l^j^H University of ^^gk Massachusetts UMASS Amherst Library BIOLOGICAL OCT 2 5 1999 SQtgNCES LIBRARY UM/Morr. Per SB 354 F68 ^"ruit Notes Prepared by the Department of Plant & Soil Sciences. UMass Extension, U. S. Department of Agriculture, and Massachusetts Counties Cooperating. Editors: Wesley R. Autio and William J. Bramlage Volume 62,'Q|^mber 1 WINTER ISSUE, 1997 Table of Contents Positioning Unbaited Pyramid Traps to Capture Plum Curculios How Do Plum Curculios Approach Host Trees and Pjrramid Traps? Do Natural Sources of Odor Enhance Plum Curculio Attraction to Traps? Petal Fall is the Most Attractive Developmental Stage of Mcintosh Apple Trees to Plum Curculio Adults Jim Anderson Dies Peach Cultivar Trials: Observations and Comments Agri-Mek: A 1996 Field Trial in a Commercial Apple Orchard Fruit Notes Publication Information: Fruit Notes (ISSN 0427-6906) is published the each January, April, July, and October by the Department of Plant & Soil Sciences, University of Massachusetts. The costs of subscriptions to Fruit Notes are $ 1 0.00 for United States addresses and $12.00 for foreign addresses. Each one-year subscription begins January 1 and ends December 3 1 . Some back issues are available for $3.00 (United States addresses) and $3.50 (foreign addresses). Pay- ments must be in United States currency and should be made to the University of Massachusetts. 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Positioning Unbailed Pyramid Traps to Capture Plum Curculios Ronald Prokopy and Starker Wright Department of Entomology, University of Massachusetts In the 1996 Winter issue of Fruit Notes, we reported results of our 1995 research on plum curculio responses to unbaited "Tedders" traps. These traps are pjrramidal in shape, dark in color, and are placed on the ground. They capture curculios that arrive on the trap surface and subsequently crawl upward to the tip, where they enter an inverted screen funnel (a cotton boll weevil trap top) placed over the tip, from which they cannot escape. All reported tests to date using Tedders traps (hereafter referred to as pyramid traps) for capturing plum curculios have involved deploying unbaited traps between canopies of apple trees within rows. In 1996, we evaluated unbaited pyramid traps at four different positions on the ground in a small commercial apple orchard (Prokopy orchard) in Conway, MA. In addition, we compared curculio captures by pyramid traps with captures by unbaited cotton boll weevil trap tops placed in tree canopies. For each position or type of trap, we compared daily trap captures with daily incidence of orchard fruit scarring by plum curculios. Materials & Methods Each pyramid trap was black and measured 40 inches in vertical height, 22 inches in base width, and 2 inches in top width. Each was staked to the ground to prevent toppling by wind. All traps were constructed from plywood in our laboratory, but beginning in 1997, traps of essentially identical type can be purchased from Gemplers Inc., Mt. Horeb, WI (only known supplier). The orchard consisted of ten rows of five trees per row. Tree trunks were 20 feet apart between rows and 13 feet apart within rows. Trees were about 12 feet tall and about 10 feet in canopy diameter. Soil beneath tree canopies was treated with glyphosate in April and was devoid of vegetation throughout our study. The remainder of the orchard floor was covered with grass, which was maintained at a height of 2 to 4 inches. Dense woods, which we considered to be prime overwintering habitat for plum curculios, lay about 25 feet north of the end tree of each row, and a large open field of grass lay immediately south. At the pink stage of bud development, pyramid traps were placed in association with each of the trees in the second through ninth rows (Figure 1). One trap was placed 10 feet north of the trunk of the northernmost tree (15 feet from the woods), one trap 10 feet south of the trunk of the southernmost tree of a row (at the edge of the open field), one trap mid-way between the canopies of the northernmost and next northernmost tree of a row, and one trap 1 foot from the trunk of the center tree of a row. At the same time, a boll weevil trap top was placed on the cut end of a 4-inch upright twig in the upper part of northernmost trees in the second through ninth rows. Traps were examined daily at 7 AM from time of installation (May 14) until four weeks after petal fall (June 27). In addition to recording numbers of curculios captured each day, we also recorded daily (from full bloom on May 23 until June 15) the number of fruit receiving a curculio feeding or oviposition scar in samples of five fruit per tree per day (200 fruit per day among 40 trees). Orchard trees received no insecticide before bloom but were treated with phosmet on May 28 (80% petal fall) and on June 15. All traps were removed during treatment, which was applied by a motorized back pack sprayer to the Fruit Notes, Volume 62 (Number 1), Fall, 1997 1 Woods J c ,f 15ft -N 0000© * 0*0000 * 00000 * 00000 ' 00000 * 00000 * 00000 * 00000 00000 Field Figure 1. Pyramid-trap deplo5rment in this experiment in relation to tree location. Table 1. Numbers of plum curculios captured by pyramids capped by boll weevil trap tops or by boll weevil trap tops alone at different locations in a small commercial apple orchard, May 14-June 27, 1996, Conway, MA. Trap type Trap location Average number per trap* PjTamid Pyramid Pyramid P5Tamid Trap top alone Apple tree trunk 6.0a Between apple tree canopies 0.8b Between apple trees and woods 1.1b Between apple trees and open field 1.1b Apple tree canopy 0.4b 'Numbers followed by a different letter are significantly different at odds of 19:1. Fruit Notes, Vol ume 62 (Number 1), Winter, 1997 12 - 10 ■ E z ■ Scars D Captured Adults ♦ Insecticide Application r M I 6-Jun 8-Jun 10-Ju 12-Jun 14-Jun 23-May 25-May 27-May 29-May 31 -May 2-Jun 4-Jun Figure 2. Egg-laying scars and trap captures from May 23 through June 15, 1996. tree canopy and trunks. Results Unbaited pyramid traps placed adjacent to tree trunks captured at least five times more curculios than unbaited pyramid traps at any other position and 15 times more curculios than unbaited boll weevil trap tops placed in tree canopies (Table 1). Capture of substantial numbers of curculios by unbaited pjn-amid traps next to tree trunks could entice one to believe that such captures might be used as a basis for determining need for and timing of insecticide sprays against curculio. Unfortunately, this did not prove to be the case in the Conway orchard in 1996. In fact, there was no trap position for which there was even a faint positive correlation between daily trap captures and daily numbers of sampled fruit injured by plum curculios. Indeed, the correlation between daily captures by pyramid traps at tree trunks and daily fruit injuries was a negative rather than a positive one (Figure 2). In other words, during periods when captures were greatest, injury was least. Conclusions Our findings show that placing black pyramid traps next to apple tree trunks is the most effective position in terms of capturing the greatest numbers of plum curculios in an apple orchard. Results of additional studies (see following article) indicate that the principal reason why this position is better than any other position stems from the strong tendency of curculios, when crawling, to move toward Fruit Notes, Volume 62 (Number 1), Fall, 1997 areas of greatest darkness within an orchard (that is, toward tree trunks). Placement of black pyramid traps next to tree trunks capitalizes on this behavioral tendency, which is expressed just as strongly in an understory of vegetation as on bare ground. Even at this most favored tree-trunk position, however, unbaited black p5Tamid traps fall well short of being an effective means of monitoring the occurrence of curculio injury to apples. Additional studies (see following article) indicate that a principal cause for the failure of captures by unbaited pyramid traps on ground to be good predictors of fruit injury in tree canopies lies in the means by which curculios approach pjrramid traps and ap- proach tree canopies: by crawling or by flight. Evidence suggests that during warm weather, curculios may enter tree canopies directly by flight, bypassing tree trunks and pjrramid traps. Injury to fruit is greatest during periods of warm weather, such as occurred from June 5 through June 9 in the Conway orchard in 1996 (Figure 2). It appears that during this time period, most curculios arrived in tree canopies by flight and not by crawling up tree trunks (or up pyramid traps). What might be a solution to this shortcoming of pyramid traps during warm weather? One solution might be to use a powerful attractive odor in conjunction with a pyramid trap positioned next to a tree trunk (see following articles). Another solution might be to develop an effective odor-baited trap for use in the tree canopy. We are working toward both solutions. Acknowledgments This work was supported by grants from the USDA Northeast Regional IPM Competitive Grants Program, the USDA SARE Program, State/Federal IPM funds, and the New England Tree Fruit Growers Research Com- mittee. •Xa •Xa *1> vl* vL* r^ 0^ rp» 0^ #^ Fruit Notes, Volume 62 (Number 1), Winter, 1997 How Do Plum Curculios Approach Host Trees and Pyramid Traps? Ronald Prokopy and Starker Wright Department of Entomology, University of Massachusetts The means by which plum curcuhos approach host trees, whether by flight or by crawhng, can provide important background information leading toward optimization of design and location of traps for monitoring and possibly even controlling curculios. We report here on several studies conducted during 1996 aimed at learning more about movement patterns of curculios toward host trees and pyramid traps under varying sorts of weather conditions. Experiments & Results Movement Toward Host Trees. In our first experiment in a small unmanaged orchard of 36 semi-dwarf trees owned by Hardigg Industries of South Deerfield, MA, we wanted to determine whether curculios entered the tree by flying, by crawling, or by both means, and whether mode of entry depended on weather conditions. We coated the trunks of 12 trees (every third tree) with a thick 1-inch-wide band of Tangletrap about 2 feet above ground to prevent curculios fi-om crawling up the trunk and into the canopy. Direct observation of curculios attempting to cross this sticky band indicated that they were unsuccessful in doing so. None of the tips of branches of these or any other trees in the orchard reached closer than 2 feet above ground, thereby precluding curculios from crawling onto branch trips to reach the canopy. Height of grass was maintained below 4 inches. Another set of 12 trees (every third tree) was not treated with Tangletrap to permit curculio arrival both by crawling and by flight. Every evening at 8 PM from May 19 (full bloom) to June 7, we tapped the branches of each of these 24 trees over white cloth sheets placed on the ground beneath the canopy and collected all fallen curculios. We also obtained an hourly record of temperature at a nearby location for each day from May 19 to June 7. Results (Table 1, experiment 1) show that that total number of curculios collected fi^om trees having a band of Tangletrap was nearly equal to that of trees without a band of Tangletrap. Results (Table 1, experiment 1) also show there was a significant positive correlation between daily numbers tapped from trees having a Tangletrap band, as well as from trees without Tangletrap, and daily high temperature. These results provide two valuable pieces of information. First, a band of Tangletrap around the tree trunk is of no apparent value in preventing curculios from accessing host trees and causing injury to fruit. One reason for this lack of deterring effect may be that those curculios which crawl up tree trunks and are unable to pass beyond a sticky barrier subsequently fly into the tree canopy, provided the temperature is warm enough to permit flight. We did, in fact, observe directly some curculios behaving in this manner on warm days. Second, our prediction at the outset that numbers of curculios in tree canopies would be equal on trees with and without a Tangletrap band on warm days (signifying movement into canopies largely or solely by flight) but would be greater on trees without than with a Tangletrap band on cool days (signifying movement into canopies largely solely by crawling) was not supported by the data. On warm days, numbers were large on both types of trees, indicating that curculios were prone to fly into tree canopies on warm days. On cool days, numbers were few on both types of trees, indicating little tendency of curculios either to fly or to crawl into trees on cool days. Fruit Notes, Volume 62 (Number 1), Fall, 1997 Table 1. Numbers of plum curculios found in daily collections at 8PM in each of three experiments in Hardigg's unmanaged orchard, May 19 - June 7, 1996, South Deerfield, MA. Number of Exp. Treatment replicates Average number of curculios* Value of correlation with temperature 1 Trees with a Tangletrap band 12 Trees without a Tangletrap band 12 2 Clear Plexiglas, low position 12 Clear Plexiglas, high position 12 3 Pyramid traps with a Tangletrap band 6 P3rramid traps without a Tangletrap band 6 100a 107a 16a 14a 7b 20a 0.56 0.46 0.43 0.48 0.73 0.39 *Numbers in each experiment followed by a different letter are significantly different at odds of 19:1. **A perfect positive correlation between daily numbers of curculios found in each treatment and daily high temperature would be 1.00. Each correlation value shown here (except P5Tamid traps without Tangletrap) indicates a significant positive relation at odds of 19:1. In our second experiment, conducted in the same orchard, we wanted to gain more direct information on the extent of curculio flight into tree canopies on warm versus cool days. Therefore, on the remaining 12 trees in the orchard (every third tree not involved in the first experiment), we positioned two squares of clear Plexiglass (2 feet by 2 feet) vertically on a pole about 2 feet to the outside of the perimeter foliage of each tree: one square at base height of foliage and one square at top height of foliage. The entire surface of each square facing away from the canopy (but not the surface facing toward the canopy) was coated with Tangletrap to capture curculios flying toward the canopy. Traps were emplaced on the same dates and examined for captured curculios at the same time (daily at 8 PM) as in the first experiment. Results (Table 1, experiment 2) show that there was no significant difi'erence in numbers of captured curculios between the low- positioned and the high-positioned traps. Results (Table 1, experiment 2) also show there was a significant positive correlation between daily numbers captured at each position and daily high temperature. Furthermore, there were significant positive correlations between daily captures on high or low traps and daily numbers of curculios tapped from canopies of trees with or without a Tangletrap band (data not shown). Together, these findings constitute strong evidence that on warm days, curculios fly directly into tree canopies, whereas on cool days there is much less tendency to do so. Movement Toward Pyramid Traps. In our first experiment, we placed an unbaited pyramid trap midway between the trunk and canopy edge of each of the 12 trees that received sticky-coated squares of Plexiglas at the Hardigg orchard. Every other pyramid trap received a band of Tangletrap 4 inches above the base to prevent curculios from crawling to the top. The remaining six traps did not receive Tangletrap. All traps were in place fi"om May 25 to June 7 and were examined daily at 8 PM for captured curculios. Results (Table 1, experiment 3) show that Fruit Notes, Volume 62 (Number 1), Winter, 1997 traps with Tangletrap captured about one- third as many curculios as traps without Tangletrap, signifying that about two-thirds of the curcuHos captured by traps without Tangletrap arrived on the traps by crawling onto them rather than by flying onto them. As with crawling curculios that encoun- tered a Tangletrap band at the base of a tree trunk, crawling curculios that encountered a Tangletrap band at the base of a pyramid trap likewise subsequently may have taken flight, temperature permitting. Such flight appar- ently did not result in landing on the middle or upper part of a pyramid trap, however. Results (Table 1, experiment 3) also show there was a significant positive correlation between daily numbers captured by pyramid traps with Tangletrap (but not traps without Tangletrap) and daily high temperature. In our second experiment, conducted in association with three large unmanaged trees near Prokopy's home in Conway, we studied in greater depth curculio captures by unbaited pyramid traps that received a band of Tangletrap at the base and traps that did not. In all, there were two traps of each type beneath each tree, midway between the trunk and edge of canopy. Grass beneath each tree was maintained below 4 inches in height. Captured curculios were counted daily at 5AM and 10PM from June 29 to July 14. Results (Table 2) show that across the entire 24-hour period of a day, traps with Tangletrap captured about one-third as many curculios as traps without Tangletrap, corrobo- rating results of the preceding experiment at Hardigg. Interestingly, traps without Tangletrap captured about twice as many curculios from SAM to 10PM as fi-om 10PM to SAM, whereas traps with Tangletrap captured more than 20 times as many curculios fi*om SAM to 10PM as from 10PM to SAM. These results signify that about twice as many curculios arrive on pjrramid traps during daylight as during darkness, that about half of those arriving on pyramid traps during daylight do so by flying and half by crawling, and that almost all of those arriving on pyramid traps during darkness do so by crawling. There may be two reasons why very few curculios fly onto pyramid traps during darkness: first, on most nights, temperature during darkness may be too cool to permit flight; and second, curculios in flight during darkness may be unable to see pyramid traps. In our third experiment, beneath a plum tree at Prokopy's in Conway, we released a group of 40 field-collected plum curculios on the ground mid-way between the tree trunk and edge of the canopy. We did this on 12 evenings at 7:30 PM between June 22 and July 14 when the temperature was about 70°F and there was no rain falling. Four of the releases were made north of the tree on ground covered by 4 inches of grass, four north of the tree on bare ground (the grass was covered with soil), and four south Table 2. Numbers of plum curculios captured by pyramid traps beneath unmanaged apple trees at different times of day, June 29 - July 14, 1996, Conway, MA. Traps Number of replicates Average number captured* SAM - 10PM 10PM - S AM With a band of Tangletrap 6 Without a band of Tangletrap 6 4.3b 7.8a 0.2c 3.Sb ^Numbers followed by a different letter are significantly different at odds of 19:1. Fruit Notes, Volume 62 (Number 1), Fall, 1997 of the tree on bare ground. We placed one unbaited pyramid trap next to the tree trunk and one at the north edge of the canopy (when releases were north) or south edge of the canopy (when releases were south). Results revealed that about 20% of released curculios were captured by the trap at the trunk and about 4% by the trap at the edge of the canopy, irrespective of where released. Further results revealed that of all released curculios, about 15% eventually flew into the tree canopy, about 15% flew toward open space, about 1% flew onto the tree trunk, about 2% flew onto the trunk trap, and about 1% flew onto the edge trap. Interestingly, about 40% of released curculios crawled toward the tree trunk, with no more than 4% crawling in any other direction. This was true irrespective of whether curculios were released north or south of the tree trunk. These results support results reported in a preceding article in this issue showing that several times more curculios were captured by pyramid traps next to tree trunks than by pjrramid traps more distant from tree trunks. Results here also indicate that when evening temperatures are moderate (somewhat condu- cive to flight but not highly so), only a very small proportion of curculios that does fly alights on pyramid traps. The great majority in flight bypasses the traps. On the other hand, a very high proportion of crawling curculios moves toward the tree trunk, where they encounter and ascend either the tree trunk or an adjacent pyramid trap. Conclusions Perhaps the most important general conclusion from this array of studies is that when temperature is high enough to permit plum curculio flight, curculios may fly directly into tree canopies (either from overwintering sites or from ground beneath trees). In so doing, it appears that most are likely to bypass unbaited pyramid traps, irrespective of trap location. Unbaited pyramid traps, especially when located next to tree trunks, appear to be very good at capturing curculios that are crawling toward the greatest area of darkness in the habitat (that is, toward the center of the tree). Substantial numbers of curculios appear to crawl toward tree trunks and adjacent pjrramid traps when temperatures are too low and/or the amount of light is too little to permit flight. Hence, unbaited pyramid traps at tree trunks may afford an accurate representation of curculio populations in orchard trees during periods that favor curculio arrival in trees by crawling but not during periods that favor curculio arrival in trees by flight. Overall, as shown here, a band of Tangletrap around the tree trunk is of little value in preventing curculios from achieving substantial numbers in tree canopies. Acknowledgments This work was supported by grants from the USDA Northeast Regional IPM Competitive Grants Program, the USDA SARE Program, the New England Tree Fruit Growers Research Committee, and State/Federal IPM funds. We thank Jim Hardigg of South Deerfield, MA for permission to work in his orchard. *X* *X» *X* *X* *X* •^ #^ #^ #y* #^ Fruit Notes, Volume 62 (Number 1), Winter, 1997 Do Natural Sources of Odor Enhance Plum Curcullo Attraction to Traps? Ronald Prokopy and Tracy Leskey Department of Entomology, University of Massachusetts In a preceding article in this issue of Fruit Notes, we suggested that addition of a powerful attractive odor might enhance the capturing power of a pyramid or cone trap to an extent that such a trap could become reliable for monitoring the abundance of plum curculios in commercial orchards. Here, we report on 1996 tests in which we evaluated plum curculio males, plum curculio females, whole stored mature apples, pieces of stored mature apples, and fresh immature apples as potential natural sources of attractive odor for plum curculios. We also evaluated ammonium carbonate (an attractant for apple maggot flies) as a potential attractant for plum curculios. Experiments & Results Curculios as Odor Sources. Curculios used as odor sources were separated by sex shortly after emergence in summer and then were held over winter in containers outdoors until ready for use here. For each experiment, they were confined in a plastic container in groups of 20 same-sex individuals per container. Each container was cylindrical, about 2 inches in diameter and 3 inches tall, covered at the top with a clear-plastic lid to prevent entry of rainfall, and covered at the bottom with window screen to allow odor to emanate from the cylinder. Each cylinder, including "check" cylinders containing no curculios, received eight fresh-picked imma- ture apples (about 1/2 inch diameter), removed every other day. Traps with which these containers were associated were examined daily at 5 AM, at which time captured curculios were removed. On average, 15 of the 20 Table 1. Mean numbers of plum curculios captured per day in traps baited with either male, female, or no plum curculios. Average number Location of Bait Number of captured Exp. bait containers source replicates per day 1 Base of pjTamid trap Males 27 4.9a Females 27 4.5a None 27 6.2a 2 Top of pyramid trap Males 8 3.8a Females 8 1.9a None 8 5.1a 3 On boll weevil Males 15 0.2a trap tops on twigs Females 15 0.6a in tree canopy None 15 0.4a *In each I experiment, numbers followed by s I different letter are significantly different at odds of 19:1. 1 Fruit Notes, Volume 62 (Number 1), FalJ, 1997 curculios per container remained alive during the course of an experiment. In the first experiment, three containers of same-sex curcuhos were attached 8 inches above ground to the wings of pyramid traps, one container per wing. Traps were placed mid- way between trunks and perimeters of unmanaged apple trees from May 23 (full bloom) until June 12. Results (Table 1) show that traps baited with "check" containers devoid of curculios captured similar numbers of curculios than traps baited with live males or live females. In the second experiment, one container of curculios was affixed to an open-trap boll weevil trap top capping a p5rramid trap in such a way that odor could move fi"om the container of curculios through the boll weevil trap top and down onto the pyramid. Traps were placed mid-way between trunks and perimeters of unmanaged apple trees from June 13 until June 21. Results (Table 1) show that traps baited with "check" containers devoid of curculios captured similar number of curculios than traps baited with live males or females. In the third experiment, one container of curculios was affixed to a boll weevil trap top in the same manner as in the second experiment. Then, each was placed on the end of an upright twig at mid-height in the canopy of an unmanaged apple tree from May 23 until June 21. Results (Table 1) show that few plum curculios were captured by any of the traps, with no significant differences in captures among traps baited with males, females, or empty traps. Apples as Odor Sources. Apples used as odor sources were either mature Fuji apples stored over winter under refrigeration and washed thoroughly before use or immature Mcintosh apples (about 2/3 inch diameter) attached to freshly cut unsprayed branchlets. In the first experiment, 16 whole mature Fuji apples were distributed evenly on the ground at the base of each pyramid trap. Traps were placed mid-way between trunks and perimeters of unsprayed apple trees from May 21 (early bloom) until June 1. Results (Table 2) show no enhancement of trap captures by additions of whole mature apples at bases of pyramid traps. In the second experiment, a 2-inch wedge Table 2. Mean numbers of plum curculios captured per day immature apples or unbaited traps. in traps baited with mature or Exp. Location of bait Bait source Number of replicates Average number captured per day 1 2 3 Base of pyramid trap Boll weevil trap top capping pyramid trap Base of pjTamid trap Whole mature Fuji apples Unbaited Wedge of mature Fuji apple Unbaited Branchlets bearing immature Mcintosh apples Unbaited 12 12 24 24 16 16 2.0a 2.5a 1.5a 2.2a 4.3a 6.0a *In each experiment, numbers followed by a different letter are signifi odds of 19:1. cantly different at 10 Fruit Notes, volume 62 (Number 1), Winter, 1997 cut from a mature Fuji apple was placed inside a boll weevil trap top capping a pyramid trap in a way that odor could move down onto the pyramid. Wedges were renewed daily. Traps were placed mid-way between trunks and perimeters of unmanaged apple trees from June 3 until June 9. Results (Table 2) show no enhancement of trap captures by additions of apple wedges to boll weevil trap tops capping pyramid traps. In the third experiment, 4 branchlets (each with 12 Mcintosh apples) were distributed evenly on the ground at the base of each pyramid trap. Traps were placed mid-way between trunks and perimeters of unmanaged apple trees from June 15-22. Results (Table 3) show no enhancement of trap captures by additions of fresh-cut branchlets bearing immature apples at bases of pyramid traps. Ammonium Carbonate as Odor Source. Ammonium carbonate crystals were distrib- uted so as to cover screen bases of cylindrical containers of the type previously described for housing live plum curculios. In the first experiment, three containers of ammonium carbonate were attached 8 inches above ground to the wings of each pyramid trap, one container per wing. Traps were placed adjacent to trunks of unmanaged trees from June 22 until June 24. Results (Table 3) show that ammonium carbonate did not enhance trap captures. In the second experiment, a container of ammonium carbonate was affixed to an open- top boll weevil trap top capping a pjTamid trap in such a way that odor could move from the container through the boll weevil trap top and down onto the p3nramid. Traps were placed adjacent trunks of unmanaged trees from June 24 until June 26. Results (Table 3) show that ammonium carbonate had a significantly negative effect on trap captures. Conclusions Disappointingly, none of the sources of odor we evaluated led to an increase in numbers of plum curculios captured, either by pyramid traps placed on the ground beneath tree canopies or boll weevil trap tops placed within tree canopies. What might have been some causes of this lack of positive response of curculios to odor baits evaluated in conjunction with traps? In the case of male or female curculios as bait, we were quite puzzled by results until we carried out some additional laboratory tests. The way in which we conducted our field tests was consistent with the way tests of potential odor attractancy of one sex of insect to another is normally evaluated in the field. We fully expected to find that odor of male or female curculios was attractive to individuals of the same or opposite sex. This expectation was Table 3. Mean numbers of plum curculios captured per day in traps baited with ammonium carbonate (AC). Average number Location of Bait Number of captured Exp. bait containers source replicates per day 1 Base of pyramid trap AC 8 1.6a None 8 2.3a 2 Top of pjTamid trap AC 8 1.4b None 8 5.0a *In each experiment, numbers followed by a different letter are significantly different at odds of 19:1. Fruit Notes, Volume 62 (Number 1), FaU, 1997 11 heightened part-way through our field tests when a pubhcation appeared by chemists in Ilhnois detaihng the chemical structure of a pheromone (grandisoic acid) produced by male plum curculios that is equally attractive to both females and males, even when used in small amounts. This was indeed exciting news. Our follow-up laboratory tests showed, however, that when curculios are confined to small areas (such as the containers we used for curculios as odor sources), they emit stress sounds and/or odors alerting other curculios. These sounds or odors apparently mask or outweigh the luring power of attractive pheromone. This suggests that the most rewarding way to evaluate pheromonal odor in conjunction with traps in the field would be to use synthetic pheromone rather than a natural source of pheromonal odor. In the case of apple odor as bait, it appears that if natural sources of odor are used in the amounts evaluated here, either such an amount is insufficient to compete with fruit odor sources on adjacent trees, or natural sources of apple odor lose attractiveness (odor composition changes) rapidly after employ- ment. As with synthetic sex pheromones, sjrnthetic apple odor hopefully will become an effective alternative to natural sources of apple odor for attracting plum curculios to traps (see following article). Acknowledgments This work was supported by grants from the USDA Northeast Regional IPM Competitive Grants Program, State/Federal IPM funds, the USDA SAKE Program, and the New England Tree Fruit Growers Research Committee. •Xa •^Ia *X* *X* *1^ *^ •^ w^ rp» #^ 12 Fruit Notes, Volume 62 (Number 1), Winter, 1997 Petal Fall is the Most Attractive Development Stage of Mcintosh Apple Trees to Plum Curculio Adults Tracy LeskeyS Michele Bakis^ Holly Gagne^ Larry Phelan^, and Ronald Prokopy^ ^Department of Entomology^ University of Massachusetts ^Ohio Agricultural Research & Development Center, Ohio State University In the 1996 winter issue oi Fruit Notes, we reported the results of laboratory assays conducted in 1995 aimed in part at examining plum curculio responses to odors emitted from Mcintosh apple trees. We obtained some evidence indicating that attractive volatiles were emitted from all parts of Mcintosh trees (not just fruit) and were emitted in the most attractive form at petal fall. Here, we report on 1996 laboratory bioassays of curculio responses to extracts of Mcintosh twigs, leaves, and fruit at eight different tree- developmental stages, using different solvents. Materials & Methods Hexane and water extracts were made from twigs, leaves, or fruit of Mcintosh at each of the following stages of development: pink, bloom, petal fall, and 2, 3, 4, 5, and 6 weeks after bloom. Curculios used in bioassays were collected from unsprayed wild plum and apple trees and sexed in the laboratory. For all tests, curculios were starved for 24 hours prior to testing. Tests were conducted at the beginning of darkness. One curculio was placed into each petri dish bioassay chamber and allowed to move toward odors emitted from a hexane or water extract of Mcintosh tissue (the treatment) or toward hexane or water alone (used as a control). Hexane was allowed to evaporate before testing and curculios were given 2 hours to respond. To measure the power of a Mcintosh odor extract to stimulate curculio response, we used a response index. The response index was calculated by subtracting the number of curculios responding to the control from the number responding to the treatment, dividing this amount by the total number of curculios tested, and multiplying by 100. The greater the value of the index, the more attractive was the Mcintosh odor extract. We consider an index of 25 to be the minimum for suggesting attractiveness. Results Hexane extracts of Mcintosh twigs, leaves, or fruit at petal fall were more attractive than hexane extracts made at any other develop- mental stage (Figure 1). Hexane extracts of fruit at petal fall (index = 43) were similarly attractive to extracts of twigs or leaves at petal fall (index = 40 for each). These response indices are nearly identical to those recorded in 1995 for curculio responses to hexane extracts of Mcintosh fruit, twigs, and leaves at petal fall. Finally, both males and females responded equally well to extracts made with hexane. Water extracts of Mcintosh twigs, leaves, or fruit at pink, petal fall, and two weeks after bloom were the most attractive developmental stages (Figure 2). At petal fall, extracts of Mcintosh fruit (index = 71) were slightly more attractive than extracts of Mcintosh twigs Fruit Notes, Volume 62 (Number 1), Fall, 1997 13 Bloom 5 Wks 6 Wks Figure 1. Response Indices for plum curculio adults during 2 hours of exposure to hexane extracts of twigs (diamonds), leaves (squares), or fruit (triangles) from Mcintosh trees at pink, bloom, petal fall, or 2, 3, 4, 5, or 6 weeks after bloom. If the difference between two means of any stage exceeds 16 (based on a sample size of 12), then the means are significantly different at odds of 19 to 1. (index = 58), whereas extracts of Mcintosh leaves were marginally attractive (index = 25), most likely because the waxy layer on leaf surfaces prevented water from extracting volatile components. Again, both males and females responded equally well to extracts made with water. Conclusions From these results and from what we observed in 1995, we conclude that petal fall is the most attractive developmental stage of Mcintosh trees to plum curculio adults. Further, we believe that all Mcintosh plant tissues (twigs, leaves, and fruit) contain the attractive odor components at this time. These results further strengthen our hope that synthetic equivalents of these attractive Mcintosh plant odors can be identified and synthesized, providing tools to enhance trap effectiveness for monitoring and possibly even controlling plum curculios. Further, were believe that if synthetic host odors can be used in conjunction with synthetic male-produced pheromone identified in 1996 by Eller and Bartlett of Illinois, the curculio-capturing power of traps will be enhanced further. Our next step will be to examine curculio responses to host-plant odors used in combination with male-produced pheromone. Acknowledgments This work was supported by grants from the USDA Northeast Regional IPM Competitive Grants Program, the USDA SARE Program, State/Federal IPM funds, and the New England Tree Fruit Growers Research Com- mittee. 