second- level blocks was no higher in 1992 than in 1991. No sampled fi-uit in either block were damaged by SJS or LAW (Table 4). Foliar Pests and Predators: Full Second-level IPM In 1991, we reported season-long average population levels of fohar pests; this year we noted their p>eak populations in an efifort to reflect damage more accurately. Cool and wet summer weather helped to maintain low popu- lations of fohar pests in most cases. Mite popxilations remained low in most cases, as were populations ofAmblysieusfallacis predators, which were not seen in full second- level blocks until late August, £md were never present in numbers thought to be sufficient to achieve biocontrol. Yellow mite predator popu- lations were slightly higher in second-level than in first-level blocks throughout the summer, but their abiUty to control any but the lowest mite populations is questionable (Table 5). Another predator, Typhlodemus pyri, which is present in orchards in Western New York, was released in two second-level IPM blocks. Sam- pling one month after release revealed high numbers of these mite predators on release trees. We wiU not know until 1993 whether or not they survived the winter and spring and successfully colonized the blocks. Both full second-level and nearby first-level blocks were treated with about one dosage equivadent of oil (Table 2). No other miticide was used in full second-level blocks, and only one grower apphed miticide to a first-level block. Potato leafhopper peak population levels on terminals were higher in full second-level than in first-level blocks. Potato leafhoppers infested 11% of sampled terminals in full second-level blocks and 2% in nearby first-level blocks. Peak potato leafhopper injury to terminals was 15% in second-level and 6% in first-level blocks. White apple leafhoppers infested 14% of sampled terminals in second-level blocks and 11% in first-level blocks; however, injury to fi-uit averaged only 0.3% in second-level blocks, ver- sus 3.4% in first-level blocks (Table 6). Injury in first-level blocks, however, was confined prima- rily to one orchard. In August, we identified rose leafhoppers in all t)T)es of orchard blocks, but further study is needed to determine their im- portance in Massachusetts orchards. Pesticide was applied against leafhoppers in early June in only one second-level block, which had a signifi- cant late-season infestation in 1991 (Table 2). Average peak leafininer population levels were similar in the second-level blocks and first- level blocks (Table 6). All of the six fiill second- level blocks were treated with DimUin™ against leafminers (Table 2). Leafininer population levels throughout the summer confirmed our previous conclusion that apphcation of DimUin against the overwintering generation of leafininer adults, when indicated by trap cap- tures, is the most effective and least invasive technique for their control. Treatment with Dimihn is preferable to use of other materials which are harsher on beneficial insects and mites. Dimilin was not available for vise in first- level blocks, and few growers chose to treat leafminers in those blocks. If registered, Dimilin will be a good option for control of leafminers without serious disruption of beneficials. We chose to apply it before bloom so that it did not affect leafi:x)ller and codling moth populations, which we are trjdng to study in the absence of insecticide use after mid-June. If registered, Dimilin could be used later in the season after first-generation mines have appeared, allowing growers to avoid its use in years in which it may not be needed. In other articles, we provide data indicating that predacious spiders are significantly more abundant late in the growing season in second- level blocks than in first-level IPM blocks, and that some of these spiders feed on leafininer larvae inside mines as well as on leafhopper nymphs. Green apple aphid (GAA) populations were almost the same in the two types of blocks. At their peak, aphids infested 69% of sampled Fruit Notes, Winter, 1993 29 terminals in full second-level blocks and 70% in nearby first-level blocks. Two aphid predators, sjrrphid and cecidomyiid flies, were slightly more prevalent in second-level blocks than in first-level blocks. These high levels indicate that predators achieved control of GAA in both second-level and first- level IPM blocks. Infesta- tion of terminals by wooly apple aphid (WAA) was similar in second-level and first-level blocks, but in both types of blocks WAA popula- tions were lower in 1992 than in 1991 (Table 6). Foliar Pests and Predators: Transitional Second-level IPM Very few Amblysieus fallacis predatory mites were seen in transitional second-level or nearby first-level blocks luitU September (Table 5). Mite levels in most cases remained low, although one grower had European red mite populations in his transitional second-level block sufficient to warrant treatment with a miticide in mid-summer (Table 2). Mid-season miticides were applied in four of the six first- level blocks, with an average of 1.1 dosage equivalents of miticide per block (Table 2). Potato leafhopper infestation levels on ter- minals averaged higher in transitional second- level blocks than in nearby first-level blocks. In transitional second-level blocks, white apple leafhoppers infested 6% and potato leaflioppers 7% of terminals at their peak, while in nearby first-level blocks, both white apple leafhopper and potato leafhopper populations peaked at about 1% of terminals infested. White apple leafhopper injury to frmt at harvest was statis- tically simUar in transitioned second-level and first-level blocks, and potato leaQiopper injury also was statistically similar in transitioned second-level and first-level blocks (Table 6). In no case did these insects cause serious problems for growers. All six transitional second-level blocks were treated with DimiUn against first generation leafminers. Only two growers treated their first-level blocks for leafminers (Table 2). Peak numbers of mines on 100 leaves averaged 10.8 in transitional second-level blocks and 11.8 in first-level blocks, considerably lower in both blocks than in 1991 (Table 6). GAA populations were higher in 1992 than in 1991. At their peak, they infested an average of 77% of terminals in transitional second-level blocks and 65% of terminals in nearby first-level blocks. Predator populations were higher this year as well; their populations peaked at an average of 55% of terminals infested in transi- tional second-level blocks and 57% of terminals in first-level blocks. In both cases predators were adequate to provide control of aphid pests. Similar numbers of terminals in the transitional second-level blocks and in first-level blocks were infested with wooly apple aphids (Table 6). Conclusions We continue to be pleased with the success of implementation of second-level IPM for apple insects and mites in six- to nine-acre blocks in commercial orchards. In 1992, full second-level IPM blocks received 28% less total dosage equivalents of insecticide and miticide and 18% fewer total spray events for insects and mites than first-level IPM blocks. Excluding pre- bloom sprays of oil (non-toxic in the environ- ment), dosage equivalents were reduced 30% and spray events were reduced 22%. Despite this difference, total firut injury by insects was similar in full second-level and first-level IPM blocks, and peak populations of foUar pests were not different, except for leafhoppers. Early season fruit injury from PC, TPB, EAS, and GFW was low in all cases, as was finiit injury by CM, LR, LAW, and SJS. GAA were controlled by predators in both second-level and first-level blocks. We continue to work toward gaining registration of Dimilin, which provides good control of leafminers without disrupting beneficial parasites and predators. Transitional second-level IPM appears to be an effective reduced-spray management pro- gram for insect and mite pests in commercial orchards. In 1992, transitional second-level IPM blocks received 37% less total dosage equivalents of insecticide and miticide and 12% fewer total spray events for insects and mites than first-level IPM blocks. Total fruit injury by insects did, however, average sUghtly but not 30 Fruit Notes, Winter, 1993 significantly higher in transitional second-level blocks than in first-level blocks. Peak popula- tions of foUar pests were Uttle different, except for leaflioppers, which were somewhat more abundant in the transitional second-level blocks. For 1991 and 1992, combined, transitional second-level IPM blocks received about 17% more insecticide and miticide and 23% more spray events than full second-level IPM blocks. Insect-caused fi*uit injury averaged over both years was virtually identical in full and transi- tional second-level blocks. Our main concern with the benefits of tran- sitional second-level IPM over the long-term Ues with the potential buildup of AMF from infested fallen drops not removed at harvest. The odor baits employed with the interception traps im- der full second-level IPM can attract these AMF. A second concern with the long-term benefits of transitional second- level IPM Hes with potential negative effects of perimeter-row sprays on im- migration of beneficial predators and parasites. Two more years of planned comparison of full second-level IPM vs. transitional second-level IPM vs. first-level IPM orchard practices should provide more insight into the benefits and costs of each practice. A second year of trials has not answered all of our questions about two foUar pests, mites and leafhoppers. Although mites were rarely a problem in this wet, cool summer, predator populations were low even where pest mites existed in numbers sufficient to support them. We need to learn more about overwintering locations of mite predators and about the exact identity of predators in Massachusetts or- chgirds. Further monitoring of the newly-re- leased predator, Typhlodemus pyri, will help us to determine if release of this pesticide-resistant predator could help to control pest mites in Massachusetts orchards. We will continue to study the role of spiders in pre3dng on leafinLners in mines and on leafhopper njrmphs. In our judgement, the key to grower adop- tion of second- level IPM practices for insects and mites hes in availabihty of a low-cost approach to interception trapping of AMF. At present, costs of labor and materials to employ odor- baited sticky red spheres exceeds by nearly twofold the cost of applying insecticide sprays against AMF and other summer finiit-injuring insects. The fi:^quent cleaning of sticky traps necessary to provide an effective capturing sur- face is a major component of the cost of this system. We believe that development of pesti- cide-treated spheres (now in progress) as a sub- stitute for sticky spheres will provide a cost- effective approach to using interception traps for this insect. Even if we assume that a pesticide-treated sphere interception trap system for AMF will be no more costly than applying insecticide after mid-Jime, why should a grower want to switch from an insecticide-based first-level IPM ap- proach? We believe there are at least four reasons for doing so: ( 1) saving money on sprays against foliar pests by allowing beneficial natu- ral enemies to build up and provide control in the absence of pesticide use; (2) reducing the UkeU- hood that foHar pests will develop resistance to pesticides, thereby preserving the long-term ef- fectiveness of these pesticides; (3) reducing pes- ticide intrusions on neighbors or the environ- ment adjacent to orchards; and (4) greatly re- ducing or eliminating pesticide residues on finait at harvest. For some growers, these potential advantages could be large. Acknowledgements This project was funded by the Massachu- setts Society for Promoting Agriculture, the USDA Northeast Regional IPM Competitive IPM Grants Program, State/Federal IPM funds, and the Northeast Region Sustainable Agricul- ture Research and Education Program (for- merly LISA). We gratefully acknowledge this funding. We are also grateful for the participa- tion and support of the following growers: Bill Broderick, Dave Chandler, Dana Clark, Dick, Greg, and Kevin Gilmore, Tony Lincoln, Jesse and Wayne Rice, Joe Sincuk, Dave Shearer, Tim Smith, £md Barry and Bud Wiles, and for the scouting assistance of Ryan Elliott, Kathy Hickey, James Gamble, £md Peter Winnick of the Department of Plant Pathology. Fruit Notes, Winter, 1993 31 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 01002 -0 SERIAL SECTION UNIV. OF MASSACHUSEHS LIBRARY AMHERST, MA 01003 Account No. 3-20685 ISSN 0427-6906 Fruit Notes Prepared by the Department of Plant & Soil Sciences. j zsi j y Q F M A S S University of Massachusetts Cooperative Extension System. United States Department of Agriculture, and Massachusetts Counties Cooperating. HP A P \^ APR -6 S3 Eklitors: Wesley R. Autio and William J. Bramlage AJr(/yan shomhtos £661 ZO -^w Volume 58. Number 2 SPRING ISSUE, 1993 Table of Contents Spiders That Feed on Leafhoppers and Leafminer Larvae Apple Growing in China Evaluation of New Apple Cultivars Implementation of the MARYBLYT Model for Fire Blight Control Fish Hydrolysate Fertilizer Should Not Be Applied Foliarly to Apple Comparative Effects of Margosan-O (Neem Extract) and Imidan on Plum Curculio and Apple Maggot Orchard Mineral Nutrition: Ground-applied vs. Foliar-applied Fertilizers ^ Fruit Notes Publication Information: Fruit Notes (ISSN 0427-6906) is published the first day of January, April, July, and October by the Department of Plant & Soil Sciences, University of Massachusetts. The costs of subscriptions to Fruit Notes are $7.00 for United States addresses and $9.00 for foreign addresses. Each one-year subscription begins January 1 and ends December 3 1 . Some back issues are available for $2.00 (United States addresses) and $2.50 (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 COOPERATIVE EXTENSION SYSTEM POLICY: All chemical use* niggetled in thii publicaiion are contingent upon continued regitmtion. Theie chemicali should be uERTY DAMAGE. Issued by the University of Massachusetts Cooperative Ejtension System, Robert G. Helgesen, Director, in furtherance of the acts of May 8 and June 30,1914. The University of Massachusetts Cooperative Extension System offers equal opportunity in programs and employment. J Spiders That Feed on Leafhoppers and Leafminer Larvae Joanna \^sniewska and Ronald Prokopy Department of Entomology, University of Massachusetts Recently in Fruit Notes [58(1): 20-23], we showed that spiders were signiRcantly more abun- dant in second-level than in first-level IPM blocks. We concluded by asking whether or not increased numbers of spiders in second-level blocks were great enough to contribute to the control of foliar pests. Here, we describe 1992 laboratory studies in which some of the most abundant types of spiders collected in second-level blocks were offered white apple leaf- hopper nymphs and adults and apple blotch leafminer larvae as potential prey. Each spider was placed in a waxed paper cup (four inches tall by three inches in diameter) with a plastic lid. Into each cup we introduced an apple leaf kept turgid by placing its stem in water. The leaf harbored one tissue-feeding (late instar) leafminer larva and two leafhopper nymphs (or one nymph and one adult). The test lasted for 24 hours. Re- sults are in Table 1. Laboratory tests of orchard-collected spiders feeding on potential prey. Family of spiders Number tested a cat stalks a mouse before the final pounce. They may even capture it in mid air and then climb back to the leaf fVom which they have jumped using a piece of silk previously attached to that leaf. Salticid spiders are successful nine times out often. They are active only during the day. Of the Araneid spiders, 28% fed on leafhoppers. Most of these spiders were smaU immature individu- als otAraniella displicatta, which are found com- monly on terminals of apple tree branches. They build tiny orb webs stretching across dorsal surfaces of leaves. Their webs are found at night and during the day. These spiders prayed mostly on the adult leafhoppers which got caught in their webs. Only members of the Anyphaenid family fed on leafminers. Predation on leafminer larvae took place by 90% of the Anyphaenid spiders tested. In all the Spiders that fed on leafhoppers (%) Spiders that fed on leafminer larvae (%) Philodromidae Araneidae Salticidae Anyphaenidae Thomisidae 27 22 11 10 7 given Table 1. Of the five families of spiders ex- a m i n e d , _^^^^^^___^^^^^^_^^^^^_ members of three families fed on leafhoppers: Anyphaenidae (hunting spiders), Salticidae (jumping spiders), and Araneidae (orb web spiders). The Anaphyenid spi- ders were the most voracious, as 100% of the tested individuals fed on leafhopper nymphs and adults (their behavior will be described later in conjunction with predation on leafminers). Of the Salticid spiders, 36% fed on leafhoppers. These visually oriented spiders are often observed running around on leaves and branches moving their heads from side to side as they search for prey. Once they locate a prey insect, they stalk it much as 4 28 36 100 0 0 0 0 90 0 cases mines were opened from the underside of the leaf and the larvae were missing. It was not possible to identify the specific spe- cies, because they all were immature. But our best guess is that 9 of the 10 individuals tested were Aysha gracillis. These hunting spiders are common on foliage. They forage for prey mostly by sensing vibrations on leaves and (possibly) branches. They were often found foraging at night but they may also be active during the day. The type of leafminer predation observed in this experiment is characterized by a very specific mark left on the leaves. For this reason it may be possible to quantify predation by Anyphaenid spiders in the field by counting the leaves which have the signs of Fruit Notes, Spring, 1993 predation and those which do not, provided that observations are made soon after predation. We conducted a preliminary study to quantify predation in this way. In one of the three orchards where spiders were collected for use in the feeding test (University of Massachusetts Horticultural Research Center, Belchertown), we inspected 600 randomly selected leaves from 60 different apple trees on October 7. Of these leaves, 228 had leafrniner mines, 20% of which appeared damaged due to spider predation. In other words, 20% of the leafrniner larvae in the orchard in late September may have been prayed upon by Anyphaenid spiders. To compare this finding with what may be taking place in an orchard that has more spiders, on November 5, we inspected 169 randomly selected leaves containing leafrniner lar- vae on four apple trees in an abandoned apple orchard (Orchard Hill area at the University of Massachusetts at Amherst). Of these mines, 37% appeared damaged due to predation of Anyphaenid spiders. Even though these findings are very prelimi- nary, they suggest that spiders of at least three families exhibiting different foragingstrategies may be able to prey upon some of the most troublesome foliar pests of apple orchards. Aysha species of the family Anyphaenidae, in particular, may play a beneficial role in leafhopper and leafrniner control. In 1993, we plan to conduct feeding tests on more spider species commonly found in second-level or- chard blocks and more individuals of each species. We also plan to conduct these tests under more natural conditions than the highly confining condi- tions of the laboratory used in 1992. We also hope to investigate the relationship between spiders feeding on leafminers and beneficial parasitoids feeding on leafminers. For example, it would be important to know if (and how much) spiders are likely to prey upon parasitized leafminers. Are spiders beneficial if they selectively extract parasitized leafrniner lar- vae but leave unparasitized larvae alone? HopefuUy our planned 1993 research wUI provide greater insight into the value of spiders as biological control agents of foliar apple pests. Acknowledgments This project was funded by the Massachusetts Society for Promoting Agriculture, the USDA Northeast Regional IPM Competitive Grant Pro- gram, and State/Federal IPM funds. We gratefiilly acknowledge this funding. We are grateful to the following growers for their participation and sup- port: Dana Clark, Dave Chandler, Dick Gilmore, Tony Lincoln, Wayne Rice, and Joe Sincuk. %f^ •S^ mS^ ^# •S^ 0^ rj% w^ r{% 0^ Apple Growing in China Ronald J. Prokopy, M^lliam M. Coli, and Jian Jun Duan Department of Entomology, University of Massachusetts In Jiine of 1992, we had the wonderful oppor- tunity of visiting several apple orchards in vari- ous parts of east-central China in combination with a trip to the International Congress of Entomology in Bejing. We thought it might be interesting to convey some of the things that impressed us. First of all, a bit of history. According to our Chinese colleagues, apples have been grown in China for at least 2000 years. Apples are planted on nearly four million acres in China, equal to about one-third of all acreage devoted to horti- cultural crops. China is roughly the size and shape of the continental United State. This means that a greater percent of the land area of China is devoted to apples than in the United States (which has about 500,000 acres in apples). Although production per acre is not nearly as great in China as in the United States, total production is about the same: 230 million bushels a year. Many Chinese orchards are newly planted, thus partly accoiinting for low Fruit Notes, Spring, 1993 average yield. In the United States, we produce about one bushel for every person. In China, production is about one bushel for every five people. Because living standards are improving very rapidly in China, there is a potential mar- ket for firuit appearing from either a major increase in Chinese apple production or mcgor importation of apples fi:t)m abroad. The most popular cxiltivars in China are DeUdous and Golden Delicious and more recently Fuji and "Red Snake." Presently, most orchards are owned by com- mimes. Each family in the commune is entitled to lease about three acres of land firom the commime and farm it in any way the family sees fit. The family can keep whatever it earns. All the trees that we saw were dwarf or semi-dwarf. One of the fascinating things to us was that every 20 rows or so were managed by a different family and often in a different way. So your immediate neighbor's horticultural practices could have a very strong influence on your crop, for better or for worse. Another fascinating thing was the absence of £my vegetation whatsoever beneath the trees but the lush vegetation of other crops grown in the allesrways between rows. These crops in- cluded peanuts, cotton, strawberries, melons, com, and several others. All vegetation beneath trees was removed by stout Chinese hoes in order to reduce the drain of vegetation on water and nutrients. We wondered how it was fmssible to run tractors and sprayers down the allejrways without crushing the other crops. The answer was: tractors and motorized sprayers are few and far between. Nearly all the sprajdng is done by attaching a hose 30 yards or so in length to an outlet fi*om an imderground pipe that supplies the spray mixtvire fi-om a central mixing point. The farmer simply sprays all trees within reach of the hose before picking up and moving on to the next attachment site. Some sprajdng is also done with backpack sprayers and "bucket- pumps." In this way there is no harm to crops in the alleyways (other than pesticide drift). Most applicators did not seem concerned about poten- tial dangers fi*om pesticide. They wore no gloves, masks or other protection, much the way it was in the United States in the 1940's! Nearly all of the 20 or so orchards that we saw were maintained in excellent condition. Tree structure was particularly good, generally better than the average Massachusetts block of dwarf trees. It w£is mainly based on a three- tiered, central-leader tree pruning and Umb training system. Advice on tree planting, tree training, fertiUzation, and pest control is given to all apple-growing members of a commune at least four times a year through visits by exten- sion pomologists from the Division of Fruit and Forestry. We were told that the average family sprays about eight times a year, mainly against mites, aphids, moth larvae, powdery mildew, scab, and canker. From our perspective, tree foUar growth was very lush (probably too lush). So it was not siuprising that mites and aphids took a strong liking to it. Maybe the lack of competition for nutrients in the absence of understory plants was too much of a good thing. The high upright growth of many trees was at least partly due to the common practice of t)dng branches down to horizontal or below horizontal positions, which then results in unnecessary uprights. There was a great deal of interest in biological control of mites and aphids but less progress on this area than we ex{)ected. We wondered how apples were stored and sold aRer harvest. It turns out that cold storage does not exist to any appreciable extent. The fi-uit are trucked by the buyer to the local mar- kets for immediate consumption. The storages that do exist are mostly in undergroimd cellars or in above-ground clay structures that are periodicedly hosed with water for cooling. Of all the many surprising things we encoun- tered, perhaps the most siurprising of all was the intent interest by the governor of a coimty of about two million people in the possibility of making applejuiceorcider. She questioned us at length about how cider was made in the United States. It seems that apples have never been iised in this way in China. She said that her people would love to have apple cider if they knew a good way to make it. What an opportu- nity for marketing low cost hand-operated cider presses. We were treated royally with unexcelled hospitality (including 35-course Ivmches) wher- ever we went. It was indeed an eye-opening, unforgettable experience. Fruit Notes, Spring, 1993 Evaluation of New Apple Cultivars Duane W. Greene and Wesley R. Autio Department of Plant & Soil Sciences, University of Massachusetts In recent years, apple cultivars originating pri- marily from New Zealand, Australia, or Japan have gained considerable consumer acceptance in the market place. Prices received for these new culti- vars have exceeded those for the traditionally-grown apples. This differential has led to a new awareness and a hei^tened interest in planting new apple cultivars. Many new apples are under test but there is a dilemma about which of these to plant. The decisions are made somewhat easier now since there are a number of good and legitimate choices avail- able to growers. About iive years ago we started planting some of the most promising new cultivars and numbered selections. Scion wood was obtained for propagating trees from several countries and from various breed- ing programs. During the 1992 season many of these cultivars fruited. This report presents evaluations of some of these new cultivars. Fruit evaluation started the first week in August and continued weekly through the third week in October. Where sufficient fruit were available, mul- tiple harvests were made. Fruit on each harvest date were evaluated in two ways. First, fruit were weighed, counted, the diameter measured, and then red color was estimated to the nearest 10% on red coloring cultivars or on those yellow cultivars that had a prominent red cheek. Flesh firmness and soluble solids were measured. Fruit then were evaluated visually and sensory characteristics were judged on a specially prepared evaluation sheet (Figure 1). Lines approximately 10 cm in length were anchored at either end with descriptive terms. In each category a line was drawn through the line at a point that was judged to be appropriate for the apple. For example, if the color was judged to be neither dull nor bright a pencil mark was drawn half way between the terms. The length of this was measured from the zero point on the left and then recorded in the blank. The numerical value given in this instance would be 5.0. All other parameters were eveiluated similarly and measured. A value of 6.5 is considered to be very good and a score of 7.5 or greater is excellent. A summary of the taste, visual, and laboratory evaluations of selected parameters are presented in Tables 1 and 2. Cultivars are listed in order of the harvest date at which they were considered best. A log was kept and notes were taken for each cultivar at each harvest date. Below, listed by alphabetical order, are summaries of observation made on many of the cultivars evaluated. The star rating system recommended by the Pacific North- west Fruit Tester's Association was used. *M* ** **** A cultivar tested in many areas and found worthy as a good risk for commer- cial recommendation. A very promising cultivar but with some possible limiting factors. A cultivar, new or old, worthy of testing for today's changing apple world. * A cultivar or strain that has been through enough testing and/or commer- cial trials to be classified as not worthy of commercial recommendation. T An upward-pointing arrow with a star indicates increasing interest i A downward-pointing arrow with a star indicates decreasing or waning interest. Akane (.***) continues to be one of the apple culti- vars that we favor. It is a very attractive apple and few apples in its season have the flavor that Akane does. It must be allowed to stay on the tree long enough to mellow. It is the most aromatic apple we evaluated. A m^or fault is that it is a shy bearer. Alkemene {**) is a yellow apple with a deep orange cheek. It is somewhat russeted which detracts from its overall attractiveness. It has a spicy, sprightly, flowery taste. Flavor was rated quite high. A problem is that it is competing with Gala, Elstar, and Arlet. It may not be different enough or better enough to compete successfully with these cultivars. It is a disease-resistant cultivar, however, and this characteristic may increase its appeal. Ambitious (*) has fiTiited for three years. It is a very late apple with too much competition from other cultivars to succeed. It ripened properly in only one of the three years. Fruit size is small. It is one of the ugliest apples in our plot with only fair flavor. Fruit are susceptible to Pseudomonas. Fruit Notes, Spring, 1993 Cultivar Visual and sensory evaluation: Color Attractiveness Aroma Skin Crispness Juiciness Sweetness Acidity Starchiness Astringency Flavor Desirable Weight Color dull dislike none tough low low low bland low low dislike dislike Date bright like intense tender high high high tart high high like like Flesh firmness Soluble solids Figure 1. Cultivar evaluation form. ArkcharmP' AA-18 (**) is a very attractive light cherry red apple with semiprominent lenticels. It has a spicy taste, not sweet, flesh not too crisp, with acidity quite high. Fruit were harvested over a two- week period. Even when watercored, they still are very acid. Arkcharm warrants further evaluation. AA~44 (**t) is a large blotchy cherry red apple. Flavor is good but not strong. It is equal to Paulared in flavor and ripens slightly before Paulared. It shows some tendency to drop. This cultivar war- rants further evaluation. AA-62 (*) looks somewhat like a Golden Delicious and ripens at about the same time. The finish is good, with no russeting; however, fruit show severe bitter pit and Pseudomonas. Fruit have a good but not an outstanding taste with an anise flavor. It is more acid than Grolden Delicious. If it is not better than Golden Delicious it may not have a future. AA-63 (**) was a very pleasant early surprise. It has speckled red skin, perhaps like an Early Mcintosh. It £dso tastes like a very good early Mcintosh, with- out the sharp astringent taste. It is smaU with a very short shelf life. We rated it very high for color, flavor, and overall. It is better than Sumac which ripens at a similar time. Arlet (**T) remains high on the new cultivar list despite its three major faults: preharvest drop, russet, and poor color. It received one of the highest flavor rating. It has a good sugar-to-acid ratio that tends to favor acid. It stores quite well and keeps it taste for a long time. The greasiness that develops on Arlet is quite different from that developing on other apples, since it can be washed off. Even though it feels greasy, internal condition can still be very good. Fruit Notes, Spring, 1993 There is a very good relationship between develop- ment of red color and drop. The quality of this apple is too good to discard right now, even with its faults. BC 9-17 (*) is a medium sized dull cherry red apple with semiprominent lenticels. The flavor is not strong, and when ripe it has a hint of perfume and pineapple. It is a fairly good apple, but certainly not outstanding. BC 78-9-28 (*) is a medium sized, attractive red apple. The skin is smooth and lightly striped. The flesh is slightly chalky and the flavor is like licorice. The very different taste makes it difficult to decide whether or not we like it. BC 8C-27-96 Sunrise i**i) is a very attractive apple but when it develops outstanding red color, it is too ripe. The flesh characteristics are outstanding. It is crisp, juicy, and just feels wonderful. A major weakness of this apple is that it has a very weak apple flavor and the flavor that it does have is acceptable but not outstanding. We do not rate Sunrise very high. BC 15-30 (*) is a large, light cherry red apple with prominent brown lenticels. Even when ripe (Sep- tember 1) acidity is high. It has a pronounced pineapple flavor that is not totally related to watercore. This apple was rated average for red color, fairly high on attractiveness, and average for taste and flavor. This fruit is neither outstanding nor poor. BC9P-14-32 (**t) was one of the pleasant surprises this year. It is not very attractive because the cherry red is not intense and there is considerable net-like russeting. Fruit size is medium, flesh is yellowish- white, flesh texture is good, and the sugar-to-acid ratio is good. The taste and appearance is reminis- cent of Arlet. This apple was rated among the highest for flavor and overall desirable. It is a very good apple. BC 2-8 (*) is a very attractive red apple that re- sembles Delicious; however, the beauty is only skin deep. Even when very ripe fruit were tasted, the acid level was almost off the scale. It is an attractive apple with only fair to good quality. Fniit were dropping on September 21. BC 8M-15-10 (**T) was the second British Columbia selection that we thought was truly outstanding. This apple has blotchy pink-red color. Overall it is not an attractive apple. The flesh is yellow with a mild banana flavor. It is extremely crisp and juicy. Unlike published reports, it does not remind us of Fuji, but is more reminiscent of Braebum. As far as taste, crispness, and juiciness are concerned, you could not ask for a better apple. It is outstanding. BC8B-1'^50(**) is a fairly attractive andfairly good tasting apple. It looks like a Delicious and has cream yellow flesh. Fruit are deep cherry red at the optimal harvest date. The longer fruit stayed on the tree the better it got, although flesh firmness and texture were poor. The flavor of this apple is very complex: fruity and tropical. Since the taste is different and it improves with age, this cultivar may benefit from a period of cold storage. DIR 98T-486 (**) is a very attractive deep red apple on a cream yellow ground color. The irregular surface detracts somewhat from the appearance, but still it was one of the most attractive to be evaluated this year. Flavor improve with time on the tree. Fruit harvested on October 5 were quite good but the ground color indicated that the shelf life then would be rather short. The fruit is very juicy, yellow-white fleshed, and slightly tough skinned. It is so attrac- tive, that based solely on appearance, it should be looked at further. BC 17-30 (**T) is a very attractive, dark-burgundy- red apple of the Mcintosh type. The flavor is remi- niscent of Mcintosh with Spartan overtones. Per- haps it tastes most like Acey Mac. The flavor may be a little bland but it is still a very good apple. Flesh is white with a greenish tinge. The pedicle is long and lenticels are semiprominent. This apple war- rants further evaluation. BC 8K-21-39 (**) is a fairly good apple with better than average appearance. It is round to conic, has yellowish-white flesh that is somewhat dry. Fruit shows some russeting. Where the surface is red it is attractive. The red looks muddy on the green-red interface. The longer the fruit remained on the tree the better it tastes. BC 8C-6-62 (*) is a dark cherry-red apple with a bumpy surface caused by raised lenticel. The flesh is yellowish white. The flesh was so acid that it was not possible to evaluate flavor effectively. This fruit was about the most highly acid apple that we evalu- ated this year. We were not impressed. Bonza (*). This is the second year that we have evaluated Bonza. It is somewhat attractive and red color is good. The surface of the apple is not smooth, the flesh is rather dry, and the flavor is acceptable but not outstanding. We are not encouraged to Fruit Notes, Spring, 1993 Table 1. Taste evaluation of apple cultivars grown at the L niversity of Massachusetts Horticultural | Research Center. 1992. Red Overall Cultivar Date Attractiveness color Sweetness Acidity Flavor desirable AA63 Aug. 6 5.1 6.8 5.3 6.1 7.4 6.7 Sumac Aug. 6 2.3 3.0 5.1 6.4 7.1 5.3 NY 66305-139 Aug. 6 3.6 2.2 1.8 9.0 3.3 2.4 BC 9-17 Aug. 11 4.5 4.5 4.0 8.8 6.5 5.0 Arkcharm (AA 18) Aug. 17 7.9 6.5 2.7 8.0 5.3 5.1 Jerseymac Aug. 17 5.5 6.7 5.6 4.8 6.2 5.9 BC 78-9-28 Aug. 17 6.9 6.5 6.5 5.3 5.0 4.8 BC 15-30 Aug. 17 4.8 5.0 2.4 7.9 4.4 4.0 Williams Pride Aug. 20 5.6 6.4 4.5 4.8 6.1 6.2 Redfree Aug. 20 8.4 8.8 5.2 5.5 7.6 7.4 OSU 31-19 Aug. 20 3.0 3.6 5.2 6.1 7.0 6.8 AA44 Aug. 24 5.5 5.9 5.1 7.8 5.7 5.8 Paulared Aug. 24 6.3 6.4 2.3 6.9 5.0 5.3 BC 8C-27-96 Sept. 1 6.3 5.0 5.2 5.5 5.1 5.3 Sansa Sept. 1 6.4 6.3 7.4 5.5 7.4 7.4 Nebuta Sept. 1 6.5 7.0 5.5 6.7 5.1 5.3 BC 15-30 Sept. 1 5.7 5.2 5.2 8.8 5.1 4.0 Himekami Sept. 8 7.0 7.0 3.3 8.5 4.1 3.9 Akane Sept. 8 8.5 8.4 5.5 6.9 6.8 6.8 BC 9P- 14-32 Sept. 8 4.1 4.4 6.2 7.0 7.9 7.4 Dayton Sept. 8 5.6 6.3 5.7 6.4 5.8 5.1 Ginger Gold Sept. 14 8.0 ... 6.5 6.2 5.8 7.4 Fiesta Sept. 14 4.2 3.5 4.8 5.0 5.7 5.2 Tsugaru Homei Sept. 14 5.2 5.0 8.1 4.8 6.3 6.3 Arlet Sept. 14 4.7 4.7 5.6 7.0 7.5 6.5 Elstar Sept. 14 4.5 4.4 3.2 8.1 4.7 4.6 NY 66305-289 Sept. 14 6.8 6.8 3.4 7.1 5.3 5.9 NY 74828-12 Sept. 21 6.7 6.8 3.4 7.3 5.5 5.8 Alkemene Sept. 21 5.3 5.6 6.3 6.8 5.9 5.6 Honeycrisp Sept. 21 2.9 3.5 6.8 5.2 6.3 5.2 BC2-8 Sept. 21 7.1 6.9 4.2 8.2 4.8 5.3 Shamrock Sept. 28 4.8 — 5.7 5.3 7.0 6.5 NY 75414-1 Sept. 28 7.8 7.8 6.2 7.0 7.3 7.4 Natco 81 Sept. 28 6.7 6.7 5.3 4.6 6.3 6.3 BC 8M 15-10 Sept. 28 3.6 4.2 7.0 5.2 7.3 7.0 NY 75413-30 Sept. 28 6.8 6.8 4.7 8.1 3.6 3.6 Bonza Sept. 28 6.4 6.9 3.3 4.8 5.5 5.0 BC 8B-20-13 Sept. 28 7.5 — 4.1 7.6 5.7 5.8 BC 8B-14-56 Sept. 28 5.0 5.0 5.6 5.0 6.2 5.8 Yataka Sept. 28 5.1 5.1 7.1 4.2 6.9 6.9 Dulcet Sept. 28 5.4 5.3 5.5 5.0 5.5 5.5 1 continue evaluating this cultivar. Bonza tasted in Australia seemed to be quite different and far supe- rior to that grown in our trials. Braebum (*) was one of the poorest performing cultivars that we had in our plots. Fruit were harvested on October 19, and they appeared not to be ripe. Fruit were unattractive, high in acid, and not sweet. Theyjust did not taste mature. We have trees fruiting that came from two sources. The fruit from both sources are equally poor. This is the second year that fruit quality was very poor. We may not Fruit Notes, Spring, 1993 Table 1 continued. | Red Overall Cultivar Date Attractiveness color Sweetness Acidity Flavor desirable DIR 98-T-486 Oct. 5 7.8 8.4 5.2 5.0 5.9 6.3 Yoko Oct. 5 5.1 5.0 6.3 6.5 6.3 5.9 NY 65707-19 Oct. 5 6.3 6.8 5.1 4.1 6.3 6.4 Rubinette Oct. 8 2.6 2.6 3.9 7.1 5.8 5.1 Freyburg Oct. 8 5.3 — 7.0 5.5 6.8 6.8 NY 75441-67 Oct. 13 5.7 6.3 3.0 7.5 5.3 4.8 BC 17-30 Oct. 13 8.2 8.4 7.1 5.3 6.9 7.1 Jonagold Oct. 13 5.7 5.1 6.9 5.3 7.5 6.9 Senshu Oct. 13 5.1 4.8 6.5 5.5 6.9 6.4 NY 429 Oct. 13 7.8 7.5 3.9 5.9 6.1 6.3 Hawaii Oct. 13 5.0 — 6.1 3.5 6.5 5.9 Shizuka Oct. 13 5.9 ... 5.2 5.8 7.4 7.3 Hokulo Oct. 13 4.8 4.6 5.5 4.4 5.7 5.6 NY 617 Oct. 13 6.2 6.1 2.7 8.4 5.3 5.5 Splendour Oct. 13 7.0 6.2 6.0 3.8 5.8 6.8 Brock Oct. 13 4.4 2.9 5.5 5.3 6.1 5.1 NY 73334-35 Oct. 13 5.5 5.5 4.2 7.6 4.5 5.0 NY 75413-30 Oct. 13 6.9 7.0 5.5 5.5 4.8 5.9 Fantazja Oct. 13 7.0 7.0 5.2 6.8 6.7 6.7 NY 752 Oct. 13 3.6 3.5 5.5 5.6 5.5 5.1 AA62 Oct. 13 4.8 — 5.3 4.8 5.9 5.6 BC 8C-5-62 Oct. 13 5.5 5.5 1.1 9.6 2.3 2.4 BC 8K-21-39 Oct. 19 5.9 5.9 5.8 5.9 6.8 6.9 Natco 24 Oct. 19 6.3 5.9 3.6 7.0 5.6 5.8 Coop 29 Oct. 19 4.2 — 3.6 6.3 5.9 5.7 Newtown Seedling Oct. 19 5.6 5.1 4.8 6.8 5.0 4.8 Criterion Oct. 19 6.1 — 4.6 3.6 5.5 5.5 Nittany Oct. 19 5.8 5.3 5.2 6.2 6.2 6.2 Reinette Simirenko Oct. 19 5.3 ... 4.6 6.3 5.7 5.5 Fiorina Oct. 19 6.3 6.2 7.1 3.8 7.1 7.1 Braeburn Oct. 19 4.1 3.9 3.5 8.2 3.9 4.0 Ambitious Oct. 19 2.9 2.3 6.5 5.9 4.1 3.6 Orin Oct. 19 5.5 — 8.2 4.1 7.1 6.5 Kinsei Oct. 19 4.4 — 7.9 4.6 7.4 6.8 NJ 100 Oct. 19 7.0 — 5.0 4.6 5.5 5.9 Natco 58 Oct. 19 5.7 5.3 3.2 8.1 3.5 4.4 Natco 3 Oct. 19 6.5 4.1 7.1 36 5.2 5.8 Suncrisp (NJ 55) Nov. 4 5.2 ... 4.8 6.5 7.0 6.7 All fruit characteristics were rated on a scale ranging from 0 to 10. Color: dull = 0, bright = 10. Attractiveness, Flavor, and Overall desirable: dislike = 0, like = 10. Sweetness: low = 0, high = 10. Acidity: bland = 0, tart = 10. have environmental conditions that favor produc- tion of this cultivar. An added observation that may contribute to the poor taste is that mites show a distinct preference for Braeburn. Only Braeburn trees were heavily damaged by mites. Since trees were located in two different locations, it appears that this is a characteristic of Braeburn. We cannot recommend Braeburn for New England, based upon our observations this year. Brock (**i) was a good but not outstanding apple this year. Red color is not attractive with a burned 8 Fruit Notes, Spring, 1993 or grayish cast. Flavor is better than appearance. We rate flavor as good but not outstanding. It tastes very much like a Spencer. Fruit was dropping on October 13. We have better apples than Brock. COOP 29 (**) is a green-yellow apple with a brown pink cheek. These characteristics, coupled with some russeting, make this apple not very attractive. Flesh was firm, tart, astringent, and crisp with a very distinct and strong strawberry taste. In fact, this is the only apple that we have ever tasted that even remotely reminds us of strawberries. Although it is unattractive and flavor only good, it is disease resistant and it may be different enough to make it. Criterion (*). We have not been able to mature Criterion properly for two out of three years. Fruit were mostly green on October 19, even when flesh firmness was only 13.5 pounds. Skin was tough, flesh whitish-green, and the flavor acceptable. Cri- terion is not going to replace Golden Delicious. Dayton (**). We evaluated Dayton for the first time this year. We were hoping for more than we got. It is a large, not-too-attractive, red apple with a bumpy irregular surface. It has a pleasant, perfumy, spicy flavor but other oiltivars ripening in early to the mid-September are better. It may have a future as a disease-resistant apple, but on its own it will not beat better apples in the same season. Dulcet (**) is a deep burgundy red apple with prominent lenticels. It is too dull a red to be a truly attractive apple. Although reminiscent of Delicious, it appears to have a fairly low L/D ratio. The flavor is sweet, buttery, but not overwhelming. The juice seemed quite thick and the whitish green flesh does not appear to brown when exposed to the air. Dulcet was a good but not an outstanding apple. Elstar (*) continues to leave us unimpressed after three years of evaluation. The color is not outstand- ing and the acid level is too high even when the ground color is yellow. Last year the trees overcropped. Even with a very light crop this year due to biennial bearing, firuit size was still unaccept- ably small. This is the same pattern that we observe here with Empire. Elstar is just not good enough to compete with other apples in its season (Gala and Arlet). If one places Elstar in storage to mellow, it still must then compete with other later cxiltivars that are vastly superior. We can not recommend Elstar. Fantazja (**t) was an unexpected surprise. It is a Polish apple that came from Dick Van Well of Van Well Nursery. We planted and cropped the same trees in 1992, so the October 13 harvest date may not be the correct harvest date, since trees were fhiiting in their first leaf. It is a very attractive red apple that resembles Mcintosh. It has white flesh and tastes similar to Mcintosh but it is crisper and has courser flesh and better flavor. We were quite impressed with our first look at this apple. Fiesta (**i). This is our second year looking at Fiesta. In both years, it showed severe preharvest drop. It is dull in color and quite unattractive. Although it is fairly large and we rated flavor quite high, we do not think it has what it takes to make it here. It is an OK apple, but certainly not very exciting. Fiorina {**) is a late-maturing, disease-resistant apple that is both attractive and has good taste. The flavor is very mild. The flesh is whitish-yellow and very crisp. It tastes sweet with a low acid level. This apple certainly deserves fiirther evaluation. Freyburg (♦*) is an elongated yellow apple that resembles Delicious in shape. The flesh is white and it seems dry. It is very sweet with a strong fi-uity flavor. The strong flavor may turn some people off. Gingergold (***) is one of the most attractive apples that we grow, regardless of the season. When ripe it is a beautiful yellow green that completely lacks russet or surface blemishes. It is the best early Golden Delicious type that we know of. It is firm crisp, but the apple flavor is not strong. September 1 was too early to harvest this apple, and finiit harvested on September 8 were yellow but still starchy. Fruit harvested on September 14 were still very crisp and the seeds were still white. The proper time of harvest of this may be later than the sug- gested time. Regardless of time of harvest, this is an excellent apple that has a future. Hawaii (**). This is the first year we finiited Hawaii. It is a somewhat attractive yellow apple that resembles a Golden Delicious without the rus- set. It has a red cheek like Goldens get in the Northeast. It is fairly sweet, has low acidity and good flavor, with a strong banana taste. It bruises easily. It probably will no replace Golden Delicious. Himekami {*) is a very attractive apple that looks like a cherry-red Delicious ripening during the first week in September. We rated flavor and overall desirability quite low. The appearance of this apple is much better than its taste. We are not enthusiastic about Himekami. Hokuto (Norihem Star) (**). The brownish red. Fruit Notes, Spring, 1993 muddy red color on the surface of this apple makes it somewhat unattractive. Even when the ground color is intensely green, it appears to be acceptable to eat. The flesh is somewhat sweet and sprightly, and this perception may be accentuated because acidity appears to be very low. We do not consider this to be an outstanding apple. There are better apples avail- able that ripen at the same time. Honeycrisp (**T) distinguished itself as one of the best apples that we evaluated. It was the most productive apple in our plot, producing over 1.5 bushels of 3-inch apples per tree on M.26 in their third leaf. It was one of the least attractive apple that was evaluated. It was also one of the crispest and juiciest apples tasted. The flavor was good but not strong. It has outstanding storage potential. It maintains crispness, juiciness, and flavor after at least 20 weeks of regular air storage. This apple requires further evaluation but the more we taste Honeycrisp, especially out of storage, the better it looks. Kinaei (**t). This is the first year that we evaluated Kinsei. It is quite an unattractive apple but it is also one of the best tasting apples in our plot at harvest time. Following 15 weeks of regular air storage, it had lost much fruit condition and flavor that was present at harvest. The appearance and taste of this apple are not dissimilar to NJ 55. Jonagold (****) was evaluated more as a marker than a new cultivar. It clearly is an outstanding apple that should be planted. It has good size and outstanding flavor; however, it lacks long storage life. New Jersey 100 (**) is a large, very attractive yellow apple with a waxy smooth surface. It has a spicy licorice taste that was very strong. It is not very sweet and is low in acid. It may just be another apple that gets lost in the crowd. Natco 3 (**) is a fairly attractive yellow apple with a prominent reddish pink cheek. It appears to have a very large L/D ratio, perhaps 1.05 or greater. It tastes sweet and it has a distinctive, strong spicy flavor that lingers after your have eaten the apple. It is an extremely interesting and complex apple. Some fruit had watercore when they were harvested on October 19. Natco 24 (**) is a fairly attractive, large, dark cherry red apple with striped red over yellow-green ground color. Flavor is good but astringency is quite high. It probably can benefit from a period of storage. Flesh is somewhat dry and it did not appear to be ready to eat at harvest; however, it is attractive enough and the taste is good enough to warrant further evaluation. Natco 58 (*) was harvested on October 19, yet the acid was so high that it was difficult to identify or characterize the taste. Color and appearance are not exceptional. This cultivar does not appear to be a good prospect for the Northeast. Natco 81 (**T) is a very attractive apple that rated rather high in red color, appearance, flavor, and overall. It is Spartan-like in appearance and bears a striking resemblance to Acey Mac in flavor, ap- pearance, and time of ripening. Although they were not compared directly, they appear to be identical twins. Nehuta (.