14 Fruit Notes, volume 62 (Number 1), Winter, 1997 Wks Figure 2. Response Indices for plum curculio adults during 2 hours of exposure to water extracts of twigs (diamonds), leaves (squares), or fruit (triangles) from Mcintosh trees at pink, bloom, petal fall, or 2, 3, 4, 5, or 6 weeks after bloom. If the difference between two means of any stage exceeds 20 (based on a sample size of 12), then the means are significantly different at odds of 19 to 1. *sL^ *^ *^ *^ *^ #^ #Y* *T* *T» *T* Fruit Notes, Volume 62 (Number 1), FaU, 1997 15 Jim Anderson Dies James F. Anderson, Emeritus Associate Professor of Pomology, passed away on February 8, 1997. Professor Anderson was born in Morgantown, West Virginia, and received his B.S. and M.S. degrees from the University of West Virginia. He served in the miUtary during World War II and participated in the Battle of the Bulge. Jim joined the faculty of the Pomology Department of Massachusetts Agricultural College in 1948 and retired from the Department of Plant & Soil Sciences of the University of Massachusetts in 1988. For many years Jim was involved in evaluation of new fruit cultivars, and he was expert at identifying fruit cultivars by their vegetative characteristics. However, his primary respon- sibility during these years was teaching, and he was honored by selection for a number of Outstanding Teacher Awards by the Stockbridge School students. In an^ interview at the time of his retirement, Jim said, 'Tou can't really learn about trees from books. You have to get out there with the trees." Many alums will remember their orchard pruning experiences with Jim in the dead of winter, because that is when the pruning is done. "But the students were all good about it; they never ambushed me," Jim said. "They'd know that I'd be out there in the cold with them." Jim leaves his wife, Edna (18 Wildwood Lane, Amherst, MA 01002). He also leaves his former colleagues, who are saddened by the loss of a true gentleman and friend, and by generations of alums who learned much more from him than was written in books. In memory of Professor Anderson's love of teaching, a memorial scholarship fund for students in Plant & Soil Sciences is being established. Anyone wishing to assist in this memorial to Jim may send a contribution to the Plant & Soil Sciences Scholarship Fund, c/o William J. Bramlage, French Hall, University of Massachusetts, Amherst, MA 01003. *sL» *X# *X* •A* *X» #^ •^ *y% #y» #^ 16 Fruit Notes, Volume 62 (Number 1), Winter, 1997 Peach Cultivar Trials: Observations and Comments Karen I. Hauschild Department of Plant & Soil Sciences, University of Massachusetts In the Fall 1995 issue of Fruit Notes, I described and commented on the first plantings of peaches and nectarines in my cultivar trial at the University of Massachusetts Horticultural Research Center in Belchertown. Since another full growing season has passed, it seems appropriate to add to the information presented previously. Additionally, in the spring of 1996, 1 added three yellow-fleshed peaches, replaced three yellow-fleshed peaches ft-om the 1993 trial, added one white peach and replaced another, and added three white-fleshed nectarines. The peach cultivar trial now includes 20 yellow- fleshed peaches, 7 white-fleshed peaches, 6 yellow-fleshed nectarines, and 3 white-fleshed nectarines. All cultivars planted prior to 1996 fruited in 1996. Following is updated information on the cultivars that were planted in 1990, as well as initial observations of fruit from the 1993 and 1994 plantings. I also will describe the cultivars that were planted in 1996. 1990 Planting Yellow- fleshed Peaches Jerseydawn was very popular at the Horticultural Research Center in 1996. For an early fruit, the flavor in 1996 was excellent, size was good, and split pits occurred in only about 20% of the crop. Redhaven. Size was not impressive this year, nor was flavor. There are several other cultivars in this harvest window that have better size and fruit quality than Redhaven. Salem fruit were very good to excellent in 1996. The flavor was excellent, size was good, and the fruit was very attractive. Flavorcrest fruit were very flavorful and had high quality in 1996. New Haven. Although fruit size in 1996 was some-what smaller than ideal, fruit quality was excellent. New Haven is a much better peach than Redhaven. Madison was an excellent peach. It had great peach flavor, was good size, and was attractive. Harrow Beauty was one of my favorites in 1996. The fruit had good size and great peach flavor. Jim Dandee fruit size was not as impressive in 1996 as it was in 1995, but the flavor of this peach was very good. Harcrest fruit were flavorful, had good size, and had very impressive quality in 1996. Fayette flavor was disappointing in 1996; however, it was a good late season cultivar. Encore may be too late for most growers, especially those who harvest large acreages of Mcintosh apples. It was a good peach for the late season. White-fleshed Peaches Summer Pearl fruit were not as flavorful in 1996 as in previous years. Quality was good, and size was good. Fruit do not hold up well after harvest. Nectarines Earliscarlet fruit sized well and had excellent flavor. Fantasia sized well and had excellent flavor and color but ripened in mid-September, a problem for some growers. Summer Beaut was an excellent nectarine. Size was good, fruits were flavorful, and color Fruit Notes, Volume 62 (Number 1), FaU, 1997 17 was good where trees were open. 1993 Planting Yellow-fleshed Peaches John Boy was a very large, flavorful peach. It was attractive, but did not have the best quality. Fruit were harvested a little late, which may have influenced quality. Sentry appeared to be a good peach, but further evaluations are required. White-fleshed Peaches Lady Nancy fruit were of good size and quality and very attractive. Red Rose fruit were medium in size and had good quality. 1994 Planting White-fleshed Peaches White Lady trees bore a few fruit in 1996, but will reserve comment until next year. Sugar Lady trees also bore fruit for the first time in 1996. Fruit were good size and had reason-able quality. Nectarines Easternglo produced a few fruit in 1996. Color was excellent, but flavor was not great. Sunglo produced few fruit in 1996. Fruit had good size, good color, and good flavor. 1996 Planting Descriptions below are based on catolog or on evaluations from other areas of the country. Yellow-fleshed Peaches PF-1 fruit ripen 20 days before Redhaven, are partial clingstone, and have very few split pits. Trees are hardy. Color is 90% red over yellow. PF-15A fruit ripen 13 days after Redhaven, are large, red over yellow, and freestone. Trees produce heavily and are hardy. PF-17A fruit ripen 17 days after Redhaven, are large, firm, and 70% red. Fruit are reported to be excellent for shipping. Trees are hardy. White-fleshed Peaches Raritan Rose fruit ripen 4 days after Redhaven, are firm, attractive, and freestone, with good quality. Trees are vigorous, hardy, and productive. White-fleshed Nectarines Arctic Glo fi"uit ripen 10 days before Redhaven, are medium-large, very firm, highly colored, and reported to ship well. Trees are vigorous and productive. Arctic Rose fi"uit ripen 7 days after Redhaven, are medium size, firm, very sweet, and highly colored. Arctic Queen fi'uit ripen 29 days after Redhaven, are large, firm, sweet, and highly colored. In 1997, I will conduct a more extensive evaluation of all the cultivars in this trial. I will evaluate fi"uit for size, color, taste, abnormali- ties (such as split pits), and texture. Tree vigor and productivity and disease resistance also will be evaluated. Also less favorable cultivars will be removed and possibly replaced with additional early cultivars. At this time, I recommend that Massachu- setts growers plant on a trial basis the following yellow-fleshed peach cultivars: Jerseydawn, Salem, Flavorcrest, New Haven, Madison, Harrow Beauty, Jim Dandee, and Harcrest. For a white-fleshed peach, Summer Pearl should be tried. Earliscarlet, Summer Beaut, and Fantasia are nectarines worthy of trial. •Xa •X* •X* *X» *JL* #Y% #T^ #Y* *i^ *V* 18 Fruit Notes, Volume 62 (Number 1), Winter, 1997 Agri-Mek: A 1996 Field Trial in a Commercial Apple Orchard Glenn Morin and Roberta Spitko New England Fruit Consultants, Montague, Massachusetts The 1996 growing season witnessed the introduction of a new pest-management tool with the federal registration of Agri-Mek (Merck and Co.) for managing both leafminer and mite in apples and pear psylla in pears. Following the withdrawal of Omite from the marketplace in April, most apple producers were pleased to have another option for European red mite (ERM) control. However, Agri-Mek's late-spring registration combined with the absence of experimental work conducted in New England left most field consultants and growers with limited informa- tion on how this product would be utilized best in the rapidly approaching season. The active ingredient in Agri-Mek, abamectin, is a naturally derived substance produced by a soil microorganism and is effective at extremely low rates. Agri-Mek is not related to other currently registered materials and therefore should prove useful in managing tolerant pest populations and prolonging the effective life of presently available compounds when used in a rotational program. Abamectin is absorbed into the leaf tissue where it forms a reservoir of active ingredient against foliar feeding pests. As a result, Agri-Mek is currently recommended within six weeks after petal fall and in combina- tion with horticultural oil in order to maximize absorption. Affected individuals essentially are paralyzed, stop feeding, and die within a few days. Optimal timing is critical to the cost-effective use of this material. Ideally, one would expect a single application to provide season- long suppression of ERM and leafminer populations. The focus of our trial was European red mite, as this pest would likely be the primary target for most Northeast growers considering the use of this material. The two most vulnerable periods for ERM within the recommended application time frame are 1) petal fall, when the majority of overwintering egg hatch has been completed and 2) first- generation egg hatch approximately 3-4 weeks later. ERM populations are fairly synchronous at these two times and are more easily disrupted than when multiple life stages are present. The following study was conducted to determine which of these two application timings would prove more effective in managing ERM populations. Procedure Treatments were applied to adjacent, non- replicated plots in a commercial apple orchard Table 1. Materials, rates and application dates for Agri-Mek trial, 1996. Materials were delivered in 150 gal /acre of water. All plots received 3 gal/acre oil on April 24. Check plot was treated July 7 with 18 oz/acre Carzol SP, July 25 with 5 lbs/acre Omite 30W, and August 9 with 3 pts /acre Vydate. Trt. Material + rate (product/acre) Timing 1 2 3 4 Savey @ 3 oz Agri-mek @ lOoz + oil @ 1 gal Agri-mek @ 10 oz + oil @ 1 gal Check May 9 May 23 June 17 Fruit Notes, Volume 62 (Number 1), FaU, 1997 19 owned and operated by Marshall Farms Inc., Fitchburg, MA. Each 1.5-acre plot consisted of three rows of primarily Mcintosh trees approximately 12 feet high, planted on 16 x 24 foot spacing with a dilute tree row volume of 280 gallons per acre. Treatments were made with a Hardie airblast sprayer calibrated to deliver 150 gal per acre while operating at 2.5 miles per hour according to the treatment schedule outlined in Table 1. European red mite populations were evaluated by selecting randomly 15 leaves per tree from each of 4 trees per treatment. Composite samples then were brushed unto glass plates and populations estimated using standard leaf-brushing protocol. Results & Discussion There were no substantial differences between treatments with respect to European red mite control in this study. Both Agri-Mek timings as well as the prebloom Savey application, included for comparison, were successful in suppressing ERM populations below injurious levels through the last week of August. Estimated mite populations in these plots ranged from 2.0 - 7.2 per/leaf on August 28 (Figure 1) with little or no foliar damage evident. ERM populations in the check plot, which received only a prebloom oil treatment, built rapidly after first-generation egg hatch and exceeded 15.0 mites per/leaf by early July. Moderate foliar damage was noted at this time and rescue treatments of miticide were applied July 7 and July 25 to prevent excessive damage. A third treatment was made on August 9 to suppress late-season build up. It is interesting to note that, although both treatments were successful in suppressing ERM populations below injurious levels, trees receiving the later Agri-Mek treatment applied on June 17 had more motile forms consistently throughout the growing season. Pre-treatment counts on June 14 revealed approximately 4.0 mites per/leaf, and although our application was successful in reducing that population, there were still significant numbers of motile forms on July 3 when one would expect to see full expression of the treatment. In contrast, the petal-fall treatment applied May 23 suppressed ERM numbers to barely detectable levels until early August and final counts on August 28 were less than 50% of the later 16-, 14 ■ -•— Agri-Mek + oil 5/23 1 12. s. «, 10- I 8- o 0) f « 3 C s 2 - 1 i —*— Agri-Mek + oil 6/17 ^ ^ .< 5-Jun 14-Jun 19-Jun 3-Jul 7-Aug 28-Aug Figure 1. Effect of various miticide treatments on European red mite populations. 20 Fruit Notes, Volume 62 (Number 1), Winter, 1997 treatment. It is unclear why this later treatment did not perform as well as the petal-fall treatment. The increased amount of foliage present in mid June may have adversely affected spray penetration and allowed for greater survival of mites in the inner tree canopy. Perhaps hardening off of the leaf tissue was a factor. This event may have decreased absorption of active ingredient to the extent that nymphs hatching several days post-application were not well controlled. Conclusion It appears from the data presented here that either a petal-fall application of Agri-Mek or an application timed to coincide with first- generation egg hatch can, under favorable conditions, provide satisfactory season long suppression of European red mite similar to that provided by a prebloom application of Savey. The treatment directed at first-generation egg hatch was less effective possibly due to decreased spray coverage or decreased absorp- tion of Agri-Mek into the leaf tissue. This difference was of little consequence in this trial, as summer weather conditions were relatively cool with ample rainfall and season-long suppression was ultimately achieved. How- ever, had weather conditions been more conducive to rapid mite build up, additional summer miticides may have been necessary to manage the residual population left by the later treatment. Based on these data, we suggest the petal- fall application as the more desirable of the two options presented here. •X* *1/* *X* *X* *X* #^ #Y* *v* *T* *T* Fruit Notes, Volume 62 (Number 1), FaU, 1997 21 Fruit Notes University of Massachusetts Department of Plant & Soil Sciences 205 Bowditch Hall Amherst, MA 01003 Nonprofit Organization U.S. Postage Paid Permit No. 2 Amherst, MA 01 002 1 SERIAL SECTION UNIV. OF MASSACHUSETTS LIBRARY AMHERST MA 01003 Account No. 3-20685 r UM/Morr Per SB 354 F68 'ruit Notes I by the Department of Plant & Soil Sciences, wividss, t^xtension, U. S. Department of Agriculture, and Massachusetts Counties Cooperating. Eklitors: Wesley R. Autio and William J. Bramlage 50 CO CD O o o Voaime 62, N&nber 2 SPR^G ISSUE, 1997 Table of Contents Improved Pesticide-treated Wooden Spheres for Controlling Apple Maggot Flies Comparative Level of Establishment of Released Typhlodromus pyri Predatory Mites in First-level and Second-level IPM Apple Orchard Blocks New England-wide Demonstration of an Integrated Pest Management (IPM) System for Apples and Consumer Education in IPM as a Pollution-prevention Strategy An Update on the 1994 NC-140 Apple Rootstock Trial An Update on the 1994 NC-140 Peach Rootstock Trial The Hay, Grain, and Feed Man: G. O. Bunnell, Northfield, Massachusetts Fruit Notes Publication Information: Fruit Notes (ISSN 0427-6906) is published the each January, April, July, and October by the Department of Plant & Soil Sciences, University of Massachusetts. The costs of subscriptions to Fruit Notes are $ 10.00 for United States addresses and $12.00 for foreign addresses. Each one-year subscription begins January 1 and ends December 3 1 . Some back issues are available for $3.00 (United States addresses) and $3.50 (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 UMASS EXTENSION 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. 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Autio Department of Plant & Soil Sciences 205 Bowditch Hall University of Massachusetts Amherst, MA 01003 Fruit Notes, volume 62 (Number 2), Spring, 1997 Improved Pesticide-treated Wooden Splieres for Controlling Apple Maggot Files Xing Ping Hu, Andrew Kaknes, and Ronald Prokopy Department of Entomology, University of Massachusetts In recent years, we have been working toward development of pesticide-treated spheres as a substitute for sticky spheres in controUing apple maggot flies. In the Spring 1996 issue of Fruit Notes, we reported on progress made through 1995 on development of pesticide- treated wooden spheres. Here, we assessed residual effectiveness against apple maggot flies of the best-performing version of pesticide- treated wooden spheres developed through 1995 versus a new tjrpe developed in 1996. We also evaluated the performance of each of these sphere types in controlling apple maggot flies in a small commercial orchard. Materials and Methods The 1995-version spheres consisted of three layers of materials: first layer = 76% sugar, 4% wheat flour, and 20% Glidden gloss red paint; second layer = 1% Digon 4E (=0.5% dimethoate), and 99% Glidden gloss red paint, third layer = shellac. The layer of shellac was intended to reduce the loss of fly feeding stimulant (sucrose) from the sphere surface during rainfall. To a significant degree, this loss was prevented. However, following rainfall or a series of heavy dews, spheres coated with shellac sometimes turned whitish in color, rendering them less visually attractive to apple maggot flies than completely red spheres. The 1996-version spheres featured a new approach to extending the residual activity of sucrose. Rather than rely on application of shellac (or several other applied substances that we evaluated prior to 1995) to extend the residual activity of sucrose, we instead drilled 14 evenly spaced holes (1/4 inch diameter x V2 inch deep) into each sphere and filled each hole with a mixture of 94% sucrose, 6% flour. This was followed by application of 2 layers of paint (same composition as first 2 layers of paint applied to 1995 - version spheres). To assess toxicity of spheres to apple maggot flies, in early July of 1995, twelve 1995- version spheres were hung fi-om branches of apple trees near Prokopy's small commercial orchard in Conway. Every other week thereafter until apple harvest, two spheres were brought to the laboratory for assays. In early July of 1996, the same procedure was followed for 1996-version spheres. For assays, thirty flies were allowed to stay and feed on each sphere for up to five minutes, follovdng which, flies were placed in cages and examined for mortality 24 hours later. Rainfall was measured by a rain gauge placed near trees. Comparison of pesticide-treated spheres with sticky spheres for providing direct control of apple maggot flies was made in the Prokopy orchard, which consisted of 50 trees (10 rows x 5 trees per row, primarily Liberty/M.26). In 1995, each tree in the five eastern rows received two 1995-version pesticide-treated spheres, whereas each tree in the five western rows received two sticky (Tangletrap-coated) spheres. In 1996, the arrangement was reversed, with each tree in the five eastern rows receiving two sticky spheres and each tree in the five western rows receiving two 1996-version pesticide- treated spheres. Spheres were deployed in July each year, were unbaited, and were positioned optimally for attracting apple maggot flies. At harvest, every tenth picked apple was Fruit Notes, Volume 62 (Number 2), Spring, 1997 Table 1. Residual effectiveness of dimethoate-treated red spheres (before treatment) against laboratory-tested apple maggot flies. Spheres* Weeks of sphere exposure Retreated in orchard with 2 4 6 8 10 12 sucrose 1995 Version Fly mortality (%) Cumulative rainfall (in.) 1996 Version Fly mortahty (%) Cumulative rainfall (in.) 90 0.4 95 1.6 80 2.0 90 2.0 60 4.3 85 2.4 40 5.1 80 3.2 30 -- 70 5.7 70 55 75 7.2 10.2 *Spheres in 1995 received two coatings of paint and a third coating of shellac. Spheres in 1996 were drilled with 14 holes subsequently filled with a sucrose/flour mixture and received two coatings of paint. examined carefully for maggot egglaying stings. Results presence of apple Results of laboratory assays of residual efifectiveness of pesticide-treated spheres against flies (Table 1) show that after four weeks of exposure and two inches of rainfall, 80% of flies placed on 1995-version spheres died compared with 90% that died when placed on 1996- version spheres. In 1995, after ten weeks of exposure (5.7 inches of rain), 1995-version spheres killed only 30% of tested flies. In 1996, after ten weeks of exposure (7.2 inches of rain), 1996-version spheres killed 70% of tested flies. In fact, for every period when assayed, 1996- version spheres outperformed 1995-version spheres (Table 1). Retreating spheres with 16% sucrose solution (in water) after twelve weeks of exposure restored effectiveness of 1995 spheres to a level of 70% fly kill, demonstrating that loss of sucrose as feeding stimulant and not loss of dimethoate as toxicant was the principal factor responsible for decreasing performance. Results of tests assessing the capability of pesticide-treated spheres for providing direct Table 2. Effectiveness of dimethoate-treated red spheres versus sticky-coated red spheres in providing control of apple maggot flies in a small commercial orchard. Year Treatment Number of fruit examined Fruit with fly egglaying stings (%) 1995 1996 Spheres - 1995 version Sticky spheres Spheres - 1996 version Sticky spheres 1263 1294 896 913 1.0 0.9 0.6 0.7 1 Fruit Notes, volume 62 (Number 2), Spring, 1997 within-orchard control of flies (Table 2) show that 1995-version spheres as well as 1996- version spheres provided a level of control essentially identical to that provided by sticky spheres (1.0% fruit injury or less). In contrast, 96 and 97% of fruit on unmanaged apple trees and about 250 yards away was injured by apple maggot flies in 1995 and 1996, respectively. In 1995, pesticide-treated spheres were dipped in a 16% sucrose solution weekly after the fifth week of exposure to renew feeding stimulant. In 1996, no such dipping was performed. Conclusions Our findings show that 1996-version pesticide-treated spheres (each with 14 sugar- filled holes) maintained high season-long residual activity against apple maggot flies and provided excellent control of this pest under commercial orchard conditions. They have a distinct advantage over earlier versions of pesticide-treated spheres in requiring no re- treatment with sucrose solution during the growing season. Their major shortcoming is the need to drill holes in each sphere and then to fill each hole with sucrose/flour mixture annually before painting. In the coming year, we plan to determine the optimum number and size of holes needed to attain season-long sphere effectiveness and to determine if one rather than two coats of paint will suffice. Acknowledgments This work was supported by a grant from the USDA Northeast Regional IPM Competi- tive grant and Hatch funds. ml0 mlm «£• mS^ %9^ •^ r|% 0^ 0^ «^ Fruit Notes, Volume 62 (Number 2), Spring, 1997 Comparative Level of Establishment of Released Typhlodromus pyri Predatory Mites in First-level and Second-level IPM Apple Orchard Blocks Ronald Prokopy, Starker Wright, and Jennifer Mason Department of Entomology, University of Massachusetts Jan Nyrop, Karen Wentworth, and Carol Herring Cornell University, NY Agricultural Experiment Station, Geneva As described in the Spring 1994 issue of Fruit Notes, Amblyseius fallacis is the most commonly occurring predatory mite in Massa- chusetts apple orchards. Unlike orchards in many other states, few Massachusetts apple orchards harbor detectable levels of Typhlodromus pyri predatory mites. Previous studies in Massachusetts have shown that A. fallacis rarely builds to levels capable of providing effective control of European red mites until mid-July at the eairliest, and often not until August. In contrast, studies in New York have shown that T. pyri, where established, can provide effective biocontrol of European red mites beginning as early as May. In 1995, we released T. pyri into two first- level IPM and two second-level IPM block of apple trees in each of six commercial apple orchards in Massachusetts. Here, we report on the abundance of T. pyri in samples taken in September of 1995 and 1996 in each of these blocks as well as in adjacent first- and second- level IPM blocks where no T. pyri were released. Materials & Methods All six orchards were located in west-central or east-central Massachusetts. Each block was comprised of about 60 trees of the cultivars Mcintosh, Empire, or Cortland (on M.7 or M.26 rootstock). First-level IPM blocks received pesticide sprays applied by growers timed according to pest and weather-monitoring activities that the growers themselves carried out. Second-level IPM blocks were treated identically to first-level blocks through early June. Thereaft;er, no pesticide of any type was applied to second-level blocks. Instead, a combination of behavioral, cultural, and biological control techniques was used. In 1995, blossom clusters harboring T. pyri were picked fi-om an orchard at the New York State Agricultural Experiment Station at Geneva, transported in a cooler by automobile to Massachusetts on the same day when picked, and placed the following day in targeted blocks. This involved using twist-ties to attach 50 blossom clusters to the central tree of each target block. In September of 1995 and 1996, 25 leaves were picked at random from the central tree (that is, the release tree) in each block receiving T. pyri and 25 leaves fi-om each of four trees nearest the central tree. A similar protocol was followed for sampling central and adjacent trees in first- and second-level blocks not receiving released T. pyri. Sample leaves were cooled and shipped to Geneva, New York for identification and counting of predatory mites. Fruit Notes, volume 62 (Number 2), Spring, 1997 Table 1. Abundance of mite predators on leaves sampled in September from first-level and second-level IPM blocks in which T. pyri were or were not released in May of 1995. Species Year Average number of predators per leaf* First-level IPM Second-level IPM Non-release block Release block Non-release block Release block T.pyri A. fallacis 1995 1996 1995 1996 0.00 b 0.02 b 0.15 a 0.28 a 0.04 ab 0.19 ab 0.14 a 0.11a 0.00 b 0.01b 0.11a 0.13 a 0.07 a 0.42 a 0.19 a 0.18 a *Values in each row followe d by the same letter are not significantly different at odds of 19 to 1. Results For T. pyri, the results (Table 1) show that for the 1995 samples, small but detectable numbers of this species were found in the release blocks, but none were found in the non- release blocks. For the 1996 samples, numbers cf T. pyri in the release blocks averaged considerably greater than they did in these same blocks in 1995, suggesting that a buildup of T. pyri had occurred. Almost no T. pyri were detected in 1996 samples taken in the non- release blocks. Interestingly, when data for 1995 and 1996 release blocks were pooled, analysis indicated a significantly greater average number of T. pyri in second-level than in first-level IPM blocks. For A. fallacis, the results (Table 1) show quite similar numbers of predators of this species present in each t3rpe of block each year. When data for 1995 and 1996 were pooled, analysis indicated no significant difference in average number of A. fallacis between second- level and first-level IPM blocks. Examination of grower spray schedules revealed that no insecticides other than Guthion, Imidan, Lorsban, or Sevin (as a thinner) and no acaricides other than oil. Omite, Apollo or Savey were applied to any blocks during either year. None of these materials is known to be harmful to T. pyri. We believe that the significant negative effect of first-level compared with second-level IPM practices on the buildup of T. pyri was due to fungicide use from early June onward in the first-level blocks. Fungicides used after early June included Penncozeb, Dithane, Ziram, Polyram, Benlate, Topsin, and Captan. The first four of these materials are known to have detrimental effects on T. pyri. Conclusions Our findings indicate that by the end of the growing season of the year following their release, T. pyri mite predators appeared in readily detectable numbers in nearly all blocks in which they were released. The only exception occurred in one of the six orchards, where they were detected in neither of the release blocks. This orchard received 2 applications of Dithane annually in May, which might have impacted establishment of T. pyri negatively. It appears from our results that pesticides, particularly certain fungicides, have Frait Notes, Volume 62 (Number 2), Spring, 1997 a greater negative impact on buildup of T. pyri Acknowledgments than on buildup of A. fallacis. We suggest, therefore, that growers who are considering releasing T. pyri to attain establishment do so only in blocks that will not be treated with pesticides that may be harsh on T. pyri, including pyrethroid insecticides, acaricides such as Carzol, and fungicides such as Ziram or EBDC-based materials. This work was supported by a USDA Northeast Regional IPM Competitive Grant and by State/Federal IPM funds. mS^ «1« m^M %S^ mS^ r|^ 0^ W^ r|% W^ Fruit Notes, volume 62 (Number 2), Spring, 1997 New England-wide Demonstration of an Integrated Pest Management (IPM) System for Apples and Consumer Education in IPM as a Pollution-prevention Strategy WilUam M. Coli and Craig S. HoUingworth University of Massachusetts James F. Dill University of Maine Alan T. Eaton University of New Hampshire Heather Faubert University of Rhode Island Lorraine M. Los University of Connecticut The strategies known collectively as IPM have been recognized as one way to reduce the amount of agricultural chemicals released into the environment. IPM has been shown to address the needs of New England agriculture, and pollution prevention, by reducing and optimizing pesticide use. Many New England growers have been in the forefront of widespread early adoption of these new technologies, partly as a conse- quence of aggressive, regional Cooperative Extension outreach programs. In Massachu- setts, for example, approximately 40% of the state's cranberry and apple acreage, and about 20% and 9% of strawberry and sweet com acreage, respectively, receive some form of IPM monitoring and advice from private-sector scouts or consultants, and still larger acreages are managed under IPM by the growers themselves. Such widespread grower adoption of IPM has set the standard for environmen- tally responsible agriculture. However, although consumers typically express concern about perceived public-health and food-safety risks associated with agrichemical use, a very small percentage of the general public has even heard of IPM, and still fewer recognize its potential benefits and the extent of its use. More widespread demonstration and consumer education of the environmental benefits of IPM are likely to enhance positive consumer attitudes towards local agriculture. In spite of the potential benefits to Fnilt Notes, Volume 62 (Number 2), Spring, 1997 agriculture of increased adoption and consumer awareness, successful IPM strategies demon- strated in one state have not always been adopted regionally. This is partly due to a tendency of growers to emphasize uncertainty associated with farm-to-farm or state-to-state differences in pest complexes, weather, normal cultural practices, intended markets, etc. Since IPM adoption has not been universal, there remains a need for regionally-consistent systems to evaluate progress toward the Federal-policy goal of IPM implementation on 75% of managed acres by the year 2000. One possible way to measure extent of grower IPM adoption is by use of commodity- specific IPM definitions, known as IPM Guidelines, originally developed in Massachu- setts. These guidelines, in the form of checklists and a related point system, have been used since 1990 as the basis for successful implementation of the state Farm Services Agency (formerly ASCS) cost-sharing program in Integrated Crop Management (ICM) and a related state-endorsed consumer education and marketing effort known as Partners With Nature. With this background in mind, in 1994, a small group of New England Extension and research specialists successfully acquired a Region I USEPA Pollution Prevention Incen- tives to the States (PPIS) grant which sought to address some of the issues identified above. The principal goals of the project, for which the University of Massachusetts served as lead unit, were: to develop consistent, well-defined, and quantifiable apple IPM guidelines for each New England state; to test state IPM guidelines as a pollution prevention methodol- ogy at the state and regional level; and to educate the media and the general public about IPM and its benefits. Our specific objectives were: to involve University research and extension staff, growers, and private-sector IPM professionals in the design of apple IPM Guidelines for each of the New England states; to demonstrate the resultant state guidelines on one 5-to-lO-acre block in each state, and compare results to a similar sized check block managed with a calendar-based spray program without pest monitoring; to calculate and compare the Environmental Impact Quotient (Kovach et al., 1992) for each block, as a measure of pollution prevention; and, to hold a field day in each state on the farm of the demonstrating grower to which the press and general public are invited. To the best of our knowledge, until this project, no successful attempt had been made within Region I to develop consistent IPM guidelines for several states in a region, to carry out an extensive and regionally-coordinated IPM demonstration for any crop, nor to use the results to educate the general public about environmentally-sound agricultural practices. An initial project planning meeting of several state collaborators was held in conjunction with the New England Fruit Meetings in January, 1995. Due to delays in getting the project organized, no growers participated in this meeting. Subsequently (Spring 1995), however, ME, CT, RI, and NH formed a Guideline Design Committee (GDC) consisting of 6-14 members, and each committee met at least once. The University of Massachusetts investigators participated in the ME and RI meetings. Each committee reviewed the University of Massachusetts guidelines template, and elected to modify it to fit the pest-management situation in that state. Modifications included: elimination and addition of some practices in the MA guidelines and changes to the point system used. In Massachusetts, an IPM Certification Study Committee was formed by the Massa- chusetts Fruit Growers' Association late in 1994, and this group solicited input on guideline modifications from growers, private IPM consultants, and University staff indepen- dently of the EPA-funded project. Modified guidelines were compiled by the University of Massachusetts investigators. Development of all state-specific apple IPM guidelines was completed by June, 1995. Each state identified one or more demon- strating growers (DG) who implemented the farm-specific IPM system, and conducted other planned activities. Cooperating growers who agreed to demonstrate the IPM system were: 10 Frait Notes, volume 62 (Number 2), Spring, 1997 Massachusetts, Joe Sincuk (Uni- versity of Massachusetts Horti- cultural Research Center, Belchertown); Connecticut, Ken Shores (Johnny Appleseed's Apple Orchard, Ellington); Rhode Island, Randy McKenzie (Phan- tom Farms, Cumberland); New Hampshire, Ben Ladd and Melanie Stephens (Great Brook Farm, Canterbury), Steve Gatcomb (Manager of Upland Farm, Peterborough); and Maine, Reed Markley (Lakeside Or- chards, Manchester). Original plans called for each cooperator to demonstrate the state IPM system, and compare results to a "convention- ally managed" block. However, given that all cooperators had been identified because of their knowledge and use of IPM, none were willing to "go backward" (i.e., apply pesticides on a preventative basis), even when funds to purchase extra chemical were offered. Al- though this development compromised the original project design somewhat, it provided testimony to the level of commitment to IPM common in the region. Hence, only the demonstration at the University of Massachusetts Horticultural Reserch Center (HRC) included both an IPM block, and a conventional (i.e., modified preventative spray program) block. The HRC, while a University research facility, is also a commercial orchard, with support for the farm dependent almost completely on fruit sales, just as with a private-sector orchard. The site has a long history of IPM adoption. Pesticide application results in HKC IPM and "conventional" blocks. IPM blocks received regular monitoring and spray recommendations by University-affiliated staff. The sole comparison block was designed to reflect the number of sprays that could be applied if a grower were inclined to use a preventative spray program. In actual fact, the "conventional" program was very conservative, using as it did only one spray for apple maggot Table 1. Number of spray events in traditional and IPM blocks, University of Massachusetts Horticultural Research Center, 1995. Conventional IPM Acaricides Fungicides Insecticides (incl. 2 oil) Herbicides TOTAL 3 10 7 1 21 4 6 5 1 16 fly, not the 2 to 3 that might normally be applied. As shown in Table 1, weekly monitoring of the IPM block and use of appropriate action thresholds resulted in 24% fewer spray application events compared to the modified preventative spray program. While this represents a savings in labor and other costs associated with spray application (e.g., fuel, oil, wear and tear) and one can hypothesize a reduced potential impact on the environment, the number of spray events alone gives no information on potential environmental im- pacts of IPM use. One measure of potential environmental benefit from IPM, calculation of the Environ- mental Impact Quotient (Kovach, et al., 1992), which takes into account toxicity of individual pesticides, is reported on elsewhere for all participating demonstration sites. A second measure, the dosage equivalent (DE), which reflects the rate of pesticide used as a percentage of the recommended rate, was completed for the HRC (Table 2). From Table 2, it can be seen that the IPM block received nearly 32% fewer pesticide DE's than the traditionally managed block. We believe this difference represents a typical situation in a grower orchard, where full recommended rates, which are known to have a wide margin for error, are rarely used. The implication of using dosage equivalents rather than spray events is Fruit Notes, Volume 62 (Number 2), Spring, 1997 11 Table 2. Dosage equivalents of pesticide used in conventionally managed and IPM blocks, University of Massachusetts Horticultural Research Center 1995. Conventional IPM Difference % Difference Acaricide 3.2 3.0 0.2 DE 7% Fungicide 13.6 7.9 5.7 DE 42% Herbicide 1.4 0.7 0.7 DE 52% Insecticide 6.1 3.6 2.5 DE 40% Oil 1.3 1.1 0.2 DE 15% Total Non-oU 21.3 14.5 6.8 DE 32% 1 most noticeable in the case of herbicide, where both blocks received a single application, but 52% less actual pesticide was applied in the IPM block. In spite of the lower dosage equivalents of pesticide use, pest damage appeared to be no different among the two blocks. No harvest survey data are presented because the entire crop was heavily damaged (over 80% injury) from a hail storm in late May. As a consequence of this extensive damage, normal harvest surveys could not be conducted easily. Pesticide residue analysis, HRC. Al- though not originally proposed as a project activity, location of the Massachusetts Pesti- cide Analj^ical Lab (MPAL) at Amherst, presented an opportunity to conduct a comparison of pesticide residues in the IPM and traditional blocks at the HRC. Such comparative residue data largely are lacking, and should provide useful baseline information for gauging the true environmental and public- health impacts of IPM use. Fruit samples were collected from each block type and frozen for later analysis during fall and winter. The authors would like to offer special acknowledg- ment for the cooperation and assistance offered to us by John Clark, Lab Director, and his staff, Dan Tessier and Andy Curtis. Table 3 shows results of residue analysis performed for 9 of 11 pesticides applied. No data are presented for azinphosmethyl (Guthion"") due to applicator error, and no analysis was attempted for the acaracide fenbutatin oxide (Vendex'*"). It is important to note that no residues were detected at a limit of detection of 0.2 ppm for seven of the materials applied in either the IPM or Conventional block. This finding is consistent with residue test results in the literature, which t5Tjically show that a minimum of 50% of all produce samples tested contain no detectable residues. Unfortunately, it is often assumed that the percent of produce containing pesticide resi- dues is much higher than it actually is. This discrepancy offers further compelling evidence of the need to educate the media and the general public about the realities of agricul- ture. For the benzimidazole fungicide benomyl, residues were no different in IPM and conventional blocks, but both showed residues in the parts per billion (ppb) range, orders of magnitude below the allowable tolerance. Residues of propargite, registration of which was recently canceled voluntarily by the registrant, also were well below tolerances, and represented the sole example of significantly lower residues in response to an IPM strategy. In this case, although more propargite 12 Fruit Notes, Volume 62 (Number 2), Spring, 1997 Table 3. Pesticide residues on apples at harvest in IPM and Traditional blocks, University of Massachusetts Horticultural Research Center, 1995. Total pesticide residues Chemical Brand name IPM Conventional Benomyl^ (Benlate"°) 0.02 ppb 0.02 ppb Captan (Captan*") ND" ND Carbaryl (Sevin'") ND ND Endosulfan (Thiodan'") ND ND Fenarimol (Rubigan™) ND ND Mancozeb (Penncozeb"") ND ND Permethrin (Ambush"") ND ND Phosmet amidan"") ND ND Propargite'" (Omite"") 0.49 ppm * 0.75 ppm tolerance of benomyl = 7 ppm. ''ND = nondetectable, limit of detection = 0.2 ppm. "Tolerance of propargite = 3 ppm. *StatisticaUy significant difference existed between IPM conventional at odds of 19 to 1. applications were used in the IPM block based on monitoring results, a lower rate was applied, and resultant residues were lower statistically. Such a low-dose strategy may represent a way for the material to be used again in the future. Environmental Impact Quotient (EIQ). Although each of the measures described above (i.e. numbers of sprays applied, dosage equivalents applied, and harvest residues) gives some information on potential reduction in environmental and other pollution, the actual measurement of such reductions is another matter. In addition to the fact that there is no agreement on the best techniques for measuring environmental impacts of pesti- cides, environmental testing of any sort is very expensive and demands the utmost care in sample collection and analysis. Partly in response to the need for some measure of environmental impacts of agricul- tural chemicals, Kovach and his colleagues at Cornell University devised the Environmental Impact Quotient (EIQ). The EIQ assigns values to chemicals based on such parameters as mode of action (i.e., non-systemic, systemic); toxicity to humans, bees, rabbits, birds, beneficial arthropods, and fish; soil residue half life; plant surface residue half life; and leaching and runoff potential. Although the resultant EIQ nvmabers have no meaning per se, they are intended to provide growers and others with a means to determine relative differences among pesticides or pest-management strategies. It should be noted that a number of flaws in the EIQ have been pointed out by Dushoff et al. (1994) in the journal American Entomologist. In addition to problems with scaling, weighting of effects, and inert ingredients, those authors point out that "...even benign substances are given ... an EIQ of at least 6.7." By way of illustrating an extreme example, "...if water were considered a pesticide, it would have an EIQ of 9.3. This means that 20 lbs per acre of water would be considered worse than a 1 lb application of parathion..." Of course, water is not a pesticide. However, another example using actual orchard pesticides can be seen in a comparison of the EIQ Field Use Rating for Fruit Notes, Volume 62 (Number 2), Spring, 1997 13 dormant oil (EIQ value of 37.7) and a 25 WP formulation of permethrin (EIQ value of 56.4). The EIQ Field Use Rating is determined by multiplying the EIQ Value (from a table) times the percent active ingredient (% A.I.) Of the material times the rate of pesticide application per acre, or: EIQ Field Use Rating = EIQ Value * % A.I. * Rate per Acre For Permethrin, used at 5 oz. per 100 gal. and applying 300 gal. per acre (or 0.9 lbs. per acre), this results in an EIQ Field Use Rating of 13 (56.4 X .25 X 0.9 lbs). This is obviously much lower than the field use rating of 226 for oil used at a rate of 2 gal. per 100 gal. and applying 300 gal. per acre (37.7 x 1 x 6 gal), because oil is 100% active ingredient, and is used at a much higher per-acre rate. In spite of the flavors in the EIQ, no other more appropriate model is in widespread use, to the best of our knowledge, although several were reviewed in 1994 by Lois Levitan and colleagues at Cornell in a report to the Northeast Sustainable Agriculture Re- search and Extension (SARE) program. Hence, with all the provisions noted above, the EIQ for each of the blocks in our demonstration is presented in Table 4. If nothing else, the EIQ numbers point out that IPM is not a "one size fits all" strategy, and that differences in pest pressure, environmen- tal conditions, and grower management style often govern both the choice of pesticides and their application frequency. For example, while fungicides contributed the largest portion of the EIQ number in five out of six IPM blocks, one site in New Hampshire, which used a new insecticide (imadacloprid) which is very safe to predator mites but highly toxic to bees, had a much higher insecticide/acaricide EIQ than any of the other blocks. This probably does not actually represent greater environmental damage, however, because imidacloprid is applied after petals have fallen, and bees are no longer foraging in fruit trees. Nonetheless, use of the material results in a substantially higher EIQ rating. Total EIQ numbers ranged from as low at 50% of the comparison traditional block to as high as 87% of that block, once again pointing out the normal differences among blocks for reasons described above. Ideally, had it been possible to set up a comparison block in each state which would have been subjected to the same weather and pest pressure, such comparisons would have had a much stronger biological basis, and their validity would have been strengthened. Field days. Field days were held successfully in four participating states in 1995. Maine held their event on May 24, 1996 Table 4. EIQ calculations for IPM demonstration blocks in five New England states, compared to a traditionally-managed block at the University of Massachusetts Horticultural Research Center, 1995. Pesticide type Conventional IPM block by state block MA MA RI CT NHl NH2 ME Insecticides/ acaricides Fungicides Herbicides EIQ Totals 586 438 765 1341 617 865 52 57 ** 1979 1112 1630 222 777 ** 999 1007 334 ** 1341 439 1288 ** 1727 306 1047 ** 1353 **Not calculated 14 Fruit Notes, volume 62 (Number 2), Spring, 1997 to coincide with bloom, a time when orchards are very attractive. In facihtating planning for these events University of Massachusetts distributed information to collaborators on how to stage and run a field day, and how to write a press release. In addition, we provided examples of press releases and other related materials. Press releases sent, informational handouts about each farm, and educational materials handed out at the events included: a 3-page fact sheet on disease-resistant apples, a fact sheet on IPM in Connecticut Apple Orchards, an "IPM Impacts" fact sheet, a 8- page handout on the Maine IPM Program, fact sheets defining relevant terms, a seven-page handout on insect and mite pests of apples, an apple pest chronology calendar and a descrip- tion of selected biological control agents (both taken fi-om the New England Apple Pest Management Guide), and a summary of comparative results (at the Massachusetts site only). Each field day consisted of a "walking tour" of the demonstration block with stops at various points of interest. For example, Connecticut collaborators (L. Los, G. Nixon, J. Clark and S. Olsen) staged a self-led walking tour which directed attendees through the orchard to view 12 different IPM "stations". Each station had a poster (approximately 2x2 feet) which explained an important apple pest and included pictures of life stages, damage, etc. Next to each poster, insect traps with appropriate insects affixed, or weather moni- toring equipment for monitoring apple scab infection periods were displayed. In addition to displays within the orchard, the Connecticut IPM group provided two large display boards in a movable stand used for the orchard's pick your own operation. One board displayed the impacts of all IPM projects in the state, and the other dealt with beneficial insects. A total of about 700 people either came by the booth or took the walking tour. The large turnout was partly due to having a "built-in" audience available at a large pick-your-own orchard on a good fall day. Results were such that Connecticut plans to hold a similar event (self- funded) next fall as well. The Rhode Island field day also consisted of stops at sites in the IPM blocks, as well as samples and displays (i.e., display board of "Pest Control Then and Now", photos of insect and disease pests, fi-uit and leaf damage, beneficial insects, samples of scab-resistant cultivars, and several insect monitoring traps). An estimated 1,000 people participated in the field day, and the event received publicity on local TV channels. In addition, a front-page article about the project also ran in the Woonsocket Call. Although attendance at the Massachusetts field day was less spectacular, the University of Massachusetts Daily Collegian (circulation of 17,000 throughout the 5-college area) sent a reporter who later wrote an article. New Hampshire had the greatest success in publicizing IPM by virtue of one front page article in the, July 16 Concord Monitor (circulation 23,500), a second fi-ont page article in the September 24 Sunday Union Leader, one Associated Press article sent out on the wire and at minimum picked up by the July 17, 1995 Union Leader (cir. 89,000), and reported on by WTSN, Dover, NH (listenership 63,000), a live interview on WNHQ, Milford, NH on July 17 (listenership 45,000), and a second AP article picked up by the September 25 Union Leader. In addition to the two IPM demonstration sites identified earlier, two other sites (the Hardy famiiys Brookdale Fruit Farm in Hollis, and Chuck and Diane Souther's Apple Hill Farm in Concord) also participated in the media tours. Cooperators in Maine arranged for the Governor to proclaim May 24 as "Maine IPM Technology Day", and the Commissioner of Agriculture delivered the Governor's proclama- tion at the event. The field day was announced to the apple grower community at the Trade Show in January, at the preseason IPM meeting in March, in the Pesticide Control Board Communicator newsletter, in the Apple Pest Report newsletter, at meetings of the Maine State Pomological Society Executive Council, and was advertised in several newspapers. The event was attended by about 75 persons and featured displays from the Maine State Pomological Society; the USDA/ Fruit Notes, volume 62 (Number 2), Spring, 1997 15 Downeast Resource Conservation & Develop- ment Cranberry IPM Program; the University of Maine Strawberry, Potato, Sweet Corn, Greenhouse, Blueberry, and Apple IPM Programs; the Maine Department of Agricul- ture; and the Maine Pesticide Control Board. In addition to the hosts, five other apple farmers agreed to serve as spokespersons and to answer questions. Arrangements were made to have a live InternetAVorld Wide Web connection, projector, and screen at the event, to demonstrate a developing technology with potential applicability for IPM users. Conclusions By virtue of the successful development of state-specific IPM guidelines in 5 of 6 New England states, by demonstrating (once again) that IPM can result in lower pesticide applications, lower dosage equivalents, and a lower EIQ rating, and by generating substan- tial media and consumer exposure for IPM throughout the region, the investigators believe that all project goals were achieved. Acknowledgments We sincerely wish to thank all the growers, consultants, university staff, and other apple industry members who participated in the guidelines design activity and the field demonstrations. Special thanks to those growers who allowed us to demonstrate the IPM systems and hold field days on their farm. Extra special thanks to Ken Shores who donated enough cider for 700 attenders of the Connecticut field day. «1« «1« «£« «% %1U 0^ r{% r|% rj% vj% 16 Fruit Notes, volume 62 (Number 2), Spring, 1997 An Update on the 1994 NC-140 Apple Rootstock Trial Wesley R. Autio Department of Plant & Soil Sciences, University of Massachusetts The NC-140 Technical Committee is comprised of about 75 university and govern- ment pomologists from the United States, Canada, and Mexico. During the more than 20 years of this group's existence, several trials have been established, managed, and reported in a cooperative manner. In 1994, a trial was established at 25 locations throughout the United States and Canada, and it is managed by Rich Marini from Virginia Tech. Each Table 1. Trunk cross-sectional area, yield, yield efficiency, and fruit weight in 1996 of Gala on several rootstocks in the 1994 NC-140 Apple Rootstock Trial in | Massachusetts.' Trunk cross- Yield Yield Fruit weight sectional area per tree efficiency (average Rootstock (in^) (lbs) (lbs/in' TCA) box count) M.9 EMLA 2.1 def 4.8 cdef 2.6 bedef 98 bed M.26 EMLA 2.8 be 2.2 efg 0.9 fg 114 de M.27EMTA 0.7 i 1.3 fg 1.7 defg 107 bcde M.9 RN29 2.5 cd 5.7 bcde 2.1 cdefg 96 bed M.9 Pajam 1 2.4 de 6.4 bed 2.8 bcdef 114 de M.9 Pajam 2 3.0 ab 9.0 b 3.1 bcde 88 b B.9 1.9 ef 4.2 defg 2.6 bcdef 105 bed B.491 0.9 hi 2.6 defg 2.7 bcdef 129 e 0.3 2.0 def 5.7 bcde 2.8 bcdef 112 de V.l 3.3 a 8.1 be 2.6 bedef 100 bed P. 2 2.1 def 0.4 g 0.1 g — P. 16 1.2 gh 2.0 efg 1.7 defg 112 ede Mark 2.3 de 9.2 b 4.3 be 105 bcde P.22 0.8 hi 3.5 defg 4.5 b 109 ede B.469 1.2 gh 4.8 cdef 3.8 bed 110 cde M.9 Fleuren 56 1.6 fg 2.9 defg 2.0 defg 104 bed M.9 NAKBT337 1.9 ef 3.7 defg 2.1 cdefg 97 bed DeliciousM.26 EMLA" 1.8 ef 1.3 fg 0.9 efg 61 a Liberty/M.9 NAKBT337 1.9 ef 13.0 a 7.2 a 96 bed Fuji/Mark" 2.2 de 8.6 be 3.7 bed 95 be ' Means within columns not followed by the same letter are significantly different at odds of 19 to 1. ' Delicious, Liberty, and Fuji are pollenizers within each replication Fruit Notes, Volume 62 (Number 2), Spring, 1997 17 M.9 Fleuren 56 M.9 NAKBT337 M.9 EMLA M.9 Pajam 1 M.9 RN29 1 .::m M.9 Pajam 2 Trunk cross-sectional area (in^) Figure 1. Trunk cross-sectional area in 1996 of Gala on six clones of M.9 in the 1994 NC-140 Apple Rootstock Trial in Massachusetts. M.9 Fleuren 56 M.9 NAKBT337 M.9 EMLA M.9 RN29 M.9 Pajam 1 M.9 Pajam 2 0.0 2.0 4.0 6.0 8.0 Yield per tree (lbs) 10.0 Figure 2. Yield per tree in 1996 of Gala on six clones of M.9 in the 1994 NC-140 Apple Rootstock Trial in Massachusetts. Fruit Notes, Volume 62 (Number 2), Spring, 1997 ■ : :- ,4^ n m i^ ■:" '^ illi^i:r '" ^;: ;; ^'^■' taiiftaMi;:.jan>.watu-.->H^,.. >^j.t. ,*■,.... - ^1 a.^>v^^.>. ISli^^^^****'^ M.9 Pajam 1 M.9 Fleuren 56 M.9 EMLA M.9 NAKBT337 M.9 RN29 M.9 Pajam 2 ^^^ 60 70 80 90 100 110 120 Fruit size (average box count) Figure 3. Fruit size in 1996 of Gala on six clones of M.9 in the 1994 NC-140 Apple Rootstock Trial in Massachusetts. plating includes Gala on 17 dwarf rootstocks, replicated 10 times. The Massachusetts planting is located in Belchertown at the University of Massachusetts Horticultural Research Center. This article will give a brief update on tree performance through the third growing season. After three growing seasons, the largest Gala trees were on V.l, M.9 Pajam 2, and M.26 EMLA (Table 1). The smallest trees were on P.22, B.491, and M.27 EMLA. The range in trunk cross-sectional area from smallest to largest was more than four fold. Yield per tree in 1996 (Table 1) was greatest for trees on V.l, M.9 Pajam 2, and Mark (ignoring the pollenizers) and least for trees on M.26 EMLA, P. 16, M.27 EMLA, and P.2. Relating yield to tree size, jdeld efficiency (Table 1) was greatest for trees on Mark and P.22 (ignoring the pollenizers) and smallest for trees on M.26 EMLA and P.2. Fruit size (Table 1) was greatest for trees on M.9 Pajam 2 and least for trees on M.26 EMLA, M.9 Pajam 1, 0.3, and B.491. Among these 17 rootstocks, it is particularly interesting to look at the differ- ences among the six M.9 clones in the study. The range was more than expected. Trees on M.9 Pajam 2 were the largest of the M.9-rooted trees, nearly double the trunk cross-sectional area of trees on M.9 Fleuren 56 (Figure 1). M.9 EMLA resulted in a tree intermediate in the range. Yield followed a similar pattern, with trees on M.9 Pajam 2 producing nearly three times the fi-uit of trees on M.9 Fleuren 56 (Figure 2). Trees on M.9 Pajam 2 produced the largest fruit, averaging between 80 count and 96 count (Figure 3). Fruit from trees on M.9 Pajam 1, on the other hand averaged only a bit larger that 120 count. Clearly these data are only preliminary. A few more years will be required to begin solid evaluation of these rootstocks, but it is interesting to observe significant differences in these young trees. %1a %i« •Im «1« «£• rj% ry» 0^ 0^ rj% Fruit Notes, Volume 62 (Number 2), Spring, 1997 19 An Update on the 1994 NC-140 Peach Rootstock Trial Wesley R. Autio Department of Plant & Soil Sciences, University of Massachusetts According the 1991A^eu; England Fruit Tree Inventory, conducted by the New England Agricultural Statistics Service, peaches com- prise only 7% (380 acres) of the tree-fruit acreage in Massachusetts; however, most of these fruit are sold directly to the consumer and are profitable. Further, acreage is expected to increase at a rate of 2-3% per year for the near future. Therefore, peaches are an important part of the Massachusetts tree-fruit industry. Peaches have a number of horticultural problems: they are subject to early decline; they can bloom too early and therefore be frosted, they often express too much vegetative vigor, and the flower buds or whole tree can be killed by winter cold. Rootstock can impact any or all of these problems. To begin to study the potential for using rootstock to overcome some limitations of peach growing, Massachusetts participated in an NC- 140 trial studying the effects of 12 rootstocks and one interstem combination on the performance of Redhaven peach. The Massachusetts planting was established in 1994 at the University of Massachusetts Horticultural Research Center in Belchertown and included eight replications. Rootstocks included were as follows with descriptions Table 1. Tnink cross-sectional area yield per tree, yield efficiency, and fi-uit size in 1996 of Redhaven peach trees planted in 1994 as part of the 1994 NC-140 Peach Rootstock Trial in Massachusetts.^ Trunk cross- Yield Yield Fruit sectional area per tree efficiency weight Rootstock (in^) (lbs) (lbs/in' TCA) (oz) Lovell 6.4 a 19.4 be 3.1 a 6.9 a Bailey 4.7 be 27.9 ab 6.2 a 7.6 a TN 281-1 4.4 be 17.6 be 4.0 a 7.2 a Stark's Redleaf 4.5 be 27.9 ab 6.0 a 7.8 a GF305 4.7 be 27.5 ab 6.0 a 7.1 a Higama 5.6 ab 33.0 a 6.0 a 6.8 a Montclar 5.3 ab 20.2 be 4.0 a 6.4 a Rubira 3.4 cd 18.7 be 5.7 a 6.8 a Ishtara 2.4 d 11.9 c 4.8 a 6.7 a H7338019 3.2 cd 16.3 be 5.1 a 6.4 a BY520-8 3.9 c 18.3 be 4.8 a 6.9 a Guardian 6.3 a 25.1 ab 4.0 a 5.9 a Ta Tao 5/Lovell 4.2 be 18.3 be 4.4 a 6.8 a ' Means within col umns not followed by the same letter are significantly different at odds of 19 to 1 20 Fruit Notes, volume 62 (Number 2), Spring, 1997 Ishtara H7338019 ETT Rubira BY520-8 ^^^^^ Ta Tao 5/Lovell TN 281-1 Stark's Redleaf GF305 Bailey Montclar gSgBW Higama Guardian Lovell t:X?!^i^iS^:Sg^^^»ss^Stismf'i^y mm^^m^'im^fi^i^A'^i^im^^^^^^'^^t^ ^^^^^3 0.0 2.0 4.0 6.0 Trunk cross-sectional area (in^) 8.0 Figure 1. Trunk cross-sectional area of Redhaven peach trees planted in 1994 as part of the 1994 NC-140 Peach Rootstock Trial in Massachusetts. Ishtara H7338019 TN 281-1 BY520-8 Ta Tao 5/Lovell Rubira Lovell Montclar Guardian GF305 Stark's Readleaf Bailey Higama 10 15 20 25 30 35 Yield per tree (lbs) Figure 2. Yield of Redhaven peach trees planted in 1994 as part of the 1994 NC-140 Peach Rootstock Trial in Massachusetts. Fruit Notes, Volume 62 (Number 2), Spring, 1997 21 provided by Greg Reighard (Clemson Univer- sity), the coordinator of the NC-140 trial: Lovell Bailey TN 281-1 Stark Redleaf GF 305 Higama Montclar Rubira Ishtara H7338019 BY520-8 Chance seedling of peach from California named in 1882, propagated by seed; Selection of peach from Iowa named in 1890, propagated by seed; Selection in Tennessee of "wild" peach, propagated by seed; Selection by Stark Bro's from a Tennessee Natural-tj^je root- stock, propagated by seed; Selection in 1940 in France from Montreuil peach, propa- gated by seed; Selection in France of peach from Japan, propagated by seed; Selection in France of peach, propagated by seed; Selection in France of peach, propagated by seed; Selection in France of a plum- peach hybrid, propagated by cutting; Selection in Ontario of peach, propagated by seed; Selection in Georgia of peach, propagated by seed; Guardian Selection in Georgia of peach, propagated by seed; Ta Tao 5 Selection in China of peach, propagated by grafting, used in the study as an interstem with Lovell as the rootstock. After three growing seasons, significant differences existed in trunk cross-sectional area (Table 1, Figure 1). Of the trees with pure peach rootstocks, H7338019 resulted in a tree only half the size of those on Lovell, the largest. Rubira also produced a small tree, and Montclar, Higama, and Guardian also pro- duced large trees. Ishtara, the plum-peach hybrid, resulted in the smallest trees, ones that on average were only 38% of the size of trees on Lovell. Yield varied similarly (Table 1, Figure 2), with trees on Higama, Bailey, Stark's Redleaf, GF 305, and Guardian producing the most, and trees on Ishtara producing the least. Because, in general, the largest trees produced the most fi-uit, yield efficiency (the expression of 5deld per unit tree size) did not vary significantly among rootstocks (Table 1). Likewise finiit size did not vary significantly among rootstocks (Table 1). Although several more years will be required to evaluate these rootstock ad- equately, it is interesting to observe the significant differences that have developed in this first fruiting season. ♦ mi^ ml^ •i^ •Ia #{« «^ 0^ 0^ 22 Fruit Notes, volume 62 (Number 2), Spring, 1997 EDITORS' NOTE: The following piece was sent to us by W. Lockeretz (Tufts University). It is from the Life Histories Collection from the Federal Writers' Project of the Works Progress Administration. It is a transcript of an interview of Mr. G. O. Bunnell during 1938 and 1939. At the time of the interview, Mr. Bunnell was 75-80 years old. The Hay, Grain, and Feed Man: G. O. Dunnell, Northfield, Massachusetts I'm getting this axe ready to fix the fences on Christian Hill that the hurricane busted. Not that the hurricane blew 'em down but it did blow down some trees. And the trees is what busted the fences. I dim' over one. Had to, to get to camp, and I see they was more down. Couldn't do anything that night because it was getting da'k, and I had to come home, but I'm going back just as soon as the roads get settled enough so's I can. It's a funny thing, but I don't think that, as a rule, there was as much wind over that way as we got here. What did most of the damage was the water. And, another funny thing I noticed was that of the trees that come down in the apple orchards, it was the ones that had never been grafted. Those that had been grafted stood up. How'd I know? I know most every apple tree they is on Colrain and Shelbume mountains, and in the north part of the town of Greenfield. 