**l) is a somewhat attractive apple that resembles Delicious in many respects. It ripens at the end of August. It is somewhat irregular in shape, shows signs of uneven ripening, and is distinctly acid even when watercored. Flesh texture is somewhat undesirable. Overall, this apple has not distin- guished itself enough to be recommended. New York 429 (**) is a very attractive, large, smooth, red apple. It is somewhat irregular in shape. Flesh is purfumy, white with a green cast, and when ripe the flesh seems somewhat on the soft side. We believe that it is a good apple. Our major question is whether or not it is good enough to stand out among all of the other good apples. New York 617 (**) was an extremely large, some- what irregularly shaped red apple. Even though the ground color is yellow, fruit are still high in acid at the optimal harvest date. It is not a good fresh market fruit; however, it appears to have the flesh characteristics required for an outstanding process- ing apple. New York 752 (**) is a large, somewhat blotchy burned-red apple with yellow flesh. It has a spicy licorice-almond flavor that may be too distinctive to be acceptable. New York 66305-139 (**) is the earliest of the disease-resistant selections from New York. The major strength of this apple is that it is one of the first disease-resistant apples to ripen. Within a very short time, apples go from green and very tart to red, soft, and still tart. This apple is good enough to compete with Early Mcintosh or Puritan, but that is really not saying much. AA 63 or Sumac are better and they all ripen at about the same time. New York 66305-289 (**) is a very attractive dis- 10 Fruit Notes, Spring, 1993 Table 2. Laboratory analysis of apple cultivars evaluated in 1992 at the University of Massachusetts Horticultural Research Center. Soluble Red Best Also Weight Diameter Firmness solids color Cultivar date evaluated (g) (in.) (lbs.) (%) (%) AA63 Aug. 6 99 2.54 9.8 11.3 74 Sumac Aug. 6 91 2.48 10.2 12.5 85 NY 66305-139 Aug. 6 8/11 115 2.65 15.4 11.8 50 BC 9-17 Aug. 1 1 & 17 151 2.84 16.4 13.9 66 Arkcharm (AA 18) Aug. 17 8/24, 9/1 196 3.10 13.8 12.4 73 Jerseymac Aug. 17 166 3.03 13.2 10.8 75 BC-78-9-28 Aug. 17 135 2.84 13.8 14.4 90 Williams Pride Aug. 20 8/11, 8/17, 8/24 202 3.20 15.6 11.6 80 Redfree Aug. 20 148 ... 17.0 11.8 73 OSU 31-19 Aug. 20 9/1 ... ... ... — — AA44 Aug. 24 8/17, 9/1 264 3.48 16.7 12.6 68 Paulared Aug. 24 145 2.94 15.3 10.4 78 BC 8C-27-96 Sept. 1 8/24, 9/8 225 3.21 13.3 12.9 77 Sansa Sept. 1 183 2.96 15.9 15.4 86 Nebuta Sept. 1 8/24 155 2.84 16.2 13.9 73 BC 15-30 Sept. 1 300 3.67 18.6 13.6 70 Himekami Sept. 8 8/24 154 2.85 16.0 13.1 79 Akane Sept. 8 194 ... 15.7 12.9 93 BC 9P- 14-32 Sept. 8 200 3.08 17.0 15.5 80 Dayton Sept. 8 9/14 290 3.52 16.9 12.9 75 Ginger Gold Sept. 14 9/8 259 3.30 20.0 13.9 — Fiesta Sept. 14 9/21 199 3.19 17.6 13.4 76 Tsugaru Homei Sept. 14 9/28 216 3.12 15.6 13.4 72 Arlet Sept. 14 9/21 195 2.99 17.8 12.8 67 Elstar Sept. 14 137 2.76 16.7 13.5 62 NY 66305-289 Sept. 14 9/21 183 3.07 15.7 12.7 85 NY 74828-12 Sept. 21 149 3.04 17.3 12.0 86 Alkemene Sept. 21 156 — 16.5 15.5 — NY 75414-1 Sept. 21 9/8, 9/14, 9/28 167 3.07 14.8 12.1 91 Honeycrisp Sept. 21 9/14, 9/28 256 3.34 15.2 12.0 69 BC2-8 Sept. 21 252 3.42 14.7 12.1 86 Shamrock Sept. 28 9/14, 9/21, 10/5 178 3.04 17.8 13.7 — Natco 81 Sept. 28 9/21 231 3.40 15.8 11.9 91 BC 8M 15-10 Sept. 28 235 3.07 16.8 14.7 50 NY 75413-30 Sept. 28 425 4.01 15.8 12.9 80 Bonza Sept. 28 10/5 210 3.30 17.3 11.9 90 BC 8B-20-13 Sept. 28 Pick Earlier 337 3.70 11.6 16.3 ... BC 8B-14-56 Sept. 28 10/5, 10/19 228 3.28 14.6 14.5 90 Yataka Sept. 28 10/5, 10/19 183 2.99 15.6 14.6 65 1 ease-resistant apple that resembles a Mcintosh ex- cept that it has dark cherry red color and a long thin pedicel. It has yellowish flesh, qviite tart, and differ- ent flesh texture than Mcintosh. It ripens between September 15 and 20 but ripen unevenly. This is a nice apple that should be evaluated further. New York 74828-12 (**) is a disease-resistant apple that looks and tastes like Jonamac. When the ground color changes to green-yellow the acidity is still very high. There is a tendency for this cultivar to ripen unevenly and show some preharvest drop. This apple was for the most part an average apple. New York 75414-1 (***). There was more excite- ment generated about this apple than any other disease-resistant apple. It is an extremely attractive medium-sized apple, that develops a deep burgundy Fruit Notes, Spring, 1993 n Table 2 continued. Soluble Red Best Also Weight Diameter Firmness solids color Cultivar date evaluated (g) (in.) (lbs.) (%) (%) Dulcet Sept. 28 10/8 185 3.03 16.1 13.2 90 EC 98T 486 Oct. 5 9/21, 9/28 204 3.08 14.5 11.0 83 Hudson Oct. 5 210 3.06 20.4 12.6 ... Yoko Oct. 5 10/13 225 3.20 19.6 15.4 65 NY 65707-19 Oct. 5 10/13 208 3.18 16.5 11.2 80 Senshu Oct. 5 10/13 205 3.10 14.3 13.8 80 Jonagold Oct. 8 278 3.43 15.8 13.3 68 Rubinette Oct, 8 10/13 155 2.88 15.1 16.4 50 Freyburg Oct. 8 10/19 193 2.97 19.6 16.5 ... Shizuka Oct. 8 10/8, 10/19 395 3.83 16.3 14.3 ... NY 429 Oct. 13 10/5 244 3.37 14.0 12.1 88 Hawaii Oct. 13 230 2.95 15.1 13.1 ... Kinsei Oct. 13 10/19 216 3.21 16.1 13.6 ... NY 75441-67 Oct. 13 9/28, 10/5 258 3.29 16.3 13.0 92 BC 17-30 Oct. 13 10/5 237 3.32 12.5 13.0 95 Hokuto Oct. 13 10/8, 10/19 302 3.59 15.0 13.1 65 NY 617 Oct. 13 10/5 420 4.03 13.8 13.6 70 Splendour Oct. 13 10/5, 10/19 206 3.20 16.0 11.8 82 Brock Oct. 13 10/8, 10/19 302 3.56 15.5 13.5 64 NY 73334-35 Oct. 13 10/5 252 3.32 16.8 11.4 89 NY 75413-30 Oct. 13 205 3.14 15.8 13.7 90 Fantazja Oct. 13 138 2.73 14.7 12.7 85 NY 752 Oct. 13 275 3.46 14.6 12.3 70 AA62 Oct. 13 242 3.26 17.9 13.5 ... BC 8C-5-62 Oct. 13 182 3.00 15.2 14.2 82 BC 8K-21-39 Oct. 19 184 2.98 17.9 13.0 84 Natco 24 Oct. 19 10/13 250 3.42 17.1 13.0 85 Coop 29 Oct. 19 196 3.14 17.8 12.2 ... Newtown Seedling Oct. 19 228 3.33 18.5 12.1 80 Criterion Oct. 19 185 2.98 13.5 11.2 ... Nittany Oct. 19 165 2.87 17.5 13.3 75 Reinette Simirenko Oct. 19 190 3.07 18.4 12.2 ... Fiorina Oct. 19 168 2.97 17.4 12.6 83 Braeburn Oct. 19 185 2.97 20.0 12.3 60 Ambitious Oct. 19 143 2.80 19.7 13.0 ... Orin Oct. 19 213 3.06 18.0 14.2 — NJ 100 Oct. 19 235 3.34 17.5 12.4 — Suncrisp (NJ 55) Oct. 19 203 3.06 17.8 14.2 ... Natco 58 Oct. 19 209 3.10 18.9 12.8 71 Natco 3 Oct. 19 260 3.21 16.1 12.2 ... red color. Its red color, prominent white lenticels, and slight scarf skin made it almost indistinguish- able from Macoun. The flesh is white, tart, not too sweet, and extremely crisp. This apple had the color to pick on September 8 but flavor and other at- tributes did not develop until later. Realistically, this apple showed no sign of drop and it could have been picked from the second week in September through the first week in October. Those who tried this apple knew that they would like it before they even tasted it. It was a classic Pavlov's dog response. New York 75413-30 (♦♦). This very large disease- resistant apple was harvested too early, on Septem- 12 Fruit Notes, Spring, 1993 ber 28. The fruit were quite pitted and the flesh seemed dense and heavy. It was rated quite high for color and attractiveness but quite low for flavor. Judgment must wait for another year, but we were not too impressed this year. New York 65707-19 (**). This disease-resistant apple is fairly attractive, round, medium sized, and red with small white lenticels and greenish white flesh. The flavor is not strong but the flavor and acidity seemed to vary quite a bit from one fruit to another. On October 13, fruit were dropping. The jury is still out on this one. New York 75441-67 (*) is a deep-red disease-resis- tant apple showing some skin russeting or blemish- ing, liie flesh is white, the skin is tough, the flavor OK, but the acidity is so high that even when ripe it is difficult to recommend this one. New York 73334-35 (**) is a disease-resistant apple with good red color, but its irregular firuit shape detracts from its appearance. Harvest on October 5 was too early while severe drop was noted on October 13. Flesh is whitish green, and the skin is tough. The acid is high, the sugar is low, and the taste is not outstanding. There is a blueberry aflertaste. It was not an outstanding apple this year. New York 75413-30 (**) is a very attractive, red, disease-resistant apple the looks much better than it tastes. The shape is ovate to conic and ribbed. Flesh is white with a tinge of yellow. Skin has a chalky, odd taste. We rated flavor only fair to good. Nittany (**). Trees fruited in the first leaf, so the October 19 harvest date may not be representative of future harvests. This apple is fairly good tasting, but it is not as good as Nittany originating from Pennsyl- vania. We will continue to follow it. Orin (**) is green apple and is fairly attractive. It is a very sweet, subacid apple with a pleasant, slightly fruity taste. This sweet apple is worthy of fiirther evaluation. Redfree (***). We used Redfree as another marker in the evaluation process. It is one of the best August apples with a rating of at least *** now. It rates very high in red color, attractiveness, flavor, and overall. Even though it is a disease-resistant apple it can stand on its own merits. It will not store for a long time. Reinette Sindrenko (**) has a very distinctive green color, similar to an immature Granny Smith. Flesh is whitish green. Flavor is somewhat tart with a distinctive but spicy taste. At the time of our sample, flesh was still green and soluble solids were only 12.2. We believe that this apple was not ripe at the time of harvest, even though it did taste reason- ably good. The taste and condition of Reinette Simirenko was excellent following several weeks in regular air storage. This cultivar warrants further evaluation. Ruhinette (*). The blotchy red-pinkish-brown color make this apple rather unattractive. Also, the large lenticels give the impression of russet. This apple is fair to good tasting but the acidity and astringency detract from its flavor. We are not very excited about Rubinette. Sanaa (**T) is a fairly attractive medium sized apple. We were very impressed with the flavor, texture, crispness, and aroma. We consider Sansa one of the jewels this year. It matures at about the time of Sunrise, and when compared with Sunrise, Sansa is the clear winner. It tastes Gala-like but it ripens fully two weeks before Grala. We did not have enough fruit to evaluate it fully, but it is one apple that we will be looking forward to eating next year. Senshu (**). The blotchy or burned reddish brown stripes on this medium sized apple make it some- what unattractive. It has prominent calyx lobes and a swelled pedicel at the attachment like Gala. It has unusual orange-yellow flesh. It is a very good tasting apple. It is not too sweet with a slightly spicy flavor. Overall, this cultivar was rated quite high. Shamrock (**T) was evaluated over a three week period and it had acceptable quality over the whole time. It did not received the highest marks for flavor but the ratings were consistently good. In mid- September, it tastes green and Granny-like. Others who were offered this apple seemed to liked it. We believe that it is a good apple that fills a niche for a green apple in September and October. There is no other green apple that we have tasted that would compete in this market. Storage life is not long. Fruit soften in storage. As it softens, it assumes the taste of a very good Mcintosh. We can recommend Shamrock. Shizuka (**T) is a large, attractive, yellow apple with a pink cheek, and it has very good flavor. This apple resembles Mutsu in many ways, a fact that is not too surprising given their common parentage. However, it also differs from Mutsu in several impor- tant ways. It appears to be more elongated in shape. It ripens about a week before Mutsu. The flesh is finer, less dense, and tastes fruitier than Mutsu. Fruit Notes, Spring, 1993 13 Mutsu is plagued by Pseudomonas spotting, and we found none on Shizuka. Although vigorous, this will be a grower-firiendly tree. Shizuka was a very nice apple that should be evaluated further. Splendour (.**) is one of the most attractive apples evaluated. The fruit is round to conic, a good cherry red, with prominent tan lenticels. We evaluated this starting on October 5. It improved in flavor with subsequent harvests, but it never reached the top of the list in flavor. The flesh is yellow white and the flavor is mild and subacid. The skin is tender, thus it may not be able to stand up in commercial market- ing channels. It is a very grower-friendly tree. Spigold (***). We did not evaluate Spigold for- mally because we have already decided that this is one of the best apples available. It is large, some- what unattractive, and tends to bitter pit. We believe that it is destined only for a niche market, but what a wonderful tasting apple! It can be very biennial. Sumac (**) was one of the first apples to be evalu- ated in the season. It is small and quite unattractive. We rated flavor quite high, but considering every- thing, we would prefer AA 63 to Sumac for an apple this early in the season. SuncrUp™ (New Jersey 55) (**t). We made our lastharvestof mostapples on October 19. At that time NJ 55 had fair appearance, a pink red cheek, and a ground color that was still green. It was quite acid and had no better than average taste. The remaining NJ 55 were harvested on November 4. The ground color had changed and it appeared ready to harvest. Although it still tasted a little tart, we rated flavor very high. At that time it was a wonder- ful tasting apple that appeared to have the potential for quite long storage. Our major reservation about this apple is that we may not have a sufficiently long growing season to mature it properly. I would say that it matures up to a week after Fuji. Tsugaru Homei (**i). On September 14 this apple was not highly colored, but it had a red mottling over a pinkish red. Ithas a shape similar to Spencer. The apple has a good sweet, crisp, juicy, and somewhat spicy taste. When evaluated two weeks later it was cherry red and had developed an extremely sweet spicy flavor. We believe that September 20 may have been an appropriate harvest date. We do not know if it has enough going for it to make it. Williams Pride (**t) was one of the best disease- resistant apples evaluated. Fruit is large, red, and irregular in shape, and the skin not smooth. It is only moderately attractive but the taste is mild, subdued, and slightly spicy and good. When ripe the firuit is quite aromatic. Fruit show some bitterpit. People who tasted Williams Pride thought that it was a very good apple. This selection requires further evaluation, primarily to confirm the charac- terization of its flavor as good. Yataka (**t) was an excellent apple again this year. It is truly an early maturing strain of Fuji. It ripens fully two weeks ahead of other Fuji strains and it is ready to eat immediately. It is not an attractive apple, and it is definitely less attractive than strains ofRedFuji. Flavor was rated very high. OflFthetree, the taste of Yataka is better than any of the other strains of Fuji. We are uncertain about its storage potential. We rate Yataka quite high. Yoko (**). This medium-sized red apple has fair to good color and attractiveness. It taste is very sweet and spicy. There is russet in the calyx, similar to Arlet. We do not think that it is outstanding enough to compete with other apples. Summary 1. Several apples were recognized from the evalu- ation in 1992 as being clearly superior. These include Arlet, Gingergold, Honeycrisp, Reinette Simirenko, Sansa, and Suncrisp"™ (NJ 55). Other apples that fall into this category but they are unavailable to the general pubic for testing at this time. Included in this group are the British Columbia selections BC 9P-14-32, BC 8M-15-10, BC 17-30, and Fantazja. 2. A second group of apples were recognized as not being quite so outstanding, but they were suffi- ciently good to be given a designation of Honor- able Mention. These cultivars include: Akane, Kinsei, Orin, Shamrock, Shizuka, and Yataka. 3. Several disease-resistant cultivars were recog- nized for their superior quality. This group includes: Alkemene, Fiorina, NY 75414-1, and Williams Pride. Liberty and Redfree are not included on this list because they already have been recognized as being good and accepted disease-resistant cultivars suitable for commer- cial planting. 14 Fruit Notes, Spring, 1993 Implementation of the MARYBLYT Model for Fire Blight Control Roberta Spitko New England Fruit Consultants Fire blight, caused by the bacterium Erwinia amylovora, is one of the most destructive and diffi- cult to manage diseases encountered by tree fruit growers throughout the world. Some might argue that apple scab, caused by Venturia inaequalis, deserves this honor but with respect to apple scab, there is always next year and the chance to try again. A severe epidemic of fire blight can damage an orchard of susceptible apple or pear trees so severely that there is no next year; that is, the orchard block must be removed. New England Fruit Consultants (NEFCON) has been observing and studying this disease in Massachusetts, Vermont, and New Hampshire for more than a decade. Overall knowledge of this disease has increased significantly since the early 1980s, much as a restilt of the excellent work of Dr. Paul Steiner and his colleagues as the University of Maryland. Their development of the MARYBLYT computer model to aid in the control decision making process is enabling us to understand disease devel- opment better and to fine tune our disease control strategies. It is not our intention to describe in detail the epidemiology of fire blight as there are many excellent sources already available (see U.S.D.A. Bulletin No. 631, Fire Blight- Its Nature, Prevention and Control). Our purpose is to describe our suc- cesses and frustrations regarding control, particu- larly with regard to the MARYBLYT model. NEFCON has been working with Dr. Steiner and Dr. Daniel Cooley at the University of Massa- chusetts since the mid-1980s as the fire blight model was being developed. We found that it described disease development accurately as we had observed it but we did not attempt to use it as a control strategy at that point. In the past several years as the model has become commercially available, we incorporated it fully into our fire blight management program. In 1992, we implemented the model in multiple sites in Massachusetts, New Hampshire, and Vermont. Our findings are as follows: 1. The model predicts with extreme accuracy when overwintering canker activity will begin as well as when symptoms of canker blight, blossom blight, shoot blight, and trauma bUght will occur. This prediction facilitates detection and removal of blighted tissues if possible (numerous infections are probably best left for winter removal). 2. If bloom phenology and meteorological data are kept judiciously, and Streptomycin sprays are used when the model predicts the risk for blossom blight is high or blossom infection has occurred, problem sites may be cleaned up, or major outbreaks of blossom blight in new sites may be avoided. 3. Although keeping track of bloom and weather data may appear simple, it is important that these be extremely accurate as the model's predictions can only be as accurate as the human input allows it to be. In our experience, we found detailing bloom to be difficult. Most orchards have many different culti- vars blooming at different times; an entire bloom period may be several weeks long. Also, many cultivars which are highly susceptible to fire blight produce secondary blossoms (Paula Red, Rome, and Cortland, as well as many kinds of pears). It is possible to have 1/2-inch fruits and open blossoms in the same fruit cluster. It has been our experience that this route is a very common one by which severe epidemics become established. Growers must keep an eye out for these late blossoms in problem areas and be prepared to spray Streptomycin should weather conditions favor infection. With respect to weather data, daily maximum and minimum temperatures must be entered. An- other very important input is wettings, however slight they may seem. In several sites in 1992, the model did not predict blossom blight epidemics which occurred. When we revised the data to reflect dews which likely happened due to extreme tem- perature drop at night during bloom, the model accurately predicted that infection of the blossoms had occurred and when symptoms would be visible. 4. With prolonged bloom periods and weather par- ticularly favorable to fire blight, the model MAY call for more Streptomycin sprays than should be ap- plied considering Streptomycin resistance manage- Fruit Notes, Spring, 1993 15 ment. In most years, however, it is unlikely that the model would call for more than three Streptomycin applications, which would be within resistance man- agement guidelines. 5. The complexity of the fire blight disease cycle and the way that symptoms manifest themselves (several different phases showing up within a short period of time) makes it at times difficult to deter- mine what is happening in an epidemic situation. An excellent feature of the model is that data files are created and unusual or unexpected situations may be studied at a later date. We have increased our understanding of how this disease operates signifi- cantly by reviewing these files over the years. 6. Although the MARYBLYT model is excellent for monitoring disease development and helpful in cleaning up known problem sites, much of the de- structiveness of fire blight is due to its erratic occur- rence. If an orchard has had no history of fire blight, there would be no incentive to implement an aggres- sive control program including Streptomycin sprays. Once a serious epidemic is in progress, it is too late for the model or Streptomycin sprays to be of much help. Repeatedly spraying Streptomycin on a raging epidemic can only favor resistance develop- ment and is of questionable value in stopping disease progression. Where an epidemic of fireblight will occur each year is still the overriding question. We have good tools now available to aid in control decisions, par- ticularly the MARYBLYT program, but where to implement them if a site has no prior history contin- ues to elude us. 7. Our best strategies for fire blight management are as follows: A. Keep nitrogen levels in check. Pushing young trees with high nitrogen regimens favors lush growth that is highly susceptible to infection. B. Watch vector populations, primarily aphids, leafhoppers, and pear psylla. Keep them low. C. Implement a copper program annually in early spring on all pears and susceptible cultivars of apples. D. Avoid planting trees, if possible, where both scion and rootstock are highly susceptible to fire blight. E. Follow proper pruning techniques for winter removal of overwintering cankers. Major epi- demics are probably bestleflto nin their course in summer infections; a few minor strikes should be removed as soon as they are detected. F. Implement the MARYBLYT program as part of your regular orchard recordkeeping activities. If any stage of fireblight is detected in the orchard or general vicinity, use the model to time application of Streptomycin sprays in an aggressive control program for at least two successive years. In conclusion, with diligence and good manage- ment techniques it seems possible to obtain satisfac- tory control of fire blight in most growing seasons. Many questions remain unanswered, however, such as the role of systemically infected, asymptomatic trees in the disease cycle, and where major epidem- ics will strike from season to season. We are un- doubtedly making progress in our understanding of this complex disease. Hopefully, at some point we will achieve the knowledge we need to be successful consistently in its management. %f^ %f# %f^ m^ «£• r{% 0^ #1% r|% #{% 16 Fruit Notes, Spring, 1993 Fish Hydrolysate Fertilizer Should Not Be Applied Foliarly to Apple J. R. Schupp, M^ Schupp, and M.M. Bates Highmoor Farm, University of Maine The four- tx) six-week period following bloom is a critical time for crop development in apples. During this period, the mfgority of seasonal vegetative growth takes place, and firuit set, return bloom, potential yield, and potential fruit size are deter- mined. Mineral nutrient reserves become depleted, as utilization is greater than root uptake, and nutri- ents, especially nitrogen, can become a Umiting factor to growlii, even though soil reserves are ad- equate. Foliar sprays of mineral nutrients during this critical period can be beneficial in supplementing ground-applied fertilizers. These applications do not replace the regular ground-applied fertilizer program, they simply fill the gap during the time that demand outstrips supply. Foliar nitrogen appli- cations in particular have been shown to increase fruit set and fruit size when applied at 8 to 12 lbs per acre during this time. Previous studies have shown that foliar urea sprays are a safe and effective method for fertilizing apple (Stiles and Reid, 1991). Fish hydrolysates, a byproduct of the fishing industry have recently been recommended as an organic nitrogen fertilizer for cranberry (DeMoranville, 1990), apple, and blueberry (Weis and Bramlage, 1992). The fishing industry is inter- ested in developing new uses for this material and in cooperation with the Portland (ME) Fish Exchange, we investigated the feasibility of using fish hydroly- sates as a foliar nitrogen source for apple. Mature Delicious/MM.lll and Golden Deli- cious/MM. 106 apple trees, growing at the University of Maine Highmoor Farm in Monmouth were used for this experiment. "Gulf of Maine" fertilizer, con- taining 2% N, 4% P, and 2% K was supplied by the Portland Fish Exchange. Treatments were as follows: 1. Control, no foliar fertilizer. 2. Fish hydrolysate, 3 gallons in 25 gallons of water. 3. Urea, 1.25 lb in 25 gallons of water. Both fertilizer treatments, calculated to provide the equivalent amount of nitrogen as an application of 12 lb urea/acre, were applied as a dilute spray with a handgun. Three applications, at petal fall (PF), PF+7 days, and PF+14 days, were made on four repUcations of each cultivar. Fish hydrolysate fertilizer reduced fruit set of both cultivars (Table 1). Foliar urea increased fruit set and yield of Golden Delicious but had no effect on Delicious. Fruit from fish hydrolysate-treated Golden Delicious trees had higher soluble solids than those from urea-treated trees, and this appears Table 1. The effects of foliar sprays offish hydrolysate fertilizer and urea on fruit set, yield, fruit soluble solids, and russeting of Delicious and Golden Delicious apple. Fruit set (%) Treatment Del. Gold. Yield (kg) Del Gold. Soluble solids (%) Russeting* Del. Gold. Del. Gold. Control 73 a" 19 b 81 ab 54 b 10.2 a 13.5 ab 1.3 b 1.8 b Fish hydrolysate 38b 7c 64b 21 b 10.2 a 14.1 a 3.7 a 4.1 a Urea 64 a 34 a 92 a 128 a 9.8 a 12.8 b 1.0 b 2.0 b • Russeting was rated on a scale of l=none to 5=100% russeted. " Means within columns not followed by the same letter are significantly different at odds of 19:1. Fruit Notes, Spring, 1993 17 to be related to the difTerences in cropping between these treatments. Neither fertilizer affected leaf or fruit mineral nutrient content, fruit size, or fruit firmness at harvest (data not presented). Russeting is a rough brown netting over the surface of the fruit that occurs when the fruit epider- mis is killed. Ciolden Delicious is an economically important cultivar that is predisposed to russeting, while Delicious is much less sensitive to russeting. Russeting results in loss of grade when fruit are packed and must be kept to a minimum if an orchard is to remain profitable. Fish hydrolysate increased fruit russeting on both cultivars (Table 1). The conductivity of the fish hydrolysate fertilizer was 45.6 mmhos/cm, the equivalent of a 29,000 ppm solution of KCl. It is probably this salt that reduced fruit set and caused the severe russeting. Regard- less of the cause, fish hydrolysate reduced fruit set and damaged the fruit and should not be foliarly applied to apple. Literature Cited DeMoranvUle, C. 1990. Fish hydrolysate fertilizer : its potential role in commercial cranberry produc- tion. HortScience 25:626 (abstract). Stiles, W.C. and W.S.Reid. 1991. Orchard Nutrition Management. Cornell Coop. Ext. Bui. 219. pp. 18-19. Weis, S.A. and W.J. Bramlage. 1992. Using fish waste hydrolysates as a fertilizer for apples and blueberries. Fruit Notes 57(3):15-19. •Im %t^ «£• •!# 9^0 •J% •J* rj% #J% •^ Comparative Effects of Margosan-0 (Neem Extract) and Imidan on Plum Curculio and Apple Maggot Ronald J. Prokopy and Margaret Christie Department of Entomology, University of Massachusetts John Bemis Hutchins Farm, Concord We are continually on the lookout for safe new pesticides that can control some of our key apple pests, such as plum curculio and apple maggot. Extracts of seeds and other parts of neem trees have been used for centuries, even millennia, to control a wide variety of insects in India and other parts of Asia. These extracts appear to be remarkably safe for human consumption as well as environmentally safe. They are known to control insects by acting as insect repellents, antifeedants, or toxicants or by disrupting the growth of insects. Recently, W.R. Grace Company began distributing an extract of neem plants called Margosan-0 for use in green- houses, commercial nurseries, forests, and homes. Although no extract of neem, including Margosan-O, is yet registered for use on crops for human consumption, we decided to evaluate its eflFectiveness against plum curculio and apple mag- got on apple trees at Hutchins Farm in Concord, MA in 1992. Hutchins Farm grows produce organically and annually contends with moderate to high popu- lations of plum curculio and apple maggot. Methods Used Against plum curculio, a treatment of Margosan-0 at one gallon per 100 gallons was ap- plied with a mist blower at 300 gallons of water per 18 Fruit Notes, Spring, 1993 Table 1. Comparative effects of Margosan-0 (neem extract) and Imidan on plum curculio and apple maggot. Injured fruit {%) Apple maggot larval tunnels Treatment Plum curculio stings On tree In drops Margosan-0 Imidan Untreated check 62 a* 16 b 63 a 14 b 13 b 38 a 42 b 30b 76 a 'Means in each column followed by a different letter are signifi- cantly different at odds of 19:1. acre to 120 mature, semi-dwarf Liberty and Jonafree trees on May 22 (petal fall), May 26, May 29, and June 2. As a control treatment, Imidan at 1.5 pounds per 100 gallons was applied on May 22 and May 29 to 120 other Liberty and Jonafree trees. Yet, another 120 trees of these varieties remained unsprayed as checks. Sampling consisted of exam- ining20 fruit per tree on four replicates of eight trees each per treatment on June 8. Against apple maggot, a treatment of Margosan- O at one gallon per 100 gtdlons was applied with a mist blower at 300 gallon of water per acre to 60 mature, semi-dwarf Prima and Burgundy trees on July 1, July 8, July 15, and July 22. As a control treatment, Imidan at 1.5 pounds per 100 gallons was applied on July 1 and July 15 to 60 other Prima and Burgundy trees. Yet, another 60 trees of these varieties remained unsprayed as checks. Sampling consisted of examining 10 on-tree and 10 dropped fruit per tree on six replicates of two trees each per treatment on August 19. Fruit were held at room temperature for one week (drops) or four weeks (on- tree fruit) before examining for larval trails in the fruit flesh. Results As shown in Table 1, use of Margosan-O failed to provide any detectable reduction in firuit injury by plum curculio compared with untreated check fruit, even though it was applied every three to four days from petal fall to within six days of sampling. Imidan applied every seven days provided reasonable curculio control in the face of the very high popula- tion of curculios. As shown in Table 1, use of Margosan-0 resulted in a significant decrease in percent fruit infested with apple maggot larval trails. In fact, it was little different from Imidan in this regard. Neither pro- duced a high level of maggot control, possibly be- cause there was a four-week gap between the last treatment and removal of fruit in sampUng for maggot injury. Conclusion We conclude that neem plant extract formulated and sold as Margosan-0 offers little or no promise for controlling plum curculio but does offer substantial promise for controlling apple maggot. We do not know if its effects on apple maggot were through reduction of fly egglaying punctures in fruit or through prevention of growth of larvae hatching from eggs. Either way, we can anticipate that application of Margosan-0 against apple maggot might need to be twice as frequent as application of Imidan to provide equivalent levels of control. We hope in the near future to be able to evaluate Margosan-0 against leafminer larvae and leafhop- per nymphs. Quite possibly, Margosan-0 might soon be registered for agricultural use. Acknowledgements This work was supported by a grant from the W.R. Grace Company, to whom we are grateful. Fruit Notes, Spring, 1993 19 Orchard Mineral Nutrition: Ground- appiied vs. Foiiar-applied Fertilizers James R. Schupp Highmoor Farm, University of Maine Why do apple growers spend time and money spraying fertilizers on foliage when for centuries we have been told that plants take up nutrients from the soil via their roots? They do it in an attempt to improve fruit quality and enhance its storage life. Apple is somewhat unique among fruit crops in that it is able to utilize a range of mineral nutrients through its leaves. Many new products are available to apple grow- ers for foliar feeding. Sometimes promotional mate- rials suggest that rather dramatic results can be obtained from using these products. One grower recently calculated the expected results for his or- chard based on such claims and found that if he would simply use several of these products, his yields would be 3000 bushels per acre with excellent fruit size and virtually 100% packout. This yield is three times that obtained in the best New England orchards and a level of production at which fruit size and quality would be very poor. Such an outcome is impossible of course, and most manufacturers of foliar nutrient products are careful to base their product claims within the realm of possibility. Still, many apple growers are uncertain what role foliar sprays should have in their nutrition plan. The first step to any orchard nutrition plan is soil and leaf analysis. Before applying any fertilizer in any manner it makes proper sense to determine whether or not there is need for nutrient supple- ments, which ones are needed, and in what amounts. This information provides the first answers to the ground-applied versus foliar-applied question. Macronutrients If leaf and soil analyses indicate the need for nitrogen, phosphorous, potassium, calcium, or mag- nesium, the cheapest and most efficient way to apply them is by ground application. Soil- applied fertiliz- ers can be applied early in the spring before the busy growing season and with little or no risk of damage to the fruit or foliage. Soil-applied nutrients also follow the natural pathway in the tree to all the locations where growth and development are taking place. By contrast, foliar-applied nutrients are less mobile and stay where they are absorbed. Micronutrienta Boron, manganese, copper, or zinc can be ap- plied to either soil or foliage; however, foliar applica- tions are more common, because it is easier to spray the small amounts needed than it is to apply them to the soU. Foliar applications allow "direct hits" to the fruit and foliage where supplemental nutrition is needed, and they allow for precision timing. The grower can apply the nutrient at a critical time in the growth stage when it is needed. Foliar fertilizers can harm the fruit and foliage that they contact, so usually, only small amounts are applied this way. Growers should pay particular attention to recom- mended rates and timings to avoid damage. Refer to the label of the product and the New England Apple Pest Management Guide for additional information on rates, timing, and nutrient compatibility in the spray tank. High-grade fertilizers, free from impu- rities, are needed for foliar application, adding to their cost. Special Nutrition Problems If a given nutrient is acutely deficient or if there is a special nutritional problem that is harmful to productivity or fruit quality, a combination of both soil- and foliar-applied nutrients may be justified. Table 1 lists several of the more common examples where supplemental foliar nutrients are used to correct specific problems. Perhaps the most common special nutritional problem in apple is low fruit calcium. Developing fruits compete with vegetative growth for calcium during the first five to six weeks following bloom. After this time, calcium uptake by the fruit via the tree's vascular system essentially stops. If soil calcium levels are low, or if vegetative growth is excessive, the fruit may be deficient in calcium, leading to the appears rce of cork spot or bitter pit and rapid loss of fruit q ality in storage. In 20 Fruit Notes, Spring, 1993 Table 1. Foliar applications for special nutritional problems in apple. | Problem Problem nutrient Material Annual rate/acre* Timing* Comments Low fruit set, small fruit size Nitrogen Urea (45%) 201b Pand PF Not recommended where calcium deficiency disorders are problems. Bitter pit, poor storing fruit Calcium Calcium chloride (80%CaCl,) 15-50 lb 1-7 Do not substitute calcium nitrate. Do not premix calcium chloride with Solubor. Premature leaf & fruit drop Magnesium Magnesium sulfate (11%) 151b PF May be applied in first or second cover. Compatible with pesticides. Low firuit Bet, poor quality Manganese Manganese sulfate (24%) 5 1b DorPH Apply in spring before growth starts. Low frmt set, poor quality Copper Copper sulfate (22%Cu) 4-6 lb DorPH Apply in spring before growth starts. Fruit pitting, shoot dieback Boron Solubor (20.5%B) 4 1b 81b PF& 1 PH Make two applications of equal rates, but do not exceed 8 pounds per acre per year fi-om Eill sources. Shoot dieback, low hardiness Zinc Zinc sulfate (89%) 5.5-11 lb DorPH Apply before growth starts. ■Commercial formulation 'Efedormant, P=pink stage, FB=full bloom, PF=petal fisdl, l-7=lst through 7th cover sprays, PH=postharve8t Adapted from Penn State Tree Fruit Production Guide, 1992-1993 and Orchard Nutrition Management, Cornell Coop. Ext Bui. 219. cases where fruit calcium is marginal, the symptoms may be apparent only after long periods in storage. If soU calcium levels are low, the soU pH likely is acidic. The cheap, long-term solution to low soU calcium is liming to correct the acidity and to add calcium to the orchard soil; however, regardless of the cause of the fruit calcium problem, foliar calcium sprays are advisable. Foliar sprays of a calcium- containing fertilizer put calcium directly on the fruit where it can be taken up, and will reduce greatly the occurrence of costly blemishes and loss of fruit qual- ity. Brand Name Products vs. Salts A large number of products are available for applying foliar nutrients. Table 2 lists some of the foliar calcium products available to the apple grower. It is not possible to discuss the qualities of each individual product in a short forum such as this article, but several comparisons can be made be- tween brand name products versus calcium chloride salts. Brand name products, when applied to provide the same amount of calcium as provided by calcium chloride are no better or worse in their effectiveness in preventing frviit disorders. Thus brand name products are more expensive sources of calcium; however, brand name products may be safer to fhiits and foliage, easier to measure, and more conve- niently packaged. Calcium chloride contains oxide impurities that can increase the pH of the spray solution in the tank, thereby reducing the effectiveness of certain pesti- cides. If calcium chloride is to be tank-mixed with pesticides, a small amount of vinegar or buffering agent should be added to prevent this problem. Finally, brand name products may contain other nutrients, which may be beneficial, but only if they are nutrients that currently are needed by the tree. It is up to the individual grower to weigh the pros and cons of each product given his or her situation. Similar considerations result when growers make comparisons between brand name products and salt formulations for other mineral nutrients. Summary and Tips for Success Foliar fertilizers are an important tool for apply- ing micronutrients, correcting acute nutrient defi- Fruit Notes, Spring, 1993 21 Table 2. Calcium materials for use on a pples, with labeled rates per acre per application, per acre per season, and per acre per year. | Product name Percent calcium Pounds/ gal Pounds of calcium/ gal or lb Manufacturer Product/ A/spray mln.-max. No. of appL Total product/ A/aeaaon min.-max. ToUl calcium/ A/season Ob) mln.-max. CaB 6.0 10.0 0.60 Stoller, Inc (800-255-9548) 3-6 pints 8 3-6 gal 1.8-3.6 CaBy 10.0 11.9 L19 Stoller, Inc (800-255-9548) 2-4 qt 8 4-8 gal 4.8-9.6 Calcium chloride (77- 80% CaCl2) 27.8 flakes 0.28 many 1.8-6.2 lb 8 14.3-50 lb 4.0- 14 Calcium chloride (35% CaC12 liquid) 12.6 11.3 1.42 many .35-1.24 gal 8 2.8-9.9 gal 4.0-14 Cor-Clear Dry 34.5 beads 0.34 SEGO Intl., Inc. (503-796-0133) 4-8 lb 8 32-64 lb 10.9-21.8 Foliar Calcium Folical 10.0 9.6 0.96 Agrimar (3orp. (800-284-9898) Igal 6-8 6-8 gal 6.8-7.7 Fung-Aid 10.0 11.9 1.19 Stoller, Inc (800-255-9548) 2-4 qt 8-16 6.5-8.2 gal 6.5-9.7 Link Calcium 6% 6.0 10.3 0.62 Wilbur-Ellis Co. (509-248-6171) 2-4 qt 4 2-4 gal 1.2-2.5 Mora-Leaf Calcium (94% CaCy 34.0 DRY 0.34 Wilbur-Ellis Co. (609-248-6171) 4-8 lb 3-6 12-48 4.1- 16.3 Nutri-Cal 8% Calcium Solution 8.0 11.1 0.89 CSl Chemical Corp. (800-247-2480) 1-2 qt 3-8 .75-4.0 gal .67-3.6 Nutra-Phoa 10 10.0 powder 0.10 Leffingwell Div. (800-262-3861) 3-10 lb 2-6 20^0 lb 2-4 Nutra-Phoa 12 11.0 powder 0.11 Leffingwell Div. (800-262-3861) 3-10 lb 2-6 20-(01b 2.2-4.4 Nutra-Phoa 24 20.0 powder 0.20 Leffingwell Div. (800-262-3861) 3-10 lb 2-6 20-40 lb 4-8 Nutra-Phos Mg 10.0 powder 0.10 LefTingwell Div. (800-262-3861) 3-10 lb 2-6 20-40 lb 2-4 Nutra-Plua 6.0 10.0 0.60 Custom Chemicides (209-264-0441) 1-3 qt 8-11 2-8.2 gal 1.2-4.9 Pit-Stop Dry Con. Foliar Cal. 32.6% 32.6 diy 0.32 Ag-Chem, Inc. (301-548-2200) 4-6 lb 4-6 16-48 lb 6.2-16.6 Pit-Stop Foliar Calcium 12% 12.0 11.3 1.36 Ag-CJhem, Inc. (301-648-2200) 1.5 gal 4-6 6-9 gal 8.1-12.1 Sett 8.0 11.4 0.91 Stoller, Inc (800-255-9548) Igal 8-11 8-11 gal 7.3-100 Sorba-Spray Cal. 8.0 10.75 0.86 LefHngwell Div. (800-262-3861) 1-4 qt 4-5 1-6 gal 0.9-4.3 Sorba-Spray CaB SO 10.0 0.50 Leffingwell Div. (800-262-3861) 1-4 qt 4-5 1-6 gal 0.6-2.5 Stopit Calcium Concentr. 12.0 10.7 1.28 Shield-Brite Div. (206-827-8717) 2-4 qt 8-11 4-11 gal 5.1-14.1 Tracite Calcium 6% 6.0 10.0 0.60 Helena (Jhem. Co. (901-748-3200) 3-6 pU 8 3-6 gal 1.8-3.5 Traco PitCal Liquid Calcium 12.0 11.7 1.40 Traylor Chem. Co. (800-348-3361) 0.5-2 gal 7 3.5-14 gal 4.9-19.6 Wuial Calcium 10.7 13.3 1.42 AGLUKON Div. (800-832-8788) 3-4 pts 5 1.9-2.5 gal 2.7.3.6 Adapted from th e Ptnn State Trte Fruit Production Guidt, 1992-1993. 22 Fruit Notes, Spring, 1993 ciencies, and solving special nutritional problems, such as getting calcium into apple fruit. For overall economy and tree health, most macronutrients should be soil-applied. When applying nutrients to apple foliage, the following suggestions will enhance the spray's effec- tiveness and safety: 1. Think dilute. Apply fertilizers with as much water as is practical. Effectiveness will be aided via thorough coverage and better absorption. 