'Cause I was the feller that grafted 'em, that's why! I used to go all over grafting trees. And I had ten or twelve hundred trees of my own, too, that I'd no business leaving. But people would come tease me and tell me how much extry they were willing to pay for my trouble, that I was generally on the move. Once I went to Greenfield. And I didn't get home for a week. Spent the nights there with the different ones. 'Course, theys a trick to it. But 'most anybody can put on a scion so's it'll grow. But that ain't all they is to it. You got to figure what the tree's going to be shaped like. You shouldn't get the scions growing into each other the way most people do. And you ought to fix; the tree so's somebody can pick the apples without tying a couple of ladders together or hiring a balloon. Apple trees like to grow among the rocks - that is, most kinds do. The hills each side of our valley here are just right. All we can grow here that's any good is the Blue Pearmain. And they got such a tough skin that people don't like 'em. They are an awful good flavor, though, until they got mealy - oh, they^s others; russets and early transparent and so on. But what I was getting at is the way I found the best of raising good flavored apples. Apples grow wild over in Colrain. It is just as natural to find a wild apple tree in Colrain as it is to find a birch in Warwick. I had a lot of 'em in my woods. 'Course, the fruit of a wild apple tree is no good except for cider. But the trees themselves is generally healthy. I'd find a good one, then I'd saw off such limbs as I thought should be off, and put a scion in it. If it was a fairly big limb that I figured would pinch the scion off if I didn't do something about it, I'd whittle a little thin wedge and put that in just beyond the scion, for the limb to pinch on to. What do I mean by scion? What that's a little shoot fi-om the brand of tree I wanted. I had Baldwin scions and Mcintosh scions and Porter scions, and all kinds of scions. I cut 'em in March - that's the best time to graft around here. Maybe, I'd make a Baldwin tree out of a wild apple tree, or a Greening, or a Northern Spy. Sometimes I fixed 'em so's they had different kind of apples on every limb. But that's nothing but a kind of joke. Nobody that runs an orchard wants trees with fruit all mixed up on 'em. I said I only put one scion to a limb. I always Fruit Notes, Volume 62 (Number 2), Spring, 1997 23 put two, 'cause somethin' might happen to one. They break off in ice storms sometimes. And I always put 'em one above the other 'cause I figured it's better and stronger that way. You whittle off one side the scion and stick it in the crack you've made with your knife in such a way that the live bark on the scion presses up against the live bark on the tree. And then you hold the scion in place with wax. Then you cut off all the limbs below the one that you've grafted. The sap has to go somewheres. And when it finds that the limbs have been cut off, and they ain't no place to go, except into the bark of the scions, that's where it goes. You've got to figger not to cut too many limbs off, though. For if thej^s more sap than can get into the scion and make it grow, it'll leak out under the w£ix and rot the scion off. I generally left the top of the tree pretty much alone until I found out how the scions were doing. If they were growing all right, I'd cut the top off then. Lot of people put on two scions the way I done. But when them both growed they let 'em grow together. That makes a crotch. And a crotch ain't strong. I always cut off one scion just before they growed together. And the bark would grow over the place and make a smooth branch. Once, I grafted a whole tree. And that tree stood up through the hurricane, too. Yer see, when a crust comes on the snow, or anjrthing happens so the mice can't hunt, you're supposed to go around the orchard tromping down the snow around the trees. You tromp it down hard right around the trunk, and the mice won't get to the bark. But I missed this tree someways. Or the mouse, maybe, was a wood rat. Anyway, it ett the bark all the way 'round. It was a good tree. Had good roots, and as it would die if I didn't do something about it, I thought I better try. I cut the trunk of the tree off and put scions all the way 'round in the bark. Enough of 'em grew so I managed to raise a tree. I told the feller who owns the place about it, and he found it hard to believe for it don't look no different than any other tree to him. Lots of people insist on growing an orchard from nursery stock, that's all right if you want to wait ten or fifteen years for a crop. But if you want your trees to begin bearing in three-four years you want to graft a few scions on to a full grown tree. If you take your scions from a tree that has apples you like, you can be sure that you'll get the same flavor apple when the scions begin to bear. But when you buy from a nursery you got to wait ten or twelve years to find out if you got what you paid for. 'Course, the/s some crook nursery men, I s'pose, but they ain't many. It's the agent who's the crook. And it's a pretty good game when a feller don't know he's been gypped until ten-twelve years. By that time the agent ain't no longer in the employ of the company, probably. And if he was, nobody would know who made the mistake and the whole thing be outlawed so's you couldn't get it into court. I don't say that a good nursery wouldn't be awful sorry it happened and make good, too. But the way they'd make good would be to give you some guaranteed new trees that you could wait for to bear for another ten- twelve years. When Doc Brown and his brother first come they lived in houses side by side. And they planted the two back lots for an orchard. I told the Doc that this wasn't a good place to raise apples, but the Doc said, "No, no," I was wrong. That he'd had the soil analyzed down at the State College. And that they said it was good soil and all right. "All right, Mister" I says. "Now you take out your little book and you write down what I'm going to tell yer. So's you won't forget it, I says. But you see more money when you took out your pocketbook to pay for them trees than you'll ever see coming back into it from your orchard." But, oh no, I was wrong. "What kind of trees be they," I wanted to know. "Baldwins," he says. And it seemed he had paid an extry price to get some real good trees. I see they wan't no use talking to him and trjdng to help him so I forgot about it 'til several years had gone by when I saw him and his brother working in the orchard. You know, they's a pest of borers that bores holes in the trunks of apple trees right above the ground, and if you're quick enough you can ram a wire in and either kill the borer, or fish him out, but if he's bored 'round a bend or two, you are out of 24 Fruit Notes, volume 62 (Number 2), Spring, 1997 luck - your tree is gone. So it pays to watch your orchard. Was a time when yer didn't need to spray your trees. But you do now - two-three times. Well, I goes down into the orchard and asks what they was doing. They told me. And I asked what kind of trees these was. 'Baldwins," they told me. A few of 'em are, I admitted. But most of 'em is Gravensteins. "Oh, no!" Says the Doc, "that can't be! It was a reliable firm we bought them of and they was guaranteed Baldwins - a 'specially good brand.' "Well," I says, "You still get your little book? Now, put it down, so you won't forget it, or tie a string around the trees, or somethin', and you just wait 'til theys apples on 'em and see.' But they didn't wait. The brother sold out to a poor, little runt of a mean, miserable, cuss that I don't want nothin' to do with. But I didn't know what a kind of low-lived skunk he was then, so I tried to be neighborly. I asked him what kind of trees he had in his orchard. He says that they was Baldwins. That that was what the ministers said that sold him the place. "Well, they ain't," I says. "They is Gravensteins - most of 'em." But they ain't no good!" he says. I told him I didn't think they was any good myself- not even for cider. He wanted to know how how I was so siire. And I showed him the difference in the leaves. He thought he had better wait and make sure before he did anything about it. That it didn't seem to him that ministers would lie. I told him he needn't wait to find that out. That everybody in Northfield knowed that ministers are the biggest liars they is, 'cause they honestly believe their lies themselves. That if he aimed to become a bonnie fidie resident of Northfield, he'd better find that out, and learn to set one against the other. That some places you needed lawyers to do business for you, but here in Northfield you needed ministers, and if you didn't have one you were all out of luck. He was going to cut down the Gravensteins but I told him no, and showed him how to graft 'em with scions fi-om the Baldwins. The little cuss never did it, though, he turned out to be too dimab lazy. That old fool was over eighty when he broke his hip. It mended good as new. The fall would a killed any decent person. And you know the saying, "The Good Die Young." Guess that's a fact. mi^ mi^ %i« «f^ m^ 0^ 0^ 0^ ^« 0^ Fruit Notes, Volume 62 (Number 2), Spring, 1997 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, l\/IA01002 1 SERIAL SECTION UNIV OF MASSACHUSETTS LIBRARY AMHERST MA 01003 PLEASE READ SUBSCRIPTION NOTICE ON PAGE 1 IMMEDIATELY! Account No. 2-22914 UM/Morr. Per SB 354 F6B Yuit Notes Prepared by the Department of Plant & Soil Sciences. UMass Extension, U. S. Department of Agriculture, and Massachusetts Counties Cooperating. Editors: Wesley R. Autio and IX^lliam J. Bramlage re r: BIOLOGICAL^ ^, APR 01 1998 1 -^ SCIENCE3 LIBRARY Volume 62, Number 3 SUMMER ISSUE, 1997 Table of Contents Effects of Natural Food Sources on Attraction of Apple Maggot Flies to Baited Traps What Part Do Flyspeck Ascospores Play in Disease Development? Tax Pointers for Farmers and Landowners in 1997 and Planning Notes for 1998 Evaluation of Peach and Nectarine Cultivars for Massachusetts Orchards Fruit Notes Publication Information: Fruit Notes (ISSN 0427-6906) is published the each January, April, July, and October by the Department of Plant & Soil Sciences, University of Massachusetts. The costs of subscriptions to Fruit Notes are $ 1 0.00 for United States addresses and $12.00 for foreign addresses. Each one-year subscription begins January 1 and ends December 3 1 . Some back issues are available for $3.00 (United States addresses) and $3.50 (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 UMASS EXTENSION POLICY: AH 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, concernmg the use of these products. USER ASSUMES ALL RISKS FOR PERSONAL INJURY OR PROPERTY DAMAGE. Issued by UMass Exlensmn. Robert G. Helf^esen. Direcuir. infunherunre iifthe acts (>l MiiySaiuLlune SU. 1914. UMass Extension offers eqiiiil opportunity in proi^rams and employment. Effects of Natural Food Sources on Attraction of Apple Maggot Flies to Baited Traps Juan Rull, Alan Reynolds, Michelle Balds, HoUy Gagne, and Ronald Prokopy Department of Entomology, University ofMiissachusetts The effectiveness of visually attractive red sticky spheres can be increased by the addition of odor lures. In recent study in commercial orchards by Reynolds and Prokopy (1996), it was shown that red sphere traps baited with butyl hexanoate (an odor emitted by ripening apples) realized a four-fold increase in captures of apple maggot flies (AMF) when compared to unbaited spheres. However, the addition of ammonium carbonate (an odor emitted by sources of food) to red sphere traps did not enhance capture of flies on baited traps. The above study involved trapping wild flies entering commercial orchards. Their physi- ological state was unknown. While the nature of fly attraction to butyl hexanoate was clear, the cause underlying lack of attractiveness of ammonium carbonate was uncertain. In order to reach a better understanding of AMF response to both lure types, we decided to perform an experiment in which flies of known physiological and nutritional state (mature protein fed or immature protein starved) would be released in blocks where different combinations of lures would be displayed. Further, all treatments would be replicated in blocks where natural food sources were added or suppressed. In this way, we could assess which synthetic lures are attractive to flies of different physiological states and whether or not the presence of natural food in orchards interferes with attraction to lures. Materials & Meth(fds Four sets of six square blocks of 49 apple trees each were selected in four commercial orchards, with one set of blocks per orchard. In every block, red sticky spheres were positioned on every perimeter tree. In two of the blocks, sources of butyl hexanoate and ammonium carbonate were placed 15 cm away from every sphere. In two other blocks, only butyl hexanoate was added to spheres. Spheres in the remaining two blocks were not lured. One block of each lure-type treatment was treated with Provado''''^ to prevent buildup of aphid and leafhopper honeydew (natural food sources). The other block of each lure-type treatment received a large amount of bird droppings (also a natural food source) that was distributed by hand (in slurry form) onto the foliage of each tree. Thus, half of the blocks of each treatment type had a paucity of natural fly food; whereas, the remaining blocks had abundant natural fly food. Apple maggot flies of known physiological state were released into the central tree of each block. The flies emerged in our laboratory and were subjected either to a diet including protein and sugar for 14 days (mature flies) or a diet limited to sugar for four days (immature flies). When ready to be released, flies were marked on the back of the thorax with a small dot of paint. Approximately 50 mature flies and 50 immature flies were released in each block. Flies of each physiological state released in each block bore a distinct color (12 different colors used across all blocks in an orchard). Flies captured by the traps in each block were counted after four days. The percentage of flies recaptured was used to compare response to treatments. Wild flies captured in the different blocks were also counted and their numbers compared. Fruit Notes, Volume 62 (Number 3), Summer, 1997 1 F igure 1 : R es ponse o f marked released mature flies 50 T v^ o <1> •o 2 a 20 ' 1 1 1 o D (> 15 - Hn "9 ■ t^m .^-^ (D F 1 0 - H ' ■ ■ ^fl r^ Q. 5- n - . 1^ P ' i. m iju o o AC+Food BH+Food -AC-Food No lure +Food ure -Food 1 X CD + ^ — I n: o m -^ Z BH= Butyl hiexanoote, AC = Ammonium carbonate, Food = Presence or absence of natural sources of food on trees . -n Percentage of markec c flies captured q 2: R esponse of marked released Immature fli es 50 45 40 35 30 25 20 15 - 10 - 5 0 y HI ^ ^ ^H i\ ^M ^ ^ m ^H ^H .^^ B F "D O O U- + X CO H = Butyl ood = P r( •o 8 U- 1 o < + X m tiexanoc Bs ence o n T! ^ ^ n o O O n o O O >? £ ^ ^ o o z z ite, AC = Ammonium carbonate, r absence of natural sources of food on trees Results Similar to the earlier findings of Reynolds and Prokopy {Fruit Notes 61(4): 1-2, 1996) on response of wild flies, we found that the addition of butyl hexanoate resulted in nearly a four-fold increase in capture of released mature flies on spheres. Presence of ammo- nium carbonate did not add to the attractive- ness of traps to mature flies, even in the Fruit Notes, Volume 62 (Number 3), Summer, 1997 Figure 3: R esponse of unmarked wild flies 25 - 20 0) -D I t a> o a 1 5 BH= B u tyl hex anoate, AC= Ammonium carbonate, Food = Presence or absence of natural sources of food on trees absence of food on the apple trees (Figure 1). Response of immature flies to lures and traps was much lower than that of mature flies. Although the combination of butyl hexanoate and ammonium carbonate in the presence as well as the absence of food was the trap treatment that caught the most immature flies (Figure 2), captures were well below those of mature flies on traps with lures. Responses of wild flies were similar to those of released mature flies (Figure 3). Again, captures on traps having butyl hexanoate alone were nearly four-fold greater than captures on unbaited traps. Again, addition of ammonium carbonate did not enhance trap capture. Conclusions Our results support the combined use of sticky red spheres and butyl hexanoate lures as an alternative to insecticides to control AMF. Addition of ammonium carbonate lures did not enhance captures of released mature flies or wild flies, and its slight enhancement of trap captures of immature flies was not great enough to justify its use. Presence or absence of natural food in orchard blocks had little detectable effect on response patterns of either released mature, released immature, or wild flies. Response patterns of wild flies seem to indicate that their populations consisted mainly of mature flies. Our findings support use of a behavioral control strategy based on the employment of visually attractive red spheres together with butyl hexanoate as an odor lure. Acknowledgments We are grateful to Stanley Baj, Dana Clark, and the Peck brothers for generously allowing use of their orchards. This work was supported by USDA CSRS NRI grant 95-37313-1890 and Cooperative agreement 94-COOP-1-0482. vT^ •^ *^ •sL^ *^ •^ •» r^ 0^ •^ Fruit Notes, Volume 62 (Number 3), Summer, 1997 What Part do Flyspeck Ascospores Play in Disease Deveiopment? S. Lemer, T. Kliorina, and D. R. Cooley Department of Microbiology, University of Massachusetts Flyspeck is one of the major summer- disease concerns of apple growers in the Northeast. Yet for most of the season, there is little evidence of the fungus within the orchard. In a dry year, signs of infection may not appear until as late as August. For several years we have been conducting investigations aimed at gaining a better understanding of the natural biology of this fungus. We know that it survives the winter on a number of wild hosts that are common to most orchard borders such as blackberry, maple, grape, Virginia creeper, and red oak. We also know that, like the apple scab fungus, it produces two types of spores: ascospores in the late spring and repeating cycles of conidia or asexual spores later in the season. However, unlike apple scab, which pro- duces its first cycle of spores within the orchard where well-timed sprays can control the disease, flyspeck ascospores are produced primarily in the orchard borders on alternate hosts. We wanted to know what part these early spores play in disease development later in the season. The flyspeck spots that form on apples, blackberries, and other hosts in late summer are pseudothecia, the overwintering structure of the organism. By late winter these structures have matured and are ready to produce spores. In the laboratory, we have seen that spore development is driven by both temperature and humidity. Humidity must be quite high - mature spores are produced at 99% humidity but not at 96%. Average tempera- tures above 50°F are also necessary for spores to develop and mature. In New England, these conditions can be met for significant portions of the day in the field by late May. In the spring of 1997, blackberry canes with pseudothecia were gathered weekly from three sites in Western Massachusetts from late May into July. Fifty pseudothecia from each cane were examined microscopically and the presence of mature spores was recorded. Table 1 shows the results of this study. The 1997 information conforms with data gathered in Amherst during 1996 that showed that there is a single period of ascospore release that occurs in late spring to early summer. An unusually warm, wet spring in 1996 com- pressed the period of ascospore maturity to a shorter period of time, earlier in the season. Apple-tree phenology can be used as an aid to predict when this period will occur in a given year. The ascospores produced on the host plants in the orchard borders are released into the air but we do not know if they are transported as far as the orchard block. Even if these initial spores are carried to apple trees however, it is likely that the spray program aimed at controlling apple scab ascospores will also control early-season infections of flyspeck. Information from Dr. David Rosenberger indicates that the broad-spectrum protectant fungicides commonly used for scab, Mancozeb and Captan, will protect against flyspeck for a significant period. Mancozeb used at 1 lb/100 gal. or Captan SOW at 2 lb/100 gal. will protect fruit for at least 21 days or 2.5 inches of rain, whichever comes first. Captan SOW at lb/100 gal. protects for 14 days or 2 inches of rain. If the last scab spray of the season contains one of these fungicides, and is made in early to mid- June, fruit will be protected to late June or early July. Fruit Notes, Volume 62 (Number .3), Summer, 1997 Table 1 . Flyspeck ascospore maturity in relation to apple tree jjhenology. Site First mature spores Last mature spores I Date Apple phenology Date Apple phenology Amherst, 1997 Shelburne, 1997 Sterling, 1997 Amherst, 1996 May 24 June 3 May 20 May 13 mid petal fall 90% petal fall full bloom late bloom July 3 July 6 July 10 May 29 1 1/8" fruit 1 1/4" fruit 1 " fruit 1/4" fruit If infections from the initial cycle of spores are not the primary cause of late season symptoms in the orchard, then conidia must be. We wanted to know if inoculum could be building up in the woods and borders, in the form of conidia, and moving into the orchard sometime later in the summer. Previous studies have shown that trees closer to the borders have a much higher incidence of flyspeck {Fruit Notes 61(2): 1-4, 1996). But flyspeck symptoms are rarely seen before the end of July and have never been seen early in the season. Based on the fact that there are repeated yearly infections of the numerous host plants in the orchard border, we knew that ascopores germinate in the field and cause infections. The typical lifecycle of the fungus begins with the ascospore germinating to form a colorless mycelium which live off the nutrients of the waxy surface layer of its host. Repeating cycles of conidia or asexual spores form on this mycelium, and then the typical flyspeck symptoms appear. It is possible that ascospores create local infections in the borders and cycles of conidia proliferate on these hosts creating a reservoir of additional infections and inoculum that can move into the orchard block when environmen- tal conditions are conducive. We know from research conducted by Dr. T.B. Sutton that flyspeck conidia are discharged primarily in the early morning hours, after periods of high humidity or heavy dews or rain, and as the levels of high humidity decrease (Sutton, Plant Disease 74:643-646, 1990). During the summer of 1997 we attempted to find out if and when asexual spores or conidia were typically present within an orchard in Shelburne, Mass. The trees had been sprayed following a first-level integrated pest management schedule with the last spray of Rubigan and Pencozeb occurring on June 4. Spore traps were placed within the blackberry border, in the first row of trees about seventeen feet from the border, and in the third row of trees about seventy feet from the border. Spore trapping rods were brought back to the laboratory and spores counted twice a week starting in mid-July. Actual numbers of spores caught on the traps were too small to analyze statistically. However, the number of conidia trapped increased dramatically during the second week of August, coinciding with an increase in heavy morning dews. The first symptoms of flyspeck were observed two weeks later on August 31. Additional data are needed to be able to predict the environmental conditions that will lead to an increase in conidial inoculum in the orchard. It does seem, though, that there is a period of time between the end of primary scab season and mid-July to mid-August, particularly in dry years, when there are few conidia in the blocks and the likelihood of flyspeck infection is very low. In the orchard where spores were trapped. Fruit Notes, Volume 62 (Number 3). Summer, 1997 the first row of trees was sprayed only on the side away from the border. The border side of those trees was highly vulnerable to infection by ascospores, being unprotected by fungicide and in close proximity to the blackberries. Yet no flyspeck occurred until late summer, when it also occurred on the sprayed side of the trees as well as in other blocks in the orchard. This coincided with a change in environmental conditions that either stimulated the fungus to grow or promoted an influx of conidial inoculum into the orchard from the borders. This supports our contention that ascospores play little or no role in direct infections on fruit, but instead it is conidia moving from border plants that inoculate the crop. In summary, flyspeck ascospores form in the orchard borders and surrounding woods rather than in the orchard. Ascospores are released during a single discrete period in the late spring and early summer, making it possible to relate the period of heaviest inoculum dose to apple tree phenology, generally 10 to 14 days after petal fall. These spores probably cause infections on border plants but not on orchard fruit. If any infection occur, sprays aimed at controlling scab will most likely control them. Therefore, ascospores do not seem to play a major role in producing the flyspeck symptoms that are seen in late summer in Massachusetts, and efforts need to be focused on controlling infections caused by conidia from mid-July thru harvest. •sl^ •^ •J^ •J^ •^ •^ #^ 0^ #^ #Y* Fruit Notes, Volume 62 (Number 3), Summer, 1997 Tax Pointers for Farmers and Landowners in 1997 and Planning Notes for 1998 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. For more details, you and your tax adviser may wish to consult the sources referenced in the square brackets [thus] (I.R. C. = Internal Revenue Code; Tres. Reg. = Treasury Regulations). New Legislation The Taxpayer Relief Act of 1997 "TRA97" (Public Law 105-34) is one of the longest and most complex pieces of tax legislation passed by Congress. It has been called "mind-numbing" by members of the accounting profession. It also contains errors and omissions, some of which would have been fixed by the Technical Corrections Bill, had it been passed before the end of the 105"" session of Congress. Many provisions become effective January 1, 1998, although some, most notably those affecting capital gains and sale of a principal residence, take effect during 1997. Note that instructions given in the Farmers' Tax Guide (Publication 225) on how to deal with capital gains and losses are out of date (or are correct only for sales of assets made before May 7, 1997). Income averaging that was repealed in 1986 has been re-instituted in a limited way for farm incomes only, starting in 1998. Self-employed Health Insurance Deduction Under the tax act passed in 1996, self- employed individuals can deduct fi-om adjusted gross income (on line 27 of Form 1040) 40% of the amount paid in 1997 for health insurance for their spouses and dependents. TRA97 increases the maximum deduction to 100% by 2007 and speeds up the rate of increase. The part of the insurance premium not deducted is allowed as a medical expense on schedule A, though this will benefit very few people. [I.R.C. § 16(a)(1)(B)] Long-term Care Insurance TRA97 applies the rules for the deduction of health insurance expenses separately for health plans that cover long-term care and for those that do not. Example: an employed husband might have employer-provided coverage that excluded long-term care. His self-employed wife could obtain long-term care insurance for both of them and deduct from adjusted gross income the same 40% of the insurance premium as shown in the previous section. [I.R.C. § 162] Self employment Tax on Rental Income If you rent farmland to another entity (individual, partnership, corporation) you do not pay SE tax on the rental income unless: 1 . There is an arrangement that you will materially participate in the production of agricultural or horticultural commodities, and 2. You actually do materially participate in production. The material participation rule applies to land only. Rent of personal property Fruit Notes, Volume 62 (Number 3), Summer, 1997 used with the land is not subject to SE tax. [I.R.C. §§ 1401(a), 1402(a) and (b)] Example: Bruce Bullock owns a farm and rents out the land for $20,000, buildings for $5,000 and machinery for $10,000 to a family partnership in which he materially partici- pates. He mus pay SE tax on the $20,000 land rent but not on the $5,000 building rent. Rent on personal property is in general subject to SE tax so he must pay SE tax on the machinery rental of $10,000. The IRS is not likely to treat it as falling under the exception for personal property rented with real estate. [I.R.C. § 1402(a)(1)] Note: If Bruce's wife had owned the farm and she was not a member of the partnership, then she probably would avoid SE tax on the land and building rental. Like-kind Exchanges Property used in a trade or business, or held for investment, that is replaced by similar property will be a like-kind exchange if certain conditions are met. Any capital gain or loss realized on the property given up in a like-kind exchange must be deferred and the basis of the new property adjusted accordingly. Deferral is not elective. [I.R.C. § 1031] Form 8824 is used to report the transfer and the basis of the property acquired. It should be filed the year the exchange takes place. Like-kind for real estate is interpreted quite broadly. For example, timberland for bare land, undeveloped farm land for a commercial building. For personal property, like-kind has a narrower definition. Automo- biles, light general-purpose trucks (under 13,000 pounds actual unloaded weight) and heavy general-purpose trucks are separate categories. A trade from one category to another is not a like-kind exchange. Any two assets that are in the same four-digit SIC (Standard Industrial Classification) code are like-kind. Farm machinery qualifies since it is all in SIC code 3523. However, small farm tools and equipment are in several different categories. [Treas. Reg. § 1.1031(a)-2] Sale of Principal Residence Up to $250,000 ($500,000 if married, fihng jointly) of gain on the sale of a principal residence is excluded from tax if all the following requirements are met: 1. The taxpayer (or either spouse) owned the home for two or more years during the five-year period preceding the sale; 2. The taxpayer (or both spouses) used the home as personal residence for two or more years during the five- year period preceding the sale; 3. The taxpayer (or neither spouse) has used the new exclusion during the two-year period preceding the sale; and 4. The sale occurred after May 6, 1997. A person who moves house every two years could claim the exclusion each time. For sales after May 6, 1997, few homeowners should be faced with pa5ang capital gains on the sale of their home. Form 2119 that was used to rollover the gain on sale is no longer needed and will be discontinued. (Note to Massachusetts homeowners: the Commonwealth still follows the Internal Revenue Code of previous years. Presumably State tax forms will in future include a substitute for Form 2119.) [I.R.C. § 121. I.R.C. § 1034, containing the rollover provisions, has been repealed.] If part of the residence was used as an office, or for business, and had been depreciated, any gain allocated to that portion would be subject to capital gains tax. See Table 1. Capital Grain Schedule D of Form 1040, which was 23 lines in 1996 has grown to 54 lines in 1997, thanks to the complexities introduced by TRA97. Profitable sales of assets held for one year or less are short-term gains, whenever sold. Profitable sales of assets held for 18 months or less, sold after July 28, 1997 are short-term gains. These are taxed at the same rate as ordinary income (maximum of 28%). For sales of long-term assets after May 6, 1997 there are three rates: 28% (or 15% for Fruit Notes, Volume 62 (Number 3), Summer, 1997 taxpayers in the 15% bracket) on collectibles (works of art, coins, etc.), on recaptured depreciation of personal property, and on recaptured depreciation on real property that exceeds the straight line depreciation amount; 25% (or 15% for taxpayers in the 15% bracket) on the depreciation of real estate taken on a straight line basis note this change, all real estate depreciation is now recaptured, not just the excess over straight line depreciation; or 20% (10% for taxpayers in the 15% bracket) on all other sales this rate is the basic rate for capital gains and losses except for the situations described for the higher rate. Beginning in 2001, the 20% rate drops to 18% (10% drops to 8%) for assets purchased on or after January 1, 2001 and then held for five years. The way to treat capital losses was not clear from TRA97. On Schedule D of Form 1040, the IRS has followed the anticipated changes in the Technical Corrections Bill that still awaits passage. Basically, short-term losses, if any, are applied first to reduce short-term gains, then to reduce long-term gains in the order: gains in the 28%, 25%, then 20% group. Long- term losses in the 28% group are used against the 25%, then the 20% group. Losses in the 20% group are set off first against the 28% group, then the 25% group. Massachusetts capital gains rules are different. Gain on property held more than one year is taxed at 5% and on property held more than two years at 4%. In each succeeding future year, the rate will drop one percentage point for each additional year that the property is held. Alternative Minimum Tax If you recently sold a commodity on a deferred-payment contract and paid alterna- tive minimum tax, you can defer the payment for both regular income tax and AMT purposes. TRA97 repealed I.R.C. § 56(a)(b), effective 1987. You can amend your return for any past year that is still open to amendment (usually the prior three years). Example: You delivered corn to an elevator in 1995 and received pajonent for it in 1996. For regular income tax purposes, you treated the sale as 1996 income. For AMT purposes it had to be treated as income in 1995. You paid AMT in 1995. You may file amended returns (1040X) for 1995 and 1996. Alternative Minimum Tax Depreciation Aef/ustment TRA97 allows the same recovery period for both regular tax and (AMT) purposes. Previously (AMT) required a longer alternative MACRS recovery period. Both regular and AMT recovery periods are now the same for assets placed in service after 1998. Income Averaging /or Farmers To give farmers subject to year-to-year fluctuations in income some relief, TRA97 institutes a new code section (I.R.C. § 1301) that permits taxpayers "engaged in the farming business" (as defined in I.R.C. § 263A(e)(4)) to average over the three prior years all or a portion of their taxable income derived fi"om farming. The provision is effective for the tax years 1998, 1999 and 2000. An eligible taxpayer elects to have all or part of farming income averaged. The election is irrevocable (cannot be changed by filing an amended return in later years). Gains from the sale of assets (other than land) "regularly used by the taxpayer in the farming business for a substantial period" can be averaged also. One-third of the amount averaged ("elected farm income") is allocated to each of the three prior years. Tax of an electing farmer would be the tax on the amount remaining after allocation (say in 1998) plus the additional taxes that would have been paid in 1995, 1996, and 1997 if the one-third of elected farm income had actually been received in each of those years. Presumably, the IRS will develop a tax form where the election and the necessary calculations can be made. The amount of income allocated to prior years stays in those years as additional income, reducing the benefits from income averaging in succeeding years. Fruit Notes, Volume 62 (Number 3), Summer, 1997 Septic Credit If you own and occupy a principal residence in Massachusetts and you incur expenses to make your sewer system comply with Title V you may claim a credit directly against taxes on your Massachusetts return. The credit is 40% of the costs up to $15,000 for design and construction to repair or replace a failed cesspool or septic system. The maximum aggregate credit of $6,000 is limited to $1,500 in any year. Unused credit may be carried forward for up to three years. Massachusetts Schedule SC must be completed and enclosed with the tax return claiming the credit. Individual Retirement Accounts (JRAsJ Several kinds of IRA are now available: 1. Deductible IRA (input is deducted from gross income, output is taxable). The maximum amount is $2000 per spouse, the amount phases out at higher incomes, and the phase-out levels keep changing. Under prior law, a spouse not covered by a retirement plan could not make a deductible IRA contribution if the other spouse was covered by a qualified retirement plan. TRA97 permits a non-covered spouse to make a deductible IRA deduction. No contributions may be made after age 70.5 at which point required withdrawals must begin. [I.R.C. § 408 and § 219(b), (c) and (g)] 2. Non-deductible IRA (non-deductible input, taxable output). Where phase-out rules have limited the amount contributed as a deductible IRA, non-deductible contributions can be made (into the same account if desired; Form 8606 must be filed and establishes the tax-free basis of the non-deductible IRA). 3. "Roth IRA" (non-deductible input, non- taxable output). The Roth IRA will be available starting in 1998. It is more flexible than existing IRA's. For an investment made more than 5 years ago and withdrawn after age 59.5, the earnings are not taxable. Not subject to the current minimum distribution requirements at age 70.5. Contributions can be made after that age. The maximum contribution that can be made to a Roth IRA is phased out for individuals with AGI between $95,000 and $110,000 and for joint filers with AGI between $150,000 and $160,000. Only taxpayers with AGI of less than $100,000 are eligible to roll over or convert a current IRA into a Roth IRA. In 1998, all or part of a current IRA can be rolled into a Roth IRA with the income tax spread over a four-year period. In no case can contributions to all an individual's IRAs for a taxable year exceed $2,000. [I.R.C. § 408A] Which IRA to choose? At a constant tax rate there is no difference to the taxpayer between a deductible IRA and a Roth IRA. (The difference is to the Government; tax payments are accelerated.) If your marginal tax rate will rise after retirement, choose the Roth IRA; if it will fall, choose the deductible IRA. In general, always make a contribution to a deductible IRA if you can, then to a Roth IRA, and then to a non-deductible IRA. If you want to increase the amount you put into a retirement fund over the $2000 per year allowed for each person's combined IRAs, consider the SIMPLE described below. SIMPLE Simplified Employee Pension IRAs Beginning in 1997, small-business employers can set up SIMPLE (Savings Incentive Match Plan for Employees) retirement plans. A self-employed person can set one up also. Generally, the SIMPLE plan must be the only retirement plan of the employer. SIMPLE plans are written qualified salary reduction arrangements that allow an employee to elect to reduce his or her compensation by a certain percentage each pay period and have the employer contribute the salary reductions to the SIMPLE plan on behalf of the employee. Any employee qualifies who 10 Fruit Notes, Volume 62 (Number 3), Summer, 1997 Table 1 . Example: Jane Carter used one room (10%) of her personal residence as a home office. She purchased the house in 1993 for $120,000 and sold it in June 1997 for $200,000. She lived in the house during the four years and took $3,000 depreciation on the business part. Jane has two transactions. Personal residence portion Business portion Amount of sale (90% of $200,000) Cost basis (90% of $ 1 20,000) Amount of sale $ 1 80,000 ( 1 0% of $200,000) $20,000 Realized and excluded gain 108,000 Unadjusted basis (10% of $120,000) $12,000 Depreciation 3,000 Adjusted basis 9,000 72,000 Recognized (taxable) gain 11,000 received at least $5,000 in compensation from the employer last year and is reasonably expected to make at least that amount next year. For 1997, the amount of the employee's salary reductions cannot exceed $6,000, however it is not subject to percentage limitations. Therefore, an employed person who has a part-time self-employment activity that earns $6,000 could deposit the entire $6,000 in a SIMPLE plan. Employers are also required to make contributions to the SIMPLE plan on behalf of eligible employees, an equal match up to 3% of pay of each contributing employee or a flat 2% of pay of all employees, whether they contribute or not. Contributions to a SIMPLE plan are not subject to income tax until they are distributed. The IRS has provided forms (Form 5303-SIMPLE for use with a designated financial institution and Form 5304-SIMPLE for use with no designated financial institution). These forms are not filed with the IRS but form the legal contract between employer and employees for implementation of the SIMPLE IRA. •J> Vl> •^1^ •si-* •X* •^ •^ rp» 0^ •^ Fruit Notes, Volume 62 (Number .3), Summer, 1997 11 Evaluation of Peach and Nectarine Cultivars for Massachusetts Orchards Karen I. Hauschild Deparfment of Plant & Soil Sciences, University ofMcissachusetts As Massachusetts apple growers face in- creasing competition from producers worldwide, they are turning to retail sales to maintain or enhance their economic viability. Additionally, the popularity of new apple cultivars has con- tributed to the decline in market share for Mcin- tosh, the major variety. As an alternative to apples, Western Mas- sachusetts growers have been especially suc- cessful with peaches. They rarely lose a crop to cold or frost injury, and have a clientele base that is looking for local, tree-ripened fruit. Cen- tral and Eastern Massachusetts retail growers also grow peaches, but these areas have been more likely to experience partial or full crop losses due to spring frosts. These growers, then, are constantly searching for hardier cultivars. For most retail growers, the decision to grow or add additional peaches is an easy one. Choos- ing cultivars is more difficult. In an effort to assist Massachusetts growers with cultivar choices, a cultivar trial was established at the University of Massachusetts Horticultural Re- search Center (HRC), included Flower bud har- diness, fruit size, harvest season, and fruit qual- ity have been evaluated. The first trees in the cultivar evaluation trial were planted in 1990, and cultivars were added in 1998, 1994, and 1996. Trees were pur- chased from commercial nurseries and planted in a 10' X 20' spacing. Four-tree plots of each cultivar were used. Trees were mananged as in commercial plantings. Results Cultivars included in the trial are listed in Table 1 was evaluated following a test winter of 1993-4 during which a low of -15EF was re- corded at Quabbin Reservoir (approx. 1.5 miles north of the HRC). On 4 May 1994, 1 evaluated bloom visually on all trees that were planted in 1990. I estimated bud survival on the top and bottom (below 4 feet) half of each tree. Table 2 lists cultivars that averaged more than 30% bud survival. From these results it appears that Madison has relatively hardy flower buds. Al- though most of the trees in the 1990 planting began fruiting in 1991 or 1992, data recorded from 1991-96 is incomplete. Fruit quality was evaluated yearly, and yield data is available for several cultivars during this time, however In 1997, at least one 10-fruit sample per cul- tivar (except the 1996 planting) was weighed, measured, and judged for quality. Table 3 lists the most promising cultivars based on size, as well as average weight, average size, and har- vest date. Recommendations Of the yellow-fleshed cultivars that met the three-inch size criterion determined by grow- ers, eight also met the criteria for quality: Bounty, Encore, Fayette, Flavorcrest, JimDandee, Madison, Salem, and Sentry. Al- though the size and quality assessments of both Fayette and Encore were very favorable, the har- vest timings of both cultivars very likely are too late for the majority of growers whose main crop is apples. Summer Pearl was the only white-fleshed peach that met size and quality criteria. It is 75% -i- red to dark red; firm, juicy, with sweet, melting flesh. Of the nectarines evaluated, Earliscarlet and Fantasia have both consistently maintained heavy yields, good size, excellent color and exceptional fruit quality. Of the cultivars that met the size criteron, but did not meet quality standards in 1997, sev- eral have shown promise in other years: 12 Fruit Notes, Volume 62 (Number 3), Summer, 1997 Table I. List of cultivars by years planted in the Massachusetts Peach Cultivar Evaluation Trial. Ripening Year date relative Cultivar planted to Redhaven Type^ Jerseydawn 1990 -5 Y Redhaven 0 Y Salem +6 Y Summer Pear! +20* W Flavorcrest -1-20 Y Newhaven +2 Y Madison +24 Y Earliscarlet -10 N Fantasia +31 N Redgold +29 N Summer Beaut +4 N Bounty Encore +36 Y Fayette +30* Y Harcrest +26* Y NJ 275 (Ernie's Choice) +9* Y Harrow Beauty +21* Y Jim Dandee +8* Y Earlired 1993 -19 Y Beekman +20 Y JohnBoy +4 Y Sentry -12 Y Mt. Rose + 15* W Lady Nancy +31* W Red Rose +15* W Sugar Lady 1994 + 11 W White Lady +15 W Eastemglo -10 N Sunglo + 12 N PF- 1 (Flaming Fury Series) 1996 -20 Y PF-15A + 13 Y PF-17A +17 Y Raritan Rose +4 W Arctic Glo -10 WN Arctic Rose +7 WN Arctic Queen +28 WN *N = yellow-fles hed nectarine; Y = = yellow-fleshed peach; W = white-fleshed peach; WN = white-fleshed nectarine. Fruit Notes, Volume 62 (Number 3), Summer, 1997 13 Table 2. Percentage bud survival , averaged over four trees per cultivar. Cultivar Lower Upper Flavorcrest 25% 75% Newhaven 10% 75% Earliscarlet 10% 50% Fantasia 10% 60% Redgold 40% 60% Summer Beaut 10% 60% Madison 75% 90% - Harcrest 10% 60% Table 3. Average size, size range, average weight, percentage of split pits, and harvest dates for more promising cultivars. | Fruit Diameter weight Splits Harvest Cultivar (in.) (g) (%) date Jerseydawn 2.9 195 40 14 Aug. Sentry 3.1 278 50 4 Aug. Earliscarlet 2.9 202 22 15 Aug. Newhaven 2.9 205 0 19 Aug. Flavorcrest 3.0 209 20 19 Aug. Bounty 3.1 278 10 27 Aug. Salem 3.1 255 20 26 Aug. Jim Dandee 3.2 261 20 26 Aug. Sugar Lady 3.0 231 0 26 Aug. Mt. Rose 3.0 217 0 26 Aug. White Lady 3.0 227 10 27 Aug. Red Rose 3.0 235 0 4 Sept. Beekman 2.9 234 0 4 Sept. Lady Nancy 3.1 232 0 10 Sept. Madison 3.2 259 20 15 Sept. Fantasia 3.0 273 10 15 Sept. Sum. Pearl 2.9 224 0 15 Sept. Harcrest 2.9 207 10 15 Sept. Redgold 3.0 267 22 15 Sept. Encore 3.1 256 0 1 Oct. Fayette 3.1 252 0 25 Sept. 14 Fruit Notes, Volume 62 (Number 3), Summer, 1997 Newhaven, Sugar Lady, White Lady, Mt. Rose, Harcrest, Redgold, and Summer Beaut. Trees in the 1993 planting did not do well. They were planted late, and suffered from a dry, hot summer. Trees of four of the cultivars in this planting were replanted in 1996, and should bear enough fruit for evaluation in 1998. JohnBoy is one cultivar that should perform well. Data from the 1990 planting will be collected for at least one more year Because the de- mand for peaches and nectarines has been high at the Horticultural Research Center farmstand, these trees will most likely remain until other, commercial, plantings come into production. Cultivars from all plantings should bear fruit in 1998, and data will be collected for at least two more seasons from the 1993, 1994, and 1996 plantings. Acknowledgments The author wishes to recognize Mr. Joe Sincuk, Mr. Jim Krupa, and the field crew at the Horticultural Research Center. This work would not have been possible without their as- sistance. •X» •^ •^ •kl> •sl^ 0^ r^ #^ •^ r^ Fruit Notes, Volume 62 (Number 3), Summer, 1997 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 1 SERIAL SECTION UNIV OF MASSACHUSETTS LIBRARY AMHERST MA 01003 -^^?€^:>'f5 Account No. 2-22914 UM/Morr. Per SB 354 Ffe8 'rult Notes Prepared by the Department of Plant & Soil Sciences. UMass Extension, U. S. Department of Agriculture, and Massachusetts Counties Cooperating. Editors: Wesley R. Autio and William J. Braxnlage BIOLOGICAL s CO — :s3 vJD •V>. MAY 2 1 1998 SCIENCES LIBRARY Volume 62, Number 4 PALL ISSUE, 1997 Table of Contents Tests of Imidacloprid-treated Spheres for Controlling Apple Maggot Fly A Preliminary Study of 1PM Options for Peaches: Brown Rot Establishment and Spread of Released Typhlodromus pyri Predator Mites in Apple Orchard Blocks of Different Tree Size: 1997 Results An Update on the 1991 Mcintosh Strain/Rootstock Trial Comparison of Ladd Traps, Red Spheres, and Yellow Panels for Capturing Apple Maggot Flies in Commercial Apple Orchards Can We Predict Flyspeck Development? Fruit Notes Publication Information: Fruit Notes (ISSN 0427-6906) is published the each January, April, July, and October by the Department of Plant & Soil Sciences, University of Massachusetts. The costs of subscriptions to Fruit Notes are $ 1 0.00 for United States addresses and $ 1 2.00 for foreign addresses. Each one-year subscription begins January 1 and ends December 3 1 . Some back issues are available for $3.00 (United States addresses) and $3.50 (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 01 003 I UMASS EXTENSION 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 UMass Exleiisinii. Ruben G Hetjtesen. Direclnr, in lurlberance of the iicis of May H and June 30, 1914. UMiiss Extension offers equal apparlunily in pnif;ianis and empliiynienl. Tests of Imidacloprid-treated Spheres for Controlling Apple Maggot Fly Starker Wright, Xing Ping Hu, and Ronald Prokopy Department of Entomology, University of Massachusetts In the 1996 and 1997 Spring issues oi Fruit Notes, we reported on studies aimed at devel- opment of pesticide-treated spheres (PTS) as a substitute for sticky spheres for direct control of apple maggot flies. In concept, a PTS would be coated with a mixture of insecticide, fly feed- ing stimulant, and residue-extending agent. A fly landing on such a sphere would feed, ingest insecticide, and die before laying any eggs. The need to use labor-intensive sticky substances (such as Tangletrap) to capture alighting flies would be eliminated. Several earlier trials in- dicated that dimethoate was the most effective among orchard-labeled insecticides for use on spheres, but its high human toxicity poses too great a risk to the handler. In 1996, we found that the newly-labeled insecticide imidacloprid was a safer alternative to dimethoate and was seemingly as effective. Sucrose (table sugar) has proven to be, by far, the most effective fly feeding stimulant. However, while mixing with latex paint pre- serves the residual activity of the insecticide, all sugar is lost from the sphere surface follow- ing rainfall. We have taken two separate ap- proaches to preserving residual activity of su- crose: (1) development of a method in which the activity of sucrose is extended on reusable wooden spheres, which are annually coated with a mixture of sucrose, insecticide, and latex paint; and (2) development of a method in which the entire sphere body is constructed of a mixture of sucrose, flour, and glycerin, coated with a mix- ture of insecticide and latex paint so as to cre- ate a biodegradable sphere. Here we report on two experiments leading to refinement of resi- due-extending agent, fly-killing agent, and evaluation of each sphere type for direct con- trol of apple maggot flies in commercial or- chards. Materials & Methods In our first experiment, we evaluated in laboratory studies three formulations of imidacloprid (EC, WP, technical grade) in com- bination with each of three formulations (flat, semi-gloss, gloss) of each of four commercial brands of red latex paint (36 treatments in all). We found the EC and WP formulations of imidacloprid in Glidden Red Latex Gloss Enamel paint to be the most promising. We then placed wooden spheres coated with two concen- trations of each formulation of imidacloprid in orchard trees and evaluated them for their abil- ity to kill apple maggot flies at 0, 3, 6, 9, and 12 weeks after placement. In our second experiment, two sphere types were assessed in an attempt to extend the re- sidual activity of sucrose on the sphere surface. Each wooden PTS was fitted with a 3-cm-di- ameter ring of specially formulated caramelized sucrose around the hook at the top of the sphere. The sucrose spread down the sides of the sphere after each rainfall, continually replenishing the sugar supply on the sphere surface. This type of sphere was developed as a replacement for spheres tested in 1996 in which holes were drilled and filled with sucrose prior to paint- ing, as described in the Spring 1997 issue of Fruit Notes. Further testing of the 'spheres with holes' revealed that construction was far too costly and time consuming to be of practical value. For sugar/flour biodegradable spheres, the following composition of ingredients proved best: sucrose/fructose syrup (25%), pregelatinized corn flour (25%), wheat flour (25%), glycerin (10%), and water (15%). After hardening in the laboratory, such spheres emit a continuous supply of sugar to the surface, ir- respective of rainfall amount. Fruit Notes, Volume 62 (Number 4), Fall, 1997 We then compared the effectiveness of our best wooden PTS and our best sugar/flour PTS with sticky-coated spheres for direct season- long control of apple maggot flies in commer- cial orchards. In all, we used eight orchards, each having four blocks of medium-sized trees (49 trees/block). Each block receiving spheres was surrounded by 26 spheres of the same type, five yards apart, each baited with butyl hexanoate. Table 1. Residual activity concentrations of imidaclopric orchard trees and exposed to w of two different formulations and two different in latex paint on sucrose-treated spheres hung in eather. Fly mortality (%)* Weeks of Exposure 0.5% EC 1.5% EC 0.5% WP 1.5% WP Check 0 97a 97a 96a 98a Ob 3 96a 93a 90a 95a 3b 6 70b 92a 85a 94a 5c 9 60b 90a 80a 90a Oc 12 45c 87ab 75b 90a 5d No. eggs laid in artificial fruit* 0 Oa Oa Oa Oa 26b 3 Oa Oa Oa Oa 28b 6 2a Oa 2a Oa 25b 9 la Oa 2a Oa 21b 12 la Oa Oa Oa 24b Median lethal feeding time* 0 30a 20a 30a 20a - 3 80b 40a 75b 35a - 6 182b 45a 180b 40a - 9 240b 50a 210b 45a - 12 300c 100a 240b 60a - * Three replicates of 20 flies per treatment. Numbers different letters are significantly different at odds of 19:1. within rows followed by Fruit Notes, Volume 62 (Number 4), Fail, 1997 Table 2. Control of apple maggot flies by odor-baited wooden pesticide treated spheres (PTS), sugar/flour PTS, sticky spheres or three applications of azinphosmethyl in blocks of apple trees in commercial orchards. Mean % maggot-injured apples'* Wooden PTS Sugar/flour PTS Sticky Spheres Azinphosmethyl 0.56b 0.32ab 0.32ab 0.11a * Total of 2800 fruit per treatment (100 fruit per block on each of four sampling dates-2 weeks apart-from late July until harvest). Numbers followed by a different letter are significantly different at odds of 19:1. Results Laboratory bioassays revealed (Table 1) that after 12 weeks of exposure to outdoor sunlight and 11 inches of natural rainfall, wooden spheres treated with 1.5% a.i. imidacloprid WP in Glidden paint killed 90% of arriving flies. Such treatment also rendered all flies incapable of lajdng eggs after feeding and required that a fly feed on the sphere surface for a median time of only 60 seconds to ingest enough toxicant to die. Performance of wooden spheres treated with 1.5% imidacloprid EC was slightly but not significantly inferior, killing 87% of arriving flies. At lower concentrations (0.5% a.i.), nei- ther the WP nor EC formulation performed as well (75% and 45% kill, respectively) as the 1.5% a.i. WP formulation. In our second experiment (Table 2), sugar/ flour PTS coated with 1.5% imidacloprid WP in Glidden paint performed as well as sticky spheres in providing direct control of apple maggot. Wooden PTS coated with 1.5% imidacloprid in Glidden paint and fitted with a 3-cm-diameter sucrose ring were inferior Two- to-three insecticide sprays resulted in the least damage. Conclusions Our first experiment provided us with the formulation of a low dose of a safe and highly effective insecticide (1.5% a.i. imidacloprid WP) that can be combined with a particular type of paint (Glidden Red Latex Gloss Enamel) which offers very long and effective residual activity of imidacloprid under field conditions. Although all sphere types used in the sec- ond experiment performed quite well in the face of high fly pressure, shortcomings need to be addressed and improvements need to be made before future use of PTS for controlling apple maggot in commercial orchard IPM blocks. Regarding wooden PTS, the caramelized sucrose rings melted away before the end of the field season, contributing to the reduced effective- ness of these spheres. Some of the sugar/flour PTS were eaten by birds and rodents while oth- ers were overgrown by fungi on the sphere sur- face, thus reducing the number of effective spheres comprising the barrier to fly entry into some blocks. For 1998 deployment of wooden PTS, we plan to reformulate the sucrose ring atop the sphere to improve residual effectiveness of the Fruit Notes, Volume 62 (Number 4), Fall, 1997 spheres. For sugar/flour biodegradable PTS, we will evaluate various bird/rodent-feeding deter- rents and various fungicides incorporated into the body of the sphere. Acknowledgments This work was supported by state/federal IPM funds and grants from the New England Tree Fruit Growers Research Committee and the USDA Northeast Regional IPM Competi- tive Grants Program. We are grateful to the eight growers that participated in this study: Bill Broderick, Dana Clark, Dave Chandler, Tony Lincoln, Wayne Rice, Dave Shearer, Joe Sincuk, and Tim Smith. *\a •Jt* •X^ •Xa •Xa ry% #Y* *T* *T* *T* Fruit Notes, Volume 62 (Number 4), Fall, 1997 A Preliminary Study of IPI\/I Options for Peaches: Brown Rot Daniel Cooley and Arthur Tuttle Department of Microbiology, University of Massachusetts Karen Hauschild and Joe Sincuk Department of Plant & Soil Sciences, University of Massachusetts Peaches have gained more attention from Massachusetts tree-fruit growers, who in recent years have been looking for crop options in addition to apples. Peaches can produce highly saleable fruit earlier in the season, and usually command a good price, particularly for direct market sales. High quality peaches which have been allowed to ripen on the tree longer than peaches shipped from California, New Jersey, or the South can get a premium price. However, the riper a peach is, the higher the chances are that it will develop brown rot or other postharvest decays. This may happen on the tree, or worse yet, on the customer's shelf. While other rots can be a problem, peach brown rot, caused by the fungus Monilinia fruciico/a, is the most serious fungal disease problem for Massachusetts growers, and fungicides used on peaches primarily are aimed at managing this disease. The timing of these fungicide applications is based largely on tree develop- ment, but it is not clear what timing scheme is most effective and efficient. The biology of the fungus suggests that there are two critical times when peaches should be protected: bloom and fruit ripening. Brown rot infections on peach develop during these two phenological stages. Blossom blight may cause flowers to wither, turn brown, and die, and later produce spores which later infect fruit. These blossom infections may also move into twigs and cause significant damage when conditions for disease development are highly favorable. Normally blossom infections remain quiescent, or latent, until fruit starts to ripen. Then, the infections will start to grow, produce spores, and spread to other ripe fruit. Between bloom and harvest, fruit susceptibility to brown rot remains quite low from pit hardening to 2 weeks before full ripeness (Biggs and Northover, 1988). By monitoring pit hardening and ground color, growers might eliminate fungicide sprays during this period, and get better brown rot control. Materials & Methods To examine the effect of reducing fungicide use for managing brown rot during pit hardening, an experiment was conducted at the University of Massachusetts Horticultural Research Center during the 1996 growing season. The experiment was conducted in two blocks of peaches, one Redhaven and the other Glohaven. Each treatment plot consisted of three trees. There were three replications of the experiment in the Redhaven block and four in the Glohaven block. Sampling for pit hardening was done in mid- through late June. Until pit hardening in early June, all treatment plots received standard calendar-based fungicide applica- tions every 7 to 10 days, starting at early bloom. These consisted Captan 80WP at 1 lb/100 gal. After that time, fungicides were applied according to four treatment patterns. In one treatment, the calendar applications were continued at 7 to 14 day intervals, using Captan (SOW, 1 Ib./lOO gal.) on the early spray dates or the same rate of Captan plus Benlate Fruit Notes, Volume 62 (Number 4), Fall, 1997 Table 1. Fungicide treatments in Redhaven Massachusetts Horticultural Research Center, B( and Glohaven jlchertown, MA, peach 1996. 3s at the University of Pesticide (rate/100 gal.) Dates Fungicide applications after pit hardening (no. after 10 July) Full spray Captan SOWPdlb.) 17 June, 2 July, 14 July 3 Captan 80WP + Benlate 50DF (6 fl oz.) 25 July, 2 Aug. 2 Reduced spray Captan SOWPdlb.) 2 July, 14 July 2 Captan 80WP + Benlate 50DF (6 fl oz.) 2 Aug. 1 Low spray Captan SOWPdlb.) 2 July 1 Captan 80WP + Benlate 50DF (6 fl oz.) 2 Aug. 1 No spray None none 0 1 (50DF 6 fl oz./lOO gal.) on later dates. In a second treatment, one fungicide application was made between pit hardening and fruit ripening, with one additional fungicide applica- tion during fruit ripening using the same fungicides and rates. In the third treatment, no fungicide applications were made following pit hardening and one fungicide application was made during fruit ripening using the same fungicides and rates. A fourth treatment was not sprayed at all. These treatments with the numbers and dates of applications are detailed in Table 1. Redhaven fruit were harvested on 15 and 2 1 Aug.; Glohaven fruit were harvested on 3 Sept. Therefore, the last fungicide applications were made from 2 to 4 weeks before harvest, depending on the cultivar, and 2 to 4 weeks after pit hardening. Therefore the experiment evaluated the effect of different numbers of fungicide sprays applied during pit hardening. from no sprays to five sprays. Evaluation of fruit rot damage was done at harvest, and 5 to 7 days after harvest. Brown rot and other rots were distinguished on the basis of symptoms. Disease incidence is the number of fruit which show any disease. Disease severity estimates the extent of fruit rot using a 1 to 5 scale, with 1 the least severe and 5 the most severe. Results & Discussion The number of fungicide applications after pit hardening but before ripening had an effect on brown rot and other rots, but it was not consistent. In Redhaven fruit at harvest, there was significantly less rot in the full spray and reduced spray treatments compared with the low spray treatment (Table 2). However, the no spray treatment also had significantly less brown rot at harvest compared with the low Fruit Notes, Volume 62 (Number 4), Fall, 1997 Table 2. Disease evaluations on Redhaven schedules, University of Massachusetts Hortic peach fruit under different pesticide ultural Research Center, 1996.* treatment At harvest Postharvest Brown rot incidence Treatment (%) Brown rot severity Incidence of other rots (%) Severity of other rots Brown rot incidence (%) Incidence of other rots (%) Full spray 2 b Reduced spray 4 b Low spray 8 a No spray 4 b 0.02 c 0.11b 0.19 a 0.07 c Ob Ob 2a Ob 0.01 b 0.00 b 0.05 a 0.00 b 24 b 21b 31b 49 a 14 a 21 a 14 a 9 a * Severity; 1 = least severe, 5 = most severe. Means in each not differ significantly from each other at odds of 19:1. column followed by the same letter do Table 3. Disease evaluations on Glohaven peach fruit under different pesticide treatment schedules, University of Massachusetts Horticultural Research Center, 1996.