2. Watch the weather. Follow the 80/80 rule : avoid 4. nutrient sprays when temperature or humidity values exceed 80 degrees or 80%, respectively. Following this nJe will reduce greatly the risk of fruit or foliage damage. Make sure that your sprayer is calibrated prop- erly and that its nozzles are adjusted to direct an even pattern to the tree canopy. More is not better, more often is better. Do not apply too much at one time. If you wish to apply more of a particular nutrient, consider soil appli- cation or repeating the foliar spray at a later date. *f^ •!# %f^ %% %f^ r|% rj% «^ r^ rj% Fruit Notes, Spring, 1993 23 Fruit Notes University of Massachiuetts Department of Plant & Soil Sciences a05 Bowditch Hall Amherst, &IA 01003 Nonprofit Organization U.S. Postage Paid PeimK No. 2 Amherst. iMA 01002 SERIAL SECTION UNIV. OF MASSACHUSEHS LIBRARY AMHERST, MA 01 003 Account No. 3-20685 arriii »r J354 Fruit Notei -\ I V 1 5 ^3 ISSN 0427-6906 rrepared by the Department of Plant & Soil Sciences. University of Massachusetts Cooperative Extension System. JHIVJOF f ASf Or 5^ 9> United States Department of Agriculture, and Massachusetts Counties Cooperatli^. i Editors: Wesley R. Autio and William J. Bramlage Volume 58, Number 3 SUMMER ISSUE, 1993 Table of Contents Costs and Returns from High Density Apple Plantings During the First Three Seasons Costs and Returns from Three Peach Training Systems During the First Three Seasons Optimal Positioning of Baited Sticky Red Spheres for Capturing Apple Maggot Flies Massachusetts Agriculture Fruit Notes Publication Information: Fruit Notes (ISSN 0427-6906) is published the first day of January, April, July, and October by the Department of Plant & Soil Sciences, University of Massachusetts. The costs of subscriptions to Fruit Notes are $7.00 for United States addresses and $9.00 for foreign addresses. Each one-year subscription begins January 1 and ends December 31. Some back issues are available for $2.00 (United States addresses) and $2.50 (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 COOPERATIVE EXTENSION SYSTEM POLICY: All chcm ical uses suggested in Ihis publicalioo arc conlingcat upon continued registration. These chetn icals should be used in accordance with federal and state laws and regulations. Growers arc urged to be familiar with all current stale regulations. Where trade names are used for identification, no company endorsement or product discrim ination 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 IN JURY OR PROPERTY DAMAGE. Issued by the University of Massachusetts Cooperative Extension System, Robert G. Hetgesen, Director, in furtherance of the acts of May 8 and June 30,1914. The University of Massachusetts Cooperative Extension System offers equal opportunity in programs and employment. Costs and Returns from High Density Apple Plantings During the First Three Seasons Wesley R. Autio Department of Plant & Soil Sciences^ University of Massachusetts In the 1989 New England Apple Survey (Autio, 1989), growers stated that 62% of the apple acreage to be planted in 1990-94 would be on dwarfing rootstocks. Since the survey, several acres of dwarf trees have been planted; however, little experience exists with methods of training these trees. Manage- ment is much different than for free-standing stan- dard or semi-dwarf trees. To become familiar with the peculiarities and to obtain accurate data on costs and returns of high- Table 1. Costs and returns per acre associated with Nicobel JonagoldTM.G in four | training systems. Land preparation costs were derived from White and Demarree 1 (1992) and Fuller et al . (1991). Establishment costs include all those associated 1 with trees, planting, support systems, and initial training (see Autio, 1990). | Growing costs, other than those associatec with training. were derived from White | and Demarree (1992) Training labor and suppUes were based on actual assessments from this planting. Picking, storing, packing, and selling costs were derived from Castaldi (1987). NE Central Slender Vertical Vertical Category leader spindle axis trellis Year 1 - 1990 Land preparation Fertilizer and lime 150 150 150 150 Seed 20 20 20 20 Labor 15 15 15 15 Equipment 38 38 38 38 Establishment 3904 5206 7172 5146 Growing costs Fertilizer 55 55 55 55 Spray material 47 47 47 47 General supplies 15 15 15 15 Training labor 14 25 57 5 Other labor 200 200 200 200 Equipment Costs - Year 1 133 133 133 133 4591 5904 7902 5824 Net - Year 1 -$4591 -$5904 -$7902 -$5824 1 Fruit Notes, Summer, 1993 Table 1. Continued. NE Central Slender Vertical Vertical Category leader spindle axis trellis Year 2 - 1991 Growing costs Fertilizer 55 55 55 55 Spray materials 45 45 45 45 Training supplies 5 23 5 8 General supplies 15 15 15 15 Training labor 10 96 34 29 Other labor 200 200 200 200 Equipment 133 133 133 133 Fruit-related costs Picking 2 1 52 0 Storing 3 1 65 0 Packing 3 2 86 0 Selling 1 0 21 0 Costs -- Year 2 472 571 711 485 Returns - Year 2 21 10 533 1 Net -- Year 2 -$451 -$561 -$178 -$484 1 density management systems, I established a trial of four training systems at the University of Massa- chusetts Horticultural Research Center (Belchertown) in the spring of 1990. This trial included Nicobel Jonagold/M.9 trained as a New England central leader, as a slender spindle, as a vertical axis, and on a four-wire vertical trellis. Previously, I published an article which included the various costs of establishment (Autio, 1990). Here, I have continued the discussion of this study, includ- ing the costs of managing these trees during the first three growing seasons and the returns obtained from the fruit. The Systems New England Central Leader. The NE central leader, simply, is a small central-leader tree (389 trees per acre, 8' x 14'). Minimal pruning has been conducted, including removal only of those branches which inhibited the developmentof thecentral leader. Some limb spreading has been done with weights. Slender Spindle. The slender spindle is typical of a European slender spindle, i.e. a small central- leader tree with a relatively large amount of branch manipulation. Trees are spaced 6' x 14' (519 trees per acre). The new growth of the central leader was headed by half in the first dormant season to encour- age lateral development. The central shoot originat- ing from the heading cut was tied to the post in June of the second season, and competing laterals were bent to 90° from vertical with rubber bands. In early July of both the second and third growing seasons, lower laterals were tied to approximately 70°, cen- tral laterals were tied to approximately 90°, and upper laterals were tied to 100°. In some cases in 1992, branches which bore fruit in 1991 were tied up to prevent devigoration. In 1991, a self-tapping sheet-metal screw was drilled into the bottom of the conduit-pipe post, and cotton kite twine was tied from this screw to limbs for positioning. This process was relatively time con- Fruit Notes, Summer, 1993 Table 1. Continued. NE Central Slender Vertical Vertical Category leader spindle axis trellis Year 3 - 1992 Growing costs Fertilizers 57 57 57 57 Spray materials 118 118 118 118 Training supplies 5 25 5 10 General supplies 15 15 15 15 Training labor 7 182 12 37 Other labor 200 200 200 200 Equipment 133 133 133 133 Fruit-related costs Picking 178 251 409 136 Storing 223 314 511 170 Packing 297 419 681 227 Selling Costs - Year 3 74 105 170 57 1307 1819 2311 1160 Returns -- Year 3 1840 2596 4227 1405 Net -- Year 3 $533 $777 $1916 $245 1 suming. In 1992, avis strapping material was used to tie limbs. This 1/2-inch, multi-stranded strapping material was split easily into five pieces of five strands each. The advantage of this material is that it can be tied directly to conduit pipe without the use of a screw and without slipping, therefore making it much easier to use than the previous method. Vertical Axis. The vertical axis utilizes a tall post to allow unrestricted tree growth to a height where it will fruit out. In this planting, posts extend 10.5 feet out of the soil. Trees were spaced 6' x 14' (519 trees per acre). A number of lateral branches existed on trees at planting, and none were removed and trees were not headed. A small amount of pinching of vigorous, upright shoots was done in June each season. Also in each season, some vigor- ous limbs were bent with weights in early July. Vertical Trellis. The trellis used in this planting is seven feet tall and includes four wires, every 18 inches beginning at 24 inches from the soil. Trees were spaced 8' x 14' (389 trees per acre). Trees were headed at approximately 22 inches from the soil. As branches grew, a central leader was chosen, and lateral branches were tied to the lowest wires at approximately 70°. Branches higher up in the canopy were tied at a greater angle. The Economics Table 1 summarizes the costs and returns asso- ciated with the four treatments used in this trial. Duringthe first season, the primary difference among the total costs related to differences in establishment costs (for details of establishment costs see Autio, 1990). Some differences existed in the amount of labor involved with training, with the vertical axis requiring the most, followed by the slender spindle, central leader, and trellis. Duringthe second growing season, significantly more labor and supplies were required for the slen- der-spindle system than the others. The NE central leader was the least intensive and least costly. Ver- Fruit Notes, Summer, 1993 Cumulative Net Returns (thousands/acre) $10 -^ NE Central Leader -^Slender Spindle -*- Vertical Axis -"-Vertical Trellis / r -$10 1990 1991 1992 1993 1994 1995 Figure 1. Cumulative net returns of four apple training systems. Dotted lines are projected returns. tical-axis trees fruited in the second season, yielding about 43 bushels per acre. Overall costs of the vertical axis were increased because of the costs of picking, storing, packing, and selling; however, $533 were returned per acre in the second growing sea- son. During the third growing season again, the slender spindle required the most labor and supplies to manage. Year three was the first significant fruiting year, with yields of 148, 209, 341, and 113 bushels per acre for the NE central leader, slender spindle, vertical axis, and vertical trellis, respec- tively. Net returns varied from the low of $245 from the trees on trellis to $1916 from trees trained to the vertical-axis system. Figure 1 presents the cumulative net returns for these four systems for their first three growing seasons, along with projections for the next three seasons. The most costly system was the vertical axis; however, it yielded sooner than the other sys- tems and is expected to net over $2000 per acre afler the fifth grow- ing season. The slender-spindle and trellis systems were similarly costly; however, the slender spindle yielded better in 1992 and is expected to yield more than the trellis for the next few seasons. The slender spindle will pay for itself by the end of the fifth grow- ing season, but the vertical trellis will not pay for itself until the end of the sixth growing season. The least costly system to establish was the NE central leader, but it is not expected to be as profitable as the slender spindle. Conclusions Significant differences in costs and returns existed among the four intensive apple-training sys- tems included in this planting. One factor came very much into play in determining what the early returns were from these trees. The early yields on a per-tree ba- sis were negatively related to the degree of pruning which was done at planting. The vertical axis trees were not pruned; therefore, one- year-old wood was retained at planting which set flower buds during the first growing season. Trees yielded in the second season. With no pruning, the canopies of these trees were larger than in the other systems and trees yielded significantly more in the third season. NE central- leader trees, slender-spindle trees, and vertical- trellis trees were all headed at planting, removing all lateral branches and most one-year-old wood and preventing them from settingflower buds during the first season. NE central-leader trees and slender- spindle trees were headed at 34 inches, and trellis trees were headed at 22 inches; the more severe the heading, the lower were the early yields. A second factor which also has come into play and will continue to be a factor is the planting density. The two systems that have been the lowest yielding on a per acre basis and probably will have the lowest returns for a number of years are at the Fruit Notes, Summer, 1993 lowest density (NE central leader and vertical trel- lis). The highest yielding systems are at the highest density (vertical axis and slender spindle). Overall, it is clear that any of these systems can be relatively successful. Even the least productive is expected to pay back the initial investment by the end of the sixth season, significantly better than free-standing central-leader trees on M.7. Selection of a system, however, must be based not only on the overall economic considerations but on the grower's interests in, abUity for, and commitment to horticul- tursd management, i.e. can and will he or she become more intensively involved with training and other horticultural practices than normally is needed for free-standing trees. References Autio,W.R. 1989. Trends in the New England apple industry. Fruit Notes 54(4):12-17. Autio,W.R. 1990. Costs ofestablishing high density apple plantings. Fruit Notes 55(4):l-5. Autio, W. R. 1993. High-density Apple Training: Costs of Establishment. University of Massachu- setts Cooperative Extension System Factsheet F- 110. Castaldi, M. 1987. Summary of Annual Apple Production Costs. Cornell Cooperative Extension. Fuller, E., W. Lazarus, and L. Carrigan. 1991. MinnesotaFarm Machinery Economic Costs for 1991. Minnesota Extension Service AG-FO-2308-C. White, G. B. and A. DeMarree. 1992. Economics of Apple Orchard Planting Systems. Cornell Coopera- tive Extension Bulletin 227. •J^ •^ •l^ •J>» •J!> 0^ •<]>• 0^ 0^ •^ Fruit Notes, Summer, 1993 Costs and Returns from Three Peach Training Systems During the First Three Seasons Wesley R. Autio Department of Plant & Soil Sciences, University of Massachusetts In southern New England, approximately 1000 acres of land are planted to peach trees. Little research has addressed the problems of peach grow- ing, particularly in the area of cultural manage- ment. Training systems are an as- pect of cultural management that can affect the economic returns of an orchard greatly. The primary training system used for peach trees in southern New En- gland is a delayed-open-center sys- tem. In a tree ofthis form, the central trunk is dominant early in the life of the tree, and as the tree grows, lower scaffolds grow upward and become equal to or stronger than the central trunk. Ideally, the central trunk should be removed above the lower scaflFolds at maturity, leaving an open center tree; however, the central trunk often is left in the tree. The problem that arises from having a central trunk in this type of tree is that light penetration into the center of the canopy is very poor, and over time, productivity declines in a large portion of the tree's interior. Because of the high value of peach fruit, production efficiency should be a major concern of peach growers. Evaluation of production practices is critical to economic viability. To this end, I established a trial in 1990, including nine replications of Ernie's Choice/Lovell trained to an open cen- ter, a central leader, or a delayed open center. The goal ofthis planting is to evaluate fully the economic vi- ability of these three training sys- tems. The Systems Open Center. Open-center trees were spaced 18 by 20 feet (121 trees per acre). Trees were headed Table 1. Costs and returns per acre associated with Ernie's Choice peach in three training systems. Land preparation costs were derived from V/hite and DeMarree (1992) and Fuller et al. (1991). Establishment costs were derived from actual measurements made during the planting of this trial. Growing costs, with the exception of pruning, were derived from Mizelle and Westberry (1989). Pruning labor costs were from actual measurements from this trial. Delayed Open Central open Category center leader center Year 1-1990 Land preparation Fertilizer and lime 150 150 150 Seed 20 20 20 Labor 15 15 15 Equipment 38 38 38 Establishment HoleE--labor 81 145 81 Holes-equipment 101 182 101 Trees 605 1089 605 Planting labor 48 87 48 Initial pruning labor 16 15 8 Growing Fertilizer 25 25 25 Spray material 38 38 38 General supplies 24 24 24 General labor 30 30 30 Equipment 56 56 56 Costs - Year 1 Net - Year 1 1247 -$1247 1914 -$1914 1239 -$1239 Fruit Notes, Summer, 1993 Table 1. Continued. Category at planting to leave four small shoots arising from the trunk be- tween 20 and 24 inches from the ground. Each of these shoots was headed to two viable buds. As the trees have developed, shoots grow- ing into the center of the trees have been removed, with either dormant or summer pruning, and outer lat- erals have been pruned to direct their growth at about 60° from ver- tical. The goal is to have trees with four major scaffolds growing out- ward from the trunk in a vase form and reaching a height of approxi- mately eight feet when they have filled their allotted space. In the mature tree, light distribution will be good, and only a small portion in the center of the tree will have too little light to maintain the produc- tion of fruiting wood. Central Leader. Central-leader trees were spaced 10 by 20 feet (218 trees per acre). Very little pruning was done at planting. As trees have developed, scaffolds have been pruned to direct their growth at about 80° from vertical. Upper limbs have been kept short so that the trees have a conical shape. Upright shoots arising from the nearly flat lateral branches have been removed during summer pruning. The goal is to produce small trees that are eight feet tall at maturity with lower laterals that extend no more than five feet from the trunk. With this form, nearly all of the canopy will maintain the potential to produce fruiting wood. With more trees per acre than a standard system, higher early pro- duction should be obtained. Delayed Open Center. Delayed- open-center trees were spaced 18 by 20 feet (121 trees per acre). Very little pruning was done at planting. As the trees have developed, lower scaf- folds have been treated much the same as in the open-center trees; however, a central trunk has been maintained. The goal of this system is to have an open-center tree at maturity, but the productivity is higher early in its life, because it has more canopy volume in the form of a central leader. The central leader must be removed before the shading in the center of the tree results in significant reductions in Delayed Open Central open center leader center Year 2 - 1991 Growing Fertilizer 49 49 49 Spray material 67 67 67 General supplies 35 35 35 General labor 59 59 59 Equipment 51 51 51 Dormant pruning labor 8 10 5 Summer pruning labor 8 15 8 Costs - Year 2 277 Net - Year 2 -$277 year 3 - 1992 Growing Fertilizer 53 Spray materials 254 General supplies 50 General labor 40 Equipment 65 Dormant pruning labor 16 Summer pruning labor 12 Thinning labor 8 Harvest and sales Harvest labor 38 Packaging 24 Selling 24 Costs - Year 3 584 Returns - Year 3 709 Net -Year 3 $125 286 -$286 53 254 50 40 65 25 22 15 89 56 56 725 1675 $950 274 -$274 53 254 50 40 65 14 12 8 64 40 40 640 1191 $551 the potential to produce fruiting wood. The Economics Table 1 presents the costs and returns over the first three growing seasons from this trial. Much of the growing costs were obtained from other sources as described in the caption of the table, but planting costs, training costs, and yields were obtained from this trial. For labor, $8 per hour was used through- out this analysis. Equipment costs were assessed at Fruit Notes, Summer, 1993 Cumulative net returns (thousands/acre) 1992 1993 Figure 1. Cumulative net returns of three peach training systems. Dotted lines are projected net returns based on projected costs and returns for 1993 and 1994. approximately $20 per hour but varied depending on the equipment used. Trees cost $5. Thinning, picking, packaging, and selling were assumed to cost $0,013, $0.04, $0,025, and $0,025 per pound of fruit, respectively. Yields were valued at $0. 75 per pound. For the first three seasons, central-leader trees were more costly to maintain than either of the other systems: total costs were $2108, $2925, and $2153 for the open center, central leader, and delayed open center, respectively. The difference came primarily from the greater establishment costs, which ac- counted for more than 80 percent of the difference between the central leader and the other systems. During the third growing season (1992), trees in this trial yielded significantly. Yield per tree was related directly to canopy size, with the delayed open center yielding the most and the open center yielding the least per tree (8, 10, and 13 pounds per tree for the open center, central leader, and de- layed open center, respectively). Once tree density was accounted for, the open-center, central-leader, and de- layed-open-center systems yielded 945, 2234, and 1588 pounds of fruit per acre, respectively. The returns for the central leader systems were considerably greater than for the other systems. At this point in the trial, it is possible to say that the additional costs of planting the higher density central-leader system have been com- pensated for by the higher yields in the third season. Figure 1 presents the cumulative net returns from these systems and shows a projection of cumulative net returns for the fourth and fifth growing seasons (1993 and 1994). For these early years, the central-leader trees should out-pro- duce the other systems because of their higher density of planting, and therefore, likely will net over $2,000 per acre cumulatively by the end of the fourth growing season and nearly $10,000 per acre by the end of the fifth growing season. The other two systems likely will net less than half that amount by the end of the fifth growing season. This information is not enough, however, to determine the ideal sys- tem for growing peaches in southern New England. These trees must be followed to maturity and beyond to determine long- term differences in costs and returns. References Fuller, E., W. Lazarus, and L. Carrigan. 1991. Minnesota Farm Machinery Economic Costs for 1991. Minnesota Extension Service AG-FO-2308-C. Mizelle, W. O., Jr. and G. O. Westberry. 1989. Cost analysis, pp. 6-12. In: S. C. Meyers (ed.) Peach Production Handbook. University of Georgia Coop- erative Extension Service Handbook 1. White, G. B. and A. DeMarree. 1992. Economics of Apple Orchard Planting Systems. Cornell Coopera- tive Extension Bulletin 227. 1994 8 Fruit Notes, Summer, 1993 Optimal Positioning of Baited Sticky Red Spheres for Capturing Apple Maggot Flies Jian Jun Duan, Max P. Prokopy, Paul Des Georges, and Ronald J. Prokopy Department of Entomology^ University of Massachusetts In a previous article [Fruit Notes 56(4): 4-6], we reported that a combination of food odor (ammonia) and fruit odor (butyl hexanoate) significantly in- creased apple maggot fly (AMF) captures on three- inch baited red sticky spheres, thus enhancing the effectiveness of interception traps currently used in the second-level IPM program. Past studies by Reissig (1975) and Drummond et £il. (1984) showed that AMF captures on unbaited spheres were influ- enced significantly by position of spheres in the tree canopy, including height above ground, proximity to fruit and foliage, and distance from the outside edge of the tree canopy. We predicted that these variables would have less influence on AMF cap- tures on sticky spheres baited with food and fruit odor than on unbaited spheres. Here we report on studies testing this prediction. Materials and Methods Three experiments were conducted in 1992 in second-level IPM orchards (commercial orchards not sprayed with insecticide after early June). We first investigated the optimal distance of fruit and foliage from spheres not baited or baited with one dispenser of ammonium acetate and one two-dram polyethylene vial of butyl hexanoate (Experiment 1). We next studied the effects of presence vs. absence of fruit within 20 inches of unbaited spheres or spheres baited with the same types of odor as in Experiment 1 (Experiment 2). In Experiment 3, we investigated the influence of height of sphere place- ment in the tree canopy on the efficacy of spheres not baited or baited with one polyethylene vial of butyl hexanoate. Experiments 1 and 2 were conducted in Clarkdale Fruit Farm, West Deerfield, MA, which consisted of a mixture of 25-year-old Early Mcin- tosh and Gravenstein trees. The trees were about 12 to 16 feet in canopy diameter. In Experiment 1, we hung four sticky spheres in each of ten trees and removed the foliage and fruit surrounding the spheres to distances of 2, 10, 20, or 40 inches. On five of the trees, we placed one dispenser of ammonium acetate (about 5 grams) and one vial of butyl hexanoate (about 5 milliliters) about six inches from the sphere. Spheres on the other five trees were not baited with any type of odor. In Experiment 2, we placed two sticky spheres in each of 14 trees. On seven of the trees, spheres were baited with ammonium acetate and butyl hexanoate in the same manner as in Ex- periment 1. Spheres on the other seven trees were not baited. One of the two spheres in each tree was cleared of all fruit within 10 inches. The other sphere was cleared of all fruit within 20 inches. The foliage surrounding each sphere was removed within a con- stant distance of 10 inches. Experiment 3 was conducted at the University of Massachusetts Horticultural Research Center, Belchertown, MA, in a block of four-to-five-year-old Liberty trees having a canopy three to five feet in diameter and a height of six to eight. In this experi- ment, we placed only one sphere (either not baited or baited with one polyethylene vial of butyl hexanoate) on each tree. Spheres were placed in trees at three different heights: upper 1/3, middle 1/3, or lower 1/3 of the canopy. Foliage and fruit within 10 inches of each sphere were removed. For all experiments, captured male and female AMF were counted and spheres were cleared of all insects captured every two weeks. In Experiments 1 and 2, unbaited and baited spheres were emplaced on July 28 and rotated among trees at each examination (every two weeks) until September 8, when the test ended. Experiment 3 began on July 27 and ended on September 11. Spheres were not rotated among trees. Fruit Notes, Summer, 1993 Table 1 . Average number of apple maggot flies captured on baited or unbaited sticky red spheres hung in fruiting trees and surrounded at different distances by foliage and/or fruit (July 28 - September 8, 1992).^ Distance (in Foliage ) of clearing of Fruit Baited spheres Unbaited spheres Experiment Female Male Total Female Male Total 1 2 2 14 b 19 b 33 b 9 b 13 b 22 b 10 10 24 a 35 a 59 a 18 a 29 a 47 a 20 20 25 a 37 a 62 a 19 a 25 a 45 a 40 40 16 b 20 b 36 b 14 ab 17 b 27 b 2 10 10 27 a 50 a 77 a 15 a 28 a 44 a 10 20 19 a 39 b 57 b 15 a 18 b 33 b ^ Five replicates per treatment type in Experiment 1 and seven replicates in Experiment 2. Values within columns and within experiment followed by the same letter are not significantly different at odds of 19:1. Results The results of Experiment 1 (Table 1) showed that for both baited and unbaited spheres, nearly twice as many AMF were captured on spheres with foliage and fruit cleared to a distance of 10 to 20 inches compared with 2 or 40 inches. Baited spheres captured 25 to 50% more flies than unbaited spheres at each distance. A previous study by Martin Aluja showed that fruit odor attracts flies from long dis- tances to a host tree or a portion of a host tree, but once a fly arrives on a tree, it primarily will use vision to find an individual fruit or fruit-odor-baited sphere. Surrounding foliage and fruit which influ- ence the visibility of a fruit-odor-baited sphere would therefore influence the probability of a fly finding the sphere. Until our test here, however, we had no knowledge that addition of food odor would fail to overcome the need for making a sphere conspicuous to AMF. The results of Experiment 2 (Table 2) indicated that when the surrounding foliage was cleared to a constant distance of 10 inches from a sphere, spheres cleared of all fruit within 10 inches captured 33% (unbaited) and 35% (baited) more flies than spheres cleared of all fruit within 20 inches. Possibly, fruit at 10 to 20 inches from a sphere attracted more AMF (either by visual or odor stimuli) toward the sphere than fruit 20 inches or further did. Results of Experiment 3 (Table 2) showed that for unbaited as well as baited spheres, spheres placed in the upper 1/3 or the middle 1/3 of the tree canopy captured about three times more AMF than spheres placed in the lower 1/3 of the canopy. DiflFer- ences in performance of spheres at the lower versus the middle or upper tree positions were greater than differences between baited and unbaited spheres at any height. Diffierences in AMF captures on both unbaited and baited spheres among different tree canopy heights likely stem from fruit-foraging be- havioral patterns of AMF within trees. A recent Table 2. Average number of apple maggot flies captured on baited or unbaited sticky red spheres hung in fruiting trees at different tree canopy heights (July 27 -September 11,1 992).^ Baited spheres Unbaited spheres Position in the canopy Female Male Total Female Male Total Upper 1/3 Middle 1/3 Lower 1/3 13 a 21 a 6 b 31 a 21 a 7 b 34 a 42 a 13 b 13 a 12 a 4 b 20 a 32 a 19 a 31 a 5 b 9 b ^ Fourteen replicates per treatment type. Values within columns followed by the same letter are not significantly different at odds of 19:1. 10 Fruit Notes, Summer, 1993 study by Martin Aluja indicated that fruit-foraging AMF have a propensity to move upward when forag- ing for fruit and spend more time foraging in the middle and upper part of the tree canopy. Conclusions Our findings indicate that the performance of sticky red spheres whether baited or not with syn- thetic food and fruit odor, is affected strongly by clearing of surrounding foliage or fruit, as well as by height of placement in the tree canopy. Baited spheres capture more flies than unbailed spheres under all conditions. To intercept AMF immigrating into or- chards, spheres should be placed in the middle 1/3 or upper 1/3 of the tree canopy and surrounded by as much foliage and fruit as possible except for a 10- inch radius around. This placement will optimize the finding of spheres by AMF within a tree. Selected References Drummond, F., E. Groden, and R. J. Prokopy, 1984. Comparative efficacy and optimal positioning of traps for monitoring apple maggot flies (Diptera: Tephritidae). Environmental Entomology 13: 232 - 235. Reissig, W. H. 1975. Performance of apple maggot traps in various apple tree canopy positions. Journal of Economic Entomology 68: 534 - 538. Acknowledgments We thank Tom Clark for the use of his orchard. This work was supported by the Northeast Regional Project on Integrated Management of Apple Pests (NE-156). vj>» •^ •^ •X* vl> •^ 0^ 0^ 0^ 0^ Fruit Notes, Summer, 1993 11 Massachusetts Agriculture Robert L. Christensen and N. Eugene Engel Department of Resource Economics, University of Massachusetts In 1991, Massachusetts farmers sold $474 mil- lion of crop and livestock products, ranking forty- second out of fifty states. Massachusetts ranked number one, however, in cranberry production, number twelve in apple production, and number seventeen in greenhouse/nursery crop production. Table 1 reports the annual cash receipts of selected commodities in Massachusetts. According to the U.S. Census, the estimated number of farms in Massachusetts increased from 5,400 in 1974 to 6900 in 1991. Table 2 gives the number of farms by county in 1982 and 1987, and Table 3 gives the acreage by county. Approximately 615,000 acres of land are used by Massachusetts farms. The average size of a farm is 100 acres, as compared to the U.S. average of 467 acres. Average Table 1. Cash receipts in thousands of dollars by sel( 3Cted commodities in Massachu- setts. Data were compiled from Economic Indicators of the Farm Sector - - Financial Summary, 1991, U.S. Department of Agriculture, Economic Research Service, ECIFS | 11-2, March, 1993. Commodity 1990 1991 All commodities 445,874 475,540 Livestock and products 124,706 120,745 Meat animals 13,750 15,919 Dairy products 70,054 64,977 Poultry and eggs 24,411 23,662 Aquaculture 8,245 8,245 All other livestock 7,725 7,645 Crops 321,168 354,795 Hay 5,037 4,689 Tobacco 13,442 14,571 Potatoes 4,677 4,522 Sweet corn 9,088 9,883 Tomatoes 8,760 6,300 Miscellaneous vegetables 40,000 39,000 Apples 20,337 19,180 Peaches 893 867 Cranberries 62,737 96,818 Other berries 5,345 5,885 Miscellaneous fruits and nuts 1,000 1,000 Maple products 922 1,483 Other field crops 3,700 2,920 Floriculture 35,551 35,364 Nursery and ornamentals 108,000 108,000 1 12 Fruit Notes, Summer, 1993 Table 2. Number of farms in Massachusetts by counties. Data are from 7987 Census of Agriculture, Bureau of the Census, U.S. Department of Commerce, Washington, | D.C. County 1987 1982 Change (%) Barnstable 158 123 +28 Berkshire 392 352 +11 Bristol 675 597 +13 Dukes 58 40 +45 Essex 439 372 +18 Franklin 616 521 +18 Hampden 490 392 +25 Hampshire 624 559 +12 Middlesex 569 567 0 Nantucket 12 6 +100 Norfolk 212 205 +3 Plymouth 775 649 +19 Suffolk 5 4 +25 Worcester 1191 1014 +17 Total 6216 5401 +15 1 Table 3. Land in farms (acres' in Massachusetts by counties. Data are from 1987 Census of Agriculture, Bureau of the Census, U.S. Department of Commerce, Washington, D.C. County 1987 1982 Change (%) Barnstable * 5,010 — Berkshire 70,792 73,434 -4 Bristol 42,562 41,883 +2 Dukes 7,314 7,355 -1 Essex 30,940 30,283 +2 Franklin 82,864 79,412 +4 Hampden 46,747 43,835 +7 Hampshire 64,567 63,624 +1 Middlesex 38,709 40.173 -4 Nantucket * * ~ Norfolk 13,124 13,398 -2 Plymouth 77,140 80,392 -4 Suffolk * * — Worcester 134,689 133,612 +1 Total 615,185 612,819 0 * Withheld to avoid disclosing data for i ndividual farms. Fruit Notes, Summer, 1993 13 Table 4. Farm balance sheet for Massachusetts in millions of dollars. Data were derived from Economic Indicators of the Farm Sector - Financial Sum.mary, 1991 , U.S. Department of Agriculture, Economic Research Service, ECIFS 11-2, March, 1993. Item 1990 1991 Assets Real estate Livestock and poultry' Machinery and motor vehicles'' Crops (inventory) Purchased inputs Financial Debt Real estate Nonreal estate' Debt/asset ratio 3,553.6 3,407.7 3,092.3 2,939.2 57.4 57.9 212.8 214.7 22.6 20.9 8.9 8.9 159.5 166.1 299.0 295.7 115.1 117.9 183.9 177.8 8.4 8.7 Excludes horses, mules, and broilers. Includes only the farm share for trucks and autos. Excludes debt for non-farm purposes. net farm income for Massachusetts is $20,841, while the U.S. average is $17,950. Of greatest significance is the fact that net farm income per acre in Massa- chusetts averages $208, nearly 5.5 times the U.S. average per acre of $38. Massachusetts farmers control assets of $3.4 billion, with a debt load of under $300 million (Table 4). This debt-to-asset ratio is among the ten lowest in the nation and is less than half the national average. Massachusetts farmers per year purchase $160 million worth of farm inputs, pay local property taxes of $22 million, employ a hired labor force with a payroll of $77 million, and pay $24 million in interest to Massachusetts financial institutions and other lenders (Table 5). Finally, Massachusetts farmers provide Massa- chusetts consumers with food that is locally grown, fresh, wholesome, and reasonably priced. 14 Fruit Notes, Summer, 1993 Table 5. Massachusetts farm income statistics in millions of dollars. Data were compiled from Economic Indicators of the Farm Sector - Financial Summary. 1991, U.S. Department of Agriculture, Economic Research Service, ECIFS 11-2, March, 1993. Item 1990 1991 Gross farm income 505.4 527.6 Farm marketings of crops 321.2 354.8 Farm marketings of livestock products 124.7 120.7 Government payments 3.0 1.5 Farm-related income 17.2 15.5 Non-cash income' 38.0 36.0 Inventory adjustment 1.3 -0.9 Total productions expenses 334.3 336.6 Feed purchased 31.7 30.6 Livestock and poultry purchased 1.4 1.4 Seed purchased 6.8 7.6 Fertilizer and lime 10.1 10.0 Pesticides 9.3 10.3 Fuel and oil 13.3 12.7 Electricity 7.0 7.0 Repair and maintenance 29.0 26.4 Miscellaneous 46.4 53.7 Interest on real estate debt 8.8 8.5 Interest on other debt 15.6 15.4 Contract and hired labor expense 77.3 77.2 Capital consumption (depreciation) 58.9 57.3 Property taxes 21.9 21.7 Net rent to landlords -3.2 -3.1 Net farm income 171.2 191.0 Returns to operators'' 158.0 178.7 ' Includes: value of home consumption and rental value of operator and hired labor dwellings. " Returns to operators is equivalent to net farm income, excluding the income and expenses associated with farm operator's dwellings. vT> •^ vi>» •^ •Jt* •» 0^ 0^ 0^ 0^ Fruit Notes, Summer, 1993 15 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 01002 -0 SERIAL SECTION UNIV. OF MASSACHUSETTS UBRARY AMHERST, MA 01003 Account No. 3-20685 5A ISSN 0427-6906 Fruit Notes rr. Prepared by the Department of Plant & Soil Sciences. _ — U ^SS • University of Massachusetts Cooperative Extension System, '^^Or- United States Department of Agriculture, and Massachusetts Counties CooperM^. Editors: Wesley R. Autio and William J. Bramlage Volume 58, Number 4 FALL ISSUE, 1993 Table of Contents Evaluation of Several Apple Roots tocks in the 1984 NC-140 Planting Effects of Orchard Spray Program on Plant-feeding and Predatory Spider Mites in Massachusetts Apple Orchards A Sampling Method for Detecting Root-feeding Woolly Apple Aphids Chemical Growth Control: Ethephon as a Growth Retardant Food Prices, Expenditures, and Income Fruit Notes Publication Information: FrM/rA^ore5(ISSN 0427-6906) is published the first day of January, April, July, and October by the Department of Plant & Soil Sciences, University of Massachusetts. The costs of subscriptions to Fruit Notes are $7.00 for United States addresses and $9.00 for foreign addresses. Each one-year subscription begins January 1 and ends December 3 1 . Some back issues are available for $2.00 (United States addresses) and $2.50 (foreign addresses). Pay- ments 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 COOPERATIVE EXTENSION SYSTEM POLICY: All chemical uses suggested in this publication arc contingentupon continued registration. These chem icals should be used in accordance with federal and state laws and regulations. Growers arc urged to be familiar with all current state regulations. Where trade names are used for identification, no company endorsement or product discrimination is itttended. 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 the University of Massachusetts Cooperative Exunsion System, Robert G. Helgesen, Director, in furtherance of the acts of May 8 and June 30, 1 914. The University (^Massachusetts Cooperative Extension System offers equal opportunity in programs and employment. Evaluation of Several Apple Rootstocks in the 1984 NC-140 Planting Wesley R.Autio Department of Plant & Soil Sciences, University of Massachusetts New England apple growers have been planting trees on clonally propagated rootstocks for a number of years. Early plantings were entirely on semidwarf and semistandard rootstocks, usually M.7, MM. 106, or MM.lll. During the 1970's, some growers experimented with M.9 and interstem trees, and now, several growers are using fully dwarf rootstocks. Until recently, plantings have used a relatively small number of roots tock clones, because only a few clones were available. Now several breeding programs have released rootstocks for trial, in- cluding the "Polish Series" from Poland, the "Budagovsky Series" from Russia, the "Ottawa Clonal Series" from Canada, the "Kentville Stock Clone Series" from Canada, the "Michigan Table 1. Characteristics in 1992 of Starkspur Supreme Delicious trees on several rootstocks in the 1984 NC-140 Cooperative Planting.' Tnmk cross- 1992 Cumulative sectional 1992 Cumulative Yield yield C rop area Yield yield eflfieiency efficiency load Rootstock (in^) (bu) (bu) (bu/in^) (huJin^ (fruit/in') Bud.9 3.4 efg 2.0 fg 5.6 g 0.57 ab 1.60 ab 57 ab MAC-1 13.8 be 5.1 c 11.0 de 0.36 de 0.80 d 37 cd MAC-39 4.5 ef 2.1 fg 5.8 g 0.43 bede 1.21 c 36 d P.l 8.8 d 3.8 de 11.1 de 0.43 bede 1.31 c 42 cd P.22 1-2 g 0.4 h 1.5 h 0.30 e 1.29 e 30 d Seedling 15.8 ab 4.9 c 11.3 cde 0.31 e 0.70 d 30 d M.4 11.8 c 6.6 a 15.3 a 0.56 ab 1.30 c 62 a M.7 EMLA 8.1 d 4.4 cd 11.8 bed 0.62 a 1.62 ab 58 ab M.26 EMLA 5.5 e 2.5 fg 7.1 fg 0.47 bed 1.34 be 41 cd Bud.490 14.2 abc 5.4 be 11.8 bed 0.38 de 0.85 d 35 d P.2 2.8 fg 1.6 g 4.8 g 0.56 ab 1.69 a 51 abed P.16 1.2 g 0.5 h 1.6 h 0.54 abc 1.67 a 53 abc P.18 16.7 a 6.6 a 14.2 ab 0.40 cde 0.85 d 40 cd C.6 5.5 ef 2.9 ef 8.6 ef 0.55 ab 1.61 ab 45 bed Ant.313 16.3 ab 6.2 ab 13.9 abc 0.39 cde 0.89 d 39 cd ' Means within columns not followed by the same letter are significantly different at odds of 19:1. FruH Notes, Fall, 1993 Table 2. Characteristics in 1992 of fruit from Starkspur Supreme Delicious trees on several rootstocks in the 1984 NC-140 Cooperative Planting.' Soluble Date of Fruit solids Starch Watercore 1 ppm weight Rootstock (%) index'' index" CjH 4 (g) Bud.9 9.8 cd 3.6 abc 1.0 b 10-11 bed 217 abed MAC-1 9.8 cd 2.8 def 1.1b 10-12 abc 181 f MAC-39 10.4 b 3.2 bcde 1.3 a 10-11 bed 232 ab P.l 10.1 bed 3.2 bcde 1.1b 10-11 bed 203 bedef P.22 11.0 a 3.7 ab 1.0 b 10-11 bed 182 f Seedling 9.7 cd 2.8 def 1.0 b 10-13 ab 185 ef M.4 9.6 d 2.6 f 1.0 b 10-12 abc 192 def M.7 EMLA 10.1 bed 2.8 def 1.1b 10-9 d 215 abede M.26 EMLA 10.1 bed 3.3 abed 1.2 ab 10-9 d 214 abede Bud.490 9.6 d 2.9 def 1.1b 10-14 a 200 edef P.2 10.1 bed 3.3 abed 1.2 ab 10-11 bed 225 abc P.16 10.2 be 3.8 a 1.0 b 10-10 cd 204 bedef P. 18 9.8 cd 2.6 f 1.0 b 10-12 abc 191 def C.6 10.1 bed 3.1 edef 1.1b 10-10 cd 237 a Ant.313 9.6 d 2.7 ef 1.0 b 10-13 ab 191 def ' Means within columns not followed by the same letter are significantly different at odds of 19:1. Soluble solids starch index, watercore index, and 1 fruit weight were assessed on October 5-6, 1992. Date of 1 ppm C2H4 was 1 assessed with several weekly samples throughout the harvest season. '' Starch index: 1 = dense starch staining, very immature; 9 = no starch staining, very overmature. * Watercore index: 1 = no watercore; 5 = severe watercore Apple Clone Series" from Michigan State Uni- versity, and the "Cornell-Geneva (or Geneva) Series" from the New York State Agricultural Experiment Station. In 1984, a trial of a num- ber of these new rootstocks was planted at approximately 30 locations throughout the United States and Csmada. One of the plantings is at the University of Massachusetts Horticul- tural Research Center in Belchertown, Mass. This article will report the results from this planting through its ninth growing season. In April 1984, Starkspur Supreme Delicious trees on Bud.9, MAC-1, MAC-39, P.l, P.22, seedling, M.4, M.7 EMLA, M.26 EMLA, Bud.490, P.2, P.16, P.18, C.6, or Ant.313 were planted in a randomized complete block design with 10 replications. The soil is a Montauk fine sandy loam. Mcintosh and Golden Delicious trees were included in each rephcation for polli- nation. All trees were trained as central leaders and supp>orted by a post only when they leaned more than 45° from vertical. All trees received the same fertilizer apphcations, pest control treatments, and chemical thinning sprays. Table 1 reports the trunk cross-sectional area, yield, jdeld efficiency, and crop load of these trees. MAC-1, seedling, Bud.490, P.18, and Ant.313 produced trees of standard size. Fruit Notes, Fall, 1993 Over their first nine years, trees on MAC-1, seedling, or Bud.490 jdelded a total of 11 to 12 bushels. Those on P. 18 or Ant.313 yielded approximately 14 bushels. P.l, M.4, or M.7 EMLA produced trees in the semidwarf to semistandard category. Trees on M.4 have yielded the most in the trial, more than 15 bushels per tree ciunulatively. Trees on P.l or M.7 EMLA yielded between 11 and 12 bushels cumulatively. Bud.9, MAC-39, M.26 EMLA, P.2, and C.6 produced trees in the dwarf cat- egory. In this category, C.6 and M.26 EMLA have resulted in the greatest )delds, 8.6 and 7.1 bushels, respectively, per tree on a cumulative basis. The other dwarf roots tocks have resulted in yields between 4.8 and 5.8 bushels per tree. The smallest trees in the planting are on P.22 or P. 16. These trees are in the very dwarf category, and they have yielded only about 1.5 bushels per tree cumulatively. To accurately assess performance of a par- ticular tree, it is important to look not only at size and yield but also at jdeld efficiency. Effi- ciency relates yield to tree size and gives an assessment of relative yield per acre. Over the life of the planting, the most yield-efficient trees have been on P.2, P. 16, M.7 EMLA, C.6, or Bud.9. M.7 EMLA is the biggest surprise in this group, because in other plantings that we have, it has not been very yield-efficient. The least efficient trees have been those of the standard size category. Table 2 reports fruit characteristics from this planting in 1992. For the four years that fruit have been assessed, no dramatic, consis- tent differences have occurred in bruit ripening, but fruit fi-om trees on C.6 often have been some of the largest in the planting, as they were in 1992. Overall, the most promising new rootstocks in this trial are P.2, C.6, and Bud.9. All are of the dwarf category. P.2 and Bud.9 produce trees similar in size to those produced by M.9, and C.6 produces a tree very similar in size to one pro- duced by M.26. They seem well adapted to our conditions, they were very precocious, and they have continued to be productive for their size. The only concern is with the potential of trees on P.2 or Bud.9 to "runt out." Trees on P.2 or Bud.9 were nearly spur-bound after nine seasons. High productivity likely will not continue imless they are pushed to produce new vegetative growth. This trial, however, is with a spur-type variety. Newer trials include these two rootstocks with more vigorous, nonspur variet- ies, and I do not expect that they will become spur bovmd as readily. We shall continue to evaluate new rootstocks in Massachusetts. We have a plant- ing scheduled for the spring of 1994 which will contain 19 of the newest dwarfing rootstocks, including some from the "Vineland Series," the newest of the "Geneva Series," and a host of M.9 strains from Europe. •1^ %f« «f# «f^ «f# r|% «^ rj% rj% 0^ Fruit Notes, Fall, 1993 Effects of Orchard Spray Program on Plant-feeding and Predatory Spider l\/lites in IVIassachusetts Apple Orchards William M. Coli and Randolph CiurUno Department of Entomology, University of Massachusetts Since the inception in 1978 of the University of Massachusetts Apple Integrated Pest Man- agement Program, growers have heard a num- ber of presentations concerning the importance of selecting orchard pesticides based on their impacts on not only the target pest but also beneficial organisms. In recent years, the New England Apple Pest Management Spray Guide has contained a table of pesticide toxicities to beneficial species, with data fix)m a number of pubhshed studies conducted in Pennsylvania, New York, New Jersey, Virginia, West Virginia, Massachusetts, and Canada. In 1987, we initiated a study of the effects of orchard groundcover comix)sition on plant-feed- ing and predatory mites. As a component of this study, we reviewed the spray records of 28 commercial apple orchards in Massachusetts. Spray programs that included carbamate insec- ticides, pyrethroid insecticides, certain acaricides, or certain herbicides known to be detrimental to predatory mites were classified as "hard" programs. Those that avoided such materials were classified as "soft" programs. Table 1. Effects of orchard apple leaves by phjrtophagoi spray program on average IS and predatory mites.' percent infestation of Mite species Leaf infestation (%) 1988 1989 "Hard" "Soft" "Hard" "Soft" European red mite Two-spotted spider mite Amblyseius fallacis Zetzellia mali 9.7 a 1.0 a 1.5 a 0.3 b 8.6 b 1.0 a 1.9 a 4.2 a 31.4 a 33.0 a 1.7 a 0.3 b 1.4 b 2.4 a 0.0 b 3.3 a " Within row and year, meems not followed by the same different at odds of 19:1. letter are significantly Fruh Notes, Fall, 1993 Those which used two or fewer appUcations of benzimidazole fungicides, whose detrimental effects on mite predators are not agreed upon universally, likewise were classified as "soft" programs. Due to seasonal variability of spray programs, blocks were reevaluated yearly and reclassified by the tjT)es of pesticide used during the previous production season. In total, the study included 14 orchards using "hard" pro- grams and 14 using "soft" programs. In 1988, the "hard" program resulted in slightly higher infestations by European red mite than did the "soft" program (Table 1). The relationship, however, varied with saimpling date, i.e. for some sampling dates, "hard" pro- grams had more European red mites, and for other dates, "soft" programs had more. Spray program had no impact on the amount of Euro- pean red mites present in 1989. The lack of a difference in 1989 likely was due to an aggres- sive spray program directed at mites in "hard" blocks which kept plant-feeding mite numbers comparable to those in "soft" blocks in spite of lower predator numbers. The "hard" spray program resulted in sig- nificantly more two-spotted spider mites than the "soft" program in 1989, but in 1988, there was no difference between programs (Table 1). The first sample in 1989, however, found fewer two- spotted spider mites in the "hard" program orchards than in the "soft" ones. Because of the differences fi"om year to year and the lack of a consistent relationship between programs, even when significant differences were noted, we can- not state conclusively that numbers of two- spotted spider mites were related to spray pro- gram in this study. "Hard" spray programs had a significantly lower proportion of leaves infested with the Phytoseiid predator Amblyseius fallacis in 1989,butnotin 1988 (Table 1). The relationship between programs, however, again varied with sample date, as with European red mite and two-spotted spider mite. Hence, these results also must be considered inconclusive. Lack of consistent spray-program effects on European red mites, two-spotted spider mites, and A. fallacis may be related to the initial grouping of spray programs, which considered the use of limited applications of potentially toxic benzimidazole fungicides as part of "soft" programs. Other factors independent of spray program, such as low prey numbers in previous years or high overwintering predator mortality in certain orchards, also could have affected predator numbers. Results were more conclusive in the case of the Stigmaeid Zetzellia mali, which was found in significantly higher numbers in "soft" pro- gram orchards in both 1988 and 1989 (Table 1). Differences were maintained across all sam- pling dates in both years. The more consistent results are not surprising withZ. mali, because this predator spends its entire life either on the tree or at its base Eind consequently would be expected to be affected severely by harsh chemi- cal sprays. Differences in time of appearance of Z. mali were particularly evident (data not shown), with individuals observed in "hard"- program orchards only in very low numbers on the last sample round in 1988. In 1989, only a single individual was found in a "hard" orchard over all sampling dates. Although, some aspects of this study were inconclusive, we believe that the results give some confirmation that insecticides, fungicides, and herbicides can affect densities of prey and predatory mites in apple trees. A clear implica- tion of this finding is that growers wishing to enhance the numbers of endemic mite predators should avoid materials which can adversely affect them. ^^ %f# •Im •Im %f^ r|% 0^ «|% 0^ 0^ Fruit Notes, Fall, 1993 A Sampling Method for Detecting Root-feeding Wooiiy Appie Apliids M. W. Brown USDAf Agricultural Research Service, Appalachian Fruit Research Station, Kearneysville, WV The woolly apple aphid generally is consid- ered to be a minor pest of apple world-wide, seldom becoming abundant enough to justify chemical control. This aphid is most often found at pruning scars, other wound sites and at the base of petioles on current year's growth. It also feeds on roots of apple trees where it survives the winter and can remain throughout the year. I have been investigating this root-feeding insect and its effects on apple tree growth and produc- tion. The research literature contains only a few studies of this problem, and those deal with nursery stock. I found that root-feeding woolly apple aphids reduced tree growth in young nonbearing orchards (Brown and Schmitt, 1990) and caused a significant economic loss in a seven-year-old 'Delicious' orchard (Brown et al., in preparation). The sampling method that I used in my research was to uproot trees and evaluate the root system. This method is efficient for re- search but not for pest management programs, for obvious reasons. To determine if some form of treatment is needed, a sampling method must be quick and easy enough to use with minimum training. The method described in this paper is based on woolly apple aphid biology. During spring, first-instar nymphs migrate up the tree from overwintering populations on roots to re- colonize above-ground portions of the tree (Hoyt and Madsen, 1960). Trapping these migrating woolly apple aphid njnuphs should give an indi- cation of the presence and intensity of root infestation. A two-inch-wide strip of masking tape was placed around the trunk of apple trees, one to two feet above the ground but below the lowest scaffold limb. The tape was placed on the smoothest section of trunk available. A continu- ous barrier, about 1/8-inch deep and one-inch wide, of Tangle-trap™ was apphed in the center of the masking tape. A portion of the masking tape band was exposed both above and below the Tangle-trap barrier. The trees that were used in this study were planted in 1985 at 308 trees per acre. The block contained Frazier (joldspur, Smoothee (jolden Delicious, both on M.7A, and Bisbee Spur Dehcious on M.7 EMLA. The orchard was located at the Appalachian Fruit Research Station in Kearneysville, West Virginia, and was managed using standard commercial practices. Trees were banded to coincide with specific tree phenologies from green tip to first cover. Twenty five trees, selected randomly, were banded at each of four sample periods in 1993, as shown in Table 1. One group of 25 trees was banded for the entire green-tip to petal-fall pe- riod. An additional eleven trees with evidence of aphid migration up the tree during bloom were banded at petal fall. At the end of the designated sample periods the bands were removed and field counts of woolly apple aphid nymphs were made. Examination of the tape bands was with the unaided eye, using a hand lens only to verify questionable nymph sightings. On May 25, the trees were uprooted, the number of woolly apple aphid colonies on roots was recorded, and the amount of root galling was evaluated on a scale of 0 to 1. The root gall rating scale incorporated both the proportion of the root system with root galls and the intensity of galling on those roots infested. It can be thought of as the proportion of the root system affected by woolly apple aphids, scored from none (0) to complete infesta- tion (1). FruH Notes, Fall, 1993 Table 1. Sample periods, trap captures, and root infestations of wooly apple aphids. Sample date Tree Trees with phenology trapped nymphs Trees with root colonies Average root rating' April 7-19 Green tip- 1/2 inch green 5 3 ' 0.24 " April 19-27 1/2 inch green-pink 0 X X April 27- May 10 Pink- petal fall 3 3 0.19 April 7- May 10 Green tip- petal fall 9 12 0.22 May 10-21 Petal fall- first cover 3 8 0.18 May 11-21* Petal fall- first cover 6 7 0.31 ' Root rating is on a scale of 0 to 1 and reflects the proportion of the root system infested with woolly apple aphids. '' Only 16 trees of the 25 sampled were uprooted, 5 with nymphs and 11 without. ' Not uprooted because no nymphs were trapped. " Eleven trees that had been sampled in the green tip to petal fall (5) or pink to petal fall (6) sample period. There were two distinct periods of woolly trapped, only 16 trees were uprooted, the five apple aphid migration from roots to above- with njmiphs and eleven without nymphs. The ground portions of the tree (Table 1). Few aphid level of root infestation was the same for trees nymphs were trapped between green tip and with and without trapped n5anphs. Therefore, half inch green; five trees had one nymph each, trapping for migrating woolly apple aphid These nymphs were a different form than nsmiphs during the green tip to half inch green nymphs trapped later and non-migrating period would not be a useful sampling method, nymphs found in the summer. These No nymphs were trapped during the half earlynymphs were black and had httle wax (the inch green to pink sample period. First-instar chEiracteristic white woolly covering), whereas nymphs were trapped on several trees that were the typical form for first-instar nymphs is hght banded during both the pink to petal-fall and the purple with a waxy covering over the body and green-tip to petal-fall sample periods (Table 1). obvious tufts of wax. Because of the small In both sets oftrees the aphid nsonphs appeared number of trees on which early nymphs were to have been trapped recently and were either Fruit Notes, Fall, 1993 Table 2. Relationship infestation rating. of trap captures to root colonies and root Variable Number of trees with nymphs Number of trees without nymphs Root Colonies >0 root colonies 0 root colonies 12 3 12 48 Root Infestation >0.21 rating <0.21 rating 11 4 13 47 1 still active or at least had not begun to shrivel. N3Tnphs in the petal-fall to first-cover sample appeared to have been trapped early in the period and were inactive, darkened, and had begun to shrivel. Eleven trees that had the tape traps removed at petal fall were re-banded to investigate further the timing of migration. In all eleven trees, those that had njmiphs trapped on bands prior to petal fall also had nymphs after petal fall, and those that did not have nymphs trapped on bands did not have any after petal fall. From these results, I conclude that the majority of root migration takes place within a few days before and after petal fall. All three samples, therefore, that included petal fall were pooled and analyzed as one sample, because the presence or absence of migrating nymphs, not the nvmiber of nymphs, was used as the predic- tor variable. From traps on the 75 trees in the pooled sample, fifteen (20%) had first-instar woolly apple aphid nymphs (the median number of nymphs per trap was 8 but ranged fi-om 1 to 2883). Trees that had traps with migrating nymphs had a larger number of root colonies and a more severe root infestation than trees without migrating njrmphs (Table 2). For trees on which nymphs were trapped, 80% had root colonies, and 73% had root gall infestation rat- ings greater than 0.21. For trees without trapped nymphs, only 20% had root colonies and only 22% had root gall infestations greater than 0.21. F\ui,her, the mean nimiber of root colonies and root gall infestations were 4.1 and 0.3 for trees with trapped nymphs, respectively, and 0.5 and 0.2 for trees without trapped njmaphs, respectively. Conclusions The presence of n5Tnphs migrating up the tree fi*om roots during petal fall is an indication of the size of the woolly apple aphid population on the roots of that tree. Masking tape with a Tangle-trap^" barrier was successful in trap- ping these migrating njmiphs. By sampling an orchard, one can estimate the number of trees that have serious woolly apple aphid root infes- tations by comparing the number of trees with migrating nymphs versus those without. One could also identify portions of an orchard that may have a woolly apple aphid problem and take suitable action: apply insecticides against above-ground feeding aphids which would even- tually lower root-feeding populations, delay re- planting or plant other crops for a year or two, or apply insect parasitic nematodes, which is a promising potential control method (Brown et al., 1992). 8 Fruit Notes, Fall, 1993 More trials of this sampling method are needed, especially to test regions outside the Shenandoah Valley. This study showed that presence of migrating nymphs indicates trees that are highly likely to have root-feeding aphids. Further trials will enable a more quan- titative prediction using the number of nymphs trapped and determination of a treatment threshold number of trees infested per acre. Cooperators are currently being sought in the U. S. and Canada to help refine this sampling method. Acknowledgements I thank Dr. S. S. Miller, USDA, ARS, Appa- lachian Fruit Research Station, for his coopera- tion in the use of his orchard; J. J. Schmitt and C. Cornell for their hard work in collecting data; and J. J. Schmitt, G. J. Puterka, S. S. Miller, B. D. Horton (Appalachian Fruit Research Sta- tion), and H. W. Hogmire (West Virginia Univer- sity) for comments on an earUer draft of this paper. References Brown, M.W., J.J. Jaeger, A.E. Pye, and J.J. Schmitt. 1992. Control of edaphic populations of woolly apple aphid using entomopathogenic nematodes and a systemic aphicide. J. Entomol. Sci. 27:224-232. Brown, M.W. and J.J. Schmitt. 1990. Growth reduction in nonbearing apple trees by woolly apple aphids (Homoptera: Aphididae) on roots. J. Econ. Entomol. 83:1526-1530. Brown, M.W., J.J. Schmitt, S. Ranger, and H.W. Hogmire. In. Prep. Yield reduction in apple by edaphic woolly apple aphid populations. J. Econ. Entomol. (in preparation). Hoyt, S.C. and H.F. Madsen. 1960. Dispersal behavior of the first ins tar nymphs of the woolly apple aphid. Hilgardia 30:267-299. %£• %i* %f# mS^ mS^ rj» •Y* *J* *V* *♦* Fruit Notes, Fall, 1993 Chemical Growth Control: Ethephon as a Growth Retardant Wesley R. Autio and Duane W. Greene Department of Plant & Soil Sciences, University of Massachusetts With the loss of Alar*, the only chemical available for reducing vegetative growth is ethe- phon. It functions as a growth retardant in the same way that it initiates early ripening: it releases ethylene within the plant tissues after application, and ethylene can retard growth. In 1991 and 1992, we conducted a study to deter- mine the effects of ethephon and a number of mechanical growth-retarding treatments (scor- ing, ringing, and root pruning) on growth and fruit characteristics. Results from other treat- ments were discussed previously in Fruit Notes [1992, 57(3):l-5,6-9]. Here we report the effects of spring ethephon application. 80 70 — ^^ ^60 Ethephon / / y^ g-50 / y^ §40 / ^"^^ Cumulati lO CO o o / / Control 10 1 Ay\ A.-'-^ Mcintosh ethophofl 1 1 1 9/15 9/20 9/25 9/30 Date of 1 ppm ethylene 10/5 Figure 3. Effects of spring-applied ethephon on the time of ripening of fruit from Gardiner Delicious/MM.106 trees and Rogers Red Mclntosh/MM.106 trees. Average count per 42-lb box 140 130 120 110 100 90 80 &tt«ph*m y >jk ^ioi^^i^^S^^^ Cont|t)l Ethephon Delicious Mcintosh Figure 4. Effects of spring-applied ethephon on size, presented as average counts per 42-lb. box, of fruit from Gardiner Delicious/MM. 106 trees and Rogers Red Mcln- tosh/MM.106 trees. 12 Fruit Notes, Fall, 1993 before ethephon is used to retard growth of mature, bearing trees: 1) ethephon is a poten- tial thinner, so significant thinning may result if appropriate conditions exist; 2) extension growth may not be reduced dramatically, but lateral shoot development may be reduced, pro- ducing more of a spur-type growth habit and reducing the time required to dormant prune trees; 3) ripening may be advanced and drop may be increased, so plans must be made to harvest ethephon-treated trees earUer than normal; and 4) fruit size may be reduced. The potential reduction in size is of major concern and may negate any positive effects of ethephon treatment on bearing trees. A strategy that was used with Alar® was to direct the spray into the top, vigorous portions of the canopy. Using this technique, carryover effects and reduction in fruit size were mini- mized. This approach may not work with ethe- phon, since it would cause finiit in the top of the tree to ripen earlier than the rest, making har- vest troublesome and possibly resulting in dam- age to lower fruit from upper frmt dropping through the canopy. For vigorous,nonfruiting trees, ethephon may be more beneficial than for bearing trees. In young trees, its major positive response is to initiate flower bud formation. The season fol- lowing the ethephon treatment should see en- hanced finiit production and, therefore, less veg- etative growth. «1# *f# %{# %f# %f# r{« 0^ #j« #2% 0^ Fruit Notes, Fall, 1993 13 Food Prices, Expenditures, and Income Robert L. Christensen and Donald R. Marion Department of Resource EconomicSy University of Massachusetts Have consumer expenditures for food been increasing or decreasing, and if so, by how much? What happens to the consumer's food dollar; what share do farmers get, and how much is absorbed by firms involved in the mar- keting process? What determines how the con- sumer food dollar is divided, and do those who receive the largest part of consumer expendi- tures have the largest profits, or vice-versa? These questions are among those most fre- quently asked about the U.S. food system. A recent U.S.D.A. publication (Dunham, D. 1993. Food Costs ... From Farm to Retail in 1992. Economic Research Service, USDA, Agricul- tural Information Bulletin Number 669) con- tains many of the answers, plus some additional insights into issues such as recent changes in food prices, consumer food expenditures, and the farmers' share. The following discussion addresses the above questions and some other highhghts from that publication. Food Prices and Expenditures Changes in consumer prices, including food prices, are measvired by the Consumer Price Index (CPI) which, in turn, is used as the mea- sure of inflation or changes in the cost of Uving. In 1991 and 1992, food prices increased less than the rate of inflation — the prices of aU. consumer goods. In other words, the modest increase in food prices helped to moderate the overall rate of inflation. For 1991 and 1992, the CPI rose by 4.2 and 3.0 percent, respec tively, while food prices rose by only 2.9 and 1.2 percent, respectively. During the same two years, total consumer expenditures for food increased slightly more (3.6 and 2.3 percent, respectively) reflecting the combined effects of food price increases, popula- tion increases, and possible changes in con- sumption patterns. In 1991, U.S. consumers spent a total of $492 bilhon for food, which amounts to $4,367 annually per household of 2.6 persons, or $1,680 per person per year, $37.30 per week, and $4.60 per day. Of that total, 62 percent was spent for food consumed at home and 38 percent away from home. Consumer Expenditures and Income For all consumers combined, 1992 food ex- penditures represented 11.4 percent of personal disposable income, though that percentage var- ied widely with variations in income levels. Households with disposable income of $5,000 to $9,999 spent 32.6 percent of their income for food, while those whose incomes were $30,000 to $39,999 spent only 15.2 percent for food. At higher income levels, even smaller proportions were spent for food. The share of consumer disposable income spent for food has, in general, been declining since 1960, when consumers spent 17.5 percent of disposable income for food. In 1970, that percentage had declined to 13.9 percent, in 1980 to 13.5 percent, and 11.7 percent in 1990. Food consumed at home has been the major factor in that decline. In fact, consumer spending for food eaten away from home rose from 3.5 percent of personal disposable income in 1960to 4.4 per- cent in 1980, and has fallen sUghtly to 4.2 percent in 1992. Why? The answer is that prices for food away from home have risen more than the prices of food consumed at home and that, year by year, we have been eating an increasing share of our meals away from home, a trend that has slowed somewhat in recent years. The fact that food expenditures in total have been declining as a percentage of income is a result of incomes increasing more rapidly than 14 Fruit Notes, Fall, 1993 food prices, and also a demand for agricultural products that is income inelastic (when income increases by one percent, food expenditures in- crease by something less than one percent). The Farm Share Modestly increasing food prices, which have contributed to the declining share of income spent for food, have occurred partly because of efficiencies and competition in food marketing, but also, because of very slowly increasing farm prices. The farm value of a "market basket" of food purchased by consumers increased by only five percent from 1982 to 1992 - less than one- half of one percent per year. (The "market bas- ket" referred to here is a group of 74 domestically produced food products used by the U.S.D.A. for its food price and cost studies.) In contrast, Massachusetts per capita, personal disposable income increased more than 200 percent from 1980 to 1991: $10,612 to $22,897 (Andrews and McNeel. 1993. Personal income per capita in current dollars by state. 1970-91. p. 244. In: The Universal Almanac - 1993). Over the same time, retail prices for food products increased by 40 percent, resulting in a decline in the farm share of consumer expendi- tures for the U.S.D.A. "market basket." For example, in 1982, farmers received 35 percent of the dollars spent by consumers for food, as payment for their products. By 1992, that share had fallen to 26 percent. The farm share of consumer expenditures varies widely among food products. It tends to be greatest for products requiring httle packaging, processing, and handling, and vice-versa. Thus, farmers receive a relatively large share (over 50%) of the retail price of products such as eggs, chicken, and beef and 10 percent or less for others such as tomatoes, bread, and com syrup. The difference between retail prices and the amount received by farmers for an equivalent amount of product (e.g., it takes an average of 2.4 pounds of Choice grade steer, to produce each pound of beef sold in retail stores) is re- ferred to as the farm-to-retail price spread. The farm-to- re tail price spread might be considered the marketing cost (or "marketing msu-gin") for farm products, being absorbed by the labor. packaging, promotion, energy, and other costs involved in the processing and marketing of farm products. In recent years that cost has risen at an average rate of 5.6 percent, meaning that the cost of marketing farm products has been increasing faster than the farm value of those same products. There are two important points to be made here. First, whether the farm share (or the marketing margin) is increasing or decreasing says very httle about the welfare of farmers or the relative profitability of farming vs. market- ing. Products sold in retail stores are much different from those sold by farmers, and the cost of creating those differences is included in the farm-to-retail price spread. If, as has been occurring recently, consumers purchase in- creasing amounts of the more highly- processed products, the farm-to-retail price spread must increase, even if farmers continue to receive the same prices for their products. Second, there are major differences in the different markets involved that contribute to the fact that farmers often receive lower price increases for their products than do the market- ing firms. There is little benevolence in any market; market participants pay what they have to pay to receive needed products and services. In the markets where farmers sell their products, they usually have less bargaining power than do the buyers to whom they must sell. As a result, farmers tend to be "residual claimants" to returns in the market place. On the other hand, in the market for inputs such as labor, energy, and packaging materials, marketing firms encounter sellers with bargain- ing power equal to or greater than their own, £uid the resulting prices are negotiated or bar- gained prices. In the market for the final prod- ucts, marketing firms usually have sufficient marketing power visa- viz consumers, to at least be able to obtain adequately profitable prices. Who Gets What Part Of The Consumer Food Dollar? The final question addressed in this article is, where does the consumer food dollar go; who receives what part of it? In 1992, 26 cents of every food dollar spent by consumers was re- FruH Notes, Fall, 1993 15 ceived by fanners. Of the remainder (some- times referred to as the "marketing bill"), 35 cents was used to pay salaries and wages for the workers involved, and 8 cents, the cost of pack- aging. Transportation, depreciation, advertis- ing, energy, and rent costs each accounted for 3.5 to 4.5 cents. About 6.5 cents was divided among a large number of costs, including re- pairs, insurance, professional services, prop>erty taxes, and many other items. The remaining 3.5 cents represented before-tax profits. Consumer Value and Their Food Dollars In conclusion, it appears that consumers have benefitted fi-om very moderate increases in retail food costs in recent years. Personal dispos- able incomes have risen at a faster rate than food costs and the percentage of income spent on food has fallen. At the same time the farm share of the consumer's dollar has steadily dechned while the farm-to-retail margin has gradually increased. Do U.S. consumers get a good value for their food dollars? Undoubtedly they do. Could it be better? Of course it could, and it is probably getting better, especially with the increased use of information about nutrition and healthful- ness of food products. Do farmers and marketers receive fair values for their contributions? Prob- ably so, at least if you base your conclusion on the availability of adequate supplies of food of adequate quality and in reasonable variety. In addition, most would conclude that food market- ing firms receive reasonable, though not ex- travagant, returns for their investments. The case for farmers is less clear; certainly their profits are not excessive. For U.S. farmers whose major occupation is farming, household net farm incomes in 1991 averaged $10,228 fi"om gross cash farm income of $94,027 and farm assets valued at $491,241 (USDA-ERS. 1993. Agricultural Income and Finance - Situ- ation and Outlook Report. Economic Research Service, USDA, AFO-49). %f# «f^ *f^ *fi» •^0 r|% #1% #^ #1% r{% 16 Fruit Notes, Fall, 1993 Fruit Notes University of Massachusetts Department of Plant & Soil Sciences 205 Bowditch Hall Amherst, MA 0 1003 Nonprofit Organization U.S. Postage Paid Permit No. 2 Amherst, MA 01002 -0 SERIAL SECTION ^^ UNIV.OFMASSACHUSETTbu AMHERST, MA 01003 Account No. 3-20685 Fruit Notes ISSN0427-6906 ' !:]RmRY HAR-7 914 Prepared by the Department of Plant & Soil Sciences. . ^ r r \ / r\r- n k n r JHIV. OF MASS. University of Massachusetts Cooperative Elxtenslon System, United States Department of Agriculture, and Massachusetts Counties Cooperating. eiOLOGCAL Editors: Wesley R. Autio and William J. Bramlage MAR 04 1994 SCIENCES UBRARY Volume 59, Number 1 WINTER ISSUE, 1994 Table of Contents Apple Integrated Pest Management in 1993: Insects and Mites in Second-level Orchard Blocks Second-level IPM in Blocks of Scab-resistant Apple Cultivars New Publication Available Second-level Integrated Pest Management, 1991 to 1993: Diseases Tax Pointers for Farmers in 1993 Fruit Notes Publicationlnformation: /^Mi/iVbtesaSSN0427-6906)ispublishedthefirstdayofJanuary,April, July, and Octoberby the Department ofPlant & Soil Sciences, University ofMassachiisetts. The costs of subscriptions toFruit Notesare $7.00 for United States addresses and $9.00 for foreign addresses. Each one-year subscription begins January 1 and ends Decembers 1. Somebackissues are available for $2.00 (United States addresses) and $2.50 (foreign addresses). Pay- ments must be in United States currency and should be made to the University ofMassachusetts. Correspondence should be sent to: Fruit Notes Department ofPlant & Soil Sciences 205BowditchHall University ofMassachusetts Amherst, MA01003 COOPERATIVE EXTENSION SYSTEM POLICY: Mdiemicalusessuggestedin this pubUcation are cQntingentupona)ntinuedregistration.TTiese chemicals slxnildte usedinaai)rdarK)ewithfedera] and slate laws and regulations. Growers are urged to befamiliarwithaDcurrentstate regulations. Where trade namesareusedforidentification, no company endorsementor product discriminationis in tended- The UniversityofMassachusettsmakesno warranty or guarantfieofanykind,expressedorimplicd, concerningtheuseoftheseptxiucts. USER ASSUMES ALL RISKSroRPERSONALINJURYORPROPERTY DAMAGE. Issued by the University of Massachusetts Cooperative Extension System, Robert G. Helgesen, Director, in furtheranceoftheaclsofMay8andJune30, 1914. TheUmversityofMasaachusettsCoopemHveExtensionSystem offersequalopportunityinprogramsandemploymenL Apple Integrated Pest Management in 1993: Insects and Mites in Second-level Orchard Blocks Jennifer Mason, Ronald Prokopy, Starker Wright, Sarah Goodall, Kristian Jones, Yu Ma, Vanessa Mohr, and Miyu Nogaki Department of Entomology, University of Massachusetts For the past two years we have reported results of our ongoing program of second-level IPM trials in Massachusetts apple orchards. Under second-level IPM, orchard management is integrated across all classes of pests: insects, mites, diseases, weeds, and vertebrates, rather than focusing on a single type of pest. Here we report results of the third year of second-level IPM trials on insects and mites in commercial Massachusetts orchards. Insect and mite management under second-level IPM practices require application of three to four selective insecticide sprays from April to early June to manage tarnished plant bug (TPB), European apple sawfly (EAS), plum curculio (PC), green fruit- worm (GFW), and the first generations of codling moth (CM), lesser appleworm (LAW), leafminer (LM), and white apple leafhopper (WALH). Insecti- cide application to the interior of the block ceases after the final plum curculio spray in early June, hopefully allowing populations of predatory insects and parasitoids to increase to levels sufficient to provide control of summer populations of foliar pests. In full second-level IPM blocks, apple maggot fiies (AMP) are controlled by perimeter in- terception traps. In transitional second-level IPM blocks, use of AMF interception traps is re- placed by perimeter-row spraying with Guthion™* or Imidan''''^ every three weeks beginning in early July. In both types of blocks, removal of unmanaged apple and pear trees within 100 yards of each block reduces immigration of CM and LAW. Removal of drops during and after harvest discourages buildup of within-orchard populations of AMF, CM, and LAW. We believe there are at least four distinct poten- tial benefits of employing biologically-based meth- ods as a substitute for insecticides from early June until harvest. These include reduction in insecticide residue on fruit at harvest, reduction in impact of insecticide on areas bordering orchards, reduction in selection pressure leading to pest resistance to insec- ticides, and buildup of beneficial natural enemies in the absence of insecticide use afi-er early season sprays. For some growers and some intended mar- kets, one or more of these potential benefits could be important in the near future, if not now. In 1993, we continued work in the same six full and six transitional second-level IPM test blocks used in 1991 and 1992. Each second-level block was matched with a nearby control block that was man- aged by the grower, using first-level IPM methods. Early-Season Fruit-injuring Pests For control of arthropod pests active up to early June, second-level IPM relies on early-season pesti- cide treatment based on monitoring. We monitored each orchard weekly beginning in mid-April, then biweekly from mid-June through September. Five each of four types of sticky traps were hung in each block to monitor for TPB, LM, and EAS. We exam- ined 100 or 200 leaves or watersprouts per block for LM, LH, aphids, mites, and mite predators. During PC season, scouts examined fruit on perimeter trees for evidence of fresh injury, while growers were urged to do likewise on a daily basis. On the basis of this monitoring, recommendations were made to the grower for treatment of the experimental block. In second-level IPM blocks (both full and transi- tional) in 1993, combined injuries from early- season fruit pests were rather similar to those in nearby first-level IPM (grower control) blocks. In both first- and second- level IPM blocks, TPB caused by far the most damage, followed by PC and EAS (Table 1). Due to a lack of alternatives to pesticidal control of early-season fruit pests, both first- and second-level blocks had similar management and therefore simi- lar insecticide use(Table2).Thisyear sawa marked increase in TPB damage over 1992 in all blocks, though injury due to PC and EAS remained similar. Fruit Notes, Winter, 1994 Table 1. Average percent injury by early-season insect pests in second- level and first-level IPM blocks in 1993.* Type of block TPB PC EAS GFW Total Full second-level First-level Transitional second-level First level 7.0 a 6.5 a 2.6 a 1.2 a 0.3 a 0.1 a 0.3 a 0.3 a 0.1 a 0.1 a 0.1 a 0.1 a 0.0 a 0.0 a 0.0 a 0.0 a 7.4 a 6.7 a 3.0 a 1.6 a * Means in each couplet in each column followed by a different letter are significantly different at odds of 19:1. Two hundred fruit of each cultivar present in both second-level and corresponding first level blocks were sampled at harvest. All blocks contained at least 1 of the following cultivars, and some contained up to 3 of these: Mcintosh, Cortland, Delicious, Empire, Golden Delicious. Average number of fruit sampled per block = 500. When sampling a cultivar, we examined 10 fruit on each of 20 interior trees and 10 on each of 10 perimeter-row trees (when cultivar present on a perimeter row). TPB = tarnished plant bug; PC = plum curculio; EAS = European apple sawfiy; GFW = green fi-uitworm. Table 2. Dosage equivalents (spray events in parentheses) of insecticides and acaricides used in second-level and first-level IPM blocks in 1993.* Type of block Fruit pests Mites After Before mid- mid- Other June June Oil miticides LH ABLM Total 2.7 0.0 1.4 1.0 0.2 0.3 5.6 (3.3) (0.0) (2.5) (0,8) (0.3) (0.5) (7.4) 2.7 1.0 1.0 1.2 0.2 0.0 6.1 (3.3) (2.2) (2.1) (1.3) (0.2) (0.0) (9.1) 2.2 0.7 1.1 0.5 0.0 0.2 4.7 (3.2) (3.2) (2.2) (0.6) (0.0) (0.2) (9.4) 2.2 1.2 1.5 1.7 0.0 0.0 6.6 (3.0) (2.8) (2.5) (1.5) (0.0) (0.0) (9.8) Full second-level First-level Transitional second-level First-level LH = leafhopper, ABLM = apple blotch leafminer. FruH Notes, Winter, 1994 Summer Fruit-injuring Pests: Full Second-level IPM Odor-baited sticky red spheres were hung every five yards on perimeter apple trees of each full second-level experimental block to intercept immi- grating AMF. These were baited with both butyl hexanoate, a synthetic fruit odor deployed in poly- ethylene vials, and ammonium acetate, a synthetic food odor released through a Consep^'* membrane. Traps were cleaned biweekly, based on data from 1992 suggesting a loss of capturing power with increase of length of time between cleanings. Interception trap captures averaged 5023 in the six full second-level blocks, as compared with 2430 in 1992 and 3562 in 1991, indicating that AMF pres- sure was exceptionally high in 1993. Even so, captures of AMF on four interior unbaited monitor- ing traps (indicative of AMF penetration into the block interior) were similar in full second-level blocks and nearby first-level blocks (Table 3). AMF injury to fruit at harvest averaged slightly but not significantly greater in second-level than first-level blocks (0.7 vs. 0.3) (Table 3). The power of intercep- tion traps for controlling AMF is illustrated in one full second-level block of 10 acres where more than 21,000 AMF were captured on the traps but less than 1% of Mcintosh, Cortland, and Delicious apples were injured by AMF. It should be noted, however, that late-ripening cultivars (e.g., Delicious and Golden Delicious) consistently have proven to be more sus- ceptible to AMF injury than mid- or earlier-ripening cultivars under full second-level practices. The problem of effective control of AMF in late- ripening cultivars remains a challenging one for us. In one block that suffered 8% AMF injury to Cortlands in late September of 1992, we hung perim- eter traps significantly higher in the tree in 1993 than in 1992 in an attempt to increase trap captures of AMF before fruit injury occurred. We found only 1% AMF damage to the Cortlands at harvest this year, though it should be noted that the fruit was Table 3. Season-long apple maggot fly (AMF) injury and trap captures in second- level IPM blocks and first-level IPM blocks in 1993.* Perimeter Interior monitoring AMF injury monitoring trap Interception to fruit at trap captures captures trap captures Type of block harvest (%) per trap per trap per block Full second-level 0.7 a** 7.7 a 22.9 a 5023 First-level 0.3 a** 11.0 a 10.7 a — Transitional second-level 0.8 a 8.4 a 8.8 a First-level 0.4 a 9.7 a 9.7 a — Means in each couplet in each column followed by a different letter are significantly different at odds of 19:1. Two hundred fruit of each cultivar present in both second-level and corresponding first-level blocks were sampled at harvest. All blocks contained at least one of the following cultivars, and some contained three of these: Mcintosh, Cortland, Delicious, Empire, Golden Delicious. Average number of fruit sampled per block = 500. When sampling a cultivar, we examined 10 fi-uit on each of 20 interior trees and 10 on each of 10 perimeter-row trees (when cultivar present on a perimeter row). Data on AMF injury to fruit from one orchard have been excluded due to excessively high late-season damage to several cultivars in both the second and first-level blocks possibly caused by lack of AMF control methods by grower in surrounding blocks. Fruh Notes, Winter, 1994 picked slightly earlier than in 1992. In other blocks, problems with AMF arose in cases where perimeter rows were comprised of early ripening cultivars, necessitating immediate movement of interception traps to interior trees upon harvest. Due to time con- straints we wereunable to move the spheres soon enough after harvest, al- lowing injury to occur in later-ripening cultivars. We continue to look for an appropriate method of hanging ammonium ac- etate membranes that will keep their fluttering mo- tion to a minimum so as not to scare AMF away. This year we attempted to stitch a wire through the top of the membrane packet only to find that the contents drained out within a few weeks. Fruit injury by CM, LR, and LAW were similar in second-level and first-level blocks (Table 4). CM averaged 0.2% in the second- level blocks while it was 0% in the adjacent first-level blocks. Leafroller injury was up from 1992, averag- ing 0.8% in second-level and 1.0% in first level blocks. LAW injury also increased, averaging 0.4% in second-level blocks and less than 0.1% in first- level blocks. No insecticide was applied against any fruit- injuring pest after mid-June. In adjacent first-level blocks growers applied an average of 1.0 dosage equivalents of insecticide against fruit pests after mid-June and sprayed the block an average of 2.2 times (Table 2). Summer Fruit-injuring Pests: Transitional Second-level IPM Every three weeks after early June, perimeter row apple trees in transitional second-level blocks were treated with insecticide to control AMF. The block interior remained free of insecticide after early June. AMF injury at harvest averaged 0.8% in transitional second-level blocks and 0.4% in nearby first-level blocks, somewhat higher for both types of Table 4. Fruit injury by codling moth (CM), leafrollers (LR), and lesser appleworm (LAW) in second-level and first-level IPM blocks in 1993.* Type of block CM LR LAW Full second-level First-level Transitional second-level First-level 0.2 a 0.0 a 0.1 a 0.0 a 0.8 a 1.0 a 0.7 a 0.2 a 0.4 a <0.1 a 0.4 a 0.0 a Means in each couplet in each column followed by a diff'erent letter are significantly different at odds of 19:1. Two hundred fruit of each cultivar present in both second-level and corresponding first level blocks were sampled at harvest. All blocks contained at least 1 of the following cultivars, and some contained 3 of these: Mcintosh, Cortland, Delicious, Empire, Golden Delicious. Average number of fruit sampled per block = 500 When sampling a cultivar, we examined 10 fruit on each of 20 interior trees and 10 on each of 10 perimeter-row trees (when cultivar present on a perimeter row). blocks than in 1992 (Table 3). Captures of AMF on interior unbaited monitoring traps were similar in transitional second-level blocks and in first-level blocks. Total insecticide used afi^r early June aver- aged 0.7 dosage equivalents in second-level blocks compared with 1.2 dosage equivalents in first-level blocks (Table 2). The relative similarities between the two sets of blocks may be explained by some growers using exclusively border row sprays for AMF in first-level blocks, mainly due to financial constraints. CM damage was very low in both types of blocks (0.1% or less). Both LR and LAW injury were somewhat (but not significantly) greater in the tran- sitional blocks (0.7 and 0.4%) than in the first-level blocks (0.2 and 0%) (Table 4). Foliar Pests and Predators: Full Second-level IPM In 1992, we reported peak populations of foliar pests; this year we return to season-long averages from time of first to last appearance of the pest on foliage. Hot, dry weather played a major role in inciting higher foliar pest populations in 1993. Fruit Notes, Winter, 1994 Table 5. Seasonal average populations of mites and mite predators in second-level and first-level IPM blocks in 1993. * Mite presence (% of leaves) Ratio of ERM-t-TSM YM to Af ERM+ Type of block TSM Af Full second-level 22.4 a 0.7 a First-level 18.6 a 2.0 a Transitional second-level 19.6 a 2.1 a First-level 16.2 a 1.0 a 4.3 a 32:1 4.5 a 9:1 3.1 a 9:1 1.2 a 16:1 * Means in each couplet in each column followed by a different letter are significantly different at odds of 19:1. ERM = European red mite; TSM = two-spotted mite; Af = Amblysieus fallacis; YM = yellow mite. Table 6. Foliar insect pest average population levels in second-level and first-level blocks in 1993.