* At harvest Postharvest Brown rot Incidence Severity Brown rot Incidence incidence Brown rot of other of other incidence of other Treatment {%) severity rots (%) rots (%) rots (%) Full sprays 7c 0.18 c 1 a O.Ola 37 a 20 a Reduced spray 20 b 0.52 b 1 a O.Ola 60 a 28 a Low spray 10 c 0.30 c 2 a 0.02 a 32 a 12 a No spray 48 a 1.30 a 1 a 0.01 a 58 a 36 a * Severity: 1 = least severe, 5 - most severe. Means in each column followed by the same letter do not differ significantly from each other at odds of 19:1. spray regime. Approximately one week after harvest, none of the sprayed treatments had significantly different brown rot incidences. and all were lower than the no spray treatment. In Glohaven fruit, the pattern was closer to what one would expect (Table 3). At harvest, Fruit Notes, Volume 62 (Number 4), Fall, 1997 the no spray treatment had more brown rot and more severe brown rot than any of the spray treatments. Again, brown rot was lowest in the full spray trees. However, in this cultivar, brown rot was just as low in the low spray treatment, and significantly higher in the reduced spray treatment. Unfortunately, this test did little to resolve the usefulness of fungicides during the period between pit hardening and harvest. None of the reduced-spray options consistently did as well as the five-spray program. It is difficult to explain the failure of two fungicide applica- tions vs. no applications in Redhaven, and of three applications vs. two applications in Glohaven. It is possible that there was contamination caused by fungicide drift. Beyond that, there may have been differences in inoculum or other factors which were not adequately controlled. This test did not conform to the recommen- dations made by Biggs and Northover. Rather than eliminating or reducing sprays after pit hardening, and then making one or two applications very near harvest as fruit ripened, this test looked at different numbers of fungicide applications made after pit harden- ing but stopping all fungicides at least two weeks before harvest. This may account for the results, as Captan and Benlate would not generally persist for more than a week against heavy brown rot pressure. Any small, random outbreak of brown rot would have been able to spread in all treatments during the 2 to 3 unprotected weeks before harvest. Only the heaviest fungicide treatment consistently reduced this problem. A similar experiment, focusing on bloom and harvest fungicide applications, will need to be done to resolve these problems. •sL* vj> vL* vl>» vL* #Y* *T* "T* *T* *Y* Fruit Notes, Volume 62 (Number 4), Fall, 1997 Establishment and Spread of Released Typhlodromus pyri Predator Mites in Apple Orchard Blocks of Different Tree Size: 1997 Results Ronald Prokopy, Starker Wright, and Jonathan Black Department of Entomology, University of Massachusetts Jan Nyrop, Karen Wentworth, and Carol Herring Cornell University, NY Agricultural Expe?ime?it Station, Geneva Pest mites are usually completely controlled by predatory mites on unmanaged apple trees that receive no insecticide or fungicide. Some commonly-used orchard pesticides (e.g., synthetic pyrethroid insecticides, EBDC fungicides) kill or otherwise harm predatory mites, leading to pest mite outbreaks and need for miticide application. In Massachusetts, the predatory mite Amblyseius fallacis is present in about 90% of commercial orchards (see 1994 Spring issue oi Fruit Notes) but usually not in numbers sufficient for providing mite biocontrol until August. Studies in New York have shown that the predatory mite Typhlodromus pyri, where established, can be an extremely effective season-long biocontrol agent of pest mites. This is a result of their ability to endure cold winter temperatures and periods of short supply of pest mites as food much better than^. fallacis. Unfortunately, few Massachusetts orchards appear to harbor significant natural populations of T. pyri. In the 1997 Spring issue oi Fruit Notes, we reported that when T. pyri obtained from Geneva, New York were released in 1995 into blocks of apple trees in six commercial orchards in Massachusetts, they became established in all blocks save those in one of the six orchards. On average, after two years, they had built to greater numbers in blocks managed under second-level IPM practices (no pesticide of any type used after early June) than in blocks managed under first-level IPM (sprayed with fungicide and insecticide through summer). These findings stimulated us to conduct further research on the establishment oiT.pyri released in Massachusetts apple orchards. We report here first-year results of a study in which T.pyri were released in 1997 on single trees in the center of blocks comprised of small, medium, or large trees and managed under third-level IPM practices. Materials & Methods Our experiment was conducted in six blocks of apple trees in each of eight commercial orchards. Of the six blocks per orchard, two each contained trees on M.9, M.26, or M.7 rootstock, designated as small, medium-size, or large trees. One block of each pair received first-level IPM practices, wherein growers applied insecticide and fungicide materials of their own choosing and timing of application, which extended from April through August. The other block of each pair received third-level IPM practices, wherein the intent was that no synthetic pjrrethroid insecticide was to be used at any time, use of EBDC fungicides was to be minimized, no insecticide of any type was to be used after mid June, and captan or benomyl were the only fungicides to be used after mid Fruit Notes, Volume 62 (Number 4), Fall, 1997 June. T. pyri is known to be highly adversely affected by synthetic pyrethroid insecticide and also adversely affected by EBDC fungicide (when applied from bloom onward) but not by captan or benomyl. Each block was comprised of 49 trees (7 rows x 7 trees per row) and of the cultivars Mcintosh, Empire, and Cortland. Third-level IPM is similar to second-level IPM in focus on using biologically-based pest management practices, but it embraces integration with horticultural concerns (such as tree size) as an added component. In May, blossom clusters harboring T. pyri were picked from an orchard at the New York State Agricultural Experiment Station at Geneva, sent by overnight mail to Massachusetts, and within three days were distributed to orchard blocks. Each third-level IPM block recieved 100 clusters, which were attached to twigs on the center tree of the block using twist ties. No T. pyri were released in first-level IPM blocks. Every 3 weeks from late July through early September in each of the 48 blocks, we sampled 25 leaves from the center tree, 15 leaves from each of the two outermost trees in the center row, and 15 leaves each from the center tree in each of the two outermost rows. The leaves were sent by overnight mail to Geneva, New York for the identification and counting of pest and predatory mites. In all, about 2,600 leaves were sampled for each of the three sampling periods. Results As shown in Table 1, significantly more T. pyri-were present on the center (release) tree on each sampling date in blocks of each tree size than on outer trees in center rows of blocks (that is, the fourth tree up row and the fourth tree down row from the center tree in a block) or on center trees in outer rows of blocks (that is, the fourth tree directly across row to either side of the center tree of a block). In fact, extremely few or no T. pyri were found on any tree except those on which they were released. In contrast, there were no significant differences among tree locations within plots in numbers of A. fallacis sampled on each sampling date in blocks of each tree size (data not shown). The same was true for European red mites (data not shown). The finding that, on average, numbers of European red mites were not significantly fewer on release trees than on non-release trees on any sampling date in blocks of any tree size suggests that T. pyri were not able to build to sufficient numbers to provide biocontrol of European red mites during the three months following release. This was not a surprising result because T. pyri populations grow slowly and usually are not capable of rapidly controlling moderate to high density red mite populations. Even so, there was one block of small trees in which T. pyri were released where every tree (save one) in that block (as well as every tree in each of the other five study blocks in that orchard) was heavily bronzed as a consequence of mite injury. The only tree that was not bronzed was the center tree on which T. pyri were released. Data in Table 2 summarize information of all leaves sampled in a block and compare average numbers of T. pyri, A. fallacis and European red mites per leaf between first-level IPM blocks and third-level IPM blocks and among small, medium, and large trees within each sampling date. For each sampling date, there was no significant difference among blocks of small, medium-sized, and large trees in numbers of 7! pyri found in third-level IPM blocks. In every case, third-level IPM blocks had significantly more T. pyri than first-level IPM blocks. For A. fallacis there were no significant differences in numbers found between first-level and third-level IPM blocks or among tree sizes for any sampling date. The same was true for European red mites. Information on type and amount of insecticide, acaricide, and fungicide used before bloom, from bloom through mid-June, and after mid- June is given in Table 3. Blocks of small, medium, and large trees in the same orchard were treated in the same manner. With respect to insecticide, some Asana was used before bloom and some Lorsban after mid- June in first-level blocks. Both of these materials are known to be detrimental to T. 10 Fruit Notes, Volume 62 (Number 4), Fall, 1997 Table 1. Abundance of T. pyri mite predators on leaves sampled in July, August, and September in 1997 from first-level and third-level IPM blocks. T. pyri were released on the center tree in each block in mid-May 1997. Mean no. per leaf ' Sample time Tree size Sample site First-level 1PM Third-level IPM Late July Mid-August Large Medium Small Large Medium Small Early September Large Medium Small Center tree 0.00 b 0.34 a Center row, outer trees 0.01 b 0.01b Outer row, center trees 0.00 b 0.00 b Center tree 0.03 b 0.54 a Center row, outer trees 0.00 b 0.00 b Outer row, center trees 0.00 b 0.00 b Center tree 0.00 b 0.68 a Center row, outer trees 0.00 b 0.09 b Outer row, center trees 0.00 b 0.00 b Center tree 0.00 b 0.62 a Center row, outer trees 0.00 b 0.01b Outer row, center trees 0.00 b 0.01b Center tree 0.00 b 1.13 a Center row, outer trees 0.00 b 0.00 b Outer row, center trees 0.00 b 0.00 b Center tree 0.00 b 0.97 a Center row, outer trees 0.00 b 0.00 b Outer row, center trees 0.00 b 0.00 b Center tree 0.00 b 0.87 a Center row, outer trees 0.07 b 0.01 b Outer row, center trees 0.01b 0.00 b Center tree 0.00 b 0.67 a Center row, outer trees 0.00 b 0.01b Outer row, center trees 0.00 b 0.00 b Center tree 0.00 b 0.55 a Center row, outer trees 0.00 b 0.00 b Outer row, center trees 0.00 b 0.01b * For each size of tree at each time of sampling, numbers followed by a different letter are significantly different at odds of 19:1. Fruit Notes, Volume 62 (Number 4), Fall, 1997 11 Table 2. Abundance of T. pyri, A. fallacis, and European red mites (ERM) on leaves sampled in July, August, and September in 1997 from first-level and third-level IPM blocks. Mean num ber per leaf* T. pyri A. fallacis ERM 1^' level S'^'' level 1"' level S-^d level 1«' level 3^d level Sample time Tree size IPM IPM IPM IPM IPM IPM Late July Large 0.00 b 0.12 a 0.04 a 0.04 a 3.6 a 7.2 a Medium 0.01b 0.18 a 0.08 a 0.10 a 3.3 a 4.9 a Small 0.00 b 0.26 a 0.05 a 0.07 a 8.8 a 5.7 a Mid-August Large 0.00 b 0.21a 0.06 a 0.15 a 9.9 a 9.0 a Medium 0.00 b 0.38 a 0.43 a 0.36 a 9.6 a 2.6 a Small 0.00 b 0.33 a 0.11a 0.24 a 4.0 a 10.4 a Early September Large 0.01b 0.21a 0.15 a 0.17 a 2.9 a 1.3 a Medium 0.00 b 0.26 a 0.15 a 0.17 a 1.0 a 3.3 a Small 0.00 b 0.26 a 0.09 a 0.13 a 1.4 a 4.5 a * Each value represents the average number of individuals found on 55 leaves per block per sampling date (25 leaves from the center tree and a total of 30 leaves from four other trees in the blocks, all of which were four trees removed from the center tree). For each tree size at each time of sampling, numbers followed by a different letter are significantly different at odds of 19:1. pyri. The fact that they were not used in third- level blocks undoubtedly aided in establishment of T. pyri. None of the acaricides used in either first-level or third-level blocks is known to affect T. pyri substantially. As hoped, none of the third-level blocks received any Manzate, Dithane, Mancozeb, or Penncozeb as fungicides, whereas first-level IPM blocks received substantial amounts of these materials up to mid-June. Third-level IPM blocks did, however, receive some Polyram before bloom and a small amount after bloom. Some data indicate that Polyram is just as harmful to T. pyri as the other four aforementioned EBDC fungicides, which are especially harmful when applied during or after bloom. In general, the profile of fungicides applied in third-leve) IPM blocks was quite (although not completely) conducive to establishment of T. pyri. Conclusions The data presented here show convincingly that T. pyri became established on trees in which they were released: the centermost trees in third-level IPM blocks of small, medium, and large trees. Growers participating in this experiment cooperated with its aims by not applying harmful insecticides or acaricides and by minimizing use of fungicides harmful to T. pyri in the blocks in which T. pyri were released. Interestingly, even more than three months after release, T. /?>//■/ failed to move (in detectable numbers) even as far as four trees 12 Fruit Notes, Volume 62 (Number 4), Fall, 1997 Table 3. Types and dosage equivalents of insecticides, acaricides, and fungicides applied per block in first-level and third-level IPM blocks in 1997. Material Before bloom 1^^ level S-^"* level Bloom through mid-June Insecticide Acaricide Fungicide Asana Dimethoate Gution Imidan Lorsban Provado Sevin Oil Savey Silwet Agrimek Pyramite Omite Benlate/Topsin Nova/Rubigan Manzate* Polyram Syllit Captec 0.06 - 0.08 0.08 0.04 0.20 3.10 0.12 1.10 3.20 0.12 1.00 1.25 0.50 0.13 1.25 0.38 0.13 0.08 0.08 0.13 0.42 1.75 0.21 0.01 0.13 1.54 0.46 0.60 0.61 0.61 0.34 1.28 0.72 - 1.05 0.28 0.16 0.01 0.73 1.7 After mid-June 1^<- level 3'''' level 1" level 3"^ level 1.00 0.13 0.26 0.06 0.16 0.06 0.67 1.2 0.15 0.13 0.17 - 0.55 0.26 0.04 - 0.13 - 1.15 0.88 * Includes also Dithane, Mancozeb, and Penncozeb. away downrow or crossrow, regardless of whether blocks were comprised of small, medium-size or large trees. We saw no evidence of suppression of European red mites by released T. pyri in any trees (except one) in which T. pyri were released. In the lone exception (a block of small trees), the foliage of the release tree remained dark green throughout summer, whereas the foliage of all other trees in the block was decidedly bronzed by mid-July. For 1998 and 1999, we plan to sample the same trees sampled in each block in 1997. We expect that by 1999, T. pyri will have spread to all parts of each third-level IPM block and will have provided effective biocontrol of European red mites in such blocks, particularly in blocks of small trees. Acknowledgments We are grateful to the eight growers participating in this experiment and who made special effort to apply pesticide selectively to third-level IPM blocks: Bill Broderick, Dave Chandler, Dave Cheney, Dana Clark, Dave Shearer, Joe Sincuk, Tim Smith, and Mo Tougas. This work was supported by state/ federal IPM Fruit Notes, Volume 62 (Number 4), Fall, 1997 13 An Update on the 1991 Mcintosh Strain/Rootstock Trial Wesley R. Autio Department of Plant & Soil Sciences, University of Massachusetts As apple growers plan for future plantings, differences and those caused by rootstocks it is important to understand how different were additive. Secondarily, tree size and yield rootstocks and scions will perform. Much performance were studied. Because of some rootstock research in recent years has studied surprising results, the tree size and yield the interaction of scion and rootstock to allow performance from the Massachusetts half of for better choice of combinations for commer- the trial are reported here, cial orchards. In 1991, a pair of plantings was established Materials & Methods (one at the University of Massachusetts Horticultural Research Center in Belchertown In the summer of 1988, scions of Pioneer and one at the University of Maine Highmoor Mac (a Mcintosh seedling), Marshall Mcintosh, Farm in Monmouth) to study effects of a Chic-A-Dee Mcintosh, and Rogers Red Mcln- combination of Mcintosh strains plus one tosh were budded onto Mark, M. 7 EMLA, M. 27 Mcintosh seedling and four rootstocks. The EMLA, and M.26 EMLA rootstocks at the original intent of this trial was to determine if University of Maine Highmoor Farm. Trees differences in ripening caused by strain were allowed to growth through the following Table 2. Yield efficiency and fruit weight in 1997of three strains of Mcintosh anc one Mcintosh seedhng on four rootstocks planted in 1991.' Yield efficiency (kg/cm^ trunk cross sectional area) Fruit weight Cumulative Rootstock/Cultivar 1997 (1993-97) (g) Mark 0.77 b 2.60 a 157 a M.7 HMLA 0.35 c 1.19 c 157 a M.27 EMLA 1.04 a 2.81 a 146 a M.26 EMLA 0.63 b 2.21 b 1 56 a Pioneer Mac 0.74 a 2.48 a 145 c Marshall Mcintosh 0.70 a 1.84 b 151 be Chic-A-Dee Mcintosh 0.76 a 2.40 a 161 a Rogers Red Mcintosh 0.59 a 2.09 ab 157 ab ' Overall rootstock means within columns or overall cultivar means within columns are significantly different at odds of 19:1 if not foil owed by the same letter. 14 Fruit Notes, Volume 62 (Number 4), Fall, 1997 Tabic 1. Trunk cross-sectional area and yield in 1997 of three strains of Mcintosh and one Mcintosh seedlir g on four rootstocks planted in 1991.' Pioneer Marshall Chic-A-Dee Rogers Red Rootstock Mac Mcintosh Mcintosh Mcintosh Average Trunk cross-sectional area (cm^) Mark 30.4 c 30.7 b 26.3 b 37.2 a 31.2c M.7 EMLA 72.8 a 49.3 a 46.7 a 47.8 a 54.2 a M.27 EMLA 10,9 d 9,8 c 7.2 c 7.9 b 9.0 d M.26 EMLA 41. 8b 54.3 a 29.1b 37.0 a 40.6 b Average 39.0 a 36.0 a 27.3 b 32.4 ab Yield per tree (kg, 1997) Mark 23 b 26 a 1 8 a 20 a 22 ab M.7 EMLA 24 ab 14b 19a 18a 19b M.27 EMLA 10c 9b 8b 9b 9c M.26 EMLA 32 a 31a 20 a 12 ab 24 a Average 23 a 20 ab 16 be 15 c Cumulative yield per tree (kg, 1993-97) Mark 91 a 76 a 59 a 84 a 77 a M.7 EMLA 93 a 44 b 67 a 59 b 66 b M.27 EMLA 32 b 20 c 23 b 24 c 25 c M.26 EMLA 106 a 93 a 70 a 65 b 83 a Average 80 a 58 b 55 b 58 b ' Rootstock means within co umns or overall cultivar means are significantly different at odds of 19:1 if not followed by the same letter. two seasons in the nursery. In April of 1991, seven replications of all combinations were planted at the University of Massachusetts Horticultural Research Center. Yield and tree size were assessed each year. Results & Discussion Overall tree size at the end of the seventh growing season followed expected patterns, with trees on M.7 EMLA the largest, and those on M.27 EMLA the smallest (Table 1). Further, Pioneer Mac and Marshall trees were significantly larger than Chic-A-Dee trees, and Rogers trees were intermediate. Interestingly, the relative differences among the four rootstocks were not similar across the cultivars. With Marshall Mcintosh, trees on M.7 EMLA were smaller than expected and similar to those on M.26 EMLA (Figure 1). Fruit Notes, Volume 62 (Number 4), Fall, 1997 15 D c O u= o a> (A o o C 3 100 90 80 70 60 50 40 30 20 10 0 Pioneer Marshall Mark M.7 EMLA M.27 EMLA M.26 EMLA Chic-A-Dee Rogers Figure 1. Trunk cross-sectional area in 1997 of three strains of Mcintosh and one Mcintosh seedHng on four rootstocks. Within cultivar, means without the same letter are significantly different at odds of 19:1. a- 140 120 M 100 0) 01 a 4) '>. > J2 3 E 3 u 80 60 40 20 "1 Pioneer Marshall 1 Chic-A-Dee Rogers Figure 2. Cumulative yield per tree (1993-97) of three strains of Mcintosh and one Mcintosh seedling on four rootstocks. Within cultivar, means without the same letter are significantly different at odds of 19:1. 16 Fruit Notes, Volume 62 (Number 4), Fall, 1997 Cumulative yield generally was as ex- pected, with trees on M.26 EMLA producing the most fruit and those on M.27 EMLA the least. Pioneer Mac produced significantly more fruit than Chic-A-Dee or Rogers, and Marshall was intermediate; however, the relative differences among the rootstocks varied with cultivar. Cumulative yield of M.7 EMLA and M.26 EMLA were similar for Pioneer Mac, Chic-A-Dee, and Rogers, but Marshall/M.26 EMLA yielded more than double Marshall/M.7 EMLA (Figure 2). Rootstock effects on yield efficiency followed consistent trends among cultivars. Cumulatively, M.27 and Mark produced the most efficient trees, followed by M.26 EMLA, and M.7 EMLA produced the least efficient trees (Table 2). Cumulatively, Pioneer Mac and Chic-A-Dee were significantly more efficient than Marshall, with Rogers interme- diate (Table 2). Rootstock did not affect fruit weight in 1997, but Chic-A-Dee resulted in significantly larger fruit than Marshall or Pioneer Mac (Table 2). Tliese results lead to an interesting question: Why does Marshall Mcintosh respond poorly to M.7 EMLA? One possibility is that M.7 EMLA is sensitive to a virus present in Marshall. Marshall is not a virus-fruit strain of Mcintosh. It may explain some of the variable results with Marshall Mcintosh in recent years, particularly reduced leaf quality, tree growth, and fruit size. If considering semi dwarf Mcintosh trees for future plantings, likely it is best to avoid the combination of Marshall and M.7 EMLA. •X* •X* *X* •X* *4^ 0^ 0^ • *\* •^ w^ #Y* *T* *T* 20 Fruit Notes, Volume 62 (Number 4), Fall, 1997 Can We Predict Flyspeck Development? James C. Hall, Michael Frank, Arthur F. Tuttle, and Daniel R. Cooley Department of Microbiology, University of Massachusetts Flyspeck, caused by Schizothyrium pomi and sooty blotch, caused by a group of fungi including Peltaster fructicola, Leptodontium elatius, and Geastrumia polystigmatis are two common summer diseases of apple in New England. Recently, summer diseases have become more problematic due at least in part to the decreased use of fungicides such as mancozeb and captan, attributable to increased label restrictions, cost cutting, and the implementation of IPM programs (Rosenberger, Proc. New England Fruit Meetings \02:b\-bl, 1997). In July and August, growers are limited to a few fungicide applications, generally using captan with or without a benzimidazol. Growers could more effectively control sooty blotch and flyspeck within the confines of an IPM program if they were able to time their sprays better so as to correspond to infection and the eventual appearance of these diseases. Specifically, a more economical and effective application of fungicides could be accomplished if growers were able to predict the appearance of flyspeck disease and sooty blotch. It would then be possible to replace a preventative spray program with one or more eradicant sprays timed to thwart the appearance of these diseases. In North Carolina, Brown and Sutton {Plant Disease 79:1165-1168) have developed a model for the prediction of sooty blotch and flyspeck disease symptoms on apples. The model is based on leaf wetness data collected at three different sites in North Carolina from 1987 through 1994, coupled with known biological information about the fungi involved. From these data, the researchers concluded that the best estimate of flyspeck and sooty blotch symptom occurrence was based on the cumulative hours of leaf wetness during periods of at least four hours duration, beginning from the first rainfall at least 10 days after petal fall. Brown and Sutton chose to include periods of at least four hours because they had previously demonstrated that the pathogens required about four to five hours of constant wetting in order to germinate (Plant Disease 77:451-455). Under these conditions, the researchers found that flyspeck and sooty Table 1 . Leaf wetness accumulation from 10 days after petal fall until the first symptoms of sooty blotch or flyspeck. Table derived from Brown and Sutton (Plant Disease 79: 1 165-1 168). Symptoms observed Accumulated wetting | Year Petal fall date Beginning date (hrs) 1987 27-Apr 5-May 15-Jun 265 1988 28-Apr 1 1-May 26-Jul 304 1989 26-Apr 9-May 23-Jun 276 1990 25- Apr 6-May 16-Jul 289 1991 25-Apr 6-May 4-Jun 267 1992 1-May 13-May 15-Jun 310 1993 7-May 17-May 6-Jul 209 1994 29-Apr 14-May 21-Jun 242 1 Fruit Notes, Volume 62 (Number 4), Fall, 1997 21 blotch symptoms occurred after an average of 270 hours of accumulated leaf wetting. They believe this that information is useful for timing eradicant (benzimidazole) fungicide spraying. An admitted limitation of this model is the questionable relevance it has for regions outside the southeastern United States. Sooty blotch and flyspeck disease pressure are extremely high in the Southeast. Weather there is particularly favorable for these diseases. Therefore, the model might fail to predict accurately the onset of sooty blotch and flyspeck symptoms for several reasons: 1) summer temperatures and relative humidities in New England are usually lower than in North Carolina; 2) the precision and accuracy of different leaf wetness sensors can vary considerably; and 3) infection of apple trees with the fungi causing flyspeck occurs about one month later in New England than in North Carolina. However, the existance of an empirical model predicting flyspeck and sooty blotch diseases anywhere raises the possibility of constructing such a model in New England. While noting the limitations and possible sources of error, Brown and Sutton's model is still a good starting place. Additionally, one only needs hourly leaf wetness data available over the course of at least one year in order to use their model. These leaf wetness data are readily available from records taken from hygrothermographs or Campbell computerized weather stations located in several Massachu- setts orchards. Thus, beginning with leaf wetness data collected from nine different orchards in 1995 and 1996, we tested Brown and Sutton's model for the prediction of flyspeck and sooty blotch. Table 1 from Brown and Sutton's article shows wetness data collected from 1987 through 1994. Symptom occurrence ranged from late June through early July, with a mean wetness duration of 270 hours between the beginning date and symptom occurrence. Note that Brown and Sutton began counting wetness hours starting from the first significant wetness period at least 10 days after petal fall. Thus, their starting date ranged from early to mid May. In contrast, Table 2 shows data collected from Massachusetts orchards during 1995 and 1996. Using Brown and Sutton's criteria, the mean leaf wetness accumulation of four hours or greater from 10 days after petal fall to symptom occurrence was 366 hours (standard deviation = 120 hours; the larger the standard Table 2. Leaf wetness accumulation from 10 days after petal fall to the first symptoms of flyspeck in Massachusetts. Petal fall Beginning Symptoms Accumulated Year Site date date observed Data source wetting (hrs) 1995 Broderick 25-May 4-Jun 8-Aug Hygrothermograph 258 1995 HRC 24-May 3-Jun 7-Aug Hygrothermograph 348 1995 Clark 28-May 7-Jun 17-Aug Hygrothermograph 264 1996 HRC 26-May 5-Jun 24-Jul Hygrothermograph 236 1996 Lincoln 27-May 6-Jun 29-Jul Hygrothermograph 295 1996 Tuitle 26-May 5-Jun 31-Jul Hygrothermograph 331 1996 Simeone 26-May 6-Jun 30-Jul Campbell 484 1996 Sholan 26-May 5-Jun 14-Aug Campbell 586 1996 HRC 26-May 5-Jun 24-Jul Campbell 275 1996 Rice 23-May 5-Jun 2-Aug Campbell 422 1996 S. Deerfield 26-May 5-Jun 1-Aug Campbell 522 1 22 Fruit Notes, Volume 62 (Number 4). Fall, 1997 deviation the more variable the sample was). The mean for the 1995-1996 hygrothermograph data alone was much closer to Brown and Sutton, however, with a mean of 289 hours (standard deviation = 44 hours). Thus, using data most favorable to the Brown and Sutton model, approximately 19 more hours of wetting occurred in Massachusetts, on average, than in North Carolina before flyspeck and sooty blotch symptoms occur. These measurements support the idea that the Brown and Sutton model may indeed be useful for disease prediction in Massachusetts. The Campbell data, however, do not provide as much support. In addition, note that the significant events of petal fall, beginning of wetness measurement, and symptom occurrence happened later in Massachusetts than in North Carolina. Judging from the differences between the two data sets as well as the previously noted regional differences between New England and the Southeast, it is reasonable to conclude that other factors besides leaf wetness are responsible for the onset of flyspeck and sooty blotch in New England. This certainly could account for the rather large variability in the New England data. A regression analysis of other weather measurements like temperature and relative humidity with disease onset may suggest some additional factors. This will be the focus of future research. It is also important to note that there is a disparity between the Campbell weather station wetness data and the hygrothermograph wetness data, and it cannot be ruled out that the measuring instruments themselves may be a source of error. There is no easy solution to this problem, and it may be that different empirical wetness- hour estimations may have to be made for use with different wetness sensors, or an easily accessible, standard weather station will have to be used. In conclusion, it is believed that an empirical model predicting flyspeck disease and sooty blotch of apple based upon the Brown and Sutton model should be created for use by New England apple growers. Such a model would be useful to Massachusetts growers for timing eradicant fungicide spraying for these diseases in a more timely and efficient manner, and may also provide researchers with further insight into the ecology of the pathogens involved. •^ vL» vL» vL« vL* •^ *Y* *Y* "T* *T* Fruit Notes, Volume 62 (Number 4), Fall, 1997 23 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 1 SERIAL SECTION UNIV OF MASSACHUSETTS LIBRARY AMHERST MA 01003 Account No. 2-22914 Fruit Notes Prepared by the Department of Plant & Soil Sciences. UMass Extension, U. S. Department of Agriculture, and Massachusetts Counties Cooperating. BIOLOGICAL Editors: Wesley R. Autio and William J. Bramlage MAY 2 9 1998 SCIENCES LIBRARV O CO CO -c CD iNJ JO -^ > -< Volume 63, Number 1 WINTER ISSUE, 1998 Table of Contents Rootstock and Scion Interact to Affect Apple Tree Performance Plum Curculio Responses to Host Fruit and Conspecific Odors Evaluation of Unbaited Pyramid Traps for Monitoring Plum Curculio in Commercial Apple Orchards Eyes on Plum Curculio: Watching Them Behave Toward Traps Alternative to Black Pyramids for Capturing Plum Curculios Fruit Notes Publication Information: Fruit Notes (ISSN 0427-6906) is published the each January, April, July, and October by the Department of Plant & Soil Sciences, University of Massachusetts. The costs of subscriptions to Fruit Notes are $ 1 0.00 for United States addresses and $ 12.00 for foreign addresses. Each one-year subscription begins January 1 and ends December 3 1 . Some back issues are available for $3.00 (United States addresses) and $3.50 (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 UMASS EXTENSION POLICY: All chemical uses suggested in this publication are contingent upon continued registration. These chemicals should be used in accordance with federal and stale laws and regulations. Growers are urged to be lamiliar with all current stale regulations. Where trade names are used tor 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 UMiiss Extension. John Geiher. Director, in furtherance of the acts of May Hand June JO, 1914 UMass Extension offers equal opportunity in profirams and employment. Rootstock and Scion Interact to Affect Apple Tree Performance Wesley R. Autio, J. LaMar Anderson, John A. Barden, Gerald R. Brown, Paul A. Domoto, David C. Ferree, Alvan Gaus, Richard A. Hayden, Frank Morrison, Charles A. MuUins, Curt R. Rom, James R. Schupp, and Loren D. Tukey NC-140 1990 CultivarlRootstock Trial Cooperators For about 20 years, the NC-140 Regional Research Committee has been stud3dng the effects of rootstock on the performance of various tree-fruit crops. The first and second cooperative plantings of NC-140 included Delicious apple on a variety of rootstocks from subdwarf to vigorous. Much useful information was generated from these trials, particularly because of the rigorous, systematic evaluation of performance and the large number of sites and conditions that trees were exposed to. A total of 25 to 30 sites were included, ranging from Mexico and the southern United States to several Canadian provinces. Delicious was the cultivar of choice for these early plantings, because it was important for all growing regions; however, little information was generated on how rootstocks may affect different cultivars. In fact, no large- scale trial had looked at the interaction of rootstock and scion in a systematic way. Therefore, planning began in 1987 to establish such a trial. Trees for the 1990 NC-140 Cultivar/ Rootstock Trial were propagated by Stark Bro's Nurseries during the winter of 1989 and were grown in Selma, CA during the 1989 growing season. Trees were dug in the fall and shipped to cooperative sites (see tables for a list of locations) in the late winter and early spring of 1990. Each site included six replications of four cultivars (Smoothee Golden Delicious, Nicobel Jonagold, Empire, and Law Rome) on five rootstocks (M.9 EMLA, B.9, Mark, 0.3, and M.26 EMLA). The four cultivars were chosen with different growth habits, ranging from the basitonic (spur-type) Empire to the acrotonic (tip-bearing) Rome. The rootstocks were the most promising from the first two NC-140 cooperative trials. Trees were individually staked and man- aged as slender spindles with a standard protocol. Pest management, irrigation, and fertilization were per local recommendations. Yield and tree size were measured annually. Data reported here are through the seventh growing season (1996). Using trunk cross-sectional area as a measure of tree size (Table 1), it is clear that rootstock affected trees size differently, depending on cultivar. M.26 EMLA, however, resulted in the largest tree, regardless of cultivar. Golden Delicious and Empire trees on M.9 EMLA were significantly smaller than those on 0.3, but Rome trees on the two rootstock were similar in size, and Jonagold trees on M.9 EMLA were signficantly larger than those on 0.3. Jonagold, Empire, and Rome trees on B.9 were similar in size to those on Mark, however. Golden Delicious trees on B.9 were larger than comparable trees on Mark. The cultivars also differed overall. Specifically, Jonagold trees were the largest and Empire trees were the smallest. Site differences were very dramatic. Trees in Wichata, Kansas were the largest, and those in Maine were the smallest, less than 1/3 of the size of the Kansas trees. Massachusetts trees were not significantly larger than those in Maine. Fruit Notes, Volume 63 (Number 1), Winter, 1998 Table 1 Trunk cross-sectional area at the end c f the 1996 growing season. Trunk cross-sectionai area ( cm-^) Golden Rootstock Delicious Jonagold Empire Rome Average M.9EMLA 49.7 c 59.8 b 45.5 c 54.7 b 52.8 b B.9 35.3 d 34.7 d 32.1 d 32.4 c 33.6 c Mark 30.0 e 31.6 d 28.3 d 30.1c 30.0 d 0.3 57.4 b 51.7 c 51.2 b 55.6 b 54.0 b M.26 EMLA 67.8 a 74.9 a 64.1 a 64.8 a 68.0 a Average 48.5 ab 50.6 a 44.3 c 47.4 b Trunk cross- sectional Site area (cm^) Arkansas 42.2 ef Colorado 34.1 g Iowa 42.0 ef Indiana 45.5 def Kansas-Manhattan 68.5 b Kansas-Wichita 89.3 a Kentucky 49.6 cd Massachusetts 30.8 gh Maine 28.1 h Ohio 46.5 de Pennsylvania 30.9 gh Tennessee 39.7 f Utah 53.4 c Virginia 66.9 b Rootstock means within columns, average rootstock means, average cultivar means, or average site means are significantly different at odds of 19:1 if not followed by the same | letter. The effects of rootstock on cumulative yield per tree also varied with cultivar (Table 2). The general trends were similar to those with tree size, with trees on 0.3 and M.26 EMLA yielding the most, those on B.9 and Mark yielding the least, and trees on M.9 EMLA yielding intermediately. Over all rootsotcks, Rome trees produced the highest yield, and Empire trees produced the lowest. Regarding the effects of site, trees in Virginia and Ohio produced the highest yields, and those in Arkansas produced the lowest. More important than yield per tree, the effects of rootstock on cumulative yield efficiency (relating yield to tree size) varied with cultivar (Table 3). The most efficient Golden Delicious, Jonagold, and Empire trees were on B.9 and Mark, and the least efficient were on M.26 EMLA. Trees on M.9 EMLA and 0.3 were intermediate. Rome trees on B.9 were Fruit Notes, VoUimc 63 (Number 1), Winter, 1998 Table 2. Cumulative yield per tree (1992-96) at the end of the 1996 growing season. Rootstock Golden Delicious M.9EMLA B.9 Mark 0.3 M.26 EMLA Average Site 74 b 69 be 61 c 94 a 89 a 78 b Arkansas Colorado Iowa Indiana Kansas-Manhattan Kansas-Wichita Kentucky Massachusetts Maine Ohio Pennsylvania Tennessee Utah Virginia Cumulative yield (kg/tree, 1992-96) Jonagold Empire 74 b 60 c 54 c 81 ab 85 a 71c 71 b 53 c 43 d 83 a 77 ab 66 d Cumulative yield (kg/tree 1992-96) 21 1 32 h 33 h 48 fg 139 b 126 c 80 d 86 d 54 f 149 a 49 gh 35 h 65 e 150 a Rome 96 a 79 b 62 c 102 a 95 a 87 a Average 80 b 65 c 55 d 90 a 87 a Rootstock means within columns, average rootstock means, average cultivar means, or average site means are significantly different at odds of 19:1 if not followed by the same letter. the most efficient, those on M.26 EMLA were the least efficient, and those on Mark, M.9 EMLA, and 0.3 were intermediate. Rome trees, overall, were the most yield efficient, and Jonagold trees were the least efficient. Ohio and Massachusetts produced the most yield- efficient trees, and Arkansas produced the least efficient. This study, which will continue through the tenth growing season, has demonstrated variation in the effects of rootstock with different cultivars. To date, however, the importance of the variation is minimal. Tlie reduced size of Jonagold trees on 0.3 is an important deviation ft-om the response with other cultivars. The tree is smaller than expected, but it is as yield efficient as it should be. Unless this observation is a reflection of some level of incompatibility between scion and rootstock, the only change that a grower needs Fruit Notes, Volume 63 (Number 1), Wmter, 199H Table 3. Cumulative yield efficiency (1992-96) at the end of the 1996 growing season. Cumulative yield efficiency (kg/cm^ trunk cross-sectional area, 1992-96) Rootstock Golden Delicious Jonagold Empire Ror Average M.9 EMLA 1.61 b 1.37 be 1.61b 1.74 b 1.59 c B.9 1.97 a 1.91a 1.91a 2.37 a 2.05 a Mark 2.09 a 1.80 a 1.88 a 1.95 b 1.93 b 0.3 1.71b 1.48 b 1.72 ab 1.83 b 1.69 c M.26 EMLA 1.35 c 1.19 c 1.16 c 1.51c 1.30 d Average 1.75 b 1.55 c 1.65 be 1.89 a Cumulative yield efficiency (kg/cm^ Site 1992-96) Arkansas 0.51 h Colorado 1.01 fg Iowa 0.90 gh Indiana 1.13 ef Kansas-Manhattan 2.34 c Kansas-Wichita 1.78 d Kentucky 1.85 d Massachusetts 2.94 b Maine 1.96 d Ohio 3.48 a Pennsylvania 1.32 e Tennessee 1.04 fg Utah 1.32 e Virginia 2.37 c Rootstock means withi n columns, average rootstock means, average cultivar means, or average site means are sign ificantly di fferent at odds of 19:1 if not followed by the same | letter. to make to use this combination is adjustment ated with Mark. In this study, rootstock did not of planting distances. Tlie rootstock that stands out in this trial is B.9. It performed similarly well with all scions. Yield efficiency was as high or higher than Mark, without many of the problems associ- affect fruit size, but in other trials, B.9 has resulted in larger-than-average fruit. It certainly is a rootstock worthy of significant grower trial, and it is available commercially in significant quantities. •JL» vT^ •X* •^ •J^ •^ W^ 0^ 0^ •^ Fruit Notes, Volume 6.