* Type of block PLH WALH RLH ABLM GAA GAAP WAA Full second-level First-level Transitional second-level First-level 8.9 a 6.7 a 6.4 a 6.9 a 4.2 a 4.2 a 2.2 a 1.4 a 7.5 a 2.4 a 2.4 a 0.8 a 8.0 a 17.2 a 6.8 a 4.4 a 28.7 a 27.1 a 35.3 a 28.9 a 17.1 a 13.4 a 19.0 a 10.1 a 8.1 a 7.6 a 4.3 a 4.5 a Means in each couplet in each column followed by a different letter are significantly different at odds of 19:1. PLH = potato leafhopper, WALH = white apple leafhopper; RLH = rose leafhopper, ABLM = apple blotch leafminer; GAA = green apple aphid; GAAP = green apple aphid predators: cecidomyiids and syrphids, WAA = woolly apple aphid. PLH, WALH, and RLH data are average percentages based on bi-weekly samples of 100 or 200 fruit cluster or terminal leaves. ABLM data are the average number of mines per 100 leaves based on bi- weekly samples of 100 or 200 fruit cluster or terminal leaves. GAA, GAAP, and WAA data are percentage watersprouts infested based on bi-weekly samples of 200 watersprouts. Fruit Notes, Winter, 1994 Mite populations were high in most orchards, appearing early in the season (Table 5). In several orchards mite problems in second-level blocks may have been inadvertently assisted by our setting aside of small areas (approximately one acre ) in the block to be left untreated with dormant oil. This was done in the hope of providing a reasonable food source for early phytoseiid mite predator popula- tions. Unfortunately Amblyseius fallacis suffered extremely heavy late winter mortality, and these areas proved useful only for raising large numbers of European red mites. Yellow mite predators were eventually present in large numbers in some or- chards. There tended to be little difference, how- ever, in densities of mite predators between full- second-level and first-level blocks (Table 5). Typhlodemus pyri obtained from Geneva, New York were released in two blocks in 1992 and again this past summer. Repeated sampling of the release sites leads us to believe that both attempts at colonization were unsuccessful. Full second-level blocks were treated with slightly higher dosage equivalents of pre-bloom and mid-season oil than nearby first-level blocks (1.4 vs. 1.0) while receiving slightly less other miticide (1.0 vs. 1.2 dosage equivalents) (Table 2). The use of post- bloom miticides in the full second-level blocks was mainly due to a need to regain control over mite populations in the areas that did not receive oil in the spring. White apple leafhopper populations were equal in both the full second-level and first-level blocks. Potato leafhoppers were slightly, although not sig- nificantly, higher in the full second-level blocks. The major leafhopper problem this year proved to be rose leafhopper (RLH) migrating into blocks from border- ing wild rosebushes and brambles. In several loca- tions RLH were present in high enough numbers to be a major irritation at harvest, and one full second- level block required late season treatment of insecti- cidal soap. RLH averaged 7.5 % infestation in full second-level blocks, versus 2.4% infestation in the first-level blocks (Table 6). Average leafminer populations were lower, al- though not significantly, in full second-level blocks than in first-level blocks (Table 6). Dimilin™ was used in three of the six full second-level blocks against overwintering LM adults and eggs even though only two of these blocks required a treat- ment. Late stage tissue mines were collected from each orchard and brought back to the lab for parasit- ism readings. The average parasitism rate of second generation larvae was 55% in full second-level blocks but only 37% in first level blocks. Research into parasitism of LM continues to be an area of interest in that parasitism appears a potentially very effective means of controlling one of our major foliar pests. Green apple aphids infested 29% and 27% of the watersprouts in full second-level blocks and in first- level blocks, respectively. Levels of two aphid preda- tors were also similar in both types of blocks, and achieved efficient control of GAA. Levels of woolly apple aphids on watersprouts were also similar in both types of blocks, but were considerably higher than in 1992. Foliar Pests and Predators: Transitional Second-level IPM Mite levels were moderate to high in most of the transitional second-level blocks and adjacent first- level blocks. Dosage equivalents of oil averaged 1.1 in second-level blocks and 1.5 in first-level blocks. Other miticide applications averaged 0.5 dosage equivalents in second-level blocks and 1.7 dosage equivalents in first-level blocks. Mid-season miticide application occurred in one second-level block as compared to three first-level blocks (Table 2). White apple leafhopper and potato leafhopper populations were about the same in second-level and first-level blocks. RLH levels were less of a problem in transitional second-level blocks than in full sec- ond-level blocks, possibly becauseperimeter row in- secticide applications every three weeks during the summer killed immigrating RLH. Only one transitional second-level block was treated with Dimilin™ against first generation leafminers. Leafminer numbers were slightly higher in second-level blocks than in first-level blocks, yet the parasitism of second generation lar- vae was slightly lower (38% vs. 44%). LM levels were similar to those found in 1992. Green apple aphid infestation levels were some- what higher in second-level blocks than in first-level blocks, as were both types of aphid predators moni- tored. In both types of blocks predators were suffi- cient to provide control of GAA populations. Woolly apple aphid populations were similar in both types of blocks (Table 6). Conclusions With regard to full second-level IPM practices that involve substitution of cultural, behavioral, and biological control methods for insecticide use after early June, we conclude the following after three consecutive years of implementation. Fruit Notes, Winter, 1994 (1) No buildup of codling moth or leafroller beyond a level existing in nearby first-level IPM blocks. (2) Slight buildup of lesser appleworm in 1993. (3) Slightly greater injury by apple maggot flies, especially in late-ripening cultivars. (4) No buildup of pest mites under slightly reduced miticide use but insufficient buildup of preda- tory mites to permit truly substantial reduction in miticide use. (5) Considerable buildup of parasitoids of leafminers, possibly sufficient to reduce or elimi- nate need for spray against leafminers. (6) No buildup of apple aphids, woolly apple aphids, or white apple leafhoppers beyond acceptable levels. (7) Substantial mid- and late-summer immigration (into some blocks) of rose leafhoppers from nearby rose bushes and brambles, causing ex- crement spotting of fi"uit and nuisance to pick- ers. With respect to transitional second-level IPM practices that involve no application of insecticide to the block interior aft.er early June but rely on perim- eter-row sprays instead of traps for controlling apple maggot flies, we conclude the following after three consecutive years of implementation. (1) No buildup of codling moth but slightly more injury by leafrollers compared with nearby first- level IPM blocks. (2) Slight buildup of lesser appleworm in 1993. (3) Slightly greater injury by apple maggot fly. (4) No buildup of pest mites under slightly reduced miticide use but not enough buildup of predatory mites to allow much reduction in miticide use. (5) No buildup of parasitoids of leafminers. (6) No buildup of apple aphids, woolly apple aphids, or white apple leaflioppers beyond acceptable levels. (7) No unacceptable immigration of rose leafhop- pers during mid- and late-summer. In sum, transitional second-level IPM offers an advantage over first-level IPM in terms of substan- tial reduction in pesticide use during summer months. Growers using transitional second-level IPM should, however, keep a careful eye on buildup of apple maggot, leafrollers, and leafminers. In the long run, we believe that if pesticide-treated spheres can be developed and registered as a substitute for sticky spheres to control apple maggot (see accompa- nying article), full second-level IPM will be as eco- nomical to employ and as effective in controlling pests as first-level IPM while offering several dis- tinct advantages outlined in the introduction. To verify further the advantages and shortcom- ings of second-level IPM, we plan to evaluate in 1994 the same full and transitional second-level practices in the same blocks used from 1991 to 1993. This will provide four consecutive years of data, which ought to be sufficient for drawing firm conclusions. We also plan to carry out intensive studies on refining those aspects of full second-level IPM that to date have proven to be shortcomings. These include: enhanc- ing the residual effectiveness of pesticide-treated spheres; studying within-orchard movement pat- terns of apple maggot flies from early- to mid- to late- ripening cultivars; evaluating elimination of rose- bushes and brambles near orchards as a means of controlling rose leafhopper; and evaluating the im- pact of summer applications of benomyl and mancozeb on mite predators, which we now believe may be the principal reason for lack of sufficient mite predator buildup to provide biocontrol of mites in second-level blocks. Acknowledgements This project was funded by the Massachusetts Society for Promoting Agriculture, the USDA North- east Regional IPM Competitive IPM Grants Pro- gram, State/Federal IPM funds, and the Northeast Region Sustainable Agriculture Research and Edu- cation Program (formerly LISA). We gratefully acknowledge this funding. We are also grateful for the participation and support of the following grow- ers: Bill Broderick, David Chandler, Dana Clark, Dick, Greg, and Kevin Gilmore, Tony Lincoln, Jesse and Wayne Rice, Joe Sincuk, Dave Shearer, Tim Smith, and Barry and Bud Wiles. •!• %l0 •!» %% •^ •Y» •^ •((»• •li* •(!>• Fruit Notes, Winter, 1994 Second-level IPM in Blocks of Scab-resistant Apple Cultivars Daniel R. Cooley, Jennifer Mason, Jian Jun Duan, Xing Ping Hu, Ryan Elliott, and Ronald J. Prokopy Departments of Plant Pathology and Entomology^ University of Massachusetts Previously, we have described methods designed to eHminate orchard applications of insecticide and miticide after early June. We have also described our concept of the evolution of integrated pest man- agement (IPM) programs, moving from first level approaches which integrate methods for controlling one class of pests, to a second level which integrates methods for controlling all classes of orchard pests. In 1991, we initiated a second-level IPM program in 12 Massachusetts commercial apple orchards com- prised of Mcintosh, Cortland, Empire, and Delicious cultivars. Our strategy used pesticides from April to early June against early-season arthropod pests (particularly mites, plant bug, sawfly, and plum curculio), early-season disease pests (apple scab and blossom-end rot) and early-season weed growth be- neath the tree canopy. After early June, the strategy called for few if any pesticide applications. Instead, cultural, behavioral, and biological control methods replaced pesticides. We felt that this strategy would allow natural enemies of arthropod pests to increase in numbers and provide biological control (especially of foliar-damaging arthropods), slow rates at which pests develop resistance to pesticides, and reduce potential human risks from pesticide residues on fruit at harvest. Over the first two years of the program, we saw successes and some problems in all pest areas, but one of the most troublesome areas was disease man- agement. In the second-level blocks, growers used 4.6 fungicide dosage equivalents (DEs) during the primary apple scab season. They also used 2.2 fungicide DEs to control summer diseases, notably flyspeck and sooty blotch. By comparison, in first- level IPM blocks, growers used 4.8 early-season fungicide DEs and 3.0 summer fungicide DEs. While the second-level blocks showed very modest fungi- cide savings, fungicide use still presented a major impediment in our efforts to reduce pesticide appli- cations, particularly late in the season. In addition to reducing risk to humans from exposure to pesticide residues, eliminating insecti- cides and miticides late in the season can assist pest control overall, since these materials oflne destroy natural enemies. Fungicides, however, also can have a negative impact on natural biocontrol. Benomyl is the best example, and has been shown to sterilize predaceous phytoseiid mites (Crofl, 1990), and eliminating fungicides from an orchard can stimulate biocontrol (Bower et al., 1993). Further- more, fungi that infect and kill insects and mites in the natural setting may be inhibited by fungicides (e.g.,Loriaetal., 1983; Tedders, 1981). Additionally, there appear to be some pesticide impacts on spiders, which may play a role in mite biocontrol (Wisniewska et al., 1993). Therefore, it is worth examining the effect of fungicide reduction or elimi- nation in the orchard. One approach to fungicide reduction is to use scab-resistant apple cultivars (SRCs). Our experi- ences (in the Northeast Apple Sustainable Agricul- ture Research and Education Project and in our own blocks) indicate that SRCs at leastwill allow the elimination of scab fungicides. The degree to which SRCs will allow us to eliminate summer fungicides needs to be determined. However, we sought to test the effects of fungicide elimination in second-level blocks, and in 1993, we added genetic control (host plant resistance) to the tactics of cultural, behav- ioral, and biological apple pest management. Spe- cifically, we emphasized a second-level IPM ap- proach in three commercial orchards having two- acre blocks of SRCs, primarily Liberty and Priscilla. The SRCs were propagated on M.26 rootstock and planted in 1988. We also introduced a new technique to tackle another problem: the need to clean red sphere maggot traps frequently. Sticky red spheres have been used in second-level IPM to trap apple maggot fiies at the orchard perimeter. For the first time in any commercial orchard, we used pesticide-treated spheres as a substitute for sticky-coated spheres as 8 Fruit Notes, Winter, 1994 a behavioral method of controlling apple maggot flies. Each of the three blocks was divided in half With respect to arthropods, one half was managed under first-level IPM practices that involved moni- toring pest abundance and weather and then apply- ing pesticide as dictated by monitoring information. The other half was managed as follows. Arthropods Two applications of superior oil were made be- fore bloom against overwintering European red mite eggs followed by two applications of phosmet or azinphosmethyl against European apple sawfly and plum curculio (one at petal fall in mid-May and one two weeks later in late May). All unmanaged wild apple trees within 100 yards of the block perimeter were cut down as a cultural method of controlling co- dling moth by reducing or prevent- ing immigration of females from nearby wild host trees (very few codling moth females appear to disperse 100 yards or more within their lifetime under northeastern US conditions). Odor-baited pesti- cide-treated eight-cm wooden red spheres were hung five to six yards apart on perimeter trees in late June as a behavioral method of controlling apple maggot flies. Two types of odor baits were used: semi-permeable membranes that released the food-type attractant ammonium acetate, and polyethyl- ene vials that released the fruit- type attractant butyl hexanoate. Odor baits were hung a few inches from spheres and released attrac- tive odor over the entire three- month period of trap use. Prior to emplacement, the spheres were dipped in a mixture of 40% latex paint, 44% corn syrup, 15% water, and 1% Cygon (dimethoate). The latex paint allowed dimethoate to be released very slowly on the sphere surface. Periodic tests showed that, provided the sphere surface contained sufficient su- crose as a feeding stimulant, 70% or more ofalightingfiies died. This was true even in late September, three months after initial treatment with dimethoate; however, rainfall can wash away the corn syrup. Without it, flies did not feed and there- fore did not acquire a fatal dose of dimethoate. Hence, we or the growers were obliged to dip each sphere in a 20% aqueous solution of table sugar after every rainfall. Following harvest, drops were re- moved to decrease wi thin-orchard buildup of codling moth and apple maggot. Diseases No fungicide was applied in the SRC blocks. We simply eliminated fungicides from the management program, in spite of the expectation that there would be some damage from flyspeck and sooty blotch. Most trees had not yet reached full maturity and had Table 1. Numbers of insecticide and miticide treatments and percent arthropod-injured finiit at harvest* in three blocks of scab-resistant cultivars under first-level versus second-level IPM management. Pesticide Number of applications First-level Second-level Insecticide Miticide 4.0 2.0 2.0 2.0 Pest Injured fruit (%) First-level Second-level European sawfly Plum curculio Codling moth Lesser appleworm Leafroller Apple maggot Total insect 0.2 0.3 0.0 0.1 0.3 0.1 1.0 0.6 0.8 0.0 0.0 2.5 0.3 4.2 * Four hundred fruit per block were sampled at harvest. Fruit Notes, Winter, 1994 comparatively open cano- pies that do not show a significant disease re- sponse to summer prun- ing, therefore we did not summer prune the blocks for disease management. In order to compare disease impacts of the SRC systems and a con- ventional IPM system, we observed disease inci- dence in conventional cultivars under normal first-level IPM practices using a block on each of the three farms consist- ing of conventional culti- vars (Mcintosh, Cortland, Delicious). We did not compare these blocks to the SRC blocks for management of and damage by arthropod pests. Pesticide Use and Injury Table 1 shows the mean number of miticide and insecticide treat- ments applied to each block. Table 1 also shows the mean number of ar- thropod-injured fruit at harvest. We focus here on fruit injury initiated after early June, the time when second-level IPM practices against insects diverged from first-level IPM practices. Injury by apple maggot was slightly greater and injury by leafroller was substantially greater in second-level compared with first-level blocks. Very little injury by codling moth or lesser appleworm occurred in these blocks. Not shown are fruit injury levels caused by larvae in one orchard that we identified as apple pith moth larvae. This injury was slightly greater in the second-level block, but definitive identification of the larvae (new to us) is pending. Table 2 shows the number of fungicides applied in the SRC blocks and the conventional blocks, as well as the disease incidence in each block type. Sooty blotch and flyspeck damage far exceeded any Table 2. Mean number of fiingicide treatments and mean percent disease-injured fruit at harvest* in three orchards comparing three systems: conventional cultivars under first-level IPM; scab-resistant cultivars under first-level IPM; and scab-resistant cultivars under second-level IPM. Pesticide Number of applications Standard cultivars first-level SRCs SRCs first-level second-level Fungicide 8.0 0.0 0.0 Pest Diseased fruit (%) Standard cultivars first-level SRCs SRCs first-level second-level Apple scab Blossom end rot Sooty blotch Fly speck Total disease 0.1 0.1 0.1 0.4 0.7 0.0 0.0 0.0 0.0 7.0 7.3 5.0 4.1 12.0 11.4 * Four hundred fruit per block were sampled at harvest. other fruit injury in each block type. This result was not surprising, since several observations have shown that in orchards which receive no fungicides in Massachusetts, there will be significant levels of sooty blotch and fiyspeck at harvest. In blocks of standard cultivars, fungicide applications greatly reduced sooty blotch and fiyspeck damage, but fiy- speck remained the most damaging disease. Table 3 shows mean abundance of principal arthropod pests of the fohage and their principal natural enemies. Notable among pests is the lower average European red mite population but the higher average white apple leafhopper and rose leafiiopper populations in the second-level blocks. Notable among natural enemies is the substantially 10 Fruit Notes, Winter, 1994 Table 3. Mean percent sampled leaves* infected with arthropod foliar pests and their natural enemies in 3 blocks of scab-resistant cultivars under first-level vs. second-level IPM management. Foliar pest Infested leaves (%) First-level Second-level Apple aphids Leafminers (2"'* gen.) European red mites White apple leafhoppers Rose leafhoppers 21 29 29 5 2 13 36 18 10 8 Natural enemies Infested leaves (%) First-level Second-level Aphid predators Leafminer parasatoids (2"'' gen.) Phytoseiid mite predator Stigmaeiid mite predator 7 46 4 38 5 71 7 66 * Samples of 200 leaves per block were taken at bi-i from mid-June to mid-September. A'eekly intervals greater incidence of leafminer parasitoids and mite predators (particularly Stigmaeiid yellow mites) in the second-level blocks. Conclusions Our findings in this first year of applying second- level IPM practices to blocks of scab-resistant culti- vars indicate promise as well as some potential problems for future application. Among arthropods, the most promising aspectswere the success of pes- ticide-treated spheres in controlling apple maggot flies, the very low incidence of codling moth and lesser appleworm, and the buildup of leafminer parasitoids and mite predators (particularly yellow mites). Among diseases, the most promising aspects were (not surprisingly) the absence of apple scab and blossom end rot. The most problematic aspects were buildup of leafroller (ex- clusively oblique-banded) and flyspeck. From the perspective of arthropod manage- ment, use of pesticide- treated spheres is the key element of second-level IPM. These spheres are far simpler to prepare and maintain than sticky spheres. The only real problem (aside from gain- ing EPA registration for use) involves the current necessity of dipping the sphere in aqueous sugar solution after each rain- fall. This is a rapid pro- cess: 10 minutes to re- move, dip and re-hang one acre's worth of spheres. But if it is not done almost immediately after rainfall has ended, there is no pro- tection against apple mag- got fly invasion. In 1993, there were several un- avoidable lapses of a day or two in dipping spheres after rainfall, possibly ac- counting for the slightly greater amount of maggot injury in second-level blocks. We need to find a new polymer capable of releasing sucrose at a slow rate rather than losing all of the sucrose during rainfall. With regard to leafrollers and flyspeck, virtually all of the injury in 1993 was restricted to just one of the three orchards. Another of the orchards had almost all of the leafhoppers found; invading rose leaflioppers at harvest were especially troublesome. Perhaps the vegetation surrounding these orchards harbored substantial "inocula" of these two pests. This demands further study. Our experience in 1993 suggests much promise for applications of low-labor second-level IPM prac- tices in scab-resistant blocks. If we can keep sucrose on pesticide-treated spheres during rainfall and control flyspeck, leafroller, and leafhoppers using habitat management and early-season fungicides, then foliar pests such as mites and leafminer might Fruit Notes, Winter, 1994 be controlled solely through natural enemies. As a result growers would no longer need to apply any pesticide in scab-resistant blocks after early June. Aknowledgements This work was supported by the USDA Sustain- able Agriculture and Research Education Program- -Northeast Region and the Massachusetts Society for promoting Agriculture. References Bower, K. N., L. P. Berkett, and J. F. Costante. 1993. Non-target effect of a fungicide on phytophagous and predacious mite populations in a disease resis- tant apple orchard. Proceedings of the Disease Resistant Apple Cultivar Workshop, Jan. 24-26, Hersey, PA (Abstract; Proceedings in press. Fruit Var. J.) Croft, B.A. 1990. Arthropod Biological Control Agents and Pesticides. Wiley and Sons. New York. Loria, R., S. Galaini, and D. W. Roberts. 1983. Survival of inoculum of the entomopathogenic fun- gus Beauveria bassianan as influenced by fungi- cides. Environ. Entomol. 12:1724-1726. Tedders, W. L. 1981. In vitro inhibition of the entomopathogenic fiingi Beauveria bassiana and Metarhizium anisopliae by six fungicides used in pecan culture. Environ. Entomol. 10:346-349. Wisniewska, J., Y. Yang and R. Prokopy. 1993. Spiders in second-level and first-level apple IPM blocks. Fruit Notes 58(l):20-23. «f« •!# %i« %t# «% v|« rj« #1% #j% vj« New Publication Available In June, 1993 the Sixth International Controlled Atmosphere Research Conference was held at Cornell University, Ithaca, New York. Presenta- tions at this three-day conference covered recent developments in use of modified (MA) and controlled (CA) atmospheres during storage and shipment of fruits, vegetables, and flowers. Proceedings of this conference are now avail- able. They are divided into two volumes, totaling nearly 900 pages. The first volume includes bio- chemical changes that occur during MA and CA, use of MA and CA during transport, recent engineering and equipment developments, and new information on disease and insect control during MA and CA. The second volume focuses on current research on CA storage of specific fruits, vegetables, and flowers. It concludes with three summary sections that present precise, current recommendations for MA and CA conditions for (1) vegetables, (2) apples, pears, and noshi (Asian pears), and (3) other fruits. These Proceedings are available for $85.00 from the Northeast Regional Agricultural Engineering Service, Cooperative Extension, 152 Riley-Robb Hall, Ithaca, NY 14853-5701. They are of great value to persons with interest in the application of MA and CA to storage and handling of horticultural crops. •^ •^ mlm ^f« ttl» rj% ry» rj% »^ rj» 12 Fruit Notes, Winter, 1994 Second-level Integrated Pest Management, 1991 to 1993: Diseases Daniel R. Cooley and Ryan Elliott Department of Plant Pathology, University of Massachusetts Jennifer Mason and Starker Wright Department of Entomology, University of Massachusetts Wesley R. Autio Department of Plant & Soil Sciences, University of Massachusetts Over the past three seasons, we have been at- tempting to develop disease-management strategies for apple which will both optimize fungicide use against diseases and integrate pest management across disciplines. The approach relies heavily on monitoring pathogen development for two key apple diseases, using cultural approaches to manage these diseases, and using fungicides which will have the least non-target efiFects. It is obvious that manage- ment of diseases in apples without fungicides is not possible, but we feel that it is possible to improve the efficiency of summer fungicide use by developing a better understanding of and appropriate monitoring techniques for summer disease pathogens, particu- Table 1. Fungicide use (dosage equivalents) in 1991 throu gh 1993. Year Treatm.ent Total Primary S ammer 1991 Test 5.9 4.8 1.1 Check 6.8 5.0 1.8 1992 Test 7.5 4.3 3.2 Check 8.5 4.5 4.1 1993 Test 6.8 5.3 1.5 Check 6.6 4.5 2.2 All Test 6.7 4.8 1.9 Check 7.3 4.7 2.7 1 larly the flyspeck fungus, and such efficiencies, combined with second-level arthropod management methods (e.g., Christie et al., 1992) may reduce the impact that pesticides have on mites and other non- target arthropods (Wisniewska et al., 1993). This article summarizes the results of the program in commercial blocks consisting of scab-susceptible cultivars. Other aspects of the research, dealing with summer pruning for disease management, fly- speck epidemiology, and the effects of the second- level IPM approach in blocks of scab-resistant apples, are reported separately. Early Season Management For purposes of disease management, the apple production season can be divided into two parts. These parts coincide closely with the two parts of the season used in second-level arthropod management. For diseases, early season management focuses on apple scab. We have used a delayed sterol inhibitor program (Cooley and Spitko, 1992) enhanced by measurement of potential as- cospore dose (PAD). For the purposes of second-level IPM, we have used a threshold of 500 ascospores per square meter (Dr. William McHardy, pers. comm.). PAD data were not available for 199 1, because funding was not available in the fall of 1990 when such assessments would have been done. Summer Management After primary scab season, which usu- ally ends by mid-June, the main diseases concern in apples are the summer diseases, typically sooty blotch and flyspeck. At the Fruit Notes, Winter, 1994 13 Table 2 . Potential ascospore dose (PAD) and scab incidence (%) by block in second-level IPM blocks in 1992 and 1993. Year ] Jlock number 1 2 3 4 5 6 7 8 9 10 11 12 PAD 1992 2041 37 2578 300 368 19 11 21 183 166 10 0 1993 6131 14338 2765 1864 1537 2992 30 12 5333 0 0 0 Scab 1992 1.0 0.5 0.5 1.5 0.0 1.0 0.0 0.0 2.0 0.8 0.0 0.5 1993 0.3 0.1 0.0 0.0 0.0 0.0 0.0 0.0 0.3 0.3 0.0 0.0 1 beginning of this project, we had limited data sug- gesting that summer pnmingcould reduce or elimi- nate the need for fungicides in the summer. We have described the results of this work elsewhere (Cooley et al., 1992). We have concluded that summer pruning reduces flyspeck and sooty blotch on trees with dense canopies, but additional measures are necessary to reduce levels below economic thresh- olds. In 1993, we focused summer fungicide applica- tions on primary inoculum for flyspeck, which was released during June and early July. Our program recommended no fungicides after June in second- level IPM blocks. Results gram has received wide-spread adoption in all or- chards, which often use first level IPM. This being so, we would expect few differences between checks and second-level blocks in terms of primary season fungicides. Second, in 1993, high levels of inoculum in many second-level blocks led to recommendations for an extra fimgicide application near the half-inch green stage, and more frequent use of scab fungi- cides in general. Table 2 shows the increase in PAD from 1992 to 1993. Two orchards exceeded the PAD threshold in 1992, and seven exceeded it in 1993. There was no From the disease perspec- tive, the terms "full" and "transi- tional" second-level blocks re- ferred to in other articles was of minor importance, and the data from both are combined here. During the early season, the fungicide use in all blocks gener- ally was the same (Table 1). In 1991 and 1992, similar fungicide use occurred in second-level blocks as in conventionally man- aged (check) blocks in the pri- mary season. In 1993, some- what more fungicide was used in primary season in the second- level blocks. There are two fac- tors which contributed to this trend. First, the delayed SI pro- Table 3. Disease incidence (%) in 1991 through 1993. Sooty Blossom Year Treatment Scab Flyspeck blotch end rot 1991 Test 0.3 4.3 0.3 0.0 Check 0.7 3.6 0.8 0.3 1992 Test 1.2 4.0 0.1 0.1 Check 0.6 0.8 0.0 0.1 1993 Test 0.2 6.7 0.1 0.0 Check 0.1 4.1 0.1 0.1 All Test 0.6 5.0 0.2 0.0 Check 0.5 2.8 0.3 0.2 1 14 FruH Notes, Winter, 1994 Table 4. Flyspeck incidence (%) in second-level IPM block 3 in early and late season harvests in 1991 through 1993. Year Treatment Before 9/15 After 9/15 1991 Test 1.5 22.3 Check 1.5 18.8 1992 Test 1.3 8.9 Check 1.3 0.0 1993 Test 0.3 7.9 Check 0.2 5.0 All Test 1.0 13.0 Check 1.0 7.9 correlation, however, between PAD and scab inci- dence in the blocks. Also, there was no correlation between scab on fruit in 1992 and PAD in 1993, indicating the danger of trying to use fruit scab incidence to predict scab inoculum in the orchard. Summer fimgicide use was higher in the check blocks than in the test blocks (Table 1), with check blocks receiving about 0.8 DE more than the test blocks. Flyspeck, however, was nearly twice as great in the test blocks compared to check blocks, though sooty blotch incidence was similar in both block types (Table 3). There was no correlation between the DEs of summer fungicide and flyspeck. The time of harvest was critical to flyspeck incidence (Table 4). Fruit harvested after September 15 were much more likely to have flyspeck than those harvested before that date. In fact, fruit harvested before September 15 (largely Mcintosh) had virtually the same fly- speck incidence in either check or test blocks. In fruit harvested later (Delicious, Cortland, and Golden Delicious), the incidence of flyspeck was higher in test blocks than in checks, but the inci- dence in either block far exceeded that in the early harvest. From these results, two points stand out. First, our major cultivar, Mcintosh, may get only marginal benefit from summer fungicide sprays. Second, minimal fungicide applications will control sooty blotch. Fungicides present a particularly difficult prob- lem to second-level IPM in apples. The nature of scab, and its potential for severe damage, limit options for further early season fungicide reduc- tions; however, the potential for reducing summer fungicides remains good. We will need to examine the role that alternative hosts,such as brambles and roses, play in providing inoculum for summer dis- eases. Removing these hosts may make flyspeck management much easier. Relatively little fungi- cide is needed to control sooty blotch under our conditions. It may be possible to spray late-season cultivars selectively. Alternatively, if early fungi- cide applications can be used to delay the epidemic, even later season cultivars may be harvested before flyspeck develops. Certainly, weather will also guide fungicide applications in summer. There are many unanswered questions, but the prospect for at least reducing, and possibly eliminating, summer fungi- cides in Massachusetts appears good. References Christie, M., R. J. Prokopy, K Leahy, J. Mason, A. Pelosi, and K. White. 1993. Apple integrated pest management in 1992: Insects and mites in second- level orchard blocks. Fruit Notes 58(1):24-31. Cooley, D. R., W. R. Autio, and J. W. Gamble. 1992. Second-level apple integrated pest management: The effects of summer pruning and a single fungi- cide application on flyspeck and sooty blotch. Fruit Notes 57(1):16-17. Cooley, D. R. and R. S. Spitko. 1992. Using sterol inhibitors. American Fruit Grower 112(l):30-32. Wisniewska, J., Y. Yang, and R. Prokopy. 1993. Spiders in second-level and first-level apple IPM blocks. Fruit Notes 58il):20-23. %f» VU fcA* %V ^if 0^ ^^ rj^ ey* ^V* Fruit Notes, Winter, 1994 15 Tax Pointers for Farmers in 1993 P. Geoffrey Allen Department of Resource Economics, University of Massachusetts Tax advice given below is intended as general advice and is believed to be correct. It does not substitute for a detailed review of the circumstances of an individual taxpayer by a professional tax practitioner. The Revenue Reconciliation Act of 1993 (1993 RRA), enacted on August 10, 1993 contains a large number of changes to the tax laws. One complication is that some items are retroactive to 1992, some to the beginning of 1993, and some only take effect in 1994. To take advantage of the retroactive changes for 1992, you must submit an amended return (Form 1040X). General Features The most publicized aspect of the 1993 RRA is that more of the tax burden will be carried by higher income taxpayers. For example, the new 36% rate applies to married taxpayers filing jointly who have taxable income over $140,000 in 1993. They, as well as all other filers, would also pay a 39.6% rate on taxable income over $250,000. For estates and trusts the new rates affect taxable income over $5,000 and $7,500, respectively, effective January 1, 1993. Some changes affect all income levels. For example, busi- ness meals and entertainment expenses that were 80% deductible will only be 50% deductible, effective January 1, 1994. Some expiring laws are reinstated. For example, for estate and gift taxes, the 1993 RRA reinstates expiring law so that the top rates and the $600,000 exemption remain the same. Health Insurance If you were a self-employed person in 1992 (or an S-corporation shareholder) who deducted (on line 26 of your 1992 Form 1040) 25% of half of your health insurance premium you may now take 25% of all of your 1992 premium. The 1993 RRA reinstated the deduction retroactive to July 1, 1992. You may file for a refund on Form 1040X. The only exception is if your total medical expenses exceeded the 7.5% floor in your 1992 tax year and you already claimed the rest of the premium as medical expense on your 1992 Schedule A. Example: Bill is self-employed. Bill and Jane file jointly, with 1992 taxable income of $21,400 and family health insurance pre- miums of $3000. They deducted $375 (^2 of 25% of $3000) in 1992. They may now file Form 1040X and deduct a further $375. In 1993, note that the eligibility for the 25% deduc- tion for the health insurance premium is made on a monthly basis. Also, unless the law is further ex- tended, the deduction will expire on December 31, 1993. Example: If Jane had worked from Novem- ber 1, 1992 until March 31, 1993 for an employer who provided subsidized health insurance for her and her family, none of the $3000 premium paid in 1992 would have been deductible on Form 1040. If the same premium was paid in 1993 then the amount allocated to the period January 1 to March 31 is ineligible for deduction on Hne 26 of Form 1040. The amount deductible is $562.50 (3/4 of 25% of $3000). Charitable Contributions Did you make charitable contributions of appre- ciated property in 1992 or 1993? Taxpayers subject to alternative minimum tax (AMT) may get some relief. Appreciated property is property that has a fair market value that exceeds its basis (which is usually your cost). Under the 1993 RRA, the appre- ciated amount (the difference between fair market value and adjusted basis) of property (real, tangible, and intangible) donated to a charity is no longer a tax preference item included in computing AMT income. The property must be used for the donee's tax- exempt purpose. The benefit does not apply to dona- tions of inventory, other ordinary income property and short-term capital gain property. Different kinds of property have different effec- 16 Fru'n Notes, Winter, 1994 tive dates. For contributions of tangible personal property this potential tax saving is retroactive to July 1, 1992 (and therefore continues prior law). Example: Earl donated a 10-year old trac- tor on August 1, 1992 to a charity that ships them to needy fanners overseas. The fair market value was $3,000 and his adjusted basis in the tractor (its cost less deprecia- tion) was $2,000. Earl paid AMT in 1992. He entered $1000 on line 6a of Form 6251. If he still has some AMT liability after the adjust- ment he will save $240 (The AMT rate in 1992 of 24% on $1000). Earl can now file an amended return (Form 1040X) for 1992 claiming the $240 refund. From January 1, 1993, the appreciated amount of donated real and intangible property will not be subject to AMT either. Example: Arthur gave the development rights on a piece of land to an organization whose charitable purpose was to preserve land from development. The rights have a fair market value of $2000. Arthur claims $2000 of charitable deductions on Schedule A (provided his adjusted gross income is sufficient to prevent the percentage limita- tions on charitable deductions coming into effect). He reduces his basis in the land by $2000. There is no AMT tax preference item. Effective January 1, 1994, single charitable do- nations of $250 or more may be deducted (on Sched- ule A) only if the charity provides you with written substantiation, including a good-faith estimate of the value of any good or service that you provided. If you donated money, you may not rely solely on a cancelled check as substantiation. Separate pay- ments to the same charity (e.g., by withholding from wages) will be treated as separate contributions, even if they aggregate to more than $250. Section 179 Expensing The limit on election to expense certain tangible property (Section 179 expensing) is raised from $10,000 to $17,500 for tax years beginning after December 31, 1992. All other provisions remain the same, including reductions in the limit for purchases over $200,000 in any one year and carryover rules. However, the IRS has issued final regulations (T.D. 8455, effective date January 25, 1993) that provide clarification for some of the provisions. The main issue appears to be the need for, or at least desirabil- ity of, precise record keeping. If you have to carryover some Section 179 expense deduction, you must select the property or properties to which the carryover is allocated. The selection must be re- corded in the year in which the properties are placed in service. If you fail to make and record the selec- tion, the IRS will assume the carryover is appor- tioned according to cost. Example: In 1993, Joe purchased a tractor for $20,000 and a baler for $10,000. He elected to deduct $17,500 ($12,500 on the tractor, $5,000 on the baler) but his taxable income was only $7,500 so he carried over $10,000. He recorded the carryover as $5,000 against the tractor and $5,000 against the baler. Had he not done so, the IRS would have assumed two-thirds ($6,667) for the tractor and one-third ($3,333) for the baler. When only part of the carryover is used in a subse- quent year, you must first use up the oldest carryover, but within the year, you may choose. Example: If Joe purchases another $10,000 machine in 1994 and elects to ex- pense the entire $10,000, he can only use $7,500 of carryover before reaching the an- nual limit (of $17,500). Assuming his tax- able income in 1994 is at least $17,500, he might choose to take the baler carryover first ($5,000) and part of the tractor carryover, leaving $2,500 carryover on the tractor to go forward. There is no limit on how long Section 179 deductions can be carried forward. However, if a property is sold, exchanged, or given away, unused section 179 carryover must be dealt with. Example: (no gain or loss) Joe gives his baler to a relative in 1994. He took half-year depreciation in 1993 of $357 (1/2 of 1/7 of $5,000, assuming MACRS straight line de- preciation) and $357 in 1994. His adjusted basis for the baler at time of transfer is $4,286 ($5,000 - $357 - $357). He must increase the basis at the time of transfer by the amount of Section 179 carryover ($5,000) and reduce his Section 179 carryover by the same amount. The recipi- ent has an initial basis of $9,286 ($5,000 + $4,286). Example: (gain on sale) Joe sells his baler Fruit Notes, Winter, 1994 17 in 1994 for $9,500. He has a gain on the sale of $214 ($9,500 - $9,286). His depreciation and Section 179 deduction is $714 (he actu- ally took no Section 179 deduction on the baler in 1993). The amount to be recaptured on Form 4797 is the lesser ($214). Joe's Section 179 carryover is reduced by $5,000. Purchase and Sale of Livestock You purchased, transported and vaccinated some young cattle in 1993, intending to sell them in 1994. As a farmer using the cash basis method of accounting, how do you report this? The purchase and transportation are your basis in the cattle, included in your 1994 Schedule F, line 2. Vaccination is a current expense, line 33 of your 1993 Schedule F. Do you pay self-employment tax on gain or loss from the sale of breeding livestock? Yes, if it is held for sale in the ordinary course of business. Report on Schedule F. No, otherwise. Report in the appropriate part of Form 4797, as follows: Held less than 12 months (24 months for cattle and horses). Also poultry (unless held for sale in the ordinary course of business) Part II of Form 4797 Held more than 12 months (24 months for cattle and horses) and (1) purchased and sold at a loss or raised (gain or loss) Part I of Form 4797 or (2) purchased and sold for a gain (depreciation recapture) Part III of Form 4797 Example: Robert breeds replacement heif- ers for his dairy herd. When they are two years old, he selects the number required to maintain his herd and sells the rest. Even if some heifers are sold as breeding livestock, all sales are reported on Schedule F. Example: Dana breeds replacement heif- ers. All are added to the dairy herd unless they fail to breed. Those that turn out to be poor milkers are sold. Dana can report all sales on Form 4797, since her intent was to keep them all for breeding. Investment Interest Previously, individual taxpayers could deduct investment interest (interest on indebtedness allocable to property held for investment) only to the extent of their net investmentincome for that year. Net investment income generally excluded capital gains, and the disallowed interest expense had to be carried forward. Now there is a faster way to use up the interest carry-forward. Effective January 1, 1993, a taxpayer may elect to include any amount of the net capital gain from Schedule D in investment income. The capital gain transferred to Form 1040 must be reduced by the same amount. For a taxpayer in the 28% marginal tax bracket, the only effect is to use up the investment interest carryover, reducing total taxes in the present year rather than some future year. Higher income taxpayers should take care to elect to include only as much gain as will offset the interest carried forward. Any larger amount would be subject to tax at rates of 31%, 36%, or 39.6%. Example: Fred and Emily have $10,000 unused investment interest expense from 1992 and $15,000 net long-term capital gains in 1993. On their 1993 return, they elect to treat $ 10,000 of the gain as ordinary income. They pay tax (maximum rate 28%) on $5,000 long-term capital gain. They de- duct the $10,000 investment interest ex- pense on Schedule A. The following sections are taken from material published by Larry C. Jenkins, Department of Agricultural Economics and Rural Sociology, Pennsylvania State University. Earned Income Tax Credit (EITC) The new rules for earned income credit involve only a basic credit; the extra credits for a child under one year of age and for health insurance coverage were eliminated in the 1993 legislation. Comment: The new law results in a decrease in benefits in 1994, compared to benefits from the earned income credit in 1992, for a family with one child under one year of age, and qualifying for the supplemental health insurance credit. For such a family, based on earned income of $7,750, the EITC in 1992 would have been $2,151. Under the new rules, the credit is $2,038. In a departure from previous earned income credit rules, the new law extends the credit to taxpayers with no qualifying children. The credit is available to taxpayers over age 25 and below age 65. For these taxpayers, the EITC is 7.65 percent of the first $4,000 of earned income (for a maximum credit of $306 in 1994). The maximum credit is reduced by 7.65 percent of earned income (or adjusted gross income, if greater) above $5,000. In 1994, the credit is completely phased out for taxpayers with earned 18 Fruit Notes, Winter, 1994 income (or adjusted gross income, if greater) over $9,000. This credit is not available on an advance payment basis. Tax on Social Security Benefits Prior to the new law, if the sum of modified taxable income plus one-half of Social Security ben- efits (the sum of the two is called provisional income) exceeded $25,000 for an unmarried taxpayer or $32,000 for a married couple filing a joint return, up to 50% of Social Security benefits were subject to income tax. Under the new law, taxpayers will be subject to tax on up to 85% of their Social Security benefits, effective for tax years beginning after 1993. The existing rule (as explained in the above paragraph) will continue to apply to taxpayers whose provi- sional income is less that $34,000 for unmarried taxpayers and $44,000 for married couples filing a joint return. If provisional income exceeds these levels, gross income will include the lesser of: (a) 85% of the taxpayer's Social Security benefit, or (b) The sum of: (1) The smaller of : (i) the amount included under pre-'93 law, or (ii) $3,500 for unmarried taxpayers or $4,000 for a married couple filing a join return plus (2) 85% of provisional income over the new $34,000 1 $44,000 threshold. For married taxpayers filing separate returns, gross income will include the lesser of: (a) 85% of the taxpayer's Social Security benefit, or (b) 85% of the taxpayer's provisional income. For purposes of the above calculation, a taxpayer's provisional income (modified adjusted gross income plus one-half of the taxpayer's Social Security ben- efit) is calculated in the same manner as under pre- 93 law. Without implicating them in any way, I thank Robert Christensen, Department of Resource Economics and Michael Whiteman, Department of Accounting and Information Systems, School of Management, both from the University of Massachusetts, for their helpful comments. %£• ttl^ ^t« «% %i« ej* •(J^ *T^ •(f* •!»• Fruh Notes, Winter, 1994 19 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 01002 <., -0 SERIAL SECTION UNIV. OF MASSACHUSETTS LIBRARY AMHERST, MA 01003 Account No. 3-20685 UM/Morr Per SB 354 F68 ruit Notes ISSN0427-6906 iricpared by the Department of Plant & Soil Sciences. University of Massachusetts Cooperative Ebctenslon System, United States Department of Agriculture, and Massachusetts Counties Cooperating. Editors: Wesley R. Autio and Williaxn J. Braxnlage Volume 59, Number 2 SPRING ISSUE. 