^ (Number 1), Wimcr, 1998 Plum Curculio Responses to Host Fruit and Conspecific Odors Tracy Leskey, Amy Wiebe, Susan Nixson, and Ronald Prokopy Department of Entomology, University of Massachusetts Many species of weevils are attracted to host plant odors and use them in host finding. Fur- ther, many species of weevils produce aggrega- tion and/or sex pheromones. Plum curculios (PCs) have been shown to be attracted to host fruit odors in the laboratory over short distances and in the field at distances up to 3 yards. Fur- ther, a male-produced aggregation pheromone, grandisoic acid, was recently identified in PCs by Eller and Bartelt of Illinois. At present, a reliable monitoring system for detecting adult PC entry into orchards from overwintering sites does not exist. However, if attractive odors such as those from host fruit and/or pheromones were employed in conjunc- tion with a trap that was also visually attrac- tive to adult PCs, then a reliable monitoring device could be created as has been done for other species of weevils. In the 1996 and 1997 Winter issues of Fruit Notes, we reported on results of laboratory Petri-dish bioassays that addressed responses of adult PCs to odors emitted from Mcintosh apple trees. Here, we present results from bio- assays conducted in large Plexiglas arenas de- signed to assess PC attraction not only to fruit odors but also to odors emitted by other PCs. Materials and Methods Large clear Plexiglas arenas with dimen- sions of 24x24x12 inches with Plexiglas lids were used as still-air arenas for the following experiments. Materials to be tested as emit- ting potentially attractive odors were placed in small cotton bags hung in the upper corners (one per corner) of each box. Originally, we tried testing PCs with cotton bags placed in lower corners of arenas, but found that because of the natural tendency of PCs to crawl upwards, hanging the bags in upper corners was a more effective means of testing PCs. Either ten male or ten female PCs starved for 24 hours and chilled 30 minutes prior to test- ing were released into the center of a box at the beginning of darkness. Numbers of PCs that crawled to within one-half inch of an odor source held within a cotton bag were recorded after 1 hour. Each experiment was repeated three more times, each time rotating the position of cotton bags containing odor sources. Treatments tested as potentially emitting attractive odors included five freshly picked wild plums, five wild plums plus five male or female PCs, five male or female PCs alone, five Table 1. Numbers of male PCs moving to within 1/2 inch treatment after 1 hour. Experiment 1.* or onto cloth bags of each Arena Treatments One Five males O.Ob Five males + five plums 3.3 a Five plums 3.0 a Control O.Ob Two Five females 0.0 c Five females + five plums 6.0 a Five plums 1.0 b Con trol 0.0 c * Means within rows not followed by the same letter are significantly different at odds of 19:1. Fruit Notes, Volume 6,3 (Number 1), Winter, 1998 Table 2. Numbers of male PCs moving to within 1/2 inch or onto treatment after 1 hour. Experiment 2.* cloth bags of each Arena Treatments One Fiue punctured plums Five plums 3.5 a 1.8 ab Control O.Ob Control O.Ob Two Five females + five plums Five males + five plums 3.8 a 1.0 b Control O.Ob Control O.Ob * Means within rows not followed by the same letter are significantly different at odds of 19:1. wild plums alone, and five punctured plums. Punctured plums were used to simulate plums that had been fed upon by PCs because we wanted to learn if plums that had been punc- tured released odors that may be attractive to PCs. Each plum was punctured twice, one punc- ture made one hour before and one puncture made immediately before an experiment. An empty cotton bag served as the control in each experiment. Results presented reflect the mean number of PCs captured for each treatment over the four replications. Results Male Responses. In experiment 1 (Table 1), we used two arenas to test male response to the following treatments. In arena one, treat- ments included males, males plus wild plums, and wild plums placed in a small cotton bag, with an empty cotton bag serving as the con- trol. Here, males responded in significantly greater numbers to cotton bags containing plums alone or males plus plums compared to males alone or the empty bag. Treatments tested in arena two included females, females plus plums, plums, and a control. In this case, males were attracted to females plus plums in significantly greater numbers than to any other treatment. In experiment 2 (Table 2), in arena 1 we then evaluated male responses to punctured plums compared to plums without punctures with two empty cotton bags serving as controls. Here, we wanted to learn if males were responding to odor emitted by punctures made in plums by feeding PCs. We saw no difference in response of males to punctured plums compared to plums not punctured, although there was a numeri- cally greater response to the former. In arena two, we compared male responses to females plus plums, males plus plums and to two empty bags serving once again as controls. Signifi- cantly more males responded to females plus plums than to any other treatment, indicating that males may be responding to a female-pro- duced odor. Female Responses. In experiment 3 (Table 3), we repeated treatments for female Table 3. Numbers of female PCs moving to within 1/2 inch or onto cloth bags of each treatment after 1 hour. Experiment 3.* Arena Treatments One Five males Five males + five plums Five plums OOb 2.8 a 1.3 ab Con trol O.Ob Two Five females Five females + five plums Five plums Control O.Ob 1.0 ab 2.8 a O.Ob * Means within rows not followed by the same letter are significantly diffcn>nt at odds of 19:1. Fruit Notes, Volume 6.^ (Numhcr 1), Winter, 1998 Table 4 Numbers of female PCs moving to within 1/2 inch or or to cloth b ags of each treatment after 1 hour. Experimen t4.* Arena Treatments Five punctured plums Five plums Control Control One 2.3 ab 2.5 a O.Ob O.Ob Five females + five plums Five males + five plums Control Control Two 1.5 a 2.3 a 0.0 a 0.0 a * Means within rows not followed by the same letter are significantly different at odds of 19:1. responders that we tested with male respond- ers in experiment 1. In arena one, female re- sponders were attracted to males plus plums in significantly greater numbers than to males alone or the control bag, with intermediate at- traction to plums alone. In arena two, signifi- cantly more females were attracted to plums alone than to controls, with intermediate at- traction to females plus plums. In experiment 4 (Table 4), we repeated the same treatments with female responders that we had tested with male responders in experi- ment 2. In arena one, females responded in nearly equal numbers to punctured plums and plums that had not been punctured. In arena two, numerically more females were attracted to males plus plums compared to females plus plums or to control. Conclusions Both sexes were attracted to odors emitted by freshly picked wild plums. Perhaps the most important result from these experiments is an indication of the existence of a female-produced sex pheromone, as evidenced by the strong at- traction of male PCs to the treatment that in- cluded females plus wild plums. Further, this putative female-produced pheromone may have been synergized or enhanced in attractivity to males by the presence of wild plum odor. Al- though we cannot rule out the possibility of sounds made by PCs as influencing these re- sults, we could smell a unique odor in arenas that included treatments containing females plus plums. We plan to use this bioassay sys- tem extensively in 1998 to confirm these pre- liminary findings and in tests aimed at identi- fying the chemical nature of these attractive compounds. We conclude that the Plexiglas arena bioas- say system is an effective way to test PC at- traction to host fruit odors as well as odors emitted by other PCs at distances of approxi- mately 16 inches under still-air conditions. Acknowledgments This work was supported by Hatch funds and by the New England Tree Fruit Growers Research Committee. vty^ vT>» vl>* vT>» vj>» •^ ^j^ •^ •^ r^ Fruit Notes, Volume 63 (Number 1), Winter, 1998 Evaluation of Unbaited PyramidTraps for Monitoring Plum Curculio in Commercial Apple Orchards Ronald Prokopy, Michael Marsello, Tracy Leskey, and Starker Wright Department of Entomology, University of Massachusetts In the 1997 Winter issue of Fruit Notes, we reported on a 1996 study evaluating unbaited black pyramid traps as devices for capturing plum curculio adults and predicting need and timing of insecticide sprays against plum curculio based on trap captures. That study, conducted in a small commercial apple orchard in Conway, showed that even though black p5Ta- mid traps in optimum positions (next to apple tree trunks) captured reasonable numbers of plum curculios, there was no correlation be- tween periods of substantial capture and peri- ods of substantial damage by curculios to fruit. In other words, trap captures were poor predic- tors of when insecticides should be applied against curculio in that orchard in 1996. Black pyramid traps, intended to mimic tree trunks, are currently receiving much attention as po- tential monitoring devices for plum curculio in peach orchards in the South. Here, we report on a study in which black pyramid traps were evaluated at three positions in eight large commercial orchards in Massa- chusetts in 1997. Materials and Methods Pyramid traps were the same as used in 1996 and were a modification of traps designed for monitoring pecan weevils in the South. Three traps were placed in each of six blocks of apple trees in each of eight commercial orchards. All blocks contained 49 trees (seven rows of seven trees each) of mixed cultivars of fruit- bearing age. Of the six blocks per orchard, there were two blocks each of trees on M.9, M.26, and M.7 rootstock, giving rise to what we term here as small, medium, and large trees, respectively. For each block, one trap was placed within 30 cm of the tree trunk (termed trunk trap) of a perimeter tree, one mid-way between the canopy of a perimeter tree and the first inte- rior tree (termed inter-tree trap), and one at the margin of the nearest woods (termed border trap). The ground beneath and between orchard trees was either free of b vegetation or vegeta- tion was mowed to prevent obscuring of traps. Traps were deployed during bloom and were examined for captured plum curculio adults ev- ery 3-4 days thereafter for 4-5 weeks. At each trap examination, beginning at petal fall, 15 fruit per tree of each of the seven perimeter trees were examined for presence of plum curculio oviposition scars (total of 105 fruit per block per sampling date). Scarred fruit were allowed to remain on the tree. All blocks received either two or three grower-applied sprays of Guthion or Imidan, beginning at petal fall and 8-11 days later(second spray), as well as 16-20 days (third spray) thereafter. Growers applied sprays ac- cording to their own estimation of need, with- out access to our data for making application decisions. To protect against insecticide, a plas- tic bag was used to envelope each trap com- pletely just before spraying and was removed immediately thereafter. This was done because in a preliminary test, only about 40% as many curculios (0.8 vs. 1.9 per trap, a significant dif- ference) were captured by traps sprayed with Imidan as by unsprayed traps. Results We combined data for the two blocks of simi- Fruit Notes, Volume 63 (Number 1), Winter, 1998 Table 1. Numbers of overwintering plum curculio adults captured on unbaited pyramid traps at tree-trunk, inter-tree or orchard-border positions and | aercent of fruit showing ovipositional injury by plum curculio across | sampling dates before, between, or after insecticide spray applications against pl um curcul 10 in blocks of small, medium-size, or large apple trees and across eight commercial orchards studied in Massachusetts in 1997. Adu Its captured aer Injured No. Sampling saff pling date _ fruit per orchard dates per Trunk Inter-tree Border sampling Tree size Sampling dates blocks block traps traps traps date (%) Small Before first spray 16 1.1 0.22 0.22 0.22 0.00 Between first and second spray 16 2.5 0.00 0.05 0.05 0.35 Between second and third spray 6 2.7 0.00 0.00 0.00 0.36 After final spray 16 4.4 0.00 0.00 0.00 0.45 Medium Before first spray 16 1.1 0.00 0.11 0.11 0.00 Between first and second spray 16 2.5 0.05 0.00 0.05 0.33 Between second and third spray 6 2.7 0.00 0.00 0.00 0.36 After final spray 16 4.4 0.00 0.00 0.00 0.42 Large Before first spray 16 1.1 0.22 0.00 0.11 0.00 Between first and second spray 16 2.5 0.10 0.00 0.05 0.31 Between second and third spray 6 2.7 0.00 0.00 0.00 0.48 After final spray 16 4.4 0.03 0.00 0.00 0.90 1 lar tree size per orchard and segregated data according to sampling dates before, between, and after insecticide applications. The data (Table 1) show that no fruit injury was detected prior to the first insecticide application even though some curculio captures by traps in each position had occurred. For none of the trap po- sitions in any block type (i.e. tree-size type) was there a significant positive relationship between mean number of captured adults per block and mean number of sampled fi-uit injured per block. This was true for sampling data between the first and second insecticide application, between the second and third insecticide application, and following the last insecticide application. In every block type, mean ft-uit injury increased between the first and second, between the sec- ond and third, and after the third insecticide application. Conversely, in most cases, mean trap captures either successively decreased fi-om levels that were reached prior to any in- secticide treatment or were nil throughout. The greatest fruit injury in any of the 48 blocks was in a block of large trees in Orchard D (a mean of 2.5% fruit injured). Not a single plum curculio was captured by any trap in this block. Conversely, in the two blocks receiving the greatest trap captures (small trees in Or- chard D and large trees in Orchard F), there were means of only 0.24 and 0.19% injured fi*uit, respectively. Most blocks received injury greater than this. Conclusions Data from this study in eight large commer- cial apple orchards in 1997 are in agreement with data ft-om our 1996 study in a single small orchard and do not support the use of captures of plum curculio adults by unbaited black pyra- mid traps as accurate predictors of the need to apply insecticide against curculio. This conclu- sion holds irrespective of the position at which unbaited pyramid traps were placed in an or- chard. For the future, we need either a differ- ent type of trap or a powerful attractive odor to enhance the value of black pyramid traps. In succeeding articles in this issue, we describe progress toward developing alternative types of traps and attractive odors to incorporate into traps. Acknowledgments This work was supported by grants fi-om the Fruit Notes, Volume 63 (Number 1), Winter, 1998 USDA Northeast Regional IPM Competitive ers that participated in this study: Bill Grants Program, State /FederallPM funds, and Broderick, Dana Clark, Dave Chandler, Dave the New England Tree Fruit Growers Research Cheney, Dave Shearer, Joe Sincuk, Tim Smith Committee. We are grateful to the eight grow- and Mo Tougas. *sL* vL* vj/* *sl>* *sL* •^ #^ 0^ *J^ #^ 10 Fruit Notes, Volume 63 (Number 1), Winter, 1998 Eyes On Plum Curculios: Watching Them Behave Ronald Prokopy and Catherine Wirth Department of Entomology^ University of Massachusetts Shortcomings of black pyramid traps for monitoring plum curculios described in the pre- ceding article have stimulated us to take a closer look at the behavior of individual curculios in hopes of discovering why black pjrramid traps perform less and less satisfactorily as the curculio season progresses. In the 1997 Winter issue of Fruit Notes, we described some pre- liminary studies that led us to postulate that perhaps curculios bypass pjramid traps under moderate and high temperature conditions, fly- ing directly into tree canopies rather than crawl- ing or flying onto tree trunks or trunk-mimick- ing pyramid traps. Here, we describe two stud- ies conducted in 1997 in which we made exten- sive direct observation of movements of plum curculios toward host trees and p5rramid traps under conditions as natural as possible for typi- cal curculio behavior, while still permitting ef- fective observation. Materials and Methods Curculios to be observed were tapped from branches of unmanaged apple trees onto a 40x40-inch white bedsheet (first study) or a 16xl6-inch white bedsheet (second study) held taut by staples driven into a wooden frame be- neath. Apple foliage was scattered across about 15% of the surface area of each framed cloth to provide hiding places for fallen curculios. Plum curculios fall frequently from limbs of host trees (sometimes more than once per day) onto the ground beneath in response to perceived dan- ger or adverse weather. We reasoned that tap- ping curculios from branches and allowing them to fall on cloth provided with shelter effectively mimicked natural behavior and conditions. As soon as four or five curculios (first study) or eight curculios (second study) accumulated on the cloth, we quickly but gently carried the frame and cloth to a position half-way between the trunk and canopy edge of a nearby semi- dwarf unmanaged apple tree (first study) or plum tree (second study). There were no curculio traps of any sort in the vicinity of the apple tree. One unbaited black p3rramid trap was placed next to the trunk and another at the edge of the canopy of the plum tree, with the framed cloth centered between and equi- distant (4 feet away) from either trap. Dressed in white cap, shirt, and shorts that hopefully were invisible to curculios, one of us knelt down nearby the cloth and quietly observed the pro- portion of curculios that departed the cloth by flight or by crawling and the proportion that moved to hide beneath foliage or rested on the cloth. Observation periods lasted 1 hour. They were evenly spaced among 1-hour intervals be- ginning at 8 AM and ending at 8 PM in the first study, or among 1-hour intervals beginning at 2 PM and ending at 6 PM in the second study. In both studies, observations commenced a day or two after petal fall and extended over a 3- week period thereafter. We recorded the direc- tion taken by each adult upon departure from the cloth and continued to track adult destina- tion until it was lost fi"om sight. Results Of the 166 plum curculios observed beneath the apple tree, 52 (31%) left the framed cloth by flight and 27 (16%) by crawling. The remain- der moved to hide beneath foliage on the cloth (18%) or rested in place (35%). Among curculios that flew, significantly more (54%) flew toward the tree canopy above than flew toward inter- Fruit Notes, Volume 63 (Number 1), Winter, 1998 11 Table 1. Type and direction of movement of 166 plum cu rculio adults observed on a framed cloth beneath an apple tree during 1-hour periods evenly distributed from 8 AM to 8 PM. Type of Number engaged Movement Curculio movement in each movement in movement direction toward direction (% of movement category)* | Flew 52 Tree trunk Tree canopy Inter-tree space Grass 17b 54a 25b 4c Crawled off 27 Tree trunk All others 88a 12b Hid 30 - - None (rested) 57 - - * For each category of movement, numbers followed by a different letter are significantly different at ode Is of 19:1. tree space (25%), the tree trunk (17%), or grass beneath the canopy (4%) (Table 1). Among curcuhos that crawled, significantly more (88%) crawled toward the tree trunk than toward all other directions combined (12%) (Table 1). Of the 104 plum curculios observed beneath the plum tree, 39 (38%) left the framed cloth by flight and 19 (18%) by crawling. The remain- der moved to hide beneath foliage on the cloth (13%) or rested in place (31%). Among those that flew, significantly more flew toward the tree canopy above (36%) or toward inter-tree space (38%) than toward the pyramid trap at the tree trunk (15%), the pyramid trap at the canopy edge (3%) or grass beneath the canopy (8%) (Table 2). Among curculios that crawled, sig- nificantly more (74%) crawled toward the pyra- mid trap at the tree trunk than toward the pyra- mid trap at the canopy edge (10%) or toward other directions (16%) (Table 2). Temperatures taken beneath each tree at the time of observed curculio movement indi- cated that no flight occurred at temperatures of 67°F or less. Also, there was a significant positive correlation between temperature and proportion of total observed curculios that flew. Table 2. Type and direction of movement of 104 plum curculio adults observed on a framed cloth beneath a plum tree during 1-hour periods evenly distributed from 2 PM to 6 PM. 1 Type of Number engaged Movement direction Curculio movement in each movement in movement toward direction (% of movement category)* Flew 39 Trap at tree trunk 15b Trap at canopy edge 3c Tree canopy 36a Inter-tree space 38a Grass Bbc Crawled off 19 Trap at tree trunk 74a Trap at canopy edge 10b All others 16b Hid 14 - - None (rested) 32 - - * For each category of movement, numbers followed by a different letter are significantly | different at odds of 19:1. 12 Fruit Notes, Volume 63 (Number 1), Winter, 1998 On the other hand, a substantial proportion of those curcuhos observed to crawl off the cloth (about 20%) did so at temperatures of 67°F or less, and there was no correlation between tem- perature and proportion of total observed curculios that crawled off. Conclusions The more robust data reported here confirm and extend the preliminary data reported in the 1997 Winter issue of Fruit Notes. Combined data indicate that when the air temperature is 67°F or less beneath the canopy of a host tree, the plum curculio adults that have dropped from the tree canopy (as they normally do on a fre- quent, even daily, basis) are reluctant or unable to fly but are able to reenter the tree canopy by crawling. Crawling is almost exclusively toward the tree trunk, or if a black pyramid trap is adjacent to the tree trunk, then toward such a trap, which is thought to be a visual mimic of a tree trunk. At temperatures of 68°F or greater, curculios exhibit an increasing propensity to reenter the tree canopy by flight. Most flights are into the tree canopy. Only a small propor- tion (15-17% according to our findings here) is toward the tree trunk or a black pyramid trap next to the tree trunk. Hence, at temperatures of 68°F or greater, there is only a small chance of capturing a tree-reentering curculio using a black pyramid trap. Other data that we col- lected in 1997 show that curculio damage to tree fruit increases with increasing temperature. It is therefore doubtful that any prospective unbaited curculio traps placed in association with the tree trunk will be able to monitor curculio entry into or abundance in the tree canopj/^ in a way that reflects accurately the probability of curculio damage to fruit. Acknowledgments This work was supported by a grant from the USDA Northeast Regional IPM Competitive Grants Program and the New England Tree Fruit Research Committee. *X* *X* *X^ *^ *X* #Y* *Y* *T* *T* *T* Fruit Notes, Volume 63 (Number 1), Winter, 1998 13 Toward Traps Alternative to Black Pyramids for Capturing Plum Curoulios Ronald Prokopy, Bonnie Dixon, and Tracy Leskey Department of Entomology, University of Massachusetts In the two preceding articles, we concluded that unbaited black pyramid traps (and prob- ably all other unbaited traps) aimed at captur- ing plum curculios intent on entering host trees by crawling or flying onto tree trunks are un- satisfactory for monitoring curculios in a way that reflects accurately the potential for curculio damage to fruit. In the 1997 Winter issue of Fruit Notes, we presented results of a prelimi- nary test in 1996 showing that sticky-coated squares of clear Plexiglas positioned just out- side of apple tree canopies captured about as many plum curculio adults as black pyramid traps next to tree trunks. Here, we report on a 1997 study further comparing these two trap types. We also report preliminary results on a potentially useful third trap type. Materials and Methods The first study was carried out in a small block of unmanaged semi-dwarf apple trees at Hampshire College in South Amherst. The Plexiglas traps were designed to capture plum curculios fl3ring toward tree canopies from over- wintering sites or from other host trees. Each trap was constructed of clear Plexiglas (2 feet by 2 feet) attached vertically on a wooden pole posi- tioned 2 feet away from the edge of the tree canopy. The outer-facing but not the inner-fac- ing surface of the Plexiglas was coated with Tangletrap to cap- ture curculios flying toward the tree canopy. Two such traps were attached to each pole, one opposite the lowermost foliage and the other opposite the uppermost foliage. Two poles with traps were placed on opposite sides of each of six trees. Two unbaited black pyramid traps were placed on opposite sides of and immedi- ately next to the trunks of each of six other trees. All traps were emplaced at the beginning of apple tree bloom (May 24) and were examined daily thereafter for 22 days for captured curculios. Each day, 16 fruitlets on each of the 12 trees were examined for evidence of plum curculio damage. Each day, temperature, rela- tive humidity, and wind speed were recorded. The second study was carried out in two unmanaged apple trees, one in Amherst and one in Conway. Traps were designed to capture plum curculios that had already arrived in tree canopies and were searching for resources of fruit borne on twigs or resting sites on twigs. Each trap, constructed of cardboard, was cylin- drical in shape (8 inches tall and either 1 or 3 inches in diameter), coated with yellow or black latex paint, and capped with an inverted screen funnel developed originally to capture boll wee- vils. The yellow cylinders were intended to Table 1. Numbers of plum curculios captured daily by traps in unmanaged apple trees. May 24 - June 15, 1997. Traps Clear Plexiglas, low position 12 Clear Plexiglas, high position 12 Black pyramid traps 12_ Number of Mean number of curculios replicates captured per trap * 10.0 a 7.6 a 9.1a * Numbers followed by a different letter are significantly different at odds of 19:1. 14 Fruit Notes, Volume 63 (Number 1), Winter, 1998 Table 2. Of plum curculios that left vials in which they were contained (i.e. curculios that were active), proportions that arrived on vertical apple twigs (1/2 inch diameter) or on cylindrical vertical mimics (1 or 3 inches diameter) of either apple twigs (black) or apple foliage and fruit (yellow). Number of Curculios that arrived on Structure active curculios tested structure (% of active)* Twigs 52 24 b Yellow cylinder (1 inch) 59 22 b Yellow cylinder (3 inches) 54 24 b Black cylinder (1 inch) 61 41a Black cylinder (3 inches) 54 48 a * Numbers followed by a different letter are significantly different at odds of 19:1. mimic foliage and fruit borne by twigs and were similar in appearance to yellow-green plastic traps used commercially to capture cotton boll weevils. The black cylinders were intended to mimic twigs themselves. Each cylinder was po- sitioned vertically on a branch over an upright clipped twig, used as support. For each trial, we collected curculios (by branch tapping) from nearby trees, placed ten in a vial, and attached the vial in horizontal position to a branch about 9 inches from a cylinder. The curculios could crawl or fly directly from the vial opening to- ward the cylinder. Of the curculios that left vials, we recorded proportions that arrived on a cylinder during a 30-minute trial period. Results There were no significant differences in numbers of curculios captured per trap among sticky-coated Plexiglas traps in low position, sticky-coated Plexiglas traps in high position, and black pyramid traps (Table 1). These re- sults confirm and are remarkably similar to those of the 1996 study reported in the 1997 Winter issue of Fruit Notes. Importantly, we found here that increases in captures by sticky Plexiglas traps but not by black pyramid traps were significantly positively correlated with increases in fruit damage caused by plum curculios the following day. Also, captures by sticky Plexiglas traps as well as fruit damage were significantly positively correlated with temperature, with the former also significantly negatively correlated with wind speed. Among plum curculios that left vials in which they were released on apple tree branches, 22-24% arrived on upright test twigs or on 1 -inch-diameter or 3-inch-diameter up- right yellow cylinders (Table 2). Significantly greater proportions (41-48%) arrived on upright black cylinders (Table 2). All observed curculios arrived on twigs and cylinders by crawling. None arrived by flight. Conclusions The findings reported here, though still pre- liminary, encourage us to believe that improved variants of the sticky Plexiglas squares and tall black cylinders studied here could be more suit- able than black pyramids for monitoring curculios, because captures by these traps bet- ter coincide with periods of curculio damage to fruit than captures by black pyramid traps. Sticky Plexiglas squares placed adjacent to tree canopies are much too cumbersome for wide- spread use by growers, but a simplified non- sticky version (possibly incorporating attractive canopy-mimicking stimuli) might be an effec- tive substitute. Similarly, an improved version of a black twig-mimicking trap could be of con- Fruit Notes, Volume 63 (Number 1), Winter, 1998 15 siderable value in monitoring within-canopy activity of curculios. We are planning further studies on these alternative trap types. Acknowledgments This work was supported by grants from the USDA Northeast Regional IPM Competitive Grants program and the New England Tree Fruit Research Committee. •X^ •^ *^T> vL* *1>* rp» 0^ 0^ #^ 0^ 16 Fruit Notes, Volume 63 (Number 1), Winter, 1998 Subscription Renewal If 1996 or 1997 appears after your name on the mailing label, your subscrip- tion to Fruit Notes has expired, and this will be your last issue. To renew, please tear out this sheet and return it with your payment. Foreign sub- scribers, please see the note at the bottom of this page. Thank you. Return this form by June 30, 1998 to insure no interuption in your subscription. Your name and address appear on the reverse side of this form. If they do not or they are incorrect, please include your correct name and address below. Name: Address: City, State, Zip Code: Country: CHECK ONE: One year I I $10.00* Two years I I $19.00* Three years I I $27.00* Make check payable to: UNIVERSITY OF MASSACHUSETTS. Send this form along with payment to: Fruit Notes Department of Plant & Soil Sciences 205 Bowditch Hall University of Massachusetts Amherst, MA 01003 * Foreign subscriptions are $12, $22, and $32 for 1,2, and 3 years, respectively. All payment must be made in United States currency. Fruit Notes, Volume 63 (Number 1), Wimer, 1998 IV 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 1 SERIAL SECTION UNIV OF MASSACHUSETTS LIBRARY AMHERST MA 01003 SEE IMPORTANT SUBSCRIPTION INFORMATION ENCLOSED. Account No. 2-22914 UM/Morr Per SB 354 F68 ruit Notes i Prepared by the Department of Plant & Soil Sciences. UMass Extension. U. S. Department of Agriculture, and Massachusetts Counties Cooperating. Editors: Wesley R. Autio and William J. Bramlage lAi liu \\i; BIOLOG'GAL FEB K FEB 2 4 1999 \'/ Volume 63, Number 2 SPRING ISSUE, 1998 Table of Contents Residues of Azinphosmethyl on Apples Using First- vs. Third-level IPM Can Apple Maggot Fly Control Benefit from Sprays of Provado Aimed at Killing Leafminers and Leafhoppers? Tax Pointers for Farmers and Landowners in 1998 Preliminary Study of 1PM Options for Peaches: Major Fruit-damaging Insects Fruit Notes Publication Information: Fruit Notes (ISSN 0427-6906) is published the each January, April, July, and October by the Department of Plant & Soil Sciences, University of Massachusetts. The costs of subscriptions to Fruit Notes are $ 1 0.00 for United States addresses and $12.00 for foreign addresses. Each one-year subscription begins January 1 and ends December 3 1 . Some back issues are available for $3.00 (United States addresses) and $3.50 (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 UMASS EXTENSION 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 stale 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, concernmg the use of these products. USER ASSUMES ALL RISKS FOR PERSONAL INJURY OR PROPERTY DAMAGE. Issued hy UMass F.xtciisuiii, John (ieiber, Direiloi. in liinbcmmr ti) the lu Is oj May S and June M). 