1994 Table of Contents Pinal Report on the 1980 NC-140 Apple Rootstock Planting: Starkspur Supreme Delicious on Eight Rootstocks Buildup of Bugs Causes Decline in EfTectiveness of Sticky for Capturing Apple Maggot Flies on Red Sphere Traps What Species of Predaceous Mites Exist in Massachusetts Commercial Apple Orchards? How Beneficial are Pre-bloom Oil Sprays Against European Red Mites? North American Strawberry Growers Meet in Ontario Promising New Apple Cultivars for 1994 Suggestions for the Use of the New Postbloom Thinner Accel* J Fruit Notes Publication Information: Fruit Notes (ISSN 0427-6906) is published the first day of January, April, July, and October by the Department of Plant & Soil Sciences, University of Massachusetts. The costs of subscriptions to Fruit Notes are $7.00 for United States addresses and $9.00 for foreign addresses. Each one- year subscription begins January 1 and ends December 31. Some back issues are available for $2.00 (United States ad- dresses) and $2.50 (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 COOPERATIVE EXTENSION SYSTEM POLICY: 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 the University of Massachusetts Cooperative Extension System, Robert G. Helgesen, Director, in furtherance of the acts of May 8 and June 30, 1914. The University of Massachusetts Cooperative Extension System offers equal opportunity in programs and employment Final Report on the 1980 NC-140 Apple Rootstock Planting : Starkspur Supreme Delicious on Eight Rootstocks Wesley R. Autio and William J. Lord Department of Plant & Soil Sciences^ University of Massachusetts Finding the apple rootstock that adapts the best to various conditions, is resistant to pests, gives an appropriate degree of dwarfing, gives the greatest precocity, results in the highest jdelds, and gives the best £ruit quality has been a research and breeding goal for nearly a cen- tury. Growers in New England, however, did not begin to look at clonally propagated rootstocks seriously until the ISeCs, when the use of semidwarfing rootstocks, such as M.7, began in earnest. During the late 1980's, seri- ous planting of fully dwarfing rootstocks began, Tree spread (ft) "T 2 I 4 I 6 8 10 12 "T" 14 16 14 12 10 8 6 4 - 2 - 0 Figure 1. Relative canopy dimensions of Starkspur Supreme Delicious trees on eight rootstocks at the end of the forteenth growing season. 0) 16 M.7 EMLA OAR1 M.26 EMLA 0.3 MAC.9 M.9 EMLA M.9 M.27 EMLA Fru'n Notes, Spring, 1994 including M.9, Mark, and M.26. Now, more than fifty percent of all trees being planted in New England are on fully dwarf rootstocks. This trend has been seen throughout the apple growing regions of North America. Throughout this period when clonal rootstock material be- came more important to the apple industry, knowledge of rootstock characteristics became essential. To help evaluate both new and old clonal rootstock material, the NC-140 Technical Re- search Committee was established. A group of scientists fi"om various universities across the country formed this committee in association with the U. S. Department of Agriculture. Indi- viduals fi-om five Canadian provinces cooper- ated in the formation and participate in the execution of the responsibilities of this commit- tee. One of the first major plantings by the committee included Starkspur Supreme DeU- cious on 0.3 (Ottawa 3), M.7 EMLA (the EMLA designation suggesting that the latent viruses were removed fi-om the mother plant), M.9 EMLA, M.26 EMLA, M.27 EMLA, M.9, MAC.9 (later, a virus indexed version was named Mark), and OARl (Oregon Apple Rootstock 1). These combinations were included in random- ized complete blocks, each with five replications at 27 sites in the U. S. and southern Canada. Most sites removed their plantings after the tenth growing season, i.e. after harvest in 1989. In this article, we report on the Massachusetts portion of this trial, including four years of data beyond the termination of the joint trial. Materials & Methods Trees were planted at a spacing of 11.5 x 18 feet in the spring of 1980 at the University of Massachusetts Horticvdtural Research Center in Belchertown. Trees were trained as central leaders, using minimal pruning. Some contain- ment pruning was required when trees reached maturity. Stakes were added for support only when trees leemed past 45 degrees. Standard pest and fertility management practices were used. Tree size and yield were measured annu- ally; however, trees were not allowed to finiit until the fourth growing season (1983). Results & Discussion Table 1 gives the trunk cross-sectional area, height, and spread of these trees after the four- teenth growing season (1993), and Figure 1 Table 1. Size of Starkspur Supreme Delicious trees on eight rootstocks after theii • fourteenth growing season. Also presented are estimated tree density and spacing.' Trunk cross- Estimated sectional density Estimated Height Spread area (trees per spacing Rootstock (ft) (ft) (in^) acre) (ft) 0.3 10.1 b 11.1 be 9.8 c 256 10x17 M.7 EMLA 14.9 a 14.7 a 21.3 a 132 15x22 M.9 EMLA 8.2 c 9.2 cd 5.7 de 363 8x15 M.26 EMLA 10.6 b 12.6 ab 14.0 b 191 12x19 M.27 EMLA 5.6 d 5.4 e L9 f 726 5x12 M.9 5.7 d 7.2 de 3.1 ef 496 6.5x13.5 MAC.9 7.5 c 8.4 d 8.4 cd 401 7.5x14.5 OARl 11.4 b 13.4 a 13.6 b 191 12x19 ' Within column , means not followe d by the same letter are sign ificantly different at odds of | 19 to 1. Fruit Notes, Spring, 1994 25 @0.3 ^ M.7 EMLA ?20 — tI^ M.9 EMLA * M.26 EMLA y (0 (0 M M.27 EMLA ♦ m.9 y^ cross-sectional O Ol - AmAC.9 'S'OARI / / n_^--''^1 — ^X\x^^ Trunk Ul .<:^^^r:^^ nE ^^2=;^ 3 i&-^ "X— 7* — i^r~ h ^^— -M — ^ ^ =^SP=i a^ — fjfc] ]g S B- 1^ '^ 1980 1982 1984 1986 1988 1990 1992 Figure 2. Trvink cross-sectional area of Starkspur Supreme Delicious trees on eight rootstocks from the end of the first growing season through the end of the fourteenth. depicts the relative canopy dimensions of these trees. M.7 EMLA produced the largest trees. Trees on M.26 EMLA and OARl were the next smaller in terms of trunk cross-sectional area, followed by trees on 0.3 and MAC. 9. Trees on M.9 EMLA were smaller still, and the smallest trees in the planting were on M.9 and M.27 EMLA. Clearly, M.9 and M.27 EMLA were not vigorous enough rootstocks for Starkspur Su- preme Delicious, since trees did not reach six feet in height. With a canopy this smgdl, ad- equate yields are not possible. Figure 2 plots the trunk cross-sectional area of these trees from 1980 through 1993, and shows that for most trees, there was a relatively constant rate of growth throughout the experi- ment. MAC. 9, however, resulted in a relatively fast growth rate for the first five growing sea- sons, but for the next nine seasons, had a signifi- cantly slower growth rate. In other words, the initial growth rate of trees on MAC. 9 was nearly as great as that of trees on M.7 EMLA, but later on, the growth rate was only similar to that of trees on M.9 EMLA. This reduction in growth rate corresponded to the onset of heavy produc- tion from trees on MAC. 9. Table 1 also gives estimates of spacing and density for these combinations. For most com- binations, the estimated in-row spacing is ap- proximately ninety percent of the tree spread; however, this assessment was not adequate for trees that had filled their allotted space and had required containment pruning. Specifically, the estimated spacing of trees on M.7 EMLA fruit Notes, Spring, 1994 8 ®0.3 ^5^ M.7 EMLA )l^ M.9 EMLA 6 — * M.26 EMLA S M.27 EMLA 4- M.9 A MAC.9 / A \ / \ Q> 0) 'S'OARI / Aa\ \ / ^^ 1 7 14 Q. / /K\ \ ^^t^^^K r-^ syosure in commercial orchard trees increased fi-om 0 to 28 days, the proportion of released flies caught decreased significantly firom 49% to 13% (Figure lA). There was no significant effect of time of sphere exposure in commercial orchards on propensity of flies to alight on spheres (Figure IB). Of the ahghting flies, only 3% escaped from spheres kept continuously in the closet (never emplaced in commercial orchards) compared with 38, 43, and 73% escapees fi-om spheres exposed in or- chards for 7, 14, and 28 days, respectively (Figure IC). As days of exposure in orchard trees increased, the percentage of sphere sur- face area occupied by captured insects increased significantly from 0 to 16, 24, and 38% afler 7, 14, and 28 days of exposure, respectively (Fig- ure ID). We conclude from this test that sticky red spheres become progressively less effective in capturing alighting apple maggot flies as the number of insects caught on the spheres in- creases over time. It appears that under com- mercial orchard conditions, odor-baited sticky spheres lose nearly half of their maggot fly capturing power after two weeks without clean- ing. After four weeks without cleaning, they lose about three-fourths of their maggot fly capturing power. We therefore recommend 8 Fru'n Nates, Spring, 1994 7 14 21 Days of Exposura In Field 7 14 21 Day* of Expoaura In Flald 7 14 21 Days of Exposure In Field < 9 U 3 m 8 o 7 U 21 Days of Exposure In Field Figure 1. Effects of duration of exposure to weather in a commercial orchard on effectiveness of sticky spheres in capturing alighting apple maggot flies: (A) proportion of released flies captured, (B) mean number of flies observed alighting, (C) proportion of alighting flies that escaped, and (D) mean % of surface area occupied by previously captured insects. cleaning sticky spheres of insects and debris every two weeks to retain reasonable fly captur- ing power for either control or monitoring pur- poses. If spheres are not cleaned, control may fail or thresholds for pesticide treatment would have to be adjusted. Acknowledgments The study was supported by grants from the USDA Sustainable Agricultural Research and Education Program and the USDA Northeast Regional EPM Program. %£• «1^ %f# %f^ %£• r|% #5% #5% rj* ^^ Fruit Notes, Spring, 1994 What Species of Predaceous Mites Exist in IVIassaciiusetts Commercial Apple Orchards? Xingping Hu and Ronald Prokopy Department of Entomology, University of Massachusetts Under favorable orchard pest management conditions, predaceous mites can provide a mod- erate to high level of control of pest mites such as European red mites and two-spotted spider mites. Reports from New York State clearly suggest considerable variation among different species of predaceous mites in ability to control pest mites. For example, the predator Typhlodromus pyri is better able to survive harsh winter temperatures and to provide sea- son-long control of low to moderate pest mite numbers than is the predator Amblyseius fallacis. In turn, the latter is better able thanT. pyri to control rapidly building numbers of pest mites in the summer. A third predator, ZeteeZZta mali, appears rather similar in biology to T. pyri, but rather Uttle is known about its ability to suppress pest mites. In 1977, we conducted a survey of 21 com- mercial apple orchards scattered throughout Massachusetts to determine the proportion of sampled orchards that contained each of these three species of preda- ceous mites. We surveyed again in 1993 in 12 dif- ferent commercial or- chards scattered across the state. Samples con- sistedof 100 leaves taken weekly in each orchard from April through June and 50 leaves taken bi- weekly from July through September. Leaves were placed in a cooler imme- diately after picking and returned to the labora- tory for predator identification. Identification involved removing the predators fi'om leaves, mounting them on microscope shdes, and using taxonomic keys to distinguish between some species on the basis of the number and location of tiny hairs on the body surface. There was remarkably little change over 1 6 years in species composition of predators (Table 1). In both surveys, A. fallacis was present in 81 to 92% of sampled orchards, Z. mali in 30 to 33%, and T. pyri in 0 to 8%. The similarity in data patterns across years is even more re- markable given the fact that all orchards sampled in 1977 were different from the ones sampled in 1993. We conclude that if we want to achieve biocontrol of pest mites with existing preda- ceous mites in Massachusetts orchards , we ought to pay particular attention to A. fallacis and ways of encouraging its buildup. T. pyri, which Table 1. Percentage of Massachusetts commercial apple orchards sampled in 1977 and 1993 containing predaceous mites. Year Number of orchards sampled Species of predator Amblyseuis Typhlodromus Zetzellia fallacis pyri mali 1977 1993 21 12 81 92 0 8 30 33 10 Fruit Notes, Spring, 1994 appears identical to A. fallacis even under a powerful hand lens, can not be counted on at this point to provide mite biocontrol in any but a small minority of orchards. In an attempt to establish T. pyri in additional orchards, we released hundreds of nymphs and adults (ob- tained from Geneva, New York) in 1992 and 1993 in two orchards. Unfortunately, there is no evidence to date that these releases have resulted in estabUshment of T. pyri. •Sm m^M •^ •9^ %% «^ r{% r{% r{% r{% How Beneficial Are Pre-bloom Oii Sprays Against European Red IVIites? Ronald Prokopy, Jennifer Mason, and Xingping Hu Department of Entomology, University of Massachusetts For decades, most Massachusetts apple growers have been applying pre-bloom oil sprays against overwintering eggs of European red mites. Just how beneficial to spring and sum- mer mite control are these sprays? Further- more, does the reduction in number of hatching mites after spraying oil cause our principal mite predator, Amblyseuis fallacis, to leave apple trees in search of more prey elsewhere? To answer these questions, in 1993, we cooperated with commercial growers in con- ducting a test in two-acre blocks of apple trees in each of nine orchards. Half of each block re- ceived no oil or other miticide through May. The other half received two applications of oil: one during half-inch green to tight cluster and the other during tight cluster to early pink. Each application was at a rate of about one gallon of oil to 100 gallons of water, with 100 to 300 gallons of water used per acre. Duiing the third week of May, following egg hatch, 200 leaves per untreated and treated block were examined for presence of motile red mites and A. fallacis. In the untreated blocks, an average of 35% of sampled leaves had motile red mites com- pared with an average of only 5% in the oil- treated blocks (an 86% reduction in mite num- bers). Nearly all untreated blocks required repeat applications of miticide beginning after petal fall. None of the treated blocks required miticide apphcation until July or August. In two sampled blocks that received only a single pre-bloom application of oil, numbers of motile mites were reduced 45% compared with un- treated blocks. No A. fallacis were found on any of the blocks in leaf samples taken before oil applica- tion began in April or during May, although by August, all of the blocks had at least some A. fallacis. Evidently, cold winter temperatures reduced populations of A. fallacis to such low levels that it was inconsequential whether or not red mite prey were low or high in numbers in May. We conclude from these 1993 tests that two pre-bloom applications of oil against red mite eggs pay high dividends in suppressing red mite populations through spring and early summer, and in some years, possibly through the entire growing season. %i« %i# %% %% %% ry» ry% ry» rj% #y* Fruit Notes, Spring, 1994 11 North American Strawberry Growers Meet in Ontario The North American Strawberry Growers Association held its seventeenth annual meet- ing February 13-16, 1994 in Niagara Falls, Ontario. Over three hundred and fifty members firom the United States, Canada, and England gathered to learn the latest information on strawberry production and marketing. Dave Whittamore of Markham, Ontario was elected President and Susan Butler of Germantown, MD was elected Vice President. Two new directors were elected to the Board: John Dzen of S. Windsor, CT and Mike Reilly of Pittsburg, PA. The annual meeting followed a one-day pro- gram emphasizing bramble culture sponsored by the Ontario Berry Growers Association (OBGA). NASGA's opening session was pre- ceded by a delightful wine and cheese reception hosted by OBGA. The evening program was highlighted by Dr. Tim Ball, Winnipeg, Manitoba, who entertained the crowd with his delightful talk "Whatever Happened to Global Warming?", a factual and fictional discussion of long-term environmental changes. NASGA was started by growers in 1977 and is run by growers today with over 400 members. Highly committed to improving strawberry pro- duction through research, more than 25% of membership dues is allocated to research each year. In 1992, the NASGA Research Founda- tion was formed to increase fimding. This year NASGA received 24 proposals requesting more than $95,000 for strawberry research. The Re- search Committee recommended funding 17 projects with a total of $34,000. Approximately 55% of the grants were for plant breeding im- provements and 40% for pest management studies. NASGA publishes the research journal Advances in Strawberry Research. A 10-day tour to study agriculture and small fi-uit growing in Eiux)pe has been arranged by NASGA. The tour will depart August 21, 1994 for stops in England, Holland, Belgium, Ger- many, and Switzerland. Reservations are on a first-come first-serve basis and non-NASGA growers/researchers are invited to participate. For information contact Linda Struye, tele- phone/FAX (414) 921-4784. The next annual meeting is scheduled for February 12-15, 1995 at the Sheraton Plaza Hotel at the Florida Mall in Orlando, Florida. The North American Bramble Growers will meet February 11-12, and immediately follow- ing NASGA, the Fourth National Strawberry Research Conference will be held, which NASGA is pleased to help cosponsor. For more information about NASGA and its publications, write to Bill & Treva Courter, P.O. Box 160, West Paducah, KY 42086, telephone/ FAX (502) 488-2116. %l0 %i^ ml^ %% mj^ rj^ rj% rf» •J^ ^J* 12 Fruit Notes, Spring, 1994 Promising New Apple Cuitivars for 1994 Duane W. Greene and Wesley R. Autio Department of Plant & Soil Sciences, University of Massachusetts Diiring the past three seasons, we have evaluated over 100 new apple cuitivars. Some of these cuitivars are newly named and are available currently, while others are only num- bered selections and are not available widely. Last year we reported on all cuitivars evaluated in 1992 [Fruit Notes 58(2):4-14]. This year we are reporting only on those cxiltivars that ap- pear to have promise in wholesale operations or fit into a special slot in retail sales operations. Fruit evaluation began the first week in July and ended the fourth week in October. Where sufficient fi*uit were available, multiple harvests were made. Fruit were evaluated both objectively and subjectively (similar to the ways reported last year). Ten fruit were harvested fi"om each cultivar one to five times at weekly intervals, and flesh firmness, percent red color (or percent red cheek if the apple was yellow), diameter, and weight were assessed. Fruit also were cut and dipped into iodine solution and starch was evaluated using a generic starch chart developed at Cornell University. The starch chart allowed us to assess taste at times when the fi-uit were ripening, and it also gave us an idea when fruit should be harvested for storage. Fruit were evaluated for visual and sensory characteristics using a specially de- signed sheet with subjective rating scales simi- lar to the one described last year. Mcintosh was evaluated at four different times and included in this report as a commercial cultivar check. The Most Promising New Apple Cuitivars Below are listed what we consider to be the most promising new cuitivars for New England. They appear in alphabetical order. was introduced in 1983. Arlet was an outstand- ing apple again this year even though it has several major faults: surface russetting, preharvest drop, and a greasy feel when fi*uit ripen. Individuals hking a tart apple may select Arlet over Gala, which is harvested in the same season. It is conic, has yellowish white flesh, and a finiity pineapple taste. Firmness is main- tained over a long period of time. If a stop-drop chemical is appUed, drop can be controlled and firaiit will develop a very attractive cardinal red color without losing much firmness. The deep red color more-or-less masks the russet even though as much as 25% of the surface can be russetted. It is one of the best storing apples that was evaluated. Grease that developed on the surface can be washed off easily. Ginger Gold Ginger Gold emerged as the best early yel- low apple and one of the top apples evaluated. It is a large apple that has a very attractive waxy lemon yellow color and no apparent russet. Ginger Gold can be picked over a long period. Fruit had acceptable flavor and good appear- ance on August 24, in late Paulared season. Three weeks later the starch rating was only 3.3, with firmness nearly 20 pounds, and fruit were still crisp. Ginger Grold has a pleasant but weak apple flavor. Fruit were harvested weekly and placed in cold storage at four different times starting on August 24. Two months later fruit fi-om all harvest dates tasted mealy and unap- pealing and firmness had dropped to 13.5 fKJunds. Ginger Gold should not be considered a long storing apple; however, it is an outstanding apple at harvest and afl;er a short period of storage. Arlet Golden Glory This apple originated in Switzerland and This limb sport ofSmoothee produces a very Fruit Notes, Spring, 1994 13 Table 1. Laboratory analy ses and bloom dates of the most promising new a pple cultivars evaluated at the University of Massachusetts Horticultural Research Center in 1993, with Mcintosh shown | as a reference. Best Also Soluble Red harvest evlauated Weight Diameter Firmness solids color Starch Bloom Cultivar date on: (g) (in) (lbs) (%) (%) index* time** Arlct 9/20 9/14,9/28 186 2.92 17.4 13.8 80 6.4 E Ginger Gold 9/7 8/24. 9/2, 9/13 283 3.35 21.0 14.0 30 2.2 M Golden Glory 10/13 10/5, 10/18 244 3.24 16.4 15.5 13 6.3 ML Golden Supreme 10/4 9/20,9/27 265 3.28 16.9 13.9 — 6.0 L Honeycrisp 9/7 9/13, 9/20, 9/27 292 3.47 17.4 14.2 68 4.8 M NY 429 10/13 — 244 3.37 14.0 12.1 88 — — NY 75414-1 10/5 9/20,9/28 194 3.21 13.1 14.3 96 5.5 M Sansa 9/13 8/24, 9/2, 9/7 178 2.94 16.3 14.2 84 6.8 ML Suncrisp 10/18 — 216 3.10 19.3 15.1 40 6.0 ML Mcintosh 9/27 9/7, 9/13. 9/20 202 3.20 13.8 11.6 85 7.0 M * Starch rating: 1-3 = immature, 4-6 = : mature , and 7-8 = overmature. ** Bloom time: E = early, EM = early-middle, ML = middle-late, and L = late. Table 2. Taste and sensory evaluations of th e most promising new apple cultivars evaluated at the University of Massachusetts Horticultural Research Center in 1993, with Mcintosh she wn as a reference.* Best Also harvest evlauated Red Cultivar date on: Attractiveness color Crispness Flavor Overall Arlet 9/20 9/14,9/28 5.5 6.7 5.7 7.2 6.6 Ginger Gold 9/7 8/24. 9/2. 9/13 7.7 — 7.9 6.0 7.6 Golden Glory 10/13 10/5, 10/18 7.1 — 5.3 7.1 7.1 Golden Supreme 10/4 9/20, 9/27 9.0 — 5.7 6.7 7.7 Honeycrisp 9/7 9/13, 9/20, 9/27 4.2 4.2 6.4 6.3 6.3 NY 429 10/13 — 7.8 7.5 — 6.1 6.3 NY75414-1 10/5 9/20. 9/28 7.1 7.1 4.4 6.2 6.7 Sansa 9/13 8/24. 9/2, 9/7 7.3 7.3 7.0 8.9 8.9 Suncrisp 10/18 — 6.7 ~ 7.1 6.9 6.8 Mcintosh 9/27 9/7, 9/13. 9/20 7.2 7.2 6.6 5.8 6.2 * All fruit characteristics were rated on a scale from 1 to 10. Color: 0 = dull and 10 = : bright. Attractiveness, flavor, and overall disirability: 0 = dislike and 10 = like. Crispness: 0 = low and 1 = high. attractive apple and the tree has a somewhat spur-type habit. It produces heavy crops of large attractive apples somewhat regularly, indicating that it may not be as biennial as one would expect. Fruit do russet but they still are very attractive. Although definitely a Golden Delicious type, we would rate this selection higher than either Golden Delicious or Smoothee for appearance, taste, and potential productivity. Golden Supreme This chance seedling was discovered in Idaho. We evaluated it for the first time in 1993. It is truly an outstanding apple. It is a very 14 Fruit Notes, Spring, 1994 attractive apple with a glossy lemon-yellow rus- set-free finish and a pink-red cheek. It ripens about seven to ten days before Golden Delicious, but some uneven ripening may force two har- vests. It shows some tendency to drop prema- txirely. Flavor was fruity, sweet and perfumy, with a taste of Ucorice. The tree is spujr-type and upright, and some reports indicate that it may not be too productive. This apple is unsurpassed for appearance and flavor. Honeycrisp This Minnesota selection is the result of a cross between Honeygold and Macoun. Many Honeycrisp trees will be planted in the next few years because it has outstanding storage poten- tial and fruit following regular air storage have 'explosive crispness'. Fruit harvested on Sep- tember 14 with firmness of 17.8 pounds still had firmness above 17 pounds at the end of January in air storage. Honeycrisp is a very large apple but its not too attractive, because color is slow to develop and is striped rather than blush. Qual- ity at harvest is good but not exceptional, and the longer Honeycrisp stays in storage the bet- ter it looks compared with other cultivars. Honeycrisp fruit from Massachusetts were in- cluded in a replicated taste evaluation at the Mid-Atlantic Fruit Variety Showcase in West Virginia in January. Numerically, Honeycrisp was judged to be the best tasting apple and statistically it was equal to Fuji and Braebum. Over the past four years Honeycrisp on M.26 has been the most productive apple in our culti- var evaluation plots. It produced over 1.5 bush- els per tree in the fourth leaf NY 429 This very large burgundy-red apple is from the New York breeding program. It has very good quahty and the flesh is creamy white. Even when cropped very heavily, fruit wiU size to 3.25 inches or larger. It may be biennial if not thinned. Trees are very productive. NY 429 is already in commercial production in the Hudson Valley of New York and prices of $20 per bushel were reported in 1993 in the Apple Report for the Massachusetts Department of Food and Agriculture. NY 429 will be named soon. NY 75414-1 This cultivar is the best disease-resistant apple from New York. It is medium large, red, and a Macoun look-alike. Scarf skin may be a problem in some areas but in New England it is a plus because it is also a characteristic of Macoun. It is attractive, somewhat tart, and very crisp. Taste is Macoun- and Mclntosh-like. Trees are vigorous and nonspur. Sansa This outstanding apple is the result of a cross between Gala and Akane. It was one of the highest rated apples, regardless of the season of harvest. Fruit were attractive, very crisp, aro- matic, sweet, and the flavor was subtly spicy at first but it soon developed into a fully flavored apple with pineapple, banana, and licorice taste. Sansa did not drop and it could have been harvested over a three-week period (the three weeks prior to Gala). It stored for up to two months. Although it softened, it maintained flavor, unlike Gala which maintains firmness and crispness but loses the essence of the flavor that makes it Gala. Fruit were of medium size. Sansa is the best tasting apple that ripens before Mcintosh. The first commercial plantings wiU go in the ground in 1995. Suncrisp (NJ 55) This cultivar produces medium to large late- season yellow apples. Finish on this apple was not very good but the striped orange-red cheek over lemon-yeUow ground color is distinctive and somewhat attractive. Fruit is conic with a crisp yellow flesh. The acidity is quite high at harvest but the sharpness and tartness mellow in storage. Flavor is excellent. It is a very good apple to help spread out the harvest season and it has good storage potential. Fruit Notes, Spring, 1994 15 Table 3. Laboratory analyses and bloom dates of the most promising new apple cu Itivars with local or niche market potential evaluated at the University of Massachusetts Horticultural Research | Center in 1993. Best Also Soluble Red harvest evlauated Weight Diameter Firmness solids color Starch Bloom Cultivar date on: (g) (in) (lbs) (%) (%) index* time*' ArkCharm 8/12 8/5,8/9 246 3.30 15.9 13.0 77 ML MonArk a/19 8/12 239 3.29 16.3 12.0 71 — M Nittany 10/18 — 154 2.75 19.5 13.8 77 7.1 L Shamrock 9/27 9/13, 9/20, 10/4 179 3.04 17.5 12.7 34 3.9 ML Splendour 10/13 10/18 241 3.24 20.1 13.3 88 2.9 L Williams Pride 8/19 8/12 164 2.95 15.7 11.3 94 — ML * Starch rating: 1-3 = immature, 4-6 = : mature , and 7-8 - overmature. ** Bloom time: E = early, EM = early-middle, ML = middle-late. and L = late. Table 4. Taste and sensory evaluations of the most promising new apple cultivars with local or niche market potential evaluated at the University of Massachusetts Horticultural Research Center in 1993.* Best Also harvest evlauated Red Cultivar date on: Attractiveness color Crispness Flavor Overall ArkCharm 8/12 8/5, 8/9 4.8 4.2 3.8 5.6 5.1 MonArk 8/19 8/12 5.3 5.5 4.7 5.6 5.8 Nittany 10/18 — 6.7 6.7 8.0 6.7 7.0 Shamrock 9/27 9/13, 9/20, 10/4 5.2 — 5.2 6.4 6.2 Splendour 10/13 10/18 7.2 7.1 4.6 6.7 6.8 Williams Pride 8/19 8/12 6.0 7.0 4.0 5.9 6.2 All fruit characteristics were rated on a scale from 1 to 10. Color: 0 = dull and 10 = bright. Attractiveness, flavor, and overall disirability: 0 = dislike and 10 = like. Crispness: 0 = low and 1 = high. Apples Worthy of Limited Planting Some apples may not be recommended for extensive planting but they have some out- standing characteristics that make them appro- priate to plant for niche markets. We feel that the following group of apples are worthy of consideration for limited planting. Akane Akane continues to be a cultivar that we favor. It is extremely attractive and few apples have the flavor and aroma of Akane. It ripens during the first two weeks of September. It develops deep cherry red color before it is ready to harvest, so it fii^quently is harvested imma- ture and tart. When allowed to ripen, it has excellent flavor. It may be a shy bearer. ArkCharm (AA 18) This large blotchy red apple from Arkansas ripens a little before Jerseymac and Paulared. Fruit is tarter than sweet but fruit quality is quite good. Storage life is rather short but it is one of the best apples for the season. 16 Fruit Notes, Spring, 1994 Monarch (AA 44) This cultivar is another blotchy cherry-red apple from Arkansas. Quahty is very good for this season. It has a good perfumy taste but because of extensive preharvest drop, few may reach the proper stage of maturity without the use of a stop-drop treatment. Acidity is quite high. It ripens slightly before Pavdared, but it is superior to Paulared in taste. Nittany Very little is heard about this open polU- nated seedling of York. It is fairly attractive, oblong, and light cherry red. It ripens late, in Rome Beauty season. It has a good sweet-tart flavor that we rated very high. Although some Nittany are grown in Pennsylvania, we believe that we can grow a more attractive and perhaps a better Nittany in southern New England. It is a vigorous tree and fruit suffer from calcium problems. Shamrock This cross between a spur Golden Delicious and a spur Mcintosh is not reported to have high quality, but we feel that it is versatile and a potentially valuable cultivar. It tastes Granny Smith-hke if picked just prior to Mcintosh sea- son. The quality is at least as good as the Granny Smith apples found in the store at this time of year. If allowed to stay on the tree iintil late September or early October it develops a very good Mcintosh taste. We feel that it is the best green apple in the season. The tree is grower-friendly, a semi-spur type, precocious, and it is not biennial. Splendour This late-ripening red apple is from New Zealand. It is attractive and has very good flavor, but the skin is so thin that it cannot withstand the rigors of packing, handling, and long-distance shipping. The tree is a semi-spur and very grower-friendly. It is a parent of the new generation of apples from New Zealand and British Columbia. Williams PHde This disease-resistant apple ripens with Paulared but the quality is superior to Paulared. Fruit are large, red, and somewhat irregular in shape and the skin is not smooth. White lenticels are prominent. Fruit is aro- matic and flavor is mild but fruity and lively. We have several other cultivars under test that we feel have the potential to go all the way to the top, although they are not commercially available yet. The most promising from the list are: BC 8M 15-10, BC 17-30, Fantazja, and NJ90. •S^ %£• %£• %f^ •S^ rj% rj% rj% ry* %^ Fru'n Notes, Spring, 1994 17 Suggestions for Use of the New Postbloom Thinner Accel® Duane W. Greene and Wesley R. Autio Department of Plant and Soil Sciences^ University of Massachusetts Chemical thinning of apples continues to be one of the most important management activi- ties. It is reqviired nearly every year to assure adequate fruit size at harvest and to encourage repeat bloom the following year. Carbaryl and NAA are the two most commonly used thinners. Both have their faults. Orchardists frequently are reluctant to use carbaryl because of the potential detrimental effect that it can have on mite predators, and it is a relatively weak thin- ner. When used alone, often it is not potent enough to thin adequately. NAA is stronger, but it also has several detrimental effects. Overthinning is possible if either cloudy or hot weather immediately follows apphcation. It can retard finiit growth, even when used accord- ing to label directions. Under these conditions, NAA may not increase fruit size, even when it causes significant thinning. This lack of size increase is emerging as a major problem associ- ated with NAA. Finally, NAA cannot be used on some cultivars because it causes pygmy finait. In the 1980's benzyladenine (BA) was found to have chemical thinning capabiUties. Since then, researchers have demonstrated repeat- edly that BA is a consistent and effective thin- ner with some unique properties that may make it the postbloom thinner of choice. Accel® re- cently was approved as a chemical thinner on apples. Accel is an altered Promalin™ formula- tion, but the primary active thinning compo- nent is B A. The purpose this article is to explain some of the characteristics of BA that make it a unique thinner, and to make suggestions for successful use of BA when applied in the Accel formulation. General Effects of Accel Thinning Activity BA can thin over a wide range of concentra- tions, starting fi*om as low as 25 ppm. Undesir- able side effects may be noted if it is appUed above 150 ppm; however, label restrictions on the active ingredient per acre make it unlikely that too high a concentration will be applied. BA has been applied in heavy set years and in light set years, and the thinning response to varying concentrations is linear. Although con- centrations as low as 25 ppm can be effective, 50 to 100 ppm generally are required to do an effective job. Comparison with other Chemical Thinners BA has been compared with NAA and car- baryl in several thinning trials in Massachu- setts. It thins as consistently, if not more consistently, than either NAA or carbaryl when applied at the proper time and at an appropriate temperature. The activity of chemical thinners differs fix)m year to year, depending on weather and other factors; however, when applied at the appropriate tree row volume, 75 ppm BA thins Mcintosh comparably to 1 Ib/100 gal carbaryl (50% WP Sevin) and 6 ppm NAA. BA has been shown to have no detrimental effects on mite predators, a problem frequently associated with the use of carbaryl. When applied alone, BA does not have the negative effects of NAA, such as leaf epinasty, reduced fruit size, or pygmy fruit. 18 Fruit Notes, Spring, 1994 Return Bloom One of the primary reasons for thinning is to assure adequate return bloom. BA appears to be quite effective at stimulating flower bud formation, and therefore, BA compares favor- ably with NAA and carbaryl at stimvdating return bloom. In some years, BA will enhance flower bud formation beyond that which would be promoted by the level of frmt thinning that it causes. Time of Application BA can thin over a three- week period. It will thin modestly when applied at full bloom to petal fall, but fruit are most susceptible to BA and it is most effective when it is applied at the 8- to 10-mm stage of fruit development (14 to 18 days after fuU bloom). Once iniit reach about 20 mm and trees experience several days of sunny weather in the 80's, no thinner, including BA, will thin. Spray Coverage Good and uniform spray coverage is impor- tant. Translocation and redistribution of foliarly appHed BA is limited. Further, research has shown that BA must come in direct contact with the spvu" leaves for fruit in that cluster to be thinned. BA application directly to the young fruit wiU increase fruit size and flesh firmness at harvest but wiU not influence fruit abscis- sion. Fruit Effects Perhaps the biggest advantage that BA has over other chemical thinners is its effects on fruit. Fruit Size Generally, chemical thinners increase fruit size by lowering fruit numbers, thus reducing competition for metabolites among the remain- ing fruits. Although BA enhances size by reduc- ing competition, it also causes increased fruit size independent of and in addition to this effect. This effect on fruit size independent of thinning is unique to BA. BA is especially effective at increasing fruit size on Mclntosh-tjrpe cultivars such as Mcintosh and Empire. Flesh Firmness and Sugars It is rare for chemical thinners to increase flesh firmness because they usually increase finiit size, and there is an inverse relationship between fruit size and flesh firmness. BA, however, increases flesh firmness approxi- mately half of the time, even though it also increases finiit size. Because BA is a cytokinin (a group of plant hormones) it likely increases flesh firmness by increasing the number of cells in an apple. Also, BA increases the sugar content of fruit about half the time. Thinners can increase sugar because they increase the leaf-to-fruit ratio. Red Color and Fruit Asymmetry If used at high concentrations, BA can re- duce red color and increase finiit asymmetry. Given the label restrictions per acre per applica- tion, we do not believe that either one of these situations is likely to occur. Cultivars BA is not equally effective on all cultivars. BA is especially effective on Empire and Mcin- tosh and extremely useful on Jonamac, Rome, Idared, and Golden Delicious. Recommendations for the Use of Accel* Accel is the first step by Abbott Laboratories to make BA available as a thinner on apples. It is not a perfect product, but it is a start. It is an altered Promalin formulation so GA, , is in- 4+7 eluded, but it is present only at 1/10 the level found in the original Promalin formulation. Also, on the present label is a limit of 35.6 fluid ounces of Accel (20 g active ingredient, ai) per acre p>er application, and this level may limit its effectiveness when used on large trees that have a high tree-row-volume requirement. * Please see the end of this article for a discussion of a pending label change. Fruit Notes, Spring, 1994 19 Concentration Twenty five ppm in a dilute spray is the minimum concentration to get any thinning response. If the tree row volume of a block requires 200 gallons per acre in a dilute spray, the label would allow only a concentration of 26 ppm (at 35.6 fluid oxinces of Accel or 20 g ai/acre) to be used. Furthermore, in situations where aggressive thinning is necessary and the tree row volume is only 100 gal/acre, the desired level of thinning may not be reached with the use of BA alone, since the label will allow only a concentration of 53 ppm (at 35.6 flxiid ounces of Accel or 20 g ai/acre). In these situations, additional thinning strategies may be neces- sary. Accel should be apphed in 50 to 200 gallons of water per acre. Applications in volumes less than 50 gallons per acre may result in poor coverage. Cultivars Use Accel on responsive cultivars first until you feel comfortable and until you see how it performs in your orchard. Responsive cultivars include Empire, Rome, Mcintosh, and Idared. Time of Application If using a single application of Accel, apply at the 8 to 10 mm stage (3/8 in), firom 12 to 18 days after full bloom. The label allows up to two applications of Accel per season. The research has not yet been done to determine the specific effects of multiple applications, so proceed with caution. If two applications are made, do not exceed a total of 71.2 fluid ounces of Accel (40 g ai) per acre for the season. With two applications, the first should be applied at the 5-mm fruit stage, and the second should be applied at no later than the 10-mm stage. Combinations with other Thinners BA has been used effectively in combination with NAA on Mcintosh. The response was additive; however, Accel interacts with NAA on Dehcious to produce small and pygmy fruit. Therefore, the label specifically states that NAA should not be used in any Accel thinning pro- gram. Where aggressive thinning is required, carbaryl should be included in the thinning program. We have tank mixed BA with car- baryl successfully. The thinning response was additive. The label does not prohibit tank mix- ing with carbaryl but the practice is discour- aged. Weather Attention to temperature is critical for effec- tive thinning with Accel. It should be applied only when the temperature is 65°F or higher. Ideally, the temperature should rise into the 80's within three days following application. If warm temperatures do not follow the applica- tion, thinning results are hkely to be disappoint- ing. Cloudy weather following application, Uke warm temperature, may increase the thinning response. Label Change Pending There is a label change pending for Accel as this issue goes to press. There are two signifi- cant changes that may occtu*. The rate of Accel per apphcation may be increased to 53.5 fluid ounces (30 g ai) per acre, and the total per season may be increased to 107 fluid ounces (60 g ai) per acre. This change must be noted, because overthinning may occur of Mcintosh, Idared, Rome, and Empire if the new maximum rate is used and tree row volume reqires less than 100 gallons per acre for a dilute spray. Conclusions In this first season of commercial use, use Accel cautiously and follow label directions. Use it first on a responsive cultivar, and do not apply it unless temperature conditions are appropri- ate. %% %% %fi» %{>• •^0 rj% r{^ rj% rj% r{% 20 Fruit Notes, Spring, 1994 Emit Notes University of Massachusetts Department of Plant & Soil Sciences 205 Bowditch Hall Amherst, MA 01003 Nonprofit Organization U.S. Postage Paid Permit No. 2 Amiierst, miA 01002 Account No. 3-20685 Fruit Notes Prepared by the Department of Plant & Soil Sciences. University of Massachusetts Cooperative Ebrtenslon System. United States Department of Agriculture, and Massachusetts Counties Coopj Editors: Wesley R. Autio and William J. Bramlage ISSN0427-6906 LISRARi JUL \h 9'4 JNIV. OF MA3 Volume 59. Number 3 SUMMER ISSUE, 1994 Table of Contents Could Bacteria in Nature be Detoxifying Compounds for the Apple Maggot Fly? A New Book on Tree Fruit Nutrition Some Thoughts on Depreciation Effects of Low Temperature, Ripening, and Light on Scald Susceptibility of Apples at Harvest Final Report on the 1984 NC-140 Cooperative Apple Rootstock Ranting in Massachusetts: Starkspur Supreme Delicious on Fifteen Rootstocks O' Say Can You See Mite Predators in Apple Orchards? Apple Orchards in Switzerland: EHfferences Small and Large Fruit Notes Publication Information: Fruit Notes (ISSN 0427-6906) is published the first day of January, April, July, and October by the Department of Plant & Soil Sciences, University of Massachusetts, The costs of subscriptions to Fruit Notes are $7.00 for United States addresses and $9.00 for foreign addresses. Each one- year subscription begins January 1 and ends December 31. Some back issues are available for $2.00 (United States ad- dresses) and $2.50 (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 COOPERATIVE EXTENSION SYSTEM POLICY: 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 the University of Massachusetts Cooperative Extension System, Robert G. Helgesen, Director, in furtherance of the acts of May 8 and June 30, 1914. The University of Massachusetts Cooperative Extension System offers equal opportunity in programs and employment. Could Bacteria in Nature be Detoxifying Compounds for tlie Apple IVIaggot Fly? Carol R. Lauzon, Bernard J. Robert*, Teresa G. Bussert, and Ronald J. Prokopy Department of Entomology, University of Massachusetts *Department of Plant & Soil Science, University of Vermont Insects are exposed, almost continuously, to a variety of harmful compounds. Adults and larvae may come into contact with harmful synthetic chemicals, such as pesticides, or harm- ful natural compounds, such as plant allelocompounds (plant substances that often protect it against pests). Insects may be exposed to these harmful compounds either through contact or through feeding. Either way, the mechanisms for ridding these poisons from the body are important survival processes. These processes, referred to as detoxification mecha- nisms, involve enzymes (proteins that facilitate chemical reactions) which alter the structure of the compound and make it more excretable (less toxic). This can be achieved by removal or addition of a chemical group. Generally, pesticides apphed by growers are in amounts that overwhelm the insect's ability to detoxify them. As time goes on, the pesticide on plants is broken down by sunhght, wind, rain, and other natural processes. Eventually, residues may reach concentrations where the insect C£in survive ingestion or contact. With repeated exposure, the insect may evolve to handle effectively a toxin in concentrations ear- lier found to be lethal, i.e. develop pesticide resistance. The apple maggot fly, Rhagoletis pomonelUt, typically is controlled by two or three applica- tions of azinphosmethyl (Guthion ), an orga- nophosphate that is a potent inhibitor of cho- Unesterase, an enzyme responsible for normal nervous system functioning. Azinphosmethyl also is used to control other orchard pests such as codling moth. Although no information exists to date regarding resistance to azinphosmethyl for the apple maggot fly, resistance has been reported for codling moth. Mechanisms of insecticide resistance tradi- tionally have been examined using genetic tech- niques focused on resistant individuals and cre- ation of models of gene flow between resistant and susceptible insects. Less attention has been paid to the potential involvement of bacteria either within or on host plants or within insects in the development of insecticide resistance. Interestingly, enzymes in bacteria capable of converting toxic compounds into less toxic compounds that are more easily excretable in- clude the same enzymes that insects themselves use in detoxification. In fact, many bacteria can detoxify compounds internally or secrete en- zymes responsible for metabolizing foreign com- pounds into their surrounding environment. Numerous reports exist on the abilities of cer- tain species of bacteria to degrade and detoxify a variety of compounds, including azinphosmethyl and plant allelocompounds. Here we report on studies designed to deter- mine if bacteria associated with the apple mag- got fly could degrade, and subsequently detoxify, azinphosmethyl and plant allelocompounds likely to be consumed by this insect. Fruit Notes, Summer, 1994 Materials & Methods Pesticide degradation and detoxification. Enterobacter agglomerans, a bacterium found to inhabit both the gut of the apple maggot fly and apple leaf surfaces in nature, was added to sterile preparations of azinphosmethyl at a con- centration typical of one sprayed by a grower. The bacteria/pesticide solutions and sterile pes- ticide solutions (void of any bacteria) were incu- bated at 73°F for 3 days. Cholinesterase was extracted from apple maggot flies and mixed with the bacteria/p)esticide solutions to deter- mine whether or not azinphosmethyl still was capable of reducing cholinesterase activity after exposure to the bacteria. Also, small amounts fi-om each sample were fed to 25 apple maggot flies and mortality values were recorded at 24- and 40-hour intervals. Additionally, the solu- tions were analyzed for degradation products of azinphosmethyl. The experiment was done twice. Plant allelocompound degradation and detoxification. We also studied four allelocompounds considered to be toxic to apple maggot and typically found in the habitat of apple maggot flies. They were: naringenin, phloridzin, cafieic acid and cinnamic acid. Each solution was inoculated with Enterobacter agglomerans and incubated at 87°F for 24 hours. Sterile solutions also were incubated along with the bacterial solutions. Degradation of each compound was measured by changes in pH (a typical phenomenon associated with degrada- tion) and by the presence or absence of degrada- tion products. Also, small amounts from each solution were fed to 10 flies individually, and mortality values were recorded after 12 days. Results Mixing cholinesterase extracted from apple maggot flies with azinphosmethyl resulted in low to no cholinesterase activity (14.8 active units). However, activity of cholinesterase was 10 times greater when mixed with azinphosmethyl in which bacteria had grown for three days (144.1 active units). The higher value indicates that cholinesterase activity was not inhibited as much in the bacterial solution and therefore, the pesticide was less effective. We found that loss of effectiveness was the result of chemical alteration of azinphosmethyl by bacteria Forty hours afl«r a 48-hour-old solution of bacteria and pesticide was fed to apple maggot flies, only three of 50 flies were dead. In con- trast, when flies were fed the sterile pesticide solution, 47 of 50 were dead after 40 hours. Fifty flies serving as controls were fed only water. All were alive after 40 hours. In the allelocompound solutions that con- tained bacteria, we saw changes in pH (indica- tive of chemical changes) which were not ob- served in the sterile solutions, and we were able to detect degradation products in the bacterial solutions that were not present in the sterile solutions. Therefore, bacteria also degraded the plant allelocompoiuids. When apple maggot flies were fed sterile solutions of the four allelocompounds, all were dead after 12 days; however, when solutions inoculated with bacte- ria were fed to the flies, none died. Conclusions Our laboratory findings indicate that Enterobacter agglomerans possesses the abihty to degrade and subsequently detoxify azinphosmethyl and certain plant allelocompounds that normally are toxic to apple maggot flies. This finding is an important first step in establishing the contribution of bacteria toward detoxification of harmful compounds encountered in nature by this and other insects. We are continuing our work in this area by studying (1) precisely how the bacteria degrade toxic compounds, (2) how fly longevity and fe- cundity are affected by detoxification, and (3) if detoxification mechanisms inherent to flies are enhanced by degradation processes of bacteria. Further comprehension of ways insects handle chemicals in the environment should contribute to pest management progrguns. Such knowl- edge also may lead to creation of new ways to decrease or eliminate pesticide crops or on spray equipment. For example, it is conceivable that a bacterial or enz)Tnatic preparation could be sprayed on trees before harvest so that the Fru'n Notes, Summer, 1994 residues may be decreased or eliminated through detoxification. Envision also, after completion of spraying, a tablet containing bacteria that one drops into the spray tank and a few hours later, the equipment is free from any pesticide. These are exciting possibilities. Acknowledgments We thank George MacCoUom of the Univer- sity of Vermont for supplying apple maggot flies during the early stages of this work (which took place at the University of Vermont), Evan Thackaberry (also of the University of Vermont) for his assistance with visualization of pesticide degradation products, and Sylvia Cooley for technical assistance with plant allelocom pound- fly mortality studies. This work was supported in part by the National Agricultural Pesticide Impact Assessment Program Grant #92-34050- 7268 and USDA National Research Initiative Competitive Grant #893715. Selected References Brattsen, L.B. and C.F. Wilkinson. 1977. Herbi- vore-plant interactions: Mixed-function oxidase and secondary plant substances. Science June 17: 1349-1352. Robertson, J.L., K.F. Armstrong, D.M. Suck- Ung, and H.K. Preisler. 1990. Effects of host plants on toxicity of azinphosmethyl to suscep- tible and resistant light brown apple moth (Lepi- doptera: Tortricidae).J. Econ. Entomol. 83: 2124- 2129. mS^ mS^ •Sm %f^ ^f^ rj% ry» •Y* •T* •^ A New Book on Tree Fruit Nutrition In February, 1992, a shortcourse on the Management of Tree Fruit Nutrition was held in Wenatchee, Washington. The proceedings from that conference have been pubhshed by Good Fruit Grower and is available for purchase. The book consists of 22 generally easy-to- read chapters and totals over 200 pages. It begins with three general chapters on fruit tree growth and development, root development and physiology, and soil characteristics. This base is followed by 12 chapters on minerals and ap- proaches to meeting their needs in trees and finiit. There are also three chapters on diagnos- ing nutritional needs in orchards, and a chapter on fertilizer effects on water quahty. Finally, the book concludes with three chapters on fertigation. Eighteen different authors contrib- uted to the shortcourse and the proceedings. This is an outstanding reference for frmt growers, and will certainly become a standard reference on nutritional problems in orchards. Copies can be obtained from the Good Fruit Grower, P.O. Box 9219, Yakima, WA 98909. Cost is $15.00 plus $3.50 for shipping. We strongly urge growers to obtain a copy £md to refer to it often. «1# •S^ •^0 %|^ •S^ rj% #J% rj% rj% •^ Fruh Notes, Summer, 1994 Some Thoughts on Depreciation Robert L. Christensen Department of Resource Economics^ University of Massachusetts Depreciation may be the most misunder- stood topic in financial management. It is prob- ably the most complicated exercise in the devel- opment of the business financial statement, and it is a critical element in preparation of income tax returns. In fact, the complexity of IRS rules and some computational methods can obscure the concept that underhes depreciation and lead to a misunderstanding of true costs and busi- ness profitability. Depreciation is an annual non-cash expense that reflects the amount by which an asset decreases in value due to use, age, and obsoles- cence. It apphes only to assets like buildings, machines, and breeding animals, as well as to improvements hke roads, bridges, fences, and drainageways that have useful hves of more than one year. Depreciation recognizes the fact that these assets can wear out with use. That is, eventually they become so worn that they be- come useless or repair costs become excessive. Depreciation also occurs through aging. Even without use, wooden or rubber compo- nents can rot, metal can rust or become brittle and break, and plastic can lose strength and crack. Assets also can become obsolete as new technology is developed to perform the same tasks more efficiently and at lower cost, or if the asset is no longer relevant to the nature of the business (e.g. , a mUking machine becomes obso- lete if the dairy herd is sold). While depreciation is a non-cash expense, there is a "day of reckoning" that comes when the asset must be replaced. One might consider the annual depreciation amounts as money to be put in a reserve account to accumulate until the day when the asset is replaced. In theory, the business then will have the capital accimiulated to replace the asset with little or no need to incur new debt. More often, however, no such reserve account exists. One sometimes observes situations where the annual income statement of a business shows a low or even negative net income and there is a suggestion of insolvency. One might immediately ask how the operator can continue in business and take care of family hving ex- penses if net income is negative. One expla- nation is that depreciation is subtracted as a cost in the income statement. It's important to recall that depreciation is a non-cash expense. Since depreciation is a non-cash cost, that amount actually is available from cash flow for debt repa)rment, other business expenses, and for family living costs. Another answer might be that past earnings in the form of savings are being depleted in order to meet costs and debt obligations. Still another explanation could be that additional debt is being incurred that allows the business to con- tinue and family living expenses to be met. This situation can continue untU the time of reckon- ing when depreciable assets must be replaced. Even though replacement might be possible from borrowed funds, it may be difficult to con- vince lenders that theyshould make the loan when past income statements show low or nega- tive net income. Comphcating the subject of depreciation are the IRS procedures relating to depreciation. For tax purposes, depreciation is a deductible ex- pense of the business just as if it were a cash cost. Regulations define what kinds of assets may and may not be depreciated. They also establish acceptable methods of calculating depreciation and stipulate recovery periods (the number of years over which different classes of property may be depreciated). Once a particular method has been established for an asset you cannot change to another method, but you can use different methods for different assets. It's not the purpose of this article to describe depreciation methods and procedures. Rather, only a few points will be made concerning depre- ciation and tax liability. First, the amount of depreciation taken on business assets can affect Fru'n Nous, Summer, 1994 tax liability substantially. Second, the selection of the method of depreciation for property can affect tax Uabihty not only in the current year but also in future years (e.g., accelerated meth- ods reduce tax UabiUty in early years of owner- ship and increase liability in later years as compared with straight line methods). It should be noted that depreciation calculations may have little actual relation to the depreciation costs that relate to wear, aging, and obsoles- cence of the assets of a particular business. For example, a single purpose farm building with integrally installed equipment can become obso- lete or worn out in less than the 10-year recovery period for the IRS General Depreciation System (GDS) regulation. On the other hand, the GDS time period for most farm machinery is seven years. Yet for practical purposes, a fully depre- ciated tractor (one with a "book value" of zero) may retain its essential usefulness for two or more decades and, therefore, still have real value as an asset. What this means is that depreciation values can overstate or understate the actual asset value. When assets last longer than the recov- ery period, the result is an income statement which understates actual net farm income and overstates production costs. In situations, how- ever, where rapid technological innovation causes assets to become obsolete more quickly than the guideline recovery period, the result is an overstatement of net incomes and an under- statement of true costs. It often is argued that, since the business typically has a set of different types of assets acquired at different times, these under- and over-statements "wash". That is, they tend to balance out and approximate the real value for the entire set of assets. There also are imphcations for the net worth statement for the business. Assets may be valued according to market value or cost value. Using cost valuation one would use the "book value" or depreciated value for the asset. Very often the market value of the asset is greater than the book value, especially when acceler- ated depreciation methods have been used. As a result, net worth may be understated and the solvency position of the business will be lower than is actually the case. This, in turn, may have a negative impact on the ability of the owner to obtain needed credit for the business. For this reason, when seekingadditional credit, the potential borrower might find it more ad- vantageous to present the lender with a net worth statement with assets stated in market value terms. %2^ ^S^ ^10 %f# %% rj% rji ry» •^ ^J^ Fruit Notes, Summer, 1994 Effects of Low Temperature, Ripening, and Light on Scald Susceptibility of Apples at Harvest Cynthia L. Harden* and William J. Bramlage Department of Plant and Soil Sciences, University of Massachusetts *Present address: Pennsylvania State University, Fruit Research Laboratory, Biglerville, PA. Many factors influence scald susceptibility of apples, including cultivar, orchard locality, weather, harvest maturity, and storage condi- tions. For example, Cortland and Delicious are very susceptible, Mcintosh is moderately sus- ceptible, and Empire and Gala seldom if ever develop scald. Also, it has long been recognized that fruit generally become less susceptible as they become more mature. Among weather conditions, preharvest temperature is espe- cially important, with cool temperatures before harvest reducing scald susceptibility. Another potentially significant factor is light, since scald is usually more prevalent on the green (shaded) portion of a fruit than on the red (sunlit) portion, and frmt from the interior of the tree usually are more susceptible than ones from the exterior. We have been attempting to predict scald susceptibility from preharvest temperature records, using hours below 50°F as our tempera- ture indicator. In attempting to apply such a predictor to orchard conditions, however, it is important to understand how much some of the other key factors contribute to changes in scald susceptibility, for if they are major contributors, they must also be included in a predictor system to avoid potential errors in predictions. Consequently, we conducted a three-year study (1988 through 1990) of the effects of preharvest hours below 50°F, fruit maturity, and light intensity on scald susceptibility of Cortland and Delicious apples grown at the University of Massachusetts Horticultural Re- search Center, Belchertown. Three experiments were conducted. In the first, both Cortland and Delicious were har- vested at three or four weekly intervals in each year, and stored at 32°F for 20 weeks, with scald being evaluated after an additional seven days at room temperature. Preharvest temperatures were recorded continuously in an enclosed shel- ter in the orchard, so hours below 50°F after August 1 could be counted at each harvest date. Fruit maturity at harvest was measured both by internal ethylene content of the fruit and by their average starch score, obtained by staining 10 fruit per sample with an iodine-potassium iodide solution and comparing their stain inten- sity to standard charts, with one indicating complete staining (very immature) and nine indicating no staining (very mature). With each succeeding harvest date, fruit were more ma- ture, as shown by increasing starch index and increasing internal ethylene content (Table 1). In all but one instance, however, fruit from each succeeding harvest date also had experienced more hours below SO'F, so later harvest repre- sented a combination of both riper fruit and more preharvest exposure to cool temperatures. After 20 weeks at 32°F plus one week at room temperature, scald development was quite vari- able among samples (Table 1). In general, scald decreased with later harvest but there were exceptions; for example, scald did not decrease from the September 15 to the September 22 harvests in 1989 on Cortland. Also, scald sus- ceptibility on corresponding dates in different years was not always comparable; for example. Fruit Notes, Summer, 1994 Table 1. Changes in scald susceptibility of apples harvested at weekly intervals in three years. Ethylene Harvest Hours below Starch concentration Scald Year date SOT index^ (log ppm) (%) Cortland 1988 Sept 13 73 1.2 -1.13 71 Sept 22 102 2.0 -1.00 36 Sept 29 134 4.0 -0.65 11 Oct 6 187 5.0 0.15 4 1989 Sept 15 62 1.0 -1.06 99 Sept 22 62 1.7 -0.86 99 Oct 4 152 4.7 0.08 29 1990 Sept 17 21 1.3 -0.97 98 Sept 24 79 1.5 -1.19 78 Oct 3 127 4.3 0.23 46 Oct 11 150 6.8 2.08 49 Delicious 1988 Oct 1 160 1.3 -1.57 12 Oct 8 232 1.6 -2.52 2 Oct 13 365 1.9 -1.16 2 1989 Sept 29 125 1.4 -0.71 83 Oct 5 170 2.6 0.32 72 1990 Sept 21 62 1.2 -1.54 94 Sept 26 104 1.6 -0.96 88 Oct 3 127 3.2 -0.26 69 Oct 11 150 5.5 1.18 51 ^1 = very immature 9 - very mature. Delicious harvested October 1, 1988 developed 12% scald, while ones harvested on October 3, 1990 developed 69% scald,even though the 1990 fruit were somewhat more mature than those in 1988. In a second experiment, Cortland apples were sprayed in August with ethephon to induce ripening before they had experienced substan- tial amounts of preharvest cool temperatures. In 1989, only 500 ppm ethephon was applied, but in 1990 both 250 and 500 ppm were used. Both concentrations caused fruit to ripen in early September. In 1989, some hours below 50°F were recorded before the harvests, but in 1990 none had occurred, so any effect of treat- ment on scald in 1990 should have been due entirely to more advanced maturity. In both years, ethephon treatment significantly re- duced scald after storage (Table 2); however, differences usually were small. In particular, in 1990 when fruit ripened in the absence of any hours below 50°F, all samples developed scald on more than 90% of the fruit. Ethephon sprays have been reported to reduce scald on Granny Smith and Delicious in several parts of the world, but clearly under our conditions, ethep- Fruit Notes, Summer, 1994 Table 2. Effects of ethephon on ripeness at harvest and on scald development on Cortland apples after storage. Ethephon was applied on August 16, 1989 and on August 20, 1990. Ethylene Harvest Ethephon Hours below Starch concentration Scald date (ppm) 5(yF index' (log ppm) (%) 1989 Sept 6 0 52 1.2 -1.05 87 500 7.4 2.00 81 Sept 13 0 62 1.3 -0.64 96 500 8.4 2.13 67 1990 Septl 0 0 1.0 -2.35 97 250 4.8 1.86 90 500 5.9 2.08 92 Sept 6 0 0 1.3 -1.82 99 250 7.3 2.12 91 500 6.9 1.95 96 ^1 = very immature; 9 = very mature. hon treatment was not effective on Cortland, as Windus and Shutak (J. Amer. Soc. Hort. Sci. 102:715-718) also reported in 1977. The third experiment was designed to test the importance of light intensity on scald sus- ceptibility. In 1989 and 1990, Cortland apples were enclosed individually in brown kraft paper bags in mid-to-late August, and kept in these bags until they were harvested. Bags had al- most no effect on fruit temperature. Each year two harvests were made. Bagging did not affect fruit maturity significantly in either year (Table 3); however, it resulted in fruit with greater scald susceptibility, and differences usually were quite large. Thus, under our conditions severe reduction of light intensity increased scald susceptibility, but it should be noted that even bagged fruit were becoming less scald sus- ceptible with later harvest, indicating that bright light is not required in order for the maturity and temperature factors to affect scald susceptibility. These results showed that under our condi- tions preharvest temperature was the most im- portant factor affecting scald susceptibility of Cortland and Delicious apples. In Figure 1, all three years of data were used to illustrate this effect. For Cortland, scald susceptibility began to decline when the fruit had experienced slightly less than 100 hours below 50°F between August 1 and harvest. By about 150 hours, susceptibility had fallen to the point where 40 to 50% of fruit scalded, and as they approached 200 hours, only about 10% scalded. Delicious re- quired about 25 more hours below 50°F to reach these same levels of susceptibility. The effects of temperature differences among different harvests and years can be seen in Table 1. For example, in 1989 no loss of scald susceptibility of Cortland occurred when har- vest was delayed from September 15 to 22, and it can be seen that temperatures were continu- 8 FruH Notes, Summer, 1994 Table 3. Effects of bagging on ripeness at harvest and on scald development after storage of Cortland apples. Fruit were bagged August 21 | to 25, 1989 and August 13 to 14, 1990. Ethylene Harvest Hours Starch concentration Scald | date Treatment below 50°F index' (log ppm) (%) 1989 Sept 18 Control 62 1.3 -1.18 95 Bagged 1.6 -1.27 100 Oct 2 Control 147 5.1 -0.21 27 Bagged 4.4 0.02 90 1990 Octl Control 107 3.2 -0.07 31 Bagged 3.4 0.24 62 Oct 9 Control 150 6.4 1.21 13 Bagged 6.0 1.41 42 Significance'' 1989 Bagging NS NS * Hours below 50°F *** NS ** 1990 Bagging NS NS * Hours below 50°F *** ** NS Bagging x Hours NS NS NS '1 = Very immature; 9 = very mature. "NS = not significant; * = = odds of 19:1;" = = odds of 99:1 ; *** = odds of 999:1. ally above 50°F between these dates. In Deli- cious, there was almost no scald in 1988 even though fruit were quite immature; this was a very cool year, and 160 hours below 50°F had been recorded by the first harvest date. Harvest of Dehcious on similar dates in 1989 and 1990 resulted in much more scald development than in 1988, and in these years fewer hours below 50°F had been recorded by the harvest dates than in 1988. Clearly, maturity and light also played roles in loss of scald susceptibility by the apples, since ethephon treatment reduced scald and bagging increased it. The results with ethephon (Table 2) are interesting in that in 1989, when some hours below 50°F had been recorded before har- vest, ethephon reduced scald more than in 1990, when no hours had been recorded. This suggests that cool temperature increased the effect of ripening (or vice versa) in reducing scald suscep- tibility, that is, that temperature and ripening worked together in reducing scaldsusceptibility. Nevertheless, cool temperature clearly was the more important factor in this relationship. How important light is in this relationship cannot be measured by our results, since we used nearly complete light exclusion by bagging the fruit. Yet, it is likely that reducing scald susceptibility is one more reason for encourag- ing light penetration into the tree interior, for Fruit Notes, Summer, 1994 100 ♦\ * \ A Delicious \^ \ A • Cortland 80 \ \ A \ *\ -7- 60 \\ (0 O CO 40 20 ♦ A ^^ L 0 ( D 50 100 150 200 250 300 350 Hours Below IOC Figure 1. Calculated changes in scald susceptibility (percent of fruit that develop scald after storage) with increasing hours below 50°F between August 1 and fruit harvest date. example, by summer pruning. Shaded fruit probably require more cool temperature and ripening to become less scald susceptible than do exposed fruit. Our results show how rapidly scald suscep- tibility can change during the harvest period, and that cool temperature is the most important factor in this change. In Figure 1 you can see that if a couple of days occur when the tempera- ture is almost continually below 50°F, scald susceptibility can drop dramatically; this situa- tion commonly occurs in early October in Massa- chusetts. Conversely, if the temperature re- mains constantly above 50°F for a period of time, httle or no loss of scald susceptibility will occur, even though the fruit may ripen substantially. We are attempting to develop a practical, reliable predictive system so that growers can estimate at harvest how scald susceptible their fruit are, and determine their scald control method according to need. At Belchertown, just counting hours below 50°F at harvest has worked well. In other regions, however, it is not as effective, which raises questions about the relationships between temperature and scald in "unusual years" in Massachusetts. The results here show that maturity and light also can be important factors, and we hope to have a much clearer picture of scald predictions in the near future. %% •i^ %I# •i^ •S^ ^^ r{% rj% rj% rf* 10 Fruh Notes, Summer, 1994 Final Report on the 1984 NC-140 Cooperative Apple Rootstock Planting in Massachusetts: Starkspur Supreme Delicious on Fifteen Rootstocks Wesley R. Autio Department of Plant & Soil Sciences, University of Massachusetts Dwarfing rootstocks clearly are part of the exceeded by returns, apple growers must take future of the apple industry in New England. At advantage of all opportunities to reduce costs or a time when production costs often are not increase returns. Dwarfing rootstocks may al- Height and spread (ft) 4 6 8 10 12 14 P.I 8 A. 313 Seedling W\W.VWVVVV\VVVVVVWVWVW\.'wV\.V\S.VWVVW\W v~^~^ MAC.1 ^^^^^^^^^^^^^^^^^^^^^ B.490 M.4 M.7 EMLA P.I M.26 EMLA C.6 MAC.39 .vwvvvvvvvvvvvvvvvvvvvvvvvvwvwvvvwvv 5S BiBSfiBi ^^ ^^k^ki^MMMri^y^il^^uMffi^^^ WWWN \.\.vvs^ SfififiB i — ^^^^^^^^^^^^^ vvvvvvvv SS55S&5fiS^5SiS^fiSS5B^^^^^^^^ ^SiSS&ifiK^ 1 .\VX\^KVVVV^^V\^VVKVV^^^ .v.\.\v.\.\.\.\.v\.^^ 1 -\- .^A^^^^^^^^^^^^^^^^^^i xxxxxxxx" ^^^^^^^^^o ^^^ ^^^^^^^^^^ vvvvwwv ^ X\\\\\\\\\\\\\\\\\\\N de S^^^^^^^ P.2 P.I 6 ^^^^^^ ^V\VVV.VV.VV.\V.VV\VN Dtca ^Height H Spread P.22tHi^^^^^ 5 10 15 20 Trunk cross-sectional area (in^) 16 25 Figure 1. Trunk cross-sectional area, height, and spread of Starkspur Supreme Delicious trees on various rootstocks after 10 growing seasons. Trunk cross-sectional area means are significantly different at odds of 19:1 if bars do not contain the same letter. Fruit Notes, Summer, 1994 11 M.4 P.18 A.313 B.490 M.7 EMLA| Seedling ^ MAC.1 § P.1 ^ eel M.26 EMLA MAC. 39 B.9 P.2 P.1 6 P.22 ab ab be c c cd cd J^^^^^^^^M^^Mm^^ $$^$MJ^^m^^^$^^^ ef ^^^^M^^mm^ fg :$^^$^$$M^M$$$^ MM^M^^ 9 de 10 15 20 Cumulative yield per tree (bu) Figure 2. Cumulative yield (per tree, 1987-93) of Starkspur Supreme Delicious trees on various rootstocks. Means are significantly different at odds of 19:1 if bars are not followed by the same letter. low both. Qiiicker return on the investment of establishment, potentially higher yields, higher packout because of better light penetration into the canopy, less pesticide needed to treat each acre, and lower labor needs for harvesting and pruning all make dwarf trees a very desirable alternative when compared to semidwarf or standard trees. In the last issue of Fruit Notes, I gave the final report of a rootstock trial that began in 1980 as part of a cooperative planting of the NC- 140 Technical Research Committee. In this article, I will detail the final report of the Mas- sachusetts portion of the 1984 NC-140 Coopera- tive Apple Rootstock Plgmting. Materials & Methods Starkspur Supreme Delicious trees on B.9 (Budagovsky 9), B.490, MAC.l (Michigan Agri- cultural College 1), MAC.39, P.1 (Polish 1), P.2, P.16, P.18, P.22, M.4 (Mailing 4), M.7 EMLA, M.26 EMLA, C.6, A.313 (Antonovka 313), and domestic seedling were planted at a spacing of 12 X 18 feet at the University of Massachusetts Horticultural Research Center in the spring of 1984. Trees were trained as central leaders using minimal pruning and limb spreading as needed. Containment pruning was required for many of the larger trees. Stakes were added for support only when trees leaned more than 45 12 Fruit Notes, Summer, 1994 degrees. Standard pest and fertility manage- ment practices were used. Tree size and yield were measured annually; however, trees were not allowed to fruit until the fourth growing season (1987). In 1989, 1990, 1992, and 1993, periodic harvests of four fruit per tree were made throughout the harvest season for the assessment of internal ethylene concentrations. Single harvests often fruit per tree were made on October 3, 1990, October 3, 1991, October 5-6, 1992, and October 11, 1993 for the assessment of soluble solids concentra- tion, starch loss, and watercore development. 7y*ce Size and Productivity Figure 1 reports the average height, spread. and trunk circiunference of trees from this planting. Due to the need for containment priming of trees that exceeded the 12-foot spac- ing, height and spread do not present an accu- rate picture of trees on P. 18, A.313, seedling, MAC.1,B.490,M.4, M.7EMLA,orP.l. Trunk cross-sectional area likely is a more accurate measure of relative tree size. These trees broke into a few distinct size groupings. Standard- sized trees were produced by P. 18, A.313, seed- ling, MAC.l, and B.490. M.4 resulted in semi- standard trees. M.7 EMLA and P.l produced semi-dwarf trees. M.26 EMLA, C.6, and MAC.39 resulted in large dwarf trees, and P.22 and P. 16 produced subdwarfs. B.9 and P.2 produced trees intermediate in size to these last two categories. P.16H ^^^^^^^^^^^^^^^^HI^^^I^^^Ih 3 P.2B ^^^^^^^^^^^^^^l^^^^^^^^^^^^l a B.gp ^^^^^^^^^^^^HI^^^^^^^^^H 3 ceH ^^^^^^^^^^^^^H^BIH^^^^^I a M.26 emlaH ■ b ■ b P.22& P.1 ^^^^^■^^^^^■H b b maU ^^^H^^^^^^HH b ) 1 1 MAC.39P A.313P p.isB ^^^^^^^^^^^1 c B.490 ■ ^^^^^^^I^HIH c MAC.iP ^^^^^^^H c Seedling U ^^^^^M c 0.0 0.5 1.0 1.5 2.0 Cumulative yield efficiency (bu/in^ TCA) Figure 3. Cumulative yield efficiency (1987-93) of Starkspur Supreme Delicious trees on varic rootstocks. Means are significantly different at odds of 19:1 if bars are not followed by the sai letter. us Tie Fruit Notes, Summer, 1994 13 Yield per tree (Figure 2) roughly correlated with tree size, with the largest trees producing the most fruit and the smallest trees producing the least. It is more important, however, to compare potential yield relative to tree size, i.e. more smaller trees can be planted per acre, which may or may not result in more overall 5deld. Yield efficiency is a somewhat accurate assessment of relative jdeld potential. It pre- sents 5deld per trimk cross-sectional area. Fig- ure 3 gives cumulative 3rield efficiencies for trees in this planting. The rootstocks break clearly into three groups. The most efficient trees were on P. 16, P.2, B.9, or C.6. The least efficient were on A.313, P. 18, B.490, MAC.l, or seedling. Trees on M.26 EMLA, P.22, M.7 EMLA, P.l, M.4, or MAC. 39 were intermediate in efficiency. A less accurate method for assessing potential 3deld uses estimates of planting density based on tree spread (Table 1). In this planting, more containment pruning was used for the largest trees than for the smallest, so potential planting Table 1. Projected spacing and tree density of Starkspur Supreme Delicious on various rootstocks in the 1984 NC-140 Cooperative Planting in Massachusetts. Spacing Between Between of trees Rootstock trees rows per acre P. 18 17 24 107 A313 17 24 107 Seedling 17 24 107 MAC.l 16 23 118 B.490 16 23 118 M.4 15 22 132 M.7 EMLA 14 21 148 PI 13 20 168 M.26 EMLA 9 16 303 C.6 8.5 15.5 331 MAC.39 8.5 15.5 331 B.9 7.5 14.5 401 P.2 6.3 13.3 520 P. 16 3.9 10.9 1025 P.22 2.8 9.8 1587 densities were very rough estimates, particu- larly for the largest trees. Multiplying density by yield per tree gives potential 3deld per acre. Figure 4 plots )deld per acre by year from 1987 through 1993. Figure 5 gives potential yield per acre on a cumulative basis over the seven fi*uit- ing years of these trees. The results were similar to those obtained when comparing yield efficien- cies among rootstocks. The highest yields per acre may be expected from trees on C.6, P.2, P.22, B.9, or M.26 EMLA. The lowest may be expected from trees on P. 18, A.313, B.490, MAC.l, or seedling. Fruit Ripening Knowledge of the effects on finiit ripening is a critical component of rootstock evaluation. The potential for advancement or delay in ripen- ing must be known so that harvest can be managed appropriately. If the delay or ad- vancement is predictable, it may be beneficial to use it to expand the harvest season. To assess the effects of rootstock on ripening, internal ethylene, soluble solids (sugars) con- centration, watercore development, and starch loss were measured in fruit fi"om this planting. Ethylene is a gaseous hormone present in all plants, but is very important to ripening in a number of fruits. Ethylene is a trigger of rip>en- ing and during the course of ripening, it in- creases many fold in apple fruit. It is possible to track ripening of apples by measuring ethylene concentration in the core cavity. Table 2 reports the date in 1989, 1990, 1992, and 1993 when the average internal ethylene concentration reached one ppm. Results were not entirely consistent from year to year, but a few rootstocks were consistently either in the lowest or highest category. Specifically, fi-uit from trees on B.9, MAC.39, M.7 EMLA, M.26 EMLA, or P. 16 consistently were among the first few to reach one ppm internal ethylene. Fruit from trees on seedling, M.4, B.490, P. 18, or A.313 consistently were among the last to reach one ppm internal ethylene. Internal ethylene is one of the most accurate measures of the progress of ripening; however, it 14 FruH Notes, Summer, 1994 Yield per acre (bu) 1,200 — B.9 + MAC.1 ^ MAC. 39 1,000 •DP.1 ^P.22 -0- Seedling ^M.4 ■ 800 9 M.7 EMLA Om.26 EMLA yf^^ ^B.490 ^ x' Jf£S^^>-^\^^^s^ ' ' Ap.2 •/ \. / •' yW^ji^ ^V^!^! c 600 BP.16 ■Spis \ ••■C.6 ^ 400 > •Xa.313 i/ff ^ v^*^ y^^ ^'j^^ mTI / Jr ^\ x.^^v\ y ^^___ 200^ r^^^^^ 0^ ^^^^y^ -»"jr 1987 1988 1989 1990 1991 1992 1993 Figure 4. Yield (per acre) of Starkspur Supreme Delicious trees on various rootstocks from 1987 through 1993. Estimates of appropriate spacings were used to calculate potential yield on a per-acre basis. is necessary to assess additionally other charac- teristics to get the most accurate picture of the difference in ripening. Soluble solids (or sugars) generally increase in concentration during the course of ripening as the result of the breakdown in starches. Table 3 give the soluble solids concentration of fruit from these trees in 1990, 1991, 1992, and 1993. Fruit from trees on B.9, MAC.39, P.22, P.2, or P. 16 consistently were among those with the highest levels of soluble soUds. On the other hand, fruit from trees on MAC.l, seedhng, M.4, M.7 EMLA, B.490, P.18, or A.313 were consistently among the lowest. Starch breakdown is measured easily by staining cut apples with an iodine-potassium iodide solution. Iodine stains the starch blue. leaving a distinctive pattern. This pattern changes during ripening in a regular way and can be compared to a standard chart to assess the progress of ripening. The index used in this study ranged from one to nine, with one staining densely and nine not staining at all. The index, therefore, increases during the course of ripen- ing. Table 4 reports starch index values from this study for 1990, 1991, 1992, and 1993. Fruit from trees on B.9, P.22, P.2, or P. 16 consistently were among the highest for starch index; whereas, fruit from trees on seedling, MAC.l, M.4, A.313, or P.18 consistently were among the lowest. As starch breaks down to sugar, osmotic imbalances may occur in the flesh of apples Fril/t Holts, Summer, 1994 15 c.6 P.2 P.22 B.9 M.26 EMLA MAC. 39 M.4 P.16 P.I M.7 EMLA P.18 A.313 B.490 MAC.1 Seedling a ab abc a be abed bede bede bede bede ede de de e e e , 0 12 3 4 Cumulative yield per acre (xlOOO bu) Figure 5. Cumulative yield (per acre, 1987-93) of Starkspur Supreme Delicious trees on various rootstocks. Estimates of appropriate spacing were used to calculate potential yield on a per-acre basis. Means are significantly different at odds of 19:1 if bars are not followed by the same letter. which result in the development of watersoaked areas. This disorder is referred to as watercore. Watercore generally becomes more severe as ripening progresses. Table 5 reports watercore index values from this study for 1990, 1991, 1992, and 1993. The index used ranges from one to seven, with one representing no watercore and seven representing severe watercore. Fruit from trees on B.9, MAC.39, P.22, P.2, or P.16 consistently were among the ones with the most watercore when there were differences. Fruit from trees on seedling, M.4, B.490, or P.18 were consistently among the lowest. Taking all of these characteristics into con- sideration, it appears that B.9 and P.16 consis- tently advanced ripening. MAC.39, P.2, and P.22 were less consistent but also may have resulted in an advancement of ripening. Seed- ling, M.4, and P. 18 delayed ripening. B.490 and A.313 were less consistent but also may have delayed ripening. MAC.1, P.l, M.7 EMLA, M.26 EMLA, and C.6 were either intermediate in their effects on ripening or were inconsistent. It is important for the grower to note the potential effects that rootstocks can have on apple ripening. In this planting, however, those effects were variable and unpredictable, pre- venting them from being exploited to expand the harvest season. Hopefully, other rootstocks will be found that have more predictable effects. 16 FruH Notes, Summer, 1994 Table 2. Date when the average internal ethylene concentration of Starkspur Supreme Delicious fruit reached one ppm. Fniit were from trees on various rootstocks in the 1984 NC-140 Cooperative Planting in Massachusetts. Means were adjusted for the effects of crop load.' Rootstock 1989 1990 1992 1993 P. 16 M.26 EMLA B.9 M.7 EMLA C.6 P.l P. 18 P.2 P.22 MAC.39 B.490 Seedling MAC.l M.4 A.313 — — 10/9 cd 10/4 ef 9/23 d 10/7 e 10/9 d 10/5 ef 9/24 cd 10/6 e 10/11 abed 10/5 ef 9/24 cd 10/5 e 10/9 cd 10/7 ede 9/27 be 10/6 e 10/9 ed 10/9 be 9/25 bed 10/6 c 10/11 abed 10/9 bed 9/27 bed 10/6 c 10/11 abed 10/9 bed — 10/13 b 10/10 abed 10/6 def — 10/21 a 10/10 bed 10/3 f 9/26 bed 10/6 c 10/11 abed 10/7 cde 9/26 bed 10/6 e 10/13 a 10/9 bed — — 10/13 ab 10/8 bed 9/28 ab 10/6 e 10/12 abe 10/7 cde 10/1 a 10/6 e 10/12 abed 10/10 ab — — 10/13 ab 10/13 a '■ Means within a column not followed by the same letter are significantly different at odds of 19:1. Table 3. Soluble solids concentration (%) of Starksp ur Supreme Delicious fruit from trees on various rootstocks in the 1984 NC-140 Coo perative Planti ng in Massachusetts. Means were adjusted for the effects of crop load.' Rootstock 1990 1991 1992 1993 P.22 10.7 ab 13.7 ab 10.8 a 12.7 a MAC.39 10.3 abe 13.3 abe 10.3 b 12.4 abe B.9 10.8 a 13.2 be 9.8 bed 12.4 ab P.2 10.5 abe 13.8 a 10.0 bed 11.9 bed M.26 EMLA 10.6 ab 13.1 e 10.0 bed 12.1 be P. 16 — 13.3 abe 10.2 be 12.2 be C.6 10.6 ab 12.8 cd 10.0 bed 11.5 d P.l 10.5 abe 12.6 de 10.0 bed 11.8 cd MAC.l 9.9 d 11.8 gh 9.7 cd 12.2 abe M.4 10.0 cd 12.3 ef 9.6 cd 12.0 bed M.7 EMLA 10.2 bed 12.0 % 10.0 bed 11.8 cd B.490 9.8 d — 9.5 d 11.9 bed Seedling — — 9.5 d 11.8 cd A.313 — — 9.5 d 12.0 bed P. 18 9.8 d 11.4 h 9.7 cd 11.9 bed '■ Means within a I column not followed by the same letter are significantly different | at odds of 19:1 Fru'n Notes, Summer, 1994 17 Table 4. Starch index values of Starkspur Supreme Delicious fruit from trees on various rootstocks in the 1984 NC-140 Cooperative Planting in Massachusetts. The starch index used ranged from one to nine, with fruit rated as one having almost complete starch staining and those rated as nine having no starch staining. Means were adjusted for the effects of crop load.' Rootstock 1990 1991 1992 1993 P.22 P. 16 P.2 B.9 M.26 EMLA P.l MAC.39 C.6 M.7 EMLA B.490 MAC.l A.313 P. 18 Seedling M.4 4.5 a 4.1 a 3.7 ab 5.2 a — 4.1 a 3.8 a 4.4 be 3.9 b 3.9 a 3.2 abed 4.6 b 3.9 b 3.5 abc 3.5 abc 4.0 bed 3.4 be 3.7 ab 3.3 abed 4.4 be 3.4 be 3.0 ed 3.2 abed 4.6 b 3.7 be 3.5 abc 3.1 bede 4.2 bed 3.3 be 3.2 bed 3.1 bcde 4.3 bed 3.6 be 3.2 bed 2.8 de 4.2 bed 3.4 be — 2.9 cde 4.3 bed 3.4 be 3.1 ed 2.8 de 4.1 bed .. — 2.7 de 4.3 bed 3.5 be 2.9 d 2.5 e 4.0 bed — — 2.8 de 3.8 ed 3.2 c 2.8 d 2.5 e 3.7 d Means within a column not followed by the same letter are significantly different at odds of 19:1. Table 5. Watercore index values of Starkspur Supreme Delicious fruit from trees on various rootstocks in the 1984 NC-140 Cooperative Planting in Massachusetts. The watercore index used ranged from one to seven, with fruit rated as one having no watercore and those rated as seven having severe watercore. Means were adjusted for the effects of crop load.' Rootstock 1990 1991 1992 1993 P. 16 MAC.39 B.9 P.2 P.22 P.l M.26 EMLA M.7 EMLA MAC.l A313 C.6 B.490 P. 18 Seedling M.4 1.1 a 1.1 a 1.2 a 1.0 a 1.1 a 1.1 a 1.1 a 1.0 a 1.1 a 1.0 a 1.0 a 1.0 a 2.5 ab 1.1 a 2.4 abc 1.4 a 2.3 abc 1.1 a 2.3 abc 1.2 a 2.3 abc 1.1 a 2.5 a 1.2 a 2.0 bed 1.3 a 2.1 abed 1.2 a 1.9 ed 1.2 a — a 2.3 abc a — a 1.8 d a — a 2.1 abed a 4.3 a 3.2 be 3.5 b 2.9 ed 3.0 c 1.8 fg 2.8 ed 2.4 de 2.3 e 2.2 ef 1.7 gh 1.9 efg 1.9 efg 1.6 gh 1.3 h Means within a column not followed by the same letter are significantly different at odds of 19:1. 18 Fruit Notes, Summer, 1994 Table 6. Fruit size, presented as the number of fruit per 42-lb box, for Starkspur Supreme Delicious trees on various rootstocks in the 1984 NC-140 Cooperative Planting in Massachusetts. Fruit size was adjusted to account for differences in crop load z Rootstock 1988 1989 1990 199] 1992 1993 C.6 80 a 77 ab 76 a 108 a 75 a 90 ab MAC.39 82 ab 73 a 78 a 113 a 77 ab 86 a P.2 86 abc 81 abed 76 a 109 a 78 abc 88 ab B.9 88 abed 82 abed 78 a 109 a 81 abed 88 ab M.26 EMLA 86 abc 83 abed 82 abc 107 a 82 abed 88 ab M.7 EMLA 93 bcde 81 abed 87 abed 102 a 81 abed 91 ab P. 16 96 cde 83 abed 82 abc 103 a 86 bcde 91 ab P.l 88 abed 82 abed 86 abed 106 a 86 bcde 102 be P. 22 92 bcde 79 abc 81 ab 100 a 97 e 114 c M.4 102 de 93 d 85 abed 105 a 90 de 93 ab Seedling 106 e 91 d 78 a 108 a 95 e 96 ab P. 18 93 bcde 82 abed 108 e 99 a 92 de 91 ab B.490 95 cde 87 bed 93 cd 102 a 88 cde 88 ab MAC.l 103 e 90 cd 90 bed 107 a 96 e 90 ab A.313 96 cde 87 bed 95 de 102 a 92 de 91 ab ' Means within a column not followed by the same letter are signifi cantly different at odds of 19:1. Fruit Size Fruit size is a very important determinant of financial return for the apple grower. In this study, fi-uit size was assessed annually from 1988 through 1993 (Table 6). Effects of root- stock on fruit size varied somewhat from year to year, but some rootstocks were more consistent in their effects than others. Fruit from trees on C.6, MAC.39, P.2, B.9, or M.26 EMLA always were among the largest; whereas, frmt from trees on A.313 or P. 18 were among the smallest. The potential effects that a rootstock can have on finiit size should be factored into the rootstock selection process. The Winners Standard sized trees are no longer economi- cally viable alternatives for orchard planting. Semidwarf trees are quickly losing their eco- nomic viability, because of labor requirements for harvest and management, fruit quality, and return on investment. As mentioned in the introduction, growers must move to dwarf trees to enhance the viability of their businesses. In this planting, trees on the various rootstocks ranged from standard sized to subdwarf The rootstocks that have the most potential based on their effects on tree size are M.26 EMLA, C.6, MAC.39, B.9, P.2, P. 16, or P.22, from the largest to the smallest, respectively. All result in what would be considered dwarf trees. As a general category, the dwarf trees outperformed other trees in the planting. In terms of potential productivity (taking into account yield efficiency and the potential yield per acre), C.6, P.2, and B.9 performed the best in the planting . These three also resulted in fruit in the largest cat- egory each year when there were differences related to rootstock. Trial plantings of C.6, P.2, and B.9 should be established by growers to determine further their suitability for New En- gland conditions. %f« %f^ %£• 9A0 •S^ rj% r|% r|% 0^ 0^ Fru'n Notes, Summer, 1994 19 O' Say Can You See Mite Predators in Apple Orchards? Ronald J. Prokopy, Xingping Hu, and Jennifer Mason Department of Entomologyy University of Massachusetts Most apple growers recognize the impor- tance of spider mites as potential pests and predatory mites as potential beneficials in or- chards. We in fruit research and extension often advise growers to scout trees both for predatory mites and pest mites before deciding whether or not to apply a miticide. The ratio of predatory to pest mites frequently is used as one of the bases for a spray decision. If there are one or more predators to every five pest mites, then there is reason to believe that predators can provide effective control without pesticide treatment. Making such a determination through scouting sounds simple enough, but in fact, it is quite demanding. Sampling a representative set of leaves in the orchard is difficult, but even more difficult is seeing predatory mites emd distin- guishing them from pest mites or mites that are neither friend nor foe. Here, we report on a study conducted in 1993 in which mite predator abundance on tree leaves assessed in the field by IPM scouts com- pared with mite predator abundance on tree leaves taken to the laboratory and examined under a microscope by a skilled mite taxono- mist. Materials & Methods We sampled leaves an average of 12 times (May to September) from a second-level IPM test block and an adjacent first-level IPM check block in each of 12 orchards, for a total of 298 sample events. For each event, we picked 10 leaves at random from each of 20 trees. All 10 leaves from each tree were examined immedi- ately by one or another member of the six- member IPM scouting team using an Optivisor (3x power). Five of these leaves (chosen at ran- dom) were placed immediately in a cooler and returned the same day to a refrigerator at 40F in our laboratory, where soon afterward they were examined under a microscope ( 15x power). In all, 59,600 leaves were examined in the field and 29,800 in the laboratory. We did not count every predator seen. Rather, we recorded the percentage of leaves in each 100-leaf batch that had predatory mites. Results Of all sampled leaves, only 0.8% were ob- served to have phytoseiid mite predators (ivory- colored Amblyseuis fallacis or ivory colored Typhlodromus pyri) by IPM scouts in orchards compared with 3.5% under a laboratory micro- scope (Table 1). For stigmaeid mite predators (yellow-coloredZetee//ia mali), percentages were 2.2 and 5.5, respectively. Among the 298 batches of sampled leaves, 17.9% were classified by both IPM scouts and lab exam as having phytoseiids present, 9.8% were classified by lab exam but not by IPM scouts as having phytoseiids, and 4.8% were classified by IPM scouts but not by lab exam as having phytoseiids (Table 2). For stigmaeid Table 1. Percent of all sampled leaves observed as having mite predators by IPM scouts in orchards versus by exami- nation under a microscope in the labora- tory. Type of predator IPM scouts Laboratory microscope Phytoseiid Stigmaeid 0.8 2.2 3.5 5.5 20 Fru'n Notes, Summer, 1994 Table 2. Percent of the 298 sampled leaf batches for which IPM scouting and laboratory microscopic examination did and did not agree on presence or absence of mite predators in the batch. Type of predator IPM absent, lab absent IPM present, lab present IPM absent, lab present IPM present, lab absent Phytoseiid Stigmaeid 67.5 63.5 17.9 19.8 9.8 9.5 4.8 7.2 1 mite predators, corresponding percentages were 19.8, 9.5, and 7.2. Remaining batches were classified by both IPM scouts and lab exam as having no predators. Conclusions Our findings indicate that the presence of predatory mites was detected more often under a microscope than by IPM scouts, particularly in the case of phytoseiids. In fact, among ail leaves examined, phytoseiids were detected more than four times as often and stigmaeids more than twice as often under a microscope than by IPM scouts. At least three factors may have contributed to this pattern of results. First, the greater magnifying power of a microscope may have facilitated detection of small, newly-hatched predators that are difficult to detect using an Optivisor or hand lens. Second, at least six IPM scouts were involved over the growing season in examining leaves for mites in orchards, and there may have been substantial variation among these scouts' ability to detect and iden- tify predators. In contrast, the same person performed all of the examinations under the microscope. Third, there may have been some redistribution of predators among leaves during transport to the laboratory, possibly resulting in the spread of predators to a greater prop>ortion of leaves. We believe, however, that this factor was minor compared with the first two factors. Regrettably, our findings suggest that a grower (who might be less skilled than an IPM scout in identif5ring mite predators) cannot rely on his or her counting of mite predators using a hand lens or Optivisor as providing an accurate assessment of the level of predators actually present. New York state IPM personnel have recognized this shortcoming and have created a tripartite sampling procedure for pest mites that excludes the need to sample for and identify mite predators. A slightly modified version of this procedure for use by Massachusetts grow- ers is described in detail in the 1994 March Message to Massachusetts Fruit Growers. In sum, we will continue to sample for mite predators in our monitored test and check IPM blocks but recommend that growers use caution in interpreting their mite predator monitoring results. Predators could be more abundant than meets the eye. Acknowledgments This work was supported by grants from the Massachusetts Society for Promoting Agricul- ture and the USDA Northeast Regional IPM Competitive Grants Program. %% %% ftl^ %% •^ 0^ r{^ 9^ rj^ r|% Fruit Notes, Summer, 1994 21 Apple Orchards in Switzerland: Differences Small and Large Donald C. Weber Institute of Plant Sciences I Applied Entomology, Swiss Federal Institute of Technology, CH-8092 Zurich Switzerland Since the beginning of 1993, when I left the University of Massachusetts, I have worked as a tree fruit research entomologist for the Swiss Federal Institute of Technology in Zurich. Since I also had experience with orchards in north- eastern U.S.A., I have found the differences in orchards and pest management between the U.S.A. and Europe to be quite fascinating. Eu- ropean agriculture offers some features which I feel could improve American pest management, and certainly some other features which should not be emulated! Most of my comments pertain in particular to Switzerland, but are more or less apphcable to neighboring countries as well. Small-scale and Intensive One of the most striking features of orchards in Switzerland is their small size, both in stature and in area. For the fresh market, dwarf roots tocks are the rule, and very high-density plantings (arovmd 1000 trees per acre) are trel- lised and on rootstocks such as M.9 and M.26. Fresh-market cultivars differ from those in the U.S.A. In Switzerland, Golden Delicious is the single most abundant cultivar, accounting for about 25% of the acreage; other important culti- vars are Idared, Maigold, Jonagold, Boskoop, Glocken, Gloster, Gravenstein, and Jonathan. Gala is being planted widely, but Cox Orange Pippin is not so common, although it is a leading cultivar in Holland and Great Britain. In Swit- zerland, the orchard acreages for any one farmer generally are small, family-owned, and often part of mixed farming including especially dairy cattle, sheep, and field crops. Government policy encourages diversified, intensive small farms which include animal husbandry. Big Money, Big Trees That is it for the small things. Two features, though, loom large: subsidies in the form of direct government payments, and the presence of large numbers of more-or-less unmanaged, high-stemmed (standard) apples and pears in the landscape. The Swiss people consider both their agriculture and their "Kulturlandschaft," or culturally -influenced landscape, to be a part of the national heritage. Agriculture is subsi- dized strongly. Because of changes in Swiss law made last year, payments to growers are based now on acreage and desirable management practices (including crop rotation and inte- grated production), rather than quantity of har- vest marketed. This is allowed by the so-called "Green Box" of GATT, under which member countries can encourage environmentally- sound practices through financial incentives. The Swiss economy is also highly regulated, aiding marketing associations in the formation of cartels that then fix quite high prices for agricultural and other goods. This combination of subsidies and quasi -monopoly marketing re- sults in food prices that are among the highest in the world. This may not be something to wish on the consumer, perhaps, but farming is more profitable! Now for the other large thing. Large pear and apple trees abound in this landscape, and are considered not only scenic but ecologically valuable. Most are minimally managed, and the apples and pears are harvested for cider. The pears thrive, thanks to the (until now)absence of fire blight. But the problem for pest manage- ment of fresh-market apples and pears is that these high-stemmed trees are great refuges for 22 Fru'n Notes, Summer, 1994 Obstbaume, vom Fachmann Fur die Pflanzsaison 1993/94 smd noch folgende Obslsonen erhalilich: M26 IVI27' M27 • Gravensteiner Rellstab M9 Summerred M9 Discovery M9 Prime Rouge M9 Cox Orange T-1 2 M9 CoxT-21, Korallo M9 Spartan M9 Kidd s Orange M9 Empire M9 Fiesta ■ M9 Rubinetle ' MS Royal Gala * M9 Gala Emia M9 Elslar • M9 Arlet M9 Sir Price V schoriresistent M9 Flonna ". schorlresistent M9 Libeny. schorlresisteni M9 Boskoop Schmta-HiJbsch M9 Jonagold Mg Jonagold Rubinslar ' M9 Jonagold Wiimuta " M9 Jonagored " M9 Jonica • M9 Glockenaplel M9 Golden Klon B M9 Golden, Smoolhee 1VI9 Golden Reinders * M9 Caiagolden ' IVI9 Gloster 69 IVI9 Idared M9 Maigold M9 Meran ' IVI9 Granny Smith M9 M25 M26 M25 K/127- M27 ■ M26 M26 M26 M26 M26 M26 ti(l26 M27 M27 M27 M26 M26 M26 M26 M26 M26 M26 M27 M27 M27 M27 •, M27 Sortenschut2 Zudem fuhren wir noch mehrere Aplelsorten sowie ein grosses Angebot an Tafelbirnen-, Zwetschgen- und KIrschbaumen sowie ein grosses Sortlment an Apfel-, Moslbirnen-. Zwetschgen- und Kirschhochstammen. Erich Dickenmann AG Dipl. Obstbautechnlker HTL 8566 Ellighausen TG TbI.072 68 16 29 Fax 072 6810 29 Typical offerings from a Swiss nursery. Note abundance of cultivars on M.9 and M.27. pests, particularly codling moths, and diseases. Not only is one not allowed to just cut them down, but the federal government rewards farmers for planting more! So the proposal of Ron Prokopy to eliminate untreated apples within 100 yards of commercial orchards, to reduce greatly codling moth colonization, would be viewed as heresy in Switzerland. Pest and Pesticide Differences The pest complex of European apple or- chards varies from country to coLintry, but in general the major insect pests are tortricids (codling moth and others), and aphids, particu- larly Dysaphis species, relatives of the rosy apple aphid. Relatively selective treatments are available to suppress these key pests, resulting in an enormous decrease in mite problems. These selective treatments include IGRs (insect growth regulators), primarily diflubenzuron (Dimilin''"'*), fenoxycarb (Insegar''""), and teflubenzuron (Nomolt'"'") for tortricids. All tor- tricid species are not equally susceptible. Spe- cies-specific viral preparations are available for codling moth and summer fruit tortrix (Adoxyphes orana). These require three to four applications against each generation of codhng moth, and superficial injury may occur never- theless because of delayed mortality of the young larvae. Pirimicarb (Pirimor"^") is a selective aphidicide (with some action against other piercing-sucking insects) registered worldwide for about 20 years, except in the U.S.A. It is extremely valuable not only in apples but in crops such as cole crops where aphids can be controlled without upsetting biological control of other pests. The availabihty of selective insecticides has reduced some pest problems, but it has increased others. Broad-spectrum insecticides against codhng moths previously also suppressed other tortricids. Non-selective treatments directed against aphids oflen re- duced populations of apple sawfly (the satoe one found in North America) and other early-s-eason pests to below economically-damaging levels. Now, more research is necessary to address these previously unimportant pest problems. FruH Notes, Summer, 1994 23 MIGROSSAIMO m 1/a Aus nafurqerechtem Anbau Full-page advertisement by Migros Supermarket (largest Swiss grocery chain) in the Tages Anzeiger, the largest daily newspaper in Switzerland. Text reads: Apple growing for the Migros-Sano program is regularly brought under close scrutiny. This assures an early knowledge of pests. And gives us the opportunity, to eliminate the problem with mild treatments and lower doses. For the benefit of nature and the environment! You can recognize apples from Migros-Sano-Production by this [orange and green] symbol: ["Aus naturgerechtem Anbau" = from agriculture which is fair to nature]. Luckily for European growers, apple maggot and plum curculio are not (yet) present, and therefore both are quarantine pests. IPM: Moving Forward A major difference in Europeem apple IPM (known as IP or Integrated Production, encom- passing more than just pest management) from that in the USA is that since at least three decades ago, the orchard working group of the International Organization of Biological Con- trol (lOBC, Western European section) has taken a lead role in development and implemen- tation of provisional treatment thresholds for the region, which now are fairly consistent among different countries. These thresholds first allowed reduction in use of broad-spectrum insecticides, which now have been replaced largely with more selective materials, resulting in a double benefit to predators and parasites, especially phytoseiid predatory mites. The 24 Fruit Notes, Summer, 1994 lOBC recently has proposed a comprehensive set of IP guidelines for grower certification, which will work through supervised participa- tion of grower groups at national and provincial levels. These would include fertilization, soil management, restrictions on size of monocul- tures, and other guidelines, in addition to regu- lation of pest management practices. The spe- cifics for individual crops, however, Eire still in process. Another major difference relates to the awareness of IPM on the part of the consumer. Supermarkets and strongly-coordinated grower associations have promoted IPM awareness. I will address this story, and more about specific pest-management innovations, in future ar- ticles. •Am mlm •Im •9^ %£• •^ r{% r{% 0^ r{% Fruit Notes, Summer, 1994 25 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 01002 SERIAL SECTION UNIV. OF MASSACHUSETTS LIBRARY AMHERST MA 01003 Account No. 3-20685 Fruit Notes Prepared by the Department of Plant & Soil Sciences. University of Massachusetts Cooperative Ebctension System. '^ United States Department of Agriculture, and Massachusetts Counties Coopei^fttr^^^^' Editors: Wesley R. Autio and William J. Bramlage ISSN0427-6906 Volume 59, Number 4 FALL ISSUE, 1994 Table of Contents Lighting Systems for Fruit Sorting A Test of a Potential Non-chemical Approach to Scald Control on Apples Influence of Understory Growth and Quantity of Drops on the Establishment of Voles in Apple Orchards Is Diphenylamine a Natural Compound in Apples and Pears? Do Bloom Applications of Fungicides Affect Fruit Set? Can Synthetic Scent of Predators Repel Deer in Orchards? J Fruit Notes Publication Information: Fruit Notes (ISSN 0427-6906) is published the first day of January, April, July, and October by the Department of Plant & Soil Sciences, University of Massachusetts. The costs of subscriptions to Fruit Notes are $8.00 for United States addresses and $10.00 for foreign addresses. Each one- year subscription begins January 1 and ends December 31. Some back issues are available for $2.00 (United States ad- dresses) and $2.50 (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 Dep£u-tment of Plant & Soil Sciences 205 Bowditch Hall University of Massachusetts Amherst, MA 01003 COOPERATIVE EXTENSION SYSTEM POLICY: 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 famiUar 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. I Issued by the University of Massachusetts Cooperative Extension System, Robert G. Helgesen, Director, in furtherance of the acts of May 8 and June 30, 1914. The University of Massachusetts Cooperative Extension System offers equal opportunity in programs and employment. Lighting Systems for Fruit Sorting Daniel Guyer, Roger Brool(, and Edwin Timm Agricultural Engineering Department, Michigan State University This article is modified from one that appeared in the Washington State University Tree Fruit Postharvest Journal, Vol. 5, No. 1, which was modified from Michigan State University -- Cooperative Extension Service Agricultural Information Series, AEIS 618, January, 1994. Fruits and vegetables are inspected prior to most processing or packing operations. While some sorting is accomplished with optical or electronic technology, much sorting is done by manual visual inspection. Each woricer must look at a few hundred items each minute and accurately discard those that are unacceptable. Good lighting conditions are required to perform this task. Sorting table lighting may not currently match the specific task for which it is intended. Specific guide- lines for lighting system design in fruit and vegetable sorting and packinglines in the U.S. do not exist. Manufacturers of packingline equipment have left lighting decisions up to the individual operation. Sorting table lighting must have both adequate intensity and color quality to enhance or reveal defects rather than to obscure or mask them. Improper lighting design promotes woilcer fatigue and eye strain, result- ing in poor sorting efficiency. Studies of several operations involving inspection of a range of commodi- ties have shown that many lighting systems are not adequate for the required task. These studies suggested that improved sorting results could be expected if relatively inexpensive changes in illumination sources, illumination intensities, and background colors were adopted in sorting areas. Principles of Lighting and Color Two common uses of lighting are (a) general area lighting, and (b) task lighting. General area lighting's purpose is to illuminate a room or building for general activity. This type of lighting is usually mounted in the ceiling or well above the floor area. Task lighting is much more specific and is concentrated in an area to enhance the ability to perform a task. Task lighting is the primary concern of this article which focuses on the task of manually sorting fruits and vegetables. Three major components interact in the process of visualizing a "color": 1 . light energy from a lamp or light fixture; 2. color reflectance potential of a fruit, caUed spectral reflectance: and 3. sensitivity of the eye to color, called receptor sensitivitv. For example, to "see" the color red there must exist a light source containing red color light, a surface which can reflect the red light and a receptor sensitive to reflected red light. Light Energy Light energy, or a source of light, is required to produce the actual visible color light which the eye can detect The natural light source is the sun which produces all visible colors in addition to energy outside the visible spectrum (ultraviolet, infrared, etc.). Colorsproduced by artificial light are influenced by tube coatings, such as phosphor in fluorescent tubes, gases, or other components contained in filament bulbs. Artificial light sources are rated by: 1. Color temperature; black body temperature generation; 2. CRI: Color Rendering Index; and 3. CPI: Color Preference Index. These ratings are explained briefly in the footnotes of Table 1. Of the three major components in visualizing color, light energy is the one most easily controlled. The important factor relating to artificial light is the spectral irradiance curve for a given light source. A spectral irradiance curve is a measured representation of a given light source showing the amount of specific light en- ergy or color contained in the source over the spectrum of colors. Spectral irradiance curves are generally available from lamp manufacturers. The spectral irra- Fruh Notes, Fall, 1994 Table 1. Artificial lighting characteristics and visual effects on common prod ice colors, 1992." Light source Rel Color Rel Visual effect on specified color (fluorescent tubes) Mfgr cost temp CRI CPI light Maroon Red Green Brown Blue Purple Yellow SP-30 1 1.8 3000 70 80 105 E E B E D E E SPX-30 I 5.9 3000 82 100 105 E E B E D E E Ultralume-30 2 3.7 3000 85 100 105 E E B E D E E Warm White 2 1.3 3000 53 37 102 E E D E D D E Warm White Deluxe 2 2.1 3000 79 90 68 E E D E D E E Oplima-32 3 4.9 3200 82 — 81 E E B E D E E Natural 2 3.1 3400 81 93 66 E E E D E E W Cool White 2 1.0 4100 67 58 100 D D E W E D W SPX-41 1 6.5 4100 82 100 103 E E E W E E W Cool White Deluxe 2 3.2 4200 89 94 70 E E D D E E D Colortonc-50 1 3.2 5000 90 92 70 E E E W E E W Ultralume-50 2 4.1 5000 85 100 105 E E E W E E W OpUma-50 3 5.2 5000 91 — 81 E E E W E E W ViuLite Plus 3 5.7 5500 91 — 100 E E E W W E D Daylight 2 1.7 6500 79 72 83 D D E W E D W Colorlone-75 1 4.2 7500 95 97 64 E E E w E E W 'Manufacturer: 1 = General Electric; 2 = Phillips; 3 = Dure Test. Rel cost: Relative bulb cost ratio to Cool White. Color temp: Lamp appearance in degrees Kelvin CRl: Color Rendering Index = effect the light source has on appearance of colored objecL . 100 = perfect appearance. CPI: Color Prefoence Index = how wel people recognize colors in that light, 100 = perfect recognition. Rel light; Relative initial lumen/watt output as a percentage of Cool White. Visual effect of tube on specified colon B = brownish cast; D = larker; E = enhanced; W = whitish cast Cool White effects arc relative to midday 1 diffuse outdoor light, other tubes are relative to Cool White. diance for a light source can be altered with various types of "filters" covering the lamp. These include undesirable coatings of dust and dirt. Spectral Reflectance Spectral reflectance of an object is basically the "color" of the object -- the ability of a fruit to reflect certain colors of light in the presence of natural light. In fruits, the chlorophyll, anthocyanin, or other natural pigments dictate the item's color. The apparent color of an item can be altered by changing the light source or by incomplete color receptor capability. Some defective and nondefective measurements for the same commod- ity vary in their reflectance over the entire spectrum while others either vary only in certain regions of the spectrum or they vary httle at all. Many defects that need to be detected on fruits and vegetables are of brown or grayish color. One might assume, therefore, that simply finding the light source with the most energy in the color regions making up the brown color would be ideal for all applications. The objective in selecting the best light source for a given task, however, is to light a commodity with a source that will accentuate the color difference between the sound tissue and the defects. For example, if we wish to find brown discoloration on red cherries, then we want to use an inspection light of a color that will accentuate brown against the normal red color of the cherry. The key is to fiTKi a color of inspection lighting that wiU make the defects show up the most, i.e., to make the commodity look its worst. Receptor Sensitivity The third component in perceiving a color is the receiving or sensing of the light. In this case, the human eye is the receptor. There is no adjustment to the human eye. The only variability is in the individual's sensitiv- ity to the color and quantity of the light. Sensitivity decreases with age and this should be a consideration during lighting design. Fruit Notes, Fall, 1994 o 0.20 0.15- S 0.10-I t; 0.05H At o.oo Doric Sw««t Cherry r40SP30 ot 500 ft-c<»ndl«» 9t o V CD c 91 ^1 "S o: Wavelength Figure la. Perceived color based on spectral irradiance, reflectance curves, and receptor sensitivity (Brown et al., 1993). 1 .00- i 0.80H E ^ 0.60H «> 67% of fruit surface affected. 32°F, a second set of samples was transferred to 70°F for five days and then returned to 32°F. A third set of samples was not treated in any way and served as controls. Mcintosh and Cortland were kept at 32°F for 22 weeks, and Delicious for 25 weeks. At the end of storage all samples were kept at 70°F for 7 days and then evaluated for scald, measuring its intensity on the scale of 1 = 1 to 10%, 2 = 1 1 to 33%. 3 = 34 to 67%, and 4 = more than 67% of the fruit surface affected. Results Results ofthe experiment are shown in Table 1. As expected, Mcintosh ripened the most during the har- vests and Dchcious ripx^ned the least, but in all cultivars, changes took place. After storage, little scald devel- oped on any of the control Mcintosh, but considerable amounts developed on Cortland and Delicious. DPA was very effective in controlling scald on Mcintosh and Delicious, but was only partly effective on Cortland. Warming had two opposite effects: it reduced scald on Delicious, but it markedly increased scald on Mcintosh and Cortland. Discussion As expected, as preharvest hours below 50°F in- creased, scald susceptibility of Delicious decreased, although the rate of decrease was somewhat more rapid than we have usually seen. We have not attempted to construct a predictive curve for Mcintosh because scald has occurred too infrequently in our tests. However, our predictive curve for Cortland is similar to that for Delicious, and the data for controls in Table 1 do not fit that curve. The first harvest should have produced nearly 100% scald, but produced only 9% scald. We have seen this happen before occasionally on early- picked fruit, and do not know what causes it to occur. Of more concern was the failure of scald to fall to very low levels with more than 150 hours below 50°F (the final two harvests of Cortland). Not only did the scald susceptibility not decline as expected, but these fruit also failed to respond fully to 2000 ppm DPA. (It is possible that an unusual form of scald developed, one that was not as controllable by DPA.) In our attempts to predict scald susceptibility, we are more concerned about underpredicting than about overpredicting scald, because in the former case a grower might experience 8 Fruit Notes, Fall, 1994 serious financial losses. Thus, we are continuing to try to refine our scald prediction system. The effects of warming on scald control on Deli- cious were just as we hypothesized. Warming reduced scald at all harvests, but only when susceptibility was relatively low did warming provide satisfactory scald control. For Mcintosh and Cortland, however, instead of reducing scald, warming clearly increased it. We have not seen this result in previous tests. The fact that all three cultivars were produced in the same orchard, harvested on the sameday, treated simultaneously, and stored in the same room shows that response to warm- ing can be very different among cultivars. We believe that the opposite results seen here among cultivars are related to the fact that Mcintosh and Cortland produce much more ethylene than Delicious, and ethylene has complex effects on scald development. These findings illustrate the risk involved in at- tempting to use a non-chemical scald-control proce- dure. Under the conditions of this experiment, using the predictive curve to determine when to rely on warming for scald control would have been a resounding success for Delicious. However, the predictive curve was not adequate for Cortiand, and warming was never effec- tive on Cortiand or Mcintosh. Whether or not warming is a suitable scald control procedure is not yet clear. Noticeable ripening can occur during warming, and it would entail major logis- tical problems to change fruit temperatures. However, the objective of this study was to use warming as an example of a non-chemical procedure applied in con- junction with scald prediction, and from this viewpoint it can be seen that at this point in time, it's a very risky approach, one that we caimot recommend. •T^ •T^ •Xa •sL* vL» #^ rp» •^ *^ •y* Fruit Notes, Fall, 1994 Influence of Understory Growth and Quantity of Drops on the Establishment of Voles in Apple Orchards Ronald Prokopy and Jennifer Mason Department of Entomology, University of Massachusetts When abundant, meadow voles and pine voles can cause severe damage to the bark or roots of apple trees, sometimes causing tree mortality. Growers are well aware that problems with voles can be especially great during winter. Under second-level IPM, a strong effort is made to integrate pest management practices across all classes of pests, including vertebrate pests such as voles. We report here on the effects on vole establishment of two IPM practices directed mainly at other kinds of pests. The first practice concerns management of understory growth (weeds) by mowing or herbicide application. In particular we wondered whether or not allowing imder- story growth to remain at a substantial height during autumn months would encourage vole establishment. The second practice concerns picking up drops during and after harvest. This practice is directed primarily at reducing emergence from drops of pest in- sect larvae such as apple maggot, codling moth, and lesser appleworm. Reduction in larval emergence from drops translates into reduced numbers of larvae overwintering within the orchard and hence reduction in threat to next year's crop. We wondered if allowing large numbers of drops to remain beneath orchard trees during autumn months would lead to vole establishment. Methods gust of 1993, we placed an asphalt roofing shingle (1 1 X 36 inches) beneath each of 10 perimeter-row apple trees in each of 12 second-level IPM test blocks and each of 12 nearby first-level IPM check blocks. The shingles were spaced evenly around the perimeter of a block. In October of each year, we lifted each shingle and examined the ground beneath for signs of vole establishment, either a trail or a hole into the earth. At the same time, we measured the height of grass or other foliage beneath the tree and categorized the number of drops in a range from few to many. Results There was no detectable difference in average plant height or average number of drops between second- In August of 1992 and Au- Table 1. Height of understory cover during October in relation to proportion of shingles that showed evidence of vole activity. Blocks represent a fu-sl-level and a second level block in each of 12 orchards in both 1992 and 1993, with years u-eated separately. Number of orchard blocks Height of cover (in) Shingles with vole activity (%) 11 5 10 14 8 0-5 6-10 11-15 16-20 21-25 10 24 36 39 48 1 10 Fruh Notes, Fall, 1994 Table 2. Amount 1993, in relation vole activity. of drops on the ground during October, 1992 and to proportion of shingles that showed evidence of Number of orchard blocks Estimated amount of drops Shingles with vole activity (%) 9 11 14 11 3 Few Few to Medium Medium Medium to Large Large 43 45 32 33 30 1 level and first-level IPM blocks. Such lack of differ- ence suggests that growers were applying understory management and drop pick-up practices equally to both types of blocks, even though our recommendation called for more intensive management of the second- level blocks. As shown in Table 1, there was a marked tendency toward increasing incidence of vole establishment with increasing height of grass. Orchards treated with herbi- cide or in which height of understory growth did not exceed 5 inches at time of sampling in October showed an average incidence of 10% of the shingles with vole activity, which we consider to be a comparatively non- damaging population level. In contrast, orchards in which understory growth exceeded an average of 21 inches showed an average incidence of 48% of the shingles with vole activity, a potentially very damaging population level. As shown in Table 2, there was no clear relationship between numberof drops and incidence of voles. Ifanything, vole establish- ment beneath shingles tended to be slightly greater in blocks with fewer drops than in blocks with greater numbers of drops. Conclusions We conclude form this two- year study that growers who maintain understory plant growth at a low height during autumn months have a much better chance of escaping establishment of voles than growers who do not. This conclusion may be particularly applicable to meadow voles. Many factors can affect the numberof voles immigrating into an apple orchard during autumn and becoming estab- lished beneath the trees. For example, a high abimdance of alternate food such as acorns might tend to discoiu-- age vole immigration into orchards. But in years when alternate food is sparse or in locales where orchards closely border woods containing many oak or ever- green trees, growers could substantially lower the risk of vole invasion by frequent mowing. Acknowledgments This study was supported by grants from the Mas- sachusetts Society for Promoting Agriculture and the USDA Northeast Regional 1PM Program. »T^ *^ vT^ *T# *^ •^ 0^ 0^ •^ 0^ Fruit Notes, Fall, 1994 11 Is Diphenylamine a Natural Compound in Apples and Pears? William J. Bramlage and Zhigao Ju Department of Plant & Soil Sciences, University of Massachusetts Thomas L. Potter Mass Spectrometry Facility, University of Massachusetts For over 30 years, dipping fruit in diphenylamine (DP A) before storage has been the standard commercial procedure to control superficial scald (scald) develop- ment on apples during and after long-term storage. However, this procedure is controversial since it consti- tutes a chemical treatment, and legally, DPA must be considered as a food additive. Some countries have banned treatment with DPA, and some prohibit impor- tation of DPA- treated fruit. In the U.S. and Canada, DPA is permitted and the maximum residue of 10 ppm should never be exceeded if DPA is applied correctly. Nevertheless, many American markets will not accept DPA-treated fruit because they have been chemically treated. In 1984, a report was published (Karawya and Wahab.y.Afamra/ProducW 47(5): 775-780) that DPA was found in relatively high concentrations as a natural product in mature onions, and that it was effective in lowering blood sugar levels in diabetics. The report also showed data that DPA was a natural product in tea. In that same year, a report of the Food and Agriculture Orga- nization of the United Nations ("Pesticide Residues in Food - 1984") stated that there "...is reasonable evidence that dipheny- lamine occurs naturally in apples though the level appears to be at or below 1 mg/kg (ppm)." No data to support this statement were cited, but in studies of DPA residues on apples, controls almost always contain measurable amounts of DPA. We became interested in this question when what appeared to be DPA was de- tectable, even though no DPA had been applied, during our measurements of ma- terials in apple peel that might be associ- ated with scald development. In 1993, the Massachu- setts Fruit Growers' Association provided us with a grant to pursue this question, and results of our study are reported here. In April, 1993 10-fruit samples were taken fiom bins of apples stored at the University of Massachusetts Horticulture Research Center (HRC), Belchertown. Five cullivars were sampled, and fruit were extracted in hexane. The extract was tested for presence of DPA using gas chromatography and mass spectroscopy, employing selected-ion-monitoring for maximum sen- sitivity. Results are shown in Table 1. All samples gave positive indication of DPA in their peel, ranging from 0.03 to 0.13 ppm, despite the fact that none had been treated with DPA after harvest. DPA is somewhat volatile, so to test for the pres- ence of DPA residues in the rooms at the HRC, one- square-foot areas of walls and doors in three different Table 1. DPA concentration in hexane extracts of apples stored 6 to 7 months in 0°C air. April, 1993. DPA Sample (ppm fr. wt. of fruit) Blank <0.01 Delicious 0.03 Mcintosh 0.03 Golden Delicious 0.13 Empire 0.13 Cortland 0.10 1 12 FruH Notes, Fall, 1994 Table 2. DPA concentrations in freshly harvested fruit . 1993. Cultivar Immature - Mature Weight DPA Weight DPA (g) (ppm fr.wt.) (g) (ppm fr.wt.) Mcintosh 440 0.002 (9/22) 1382 0.002 (10/7) 1190 0.001 Cortland 659 0.002 1620 0.001 RI Greening 319 0.003 1190 0.002 Empire 316 0.007 1147 0.002 Delicious 430 0.003 1396 0.003 Golden Delicious 510 0.004 1641 0.001 Anjou pear — — 2334 0.001 1 rooms were swabbed with dry cotton balls that had been pre-rinsed in hexane. The swabs were then extracted in hexane, which was monitored for DPA. All samplings produced DPA residues on storage surfaces, ranging from 0.4 to 13.1 ug/meter^ of surface. Thus, DPA in apple peel could have been the result of contamination from residues in the storage. To eliminate this possibility, 10-fruit samples of fruit were taken direcdy from trees at the HRC in August, 1993 while fruit were immature. The same four cultivars tested out of storage were sampled from the trees, and also fruit were taken from an organically- grown treeof Rhode Island Greening. Fruit again were sampled from these trees when they were mature. In addition, Mcintosh were sampled again when they were ovenmature, and Anjou pears were sampled at maturity. All of these samples were extracted in hexane immedi- ately after harvest, and the extracts were frozen until analysis. All samples exhibited the presence of DPA (Table 2), although the concentrations were about one- tenth those found in stored fruit. It is interesting to note the increase in fruit weight between the two harvests, without a reduction in DPA concentration, which indi- cates that the material continued to accumulate as the fruit grew. These results strongly supported the suggestion that DPA is a natural product in apples... and also in pears. However, for additional confirmation, two more tests were run. First, a Mcintosh extract was spiked with a minute amount of authentic DPA to make sure the method was recovering and measuring DPA. Spik- ing doubled the DPA measurement, with a 61% recov- ery of added DPA, so the procedure is capable of extracting and measuring DPA. A more rigorous evaluation of the procedure was made by producing a derivative of DPA, i.e., attaching another molecule to it, and separating and measuring the deri vatized molecule. This procedure is a test to see if it is truly DPA that was being measured. Derivatization produced three different ions; DPA plus the derivatizing substance, DPA plus part of the derivatizing substance, and DPA with a single proton removed from it. Using authentic DPA, these ions were in a ratio of about 1.0:0.6:0.3. When fruit extracts were derivatized, the three ions were not present in that ratio, raising doubts that we truly were measuring DPA. To test this further, 10-fruit samples of Delicious apples, from the same tree, that had and had not been dipped in DPA before storage were taken from storage in March, extracted, derivatized, and measured. The DPA-treated fruit contained 10 times as much derivatized DPA as did the non-u-eated fruit, and in the treated fruit the ion ratio was 1 .0:0.6:0.3, indicating that it was DPA that was being measured. In the non-treated fruit, the ratio was about 1.0:0.3:0.2, just as we found in the freshly harvested fruit. That result reaffirmed that at least part of what we were measuring as "DPA" in apple extracts probably Fru'n Notes, Fall, 1994 13 was something very similar to DPA, but not DPA itself. This does not mean that apples and pears do not contain natural DPA. If only half of the derivatized material in the Delicious extract was DPA, it could produce the ion ratio that was obtained. Therefore, our results leave imanswered the question, "Is DPA a natural compound in apples?" Clearly, something very similar to DPA is produced, and possibly some of what we were measur- ing was DPA. There is an important ramification of this study. Clearly, DPA or DPA-like compounds are being mea- sured on fruit that have not been treated with this chemical. It is present at harvest and accumulates during storage, since our fruit out of storage showed 10- times the concentrations of the fruit picked directly off the tree. DPA is a somewhat volatile compound, and the abundant residues we measured on the walls of our storage rooms show that there is likelihood of contami- nation of untreated fruit with DPA from the atmosphere in the storage or possibly from contact with bins and other equipment. Large quantities of DPA are used in industry as an antioxidant/stabilizer. For example, rubber products commonly contain DPA. Thus, fruit may absorb some DPA directly or indirectly from industrial products. If a test of fruit indicates the presence of DPA, its source could be any or all of the following: 1 . DPA application. 2. Contamination from residues in fruit storages, containers, or equipment. 3. Contamination from industrial use of DPA. 4. A natural product in apples that while not being DPA, is being measured as DPA. 5. Possibly, natural-product DPA in the fruit. Therefore, measurement of "DPA" in fruit is not proof that fruit were treated with DPA. There apparently is no such thing as "zero DPA" in apples. Conclusions must be based on thequantityofDPA present in the fruit, not on its absolute presence. In conclusion, we have not resolved the question of whether or not DPA is a natural product in apples and pears. Small quantities of something very similar to DPA, and possibly of DPA itself, is/are naturally occur- ring, but remain to be identified. However, we have shown clearly that conclusions drawn from DPA resi- due analyses must be based on quanfities measured, not on its presence in the fruit. An analysis showing the presence of DPA in fruit is not positive evidence of DPA application to the fruit. •X» *^ •X* *J>* *-£-• ry% •^ rp» #Y* •T* 14 Fruit Notes, Fall, 1994 Do Bloom Applications of Apple Fungicides Affect Fruit Set? Daniel R. Cooley Department of Plant Pathology^ University of Massachusetts Duane W. Greene Department of Plant & Soil Sciences, University of Massachusetts We reported previously [Fruit Notes 56(4): 18- 1991] that researchers in Great Britain found that fungicide captan may be toxic to apple pollen, and thereby reduce fruit set. Since then, a test in Virginia has shown similar reductions in fruit set, apparently caused by captan applied at bloom. Furthermore, growers have on occasion speculated that sterol-inhibiting fungicides re- duce fruit set. In the work reported here, we asked two questions. First, does captan or the sterol-inhibiting fungicide, fenarimol, applied at bloom reduce fruit set? Second, does captan or fenarimol interact with oil or copper to reduce fruit set? In 1992, mature Mclntosh/M.7 apple trees were selected at the University of Massachu- setts Horticultural Research Center in Belcherlown. In the first experiment, six limbs of similar blossom density were selected per tree. Three of the limbs were treated with copper hydroxide (Kocide 50 WP, 2 lbs/100 gal.) at tight cluster. Each of the three limbs treated with copper hydroxide and each of the three not treated with it were sprayed with captan (Captan 50 WP, 2 lbs/100 gal.) or fenarimol (Rubigan 1.6 EC, 12oz./100gal.)or left untreated. A second experiment was iden- tical except that oil (1 gal./lOO gal.) appUed at tight cluster replaced the copper hydroxide treatment. For both experiments, fungicide applications began when the primary blossoms were expanded completely, and captan and fenarimol applications continued at seven- or ten-day intervals, respectively, until mid-June. Treatments were applied to the drip point using a handgun. After June drop was complete, final 19, fruit set was counted on each limb, the In the first year of study, captan and fenarimol, with or without oil or copper hydroxide application, did not Table 1. Fruit set following various treaunents in 1992 and 1994. Within an experiment, no si gnificant differences were found among treaUnent means. Fruit set Treatment (number/cm^ 1992, Experiment 1 Check 3.8 Captan 5.7 Fenarimol 6.7 Copper hydroxide 5.7 Copper hydroxide plus captan 5.8 Copper hydroxide plus fenarimol 5.1 1992, Experiment 2 Check 5.8 Captan 8.3 Fenarimol 6.8 Oil 4.9 Oil plus captan 5.3 Oil plus fenarimol 4.6 1994 Experiment Check 4.2 Captan at king bloom 5.3 Captan at king bloom + 1 day 5.6 Captan at king bloom + 2 days 4.4 1 Fruit Notes, Fall, 1994 15 alter fruit set significantly (Table 1 ). The results from Great Britain were very specific in terms of time of sensitivity to captan, possibly explaining some of the lack of effect that we observed. In 1994, we conducted an additional experiment to study the specific timing of captan application. Mature Marshall Mclntosh/M.26 trees were selected and blocked according to blossom density. Within each block, one tree was treated with captan (Captan 50 WP, 2 lbs/ 100 gal.) when king blossoms were expanded fully, one was treated one day later, and one was treated two days later. A fourth tree was left untreated. Other than these captan treatments at bloom, all trees were managed similarly. After June drop was complete, final fruit set was counted on two limbs per tree. The different timings of captan application did not result in any significant reduction in fruit set (Table 1). Therefore, none of our experiments confirmed the results of studies conducted in Great Britain and Vir- ginia. We can only speculate that our growing condi- fions in 1992 and 1994 did not interact with captan in a way that caused reduced fruit set. Qearly, New En- gland apple growers should not be overly concerned that captan will reduce fruit set on Mcintosh. •1^ •l^ %1a •^ •J^ ry* •^ •Y* •T* "T* Publications Available Two publications recently released by Agriculture and Agri-Food Canada should be of interest to many readers of Fruit Notes. One is titled "Techniques for controlled atmosphere storage of fruits and vegetables" (Research Branch Technical Bulletin 1993- 18E), and it is a brief general review of the techniques currently in use for CA storage. The second is tided "Postharvest disorders of apples and pears" (Publication 1737/E), and it is a detailed review and update on postharvest physiological disorders of these fruit, including numerous photographs of the disorders. Both of these publications can be obtained without cost by sending your request to: The Librarian Agriculture and Agri-Food Canada Research Center Kentville, Nova Scotia B4N 1J5 CANADA 16 FruH Notes, Fall, 1994 Can Synthetic Scent of Predators Repel Deer in Orcliards? Ronald Prokopy and Jennifer Mason Department of Entomology, University of Massachusetts There is a growing number of studies suggesting that predator odors are repellent to potential prey. Repellency appears to stem at least in part from chemi- cal constituents of predator urine or feces. Deer can be very troublesome pests in apple orchards, especially during winter months, when they chew apple buds and twigs. Cougars and other large members of the cat family are among predators which deer fear the most. We report here on a small pilot study that we conducted to evaluate potential repellency to deer of synthetic odor of cougar feces. Materials and Methods TTie odor consisted of a 50:50 mixture of 3-propyl- 1 ,2-dithiolane and 2-propylthietane, encapsulated in polymeric plastic fibers to provide slow release. Both components of this mixture are present in cougar feces. Together, they convey a strong sulfur-like stench vaguely similar to the smell of a skunk but more pungent. The odorous fibers are still in a developmental stage, not yet available commercially. They were provided to us by Phero Tech Inc. of Delta, British Columbia. In November of 1992 and December of 1993, we hung 4 fibers on each of 25 perimeter-row apple trees at Rice's fruit farm in Wilbraham, Massachusetts. Each tree with fibers was separated by three perimeter-row trees without fibers, the middle tree of which served as the check tree. Ten twigs on each treated and check tree were examined for signs of deer injury just before emplacement of fibers and again one to three months afterward. Results and Conclusions The data in Table 1 show there was little if any repellent effect of the odorous fibers against deer feed- Table 1 . Percent of sampled twigs showing evidence of feeding by deer in plots of apple trees with and without synthetic odor of cougar feces. Test Injured twigs in trees (%) Sampling time With odor No odor 1 2 November, 1992' January, 1993 February, 1993 December, 1993" January, 1994 0 36 38 3 11 1 37 40 2 5 'Samples taken just prior to odor emplacement Fruit Notes, Fall, 1994 17 ing on apple trees in Rice's orchard. We were disap- pointed in this finding, especially because in a 1993 study, the fibers had shown strong repeUency for as long as 3 months against deer feeding on Sitka spruce seedlings in a plantation in McClinton, British Colum- bia. Several factors may have been responsible for the lack of repellency in our study. First, the number of fibers used (four per tree) may have been too few to provide effective repeUency, although employment of more than four per tree would have been too expensive for practical commercial use. Second, the fibers may emit too little odor under cold winter weather tempera- tures in New England to be effective against deer. Perhaps they are better suited for use imder warmer West Coast winter conditions. Third, the deer at Rice's may have been so hungry for winter food that hunger compromised their instinctive fear of cougars. Despite this lack of encouraging result, we firmly believe that improved knowledge of the chemical ecol- ogy of predators of orchard pests such as deer and voles will some day lead to development and fomiulation of blends of predator odor that wiU indeed effectively repel these orchard vertebrate pests, just as synthetic plant and insect odors are now being used effectively in managing orchard insect pests. A cknowledgments We thank Phero Tech Inc. for providing us with the odorous fibers. This work was supported by the Mas- sachusetts Society for Promoting Agriculture and the USDA Northeast Regional IPM Program. •X« •^ •sL» •sL* VL* •^ •^ •^ r^ •^ 18 Fru'n Nates, Fall, 1994 3^1 9 8 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 01002 SERIAL SECTION UNIV. OF MASSACHUSETTS LIBRARY AMHERST MA 01003 \ Account No. 3-20685 BOOKBINDING CO.. INR APR 27 1995 CI-IAi.