1914. UMass Extension ntjers equal (ipjiariunity in i>iiif;iiiiiis iiiul einploymcnl Residues of Azinphosmethyl on Apples Using First- vs. Third-level IPM Starker Wright and Ronald Prokopy Department of Entomology, University of Massachusetts Scott Carrier, Raymond Putnam, and J. Marshall Clark Massachusetts Pesticide Analysis Laboratory The apple maggot fly ( AMF) is a key summer pest of apples in New England and other parts of eastern North America. According to recent surveys, AMF was ranked as one of the two most important insect pests attacking apple fruit by commercial apple grow- ers in Massachusetts [Fruit Notes 61(3)]. AMF are active in orchards from late June through mid-Septem- ber, with peak activity generally in early August. Most growers are able to achieve effective control of AMF by applying two to four insecticide sprays during July and August. Over the past two decades, we have attempted to develop an alternative behavioral approach to AMF control. This approach involves surrounding an or- chard block with odor-baited red spheres placed about 5 yards apart on perimeter trees. Each sphere is either coated with Tangletrap or is treated with a feeding stimulant and an insecticide to kill alighting flies [Fruit Notes 62(4)]. Ideally, this system of management would allow the grower to cease insecticide applica- tion after plum curculio season, in effect extending the pre-harvest interval for summer insecticide use to 80 days or more. One grower-perceived advantage to be- havioral control of AMF is reduction in use of sum- mer insecticides and subsequent reduction in level of insecticide residue on fruit at harvest [Fruit Notes 60(4)]. The EPA sets standards for commercially accept- able levels of pesticide residue on marketed fruit. Currently, the standard for azuiphosmethyl residue on apples is 2 parts per million (2000 parts per billion). However, the Food Quality Protection Act (FQPA) may strongly affect tolerable levels of residue. The intent of the FQPA is to establish tolerance levels that are ?safe,? defined as ?a reasonable certainty that no harm will result from aggregate exposure, including all ex- posure from diet, drinking water, and other non-occu- pational exposures.? In order to calculate health risks associated with exposure to pesticide residues, the FQPA dictates that aggregate exposure be measured by use of a ?risk cup,? meaning that all exposures (fresh and processed foods, water, and household exposure) are combined into the same cup. All existing toler- ances must be re-evaluated, and organophosphate in- secticides (such as azinphosmethyl) are included in the first round of review, slated for completion in August of 1 999. Tolerance levels are based on residues present on fruit at harvest. Our aim here was to determine the amount of azinphosmethyl on fniit at harvest in blocks of apple trees that received azinphosmethyl for AMF control versus blocks that received only odor-baited red spheres for AMF control. Materials & Methods In 1997, we began a pilot third-level IPM project in order to determine the influence of apple tree archi- tecture and planting density on biologically-based pest management and fruit quality. In each of eight com- mercial orchards, we identified and flagged six blocks of trees: two each of high, medium, and low tree den- sity. One block of each density was managed under first-level IPM practices that involved application of two to four sprays of insecticide from early July to harvest. The other block was managed under third- level practices that involved surrounding the block with odor-baited red spheres. For purposes here, fruit were sampled only from the medium-density trees, which, at -240 trees/acre, represent the majority of apple trees Fruit Notes, Volume 63 (Number 2), Spring, 1998 rablu I. A/inphosiiiclhyl ihsccIickIl- appliciilions. a/.inpliosiiKiliyl icsidiics and AMI' in|iiry on luiil al liarvcsl 111 blocks iiianaL'cd under liisl Il-vl-I vcislis ihird-lcvcl II'M in live eoinnicieial apple oreliards Orchard Dales ol azinphosmcthyl applieations Dt)sage equivalcnl per application'' A/Jnphosnielhyl residue at harvest (pph) AMF injury (%) First Level IPM Blocks C D Mean Third Level IPM Blocks B C D Mean May 20 June 3 July 20 August 2 May 29 June 6 June 13 July 10 August 6 May 28 June 7 June 23 July 16 July 31 August 14 June 5 June 13 August 7 August 26 May 25 June June June July August August 9 20 30 21 11 30 1,5 1.0 0.25 0.25 0.67 0.67 1.3 0.7 0.67 1 .0 1.0 0.5 1.0 1.0 1.0 1.0 1.0 0.5 0.25 LO 1.3 0.67 1.3 1.0 0.67 0.67 4.37 May 20 1.5 June 3 1.0 May 29 0.67 June 6 0.67 June 13 1.3 May 28 1,0 June 7 1.0 June 23 0.5 May 14 0.25 June 5 1.0 June 13 1.0 May 25 1.0 June 9 1.3 June 20 0.67 June 30 1.3 2.83 N/D'' 80 239 N/D" 159 96 N/D" N/D" N/D'' N/D'' N/D" 0.0 0.0 0.0 0.0 LO 0.2 2.0 0.0 0.0 0.0 0.0 N/D' 0.4 One dosage equivalent = 8 o/.. formulated a/inphosniethyl per 100 gallons water. Applications in May and June were made against plum curculio, ' ppb: parts per billion. '' N/D: not detected (detection limit = 40 ppb). Fruit Notes, Volmne 63 (Number 2), Spring, 1998 in Massachusetts. Of the eight medium-density third- level IPM blocks and the eight companion first-level blocks, five pairs were selected for sampling here. Se- lection was based on the fact that azinphosmethyl was the insecticide applied against AMF in all five first- level blocks. Within one week of harvest, ten mid-sized Mcin- tosh fruit were selected randomly from each block, bagged, and placed within 6 hours in a deep-freeze at ?20"C until the analyses were performed. Fruit forti- fied with known levels of azinphosmethyl showed that there is no significant breakdown of residues while in storage. From each experimental block, three samples were analyzed, each sample consisting of three fruit. For analysis details, see the note at the end of the text. Results In the five blocks under first-level IPM, growers used an average of 2.4 sprays against AMF between early July and late August, resulting in an average of 0.2% AMF injury (Table 1). Analysis revealed that fruit treated with 2-3 sprays of azinphosmethyl con- tained an average of 95.6 parts per billion of azinphosmethyl residue at harvest, roughly 5% of the current EPA tolerance. In keeping with the principles of behaviorally- based AMF control, no insecticides were applied to the five third-level IPM blocks after mid-June. Expectedly, none of the samples taken from these blocks contained a detectable level of azinphosmethyl residue, even though these blocks received an average of 2.8 applications of azinphosmethyl against plum curculio in May and June (Table I ). Blocks managed under third-level practices received slightly more in- jury by AMF (0.4%) than did first-level blocks. Conclusions This study has shown that the amount of azinphosmethyl residue present on apples at harvest in 1997 in test blocks managed under first-level IPM practices averaged far less (about 95% less) than the amount of residue allowed by current EPA regulations. This study also showed that no detectable residues of azinphosmethyl were found on apples at harvest in test blocks managed under third-level IPM practices. Although it may seem logical that no insecticide treatment during July and August (as under third-level 1PM) ought to result m no insecticide residue on frait at harvest, such would not necessarily be the case if insecticide applied against plum curculio were to be present on harvested fruit. All ten blocks in this study received two to four sprays of azinphosmethyl from mid-May to late June against plum curculio. Our data from fruit samples taken in third-level IPM blocks clearly show that treatments of azinphosmethyl applied in May and June did not result in detectable levels of azinphosmethyl on harvested fruit (Table I). This in- formation could be important to EPA consideration of continued allowable use of azinphosmethyl against plum curculio. Even though our findings here indicate that use of third-level IPM practices results in no detectable resi- dues of azinphosmethyl on fruit at harvest and pro- vides acceptable commercial-level control of AMF, more work is needed to refine third-level IPM prac- tices so that they will become as economical and reli- able as first-level IPM practices. Acknowledgments This work was supported by state/federal IPM funds and USDA SEA CSREES Grant # 97-34365- 5043. We are grateful to the eight growers that par- ticipated in this study: Bill Broderick, David Chan- dler, David Cheney, Dana Clark, David Shearer, Joe Sincuk, Tim Smith, and Mo Tougas. Note: Whole fruit were blended with water and sub- mitted to extraction with ethyl acetate, then reduced using a sample concentrator, leaving a concentrate of residual material. Azinphosmethyl residues from ex- tracted apples were analyzed using a Varian model 3400 GC gas chromatograph (Varian Associates, Sunnyvale, CA) equipped with a nitrogen phosphorous detector (NPD). The capillary column was a fused silica DB-5 liquid phase, 0.53 mm i.d. X 1 5 m, 0.25mm film thick- ness (J & W Scientific). A deactivated cyclodouble- gooseneck injection port liner (Restek, Bellefonte, PA) was used for splitless injections. Operating conditions were as follows: injection volume, 1.0 ml; injection port temperature, 250"C; detector temperature, 300"C; column temperature, 1 75"C for 0.5 min, ramped at 20'C/min to 250"C and held for 12 min. The carrier gas was helium at a rate of 8 ml min '. Detector gas flow rates were: nitrogen, 25 ml min'; oxygen, 175 ml min ': hydrogen, 2.5 ml min ' (Kadenczki et al., J. Assoc. Off. Anal. Chem. 75, No.l, 53-61). %f^ «t# m^A %£• aI^ rj* ry» ry» ry» ry» Fruit Notes, Volume 63 (Number 2), Spring, 1998 Can Apple Maggot Fly Control Benefit from Sprays of Provado Aimed at Killing Leafminers and Leafhoppers? Xing Ping Hu, Andrew Kaknes, and Ronald Prokopy Department of Entomology, University of Massachusetts The insecticide Provado (containing imidacloprid as the active ingredient) was synthesized by Japanese Chemists in 1985. In 1995, it was labeled for use on apple in the United States. One of its greatest perceived advantages is its high toxicity to several major apple pests but comparative lack of toxicity to beneficial predators and parasitoids. Indeed, Provado has proven very effective against leafminers, leafhoppers, and aphids in apple orchards of Massachusetts and other states [Fruit Notes 60(4)]. Provado may be used ef- fectively when applied against either first-generation leafminers and leafhoppers at petal fall in May, or against second-generation leafminers and leafhoppers in late June. Application in late June conceivably also could provide control of early-invading populations of apple maggot flies. One reason for believing this might be so stems from recent tests of Provado applied, to- gether with latex paint, on red spheres aimed at killing alighting apple maggot flies. Results of these tests showed high toxicity of Provado against the flies even at very low doses [Fruit Notes 62 (4)] . Here, we evalu- ated effects of Provado against apple maggot flies when applied to the foliage and fruit of apple trees. Materials & Methods Provado was provided by Bayer Corporation (Kan- sas City, MO). Flies used in bioassays were obtained >. o E u. 40 35 30 25 20 15 10 5 i 0 — •— Flies caged immediately following spray -•— Flies caged 24 hours after spray -•— Flies caged on insprayed leaves 1 I 4 6 2 3 4 5 Days of exposure to sprayed foliage and fruit Figure 1 . Mortality of apple maggot flies caged on apple trees sprayed with Provado (0.03% a.i.). Fruit Notes, Volume 63 (Number 2), Spring, 1998 35 30 ^ 0) Si ?5 h 3 C 20 C ra IS 0) S 10 5 0 D Flies caged immediately following spray ■ Flies caged 24 hours after spray ■ Flies caged on unsprayed leaves Oviposition puncture Eggs laid Egg load Figure 2. Mean number of oviposition punctures, eggs laid, and egg load per female among apple maggot Hies that survived exposure to Provado during 7 days in field cages from pupae collected from unsprayed apple drops. Five apple trees were selected from an abandoned orchard near Amherst, Massachusetts. Branches of four trees were sprayed to runoff at a dose of 0.03% a.i. of Provado, the rate labeled for controlling sucking in- sects in apple orchards. The fifth tree was not sprayed and used as a control. For each tree, four branches were selected for caging flies, using 30x50-cm cloth screen net. Two fruit were allowed to remain on each branch. Four leaves on each branch received an aque- ous slurry of a mixture of 8% sugar and 10% bird drop- pings to serve as a food supply for flies. Two cages per tree received 20 flies (10 males and 10 females) immediately following spray application. The other two cages received like numbers of flies 24 hours later. Mortality counts were made daily for 7 days. To determine possible effects on fly reproduction, apples and surviving flies from each cage were brought back to the laboratory on the 7"' day. Apples were exam- ined to detemiine the effects of Provado on fly ovipo- sition behavior by counting the number of oviposition punctures and number of eggs laid. Female flies were dissected to determine effects of Provado on egg load by counting the number of mature eggs in fly ovaries. Results Our results indicate that application of Provado to apple tree foliage and fruit neither effectively reduced fly survival (Figure 1 ) or fly reproductive ability (Fig- ure 2). Less than 20% of flies caged immediately after spray application were killed over the 7-day test pe- riod, too low to provide effective control. Mortality was even lower (8%) for flies released into cages 24 hours after spraying. This was essentially no greater than the 5% mortality of flies in the control cages. The results suggest a rapid decline of Provado activity on leaf and fruit surfaces after application. Figure 2 shows that fly oviposition behavior was only slightly reduced for flies exposed to sprayed com- pared with unsprayed leaves and fniit. Groups of flies exposed to foliage and fruit immediately after spray- ing with Provado made an average of 16 ovipositional punctures and laid an average of 14 eggs over 7 days, compared with 1 9 ovipositional punctures and 1 7 eggs laid by tlies expo.sed to foliage and fruit 24 hours after spraying, and 21 ovipositional punctures and 19 eggs laid by control flies. The egg load per female remained at essentially the same level for all the treatments. These results suggest that Provado applied to apple foliage and fruit had minimal effects of fly oviposi- tion. Conclusions Even though Provado has proven excellent in pro- viding season-long control of .sucking in.sect pests on apple trees, and even though our laboratory tests showed high toxicity of Provado to apple maggot flies, the results generated here indicate that Provado ap- Fruit Notes, Volume 63 (Number 2), Spring, 1998 plied to apple tree foliage and fruit has little or no ef- fect on apple maggot fly mortality and oviposition. There may be two reasons for the ineffectiveness of Provado spray on tree foliage and fruit against apple maggot flies. First, Provado is a systemic insecticide, and is quickly absorbed by foliage (and perhaps also fmit) once sprayed. Thus, it kills pests that suck sap from the interior of foliage but does not remain on plant surfaces long enough to kill pests, such as apple mag- got flies, that do not suck plant sap. Second, Provado on exterior surfaces of plants is subject to rapid degra- dation by sunlight. Nevertheless, when applied to- gether with latex paint to red spheres, Provado, even at very low doses, has provided excellent control of apple maggot flies alighting on treated spheres for up to three months after initial application. Thus far, it has proven more effective than any other insecticide that we have evaluated for this purpose. Acknowledgements We thank Richard H. Ackerman from Bayer Cor- poration for providing us with samples of imidacloprid and John Clark and David Ferro from our department for helpful suggestions. This work was supported by funds from USDA Cooperative Agreement 58-3620- 104, the Northeast Regional IPM Competitive Grants programs and the Washington State Tree Fruit Research Commission. «t« «t« %f# %% ftl^ •^ 0^ ^Y* ^i^ •(ji^ Fruit Notes, Volume 63 (Number 2), Spring, 1998 Tax Pointers for Farmers and Landowners in 1998 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. For more details, you and your tax adviser may wish to consult the sources referenced in the square brackets [thusj (see footnote). Taxpayers filing returns other than for calendar year 1998 may face different rules than those described here . New Legislation Life seems to be getting ever more complicated. • On January 1 , 1 998, many of the provisions of the Taxpayer Relief Act of 1997 "TRA97" (Public Law 105-34) became effective. • On July 22, 1998, the IRS Restructuring and Reform Act/ Taxpayer Bill of Rights 3 "RRA98"(H.R. 2676) was enacted mto law (P.L. 105-206), and many of its provisions became effective on that date. While mostly concerned with internal operations of the IRS, changes in laws governing collection of taxes and "innocent spouse" provisions will affect some taxpayers. The Act also makes technical corrections to TRA97 that affect treatment of some capital gains and losses and sale of a principal residence. • Finally, as the last act of the 105"" Congress, the Omnibus Appropriations Act for FY99 "OAA99" (H.R. 4328) was enacted into law on October 21, 1998 as P.L. 105-277. It contains several retroactive tax provisions of specific interest to farmers. They are discussed below. Income Averaging for Farmers Made Permanent [IRC §1301] TRA97 introduced income averaging for farmers for 1998-2000. OAA99 made the averaging provisions permanent. Use income averaging if you had a successful year in 1 998 and less profit in prior years. The idea is to shift some of your income from the high marginal tax rate you would otherwise face in 1998 to the rate it would have been taxed in earlier years. Schedule J of Form 1040 is used for calculations. Step 1 . Calculate the tax on your taxable income (farm and non-farm) in 1998. If the last dollar of income is in a higher tax bracket than the last dollar of taxable income in any of the three prior years then income averaging will reduce your 1998 taxes. Step 2. Elect the amount of farm income to be averaged. Only farm income can be averaged. However, if your family has high taxable income in 1998 because of both farm and non-farm income, you can average the farm income part. Farm income includes gains from the sale of assets (except land) used in the farming business for a "substantial period" (not defined). Sales of machinery and breeding livestock reported on Form 4797 would be eligible. Elect as much of the current year's eligible farm income as you want to distribute over the three prior years. The principle is to get income after averaging approximately level across the years. The more detailed operational rule is explained after the example. Step 3. Divide the elected amount of income into three equal parts and add each part to your taxable income (farm and non-farm) in each of the three prior years. Subtract the elected amount from 1998 income. Step 4. Using the income levels from step 3, figure the tax for each year using the tax table for that year and add the tax amounts together. Step 5. Add the actual taxes paid in the three prior years to the 1 998 taxes from step 1 . Step 6. Compare the total from step 4 with the total Fruit Notes, Volume 63 (Number 2), Spring, 1998 Irom step 5 H the total from step 4 is smaller then income averaging will be advantageous. Example: Andy Farmer, who is married, filing jointly, has both farm and non-farm income for the last four years as shown in Table I . Net losses are within parentheses. If Andy does not elect income averaging then the family income tax liability for 1998 will be $32,346. [. 1 5 X $42,350 + .28 x ($ 1 02,300 - $42,350) + .31 x ($132,000 - $102,300)]. Andy can elect to Table 1 Taxable income and tax before averaging. Year Taxable income Tax on unaveraged income Income reported on Schedule F Livestock and machinery gains reported on Form 4797 1995 1996 1997 1998 $6,000 $8,000 $11,000 $132,000 $900 $1,200 $1,650 $32,346 $(14,000) $(10,000) $(8,500) $114,000 $4,000 $1,500 $2,000 $3,000 Total tax 1995-98 $36,096 1 average up to $ 1 1 7,000 of 1 998 income (the total of the Schedule F and Form 4797 amounts). If he elects to average $90,000, then $30,000 is added to the taxable income of 1995, 1996 and 1997. Results of averaging are shown in Table 2. Note that if Andy elects to income average in 1999 the amounts in Table 2 become the initial taxable incomes. The saving from averaging is $12,546 [= $36,096 - $23,550]. The 1998 tax liability is $19,800 [$23,550 -$900 -$1,200 -$1,650]. Note: the tax is figured at 15% of taxable income. U.se of tax tables will give slightly different answers ($4 more m each case). The operational rule is to increase the amount of the election as long as the average marginal tax rate over the three prior years is as low or lower after averaging than the marginal rate on the income remaining in 1998. In the example, the last dollar of taxable income before averaging (Table 1 ) in each of the prior years is taxed at 15%, against the marginal rate for 1998 of 31 %. Therefore, moving $3 from 1998 to the prior years reduces the tax rate on that income from 31% to 15%. After averaging (Table 2) the marginal rates are 15% throughout. If the election was increased by more than $600 (to over $90,600) this would bring 1997 taxable income over $41,200, increasing the marginal rate of tax in 1997 to 28%. Now the average marginal tax rate of the three prior years (15% -i- 15% -f- 28%)/3 = 19.3%> exceeds the marginal rate for 1 998, which has dropped to 15%. Caution: If you are subject to alternative minimum tax in the year for which averaging is elected ( 1 998 in the example) then income averaging will be of no benefit. Table 2. Taxable income and tax after averaging. Year Taxable income Lndof IS'/r taxable income bracket Tax on averaged income 1995 IW6 l'W7 1998 $36,000 $38,000 $4 1 ,000 $42,000 $39,000 $40,100 $41,200 $42,350 $5,400 $5,700 $6, 1 50 $6,300 Total lax 1995-98 $23,550 Fruit Notes, Volume 63 (Number 2), Spring, 199cS Averaging Does Not Alter Self-employment Tax [IRC §1301] Andy's self-employment tax in 1998 in the example above would be $11,535. [92.35% of $114,000 = $105,279. The first $68,400 is taxed at 15.3% = $10,465. The balance. $105,279 - $68,400 = $36,879 IS taxed at 2.9% = $1070.] Income averaging does not change the self-employment tax amount. Conservation Reserve Payments Are Rent Not Farm Income, Are Not Subject to Self-employment Tax, and Are Reportable on Schedule E [Wuebker vs Commissioner, 1 10 T.C. No. 31 (June 23, 1998); IRC §1402] For several years the IRS has taken the position that Conservation Reserve Program (CRP) payments to materially participating farmers are subject to self-employment tax. (If you do not fall under the material participation rules, see below, you were not and still are not subject to SE tax on CRP payments.) . The Tax Court in the Wuebker case determined that CRP payments are rent; however, CRP agreements prevent the land from being used for agricultural production. Therefore, the language in IRC § 1402 that called for the payment of SE tax on rent by a materially participating farmer does not apply. The IRS may appeal the Court's decision. Note: There are reasons why you might not wish to treat CRP payments as rent. Some estate tax benefits might be lost. For example, to get the favorable valuation as farmland rather than fair market value (in highest and best use), the deceased owner must have materially participated in using the land for farming purposes. In this situation, you would want to report the CRP payments on Schedule F and pay SE tax on them. If taking this position, filing the disclosure form, Form 8275, is probably wise, relying on the past IRS position and its likely appeal of the Wuebker decision. [IRC § 1402(a)(1)] Material Participation There are two sets of material participation rules. A taxpayer who is materially participating for the purposes of self-employment tax may or may not be materially participating for the puqjo.ses of passive activity loss rules. The reverse is true: a taxpayer who materially participates for the purposes of passive activity loss rules may not be materially participating for the purposes of self-employment tax. The Farmer's Tax Guide (IRS Publication 225) lists the tests of material participation of a farm- landlord to determine whether or not self-employment tax must be paid. You are materially participating if you have an arrangement with your tenant and you meet one of the following tests: Test No. 1 . You do any three of the following: ( 1 ) pay or stand good (e.g. sign for materials bought on credit) for at least half the direct costs of producing the crop; (2) furnish at least half the tools, equipment, and livestock used in producing the crop; (3) consult with your tenant; and (4) inspect the production activities periodically. Test No. 2. You regularly and frequently make, or take an important part in making, management decisions substantially contributing to or affecting the success of the enterprise. Test No. 3. You work 1 00 hours or more spread over a period of 5 weeks or more in activities connected with crop production. (Note: these numbers do not appear in either the tax code or the regulations.) Test No. 4. You do things which, considered in their total effect, show that you are materially and significantly involved in the production of the farm commodities. If you pass the test for material participation you file Schedule F and are subject to self-employment tax on the income. [I.R.C. §1402. Treas. Reg. §1. 1402(a)- 4(b)(6) gives six examples] Capital Gains Changes TRA97 set up three rate groups of assets: 1 . 28%. Short-term gains and losses, assets held not more than 1 2 months; all collectibles (coins, paintings, stamps, wine, etc.); long-term capital loss carryovers. (Note: Excess depreciation (above straight-line amounts) recaptured from the sale of § 1 250 property (basically, buildings) is ordinary income, does not appear on Schedule D.) 2. 25% Long-term gains (no losses in this group) from Fruit Notes, Volume 63 (Number 2), Spring, 1998 sale of buildings and improvements that result from straight-line depreciation (generally, the rest of the depreciation you have taken), limited by net §1231 gain [Technical correction in RRA98 to IRC §l(h)(7)(B)]. Section 1231 property is those durable assets used in a trade or business (not in inventory, not supplies). 3. 20% All other long term gains and losses, including the gain over purchase price from selling a building. The 1997 Act also set complicated holding periods. RRA98 has simplified matters in several areas. 1. Sales on or after January 1, 1998, of assets held more than 12 months qualify for long term capital gains. 2. The amount of gain at the 25% rate is limited to the net §1231 gain. [IRC § 1(h)(7)(b)] Generally, this change only becomes a concern during a year when you sell some property for less than you paid for it. Example: In 1998, Bruce Bullock sells a piece of land for $80,000 that he had purchased for $100,000. He also sold a building for $80,000 that he purchased for $70,000. He had taken $40,000 of straight line depreciation on the building. He had no unrecaptured §1231 losses from prior years. Bruce also sold some mutual fund shares for a gain of $20,000. The basis of the building is $30,000 ($70,000 - $40,000). Therefore, in 1998 Bruce has: Gain on building Loss on land Net §1231 gain $50,000 (20.000) $30,000 On the building alone, Bruce has $40,000 of gain taxed at 25% (the straight-line depreciation) and $10,000 of gain taxed at 20%. (Refer to the rate groups listed above.) However, because of the loss on sale of his land, the amount of gain subject to the 25% rate is only $30,000. Note that the gain on sale of the mutual funds offsets the loss on the sale of the land and normally these would be netted out, since they are in the same (20%) rate group, to give a net gain of zero for that group. But the limitation described in the example is done first. 3. Netting of gains and losses. Form 4979 and the worksheet on page .seven of the instructions for Schedule D together perform the desired calculations. If you have losses in the 28% or 20% rate group and a gain from selling depreciable property (25% group) the worksheet will reduce the recapture amount you enter on line 25 of Schedule D. Details of the netting are as follows: ( 1 ) Within each group, net out the gains and losses for that group. (2) Short term losses first reduce short-temi gains, if any. (3) Any residue from (2) is applied first to reduce long- term gains at the 28% rate, then to reduce gains at the 25% rate then to reduce gains at the 20% rate. (4) A net loss from the 28% group (including long- term loss carryovers) is applied first to reduce gains at the 257o rate , then to reduce gains at the 20% rate. (5) A net loss from the 20% group is applied first to reduce gains in the 28% rate, then to reduce gains at the 25% rate. Order of computing tax on gains. For taxpayers in the 15% bracket, the capital gains rate will be less than the amounts given in the rate groups above. Schedule D does a masterful job of figuring out the amounts subject to the various rates of tax. It performs computations by taking income in the following order: ordinary income, taxed at 1 5%; gains in the 25% class , taxed at 15%; gains in the 28% class, taxed at 15%; and gains in the 20% class, taxed at the reduced rate of 1 0%. Once the 15% bracket has been used up, the rate of the asset group is applied to the capital gains. Sale of Farm and Principal Residence TRA97 and corrections in RRA98 permit much or all of the capital gain on the sale of your principal residence ($250,000 if single, $500,000 if married filing jointly) to be excluded from income if you meet ownership and occupancy requirements (generally, to have owned and occupied the house in two out of the last five years). [IRC §121] Instead of the single lifetime exclusion available previously, you can now use the exclusion every time you .sell your home. Farmers, therefore, have an even bigger incentive to declare their house a principal residence and not part of the farm. To get the exclusion you must show that your hou.se is residential not agricultural. For example, use the area around it to graze horses used for plea.sure by your children; maintain the area around it 10 Fruit Notes, Volume 63 (Number 2), Spring, 1998 as a garden giving scenic enjoyment; report mortgage interest and property taxes on Schedule A rather than on Schedule F; retain the house and some land for some period of time after the sale of the farm. Net Operating Losses on the Farming Business Now Carried Back Five Years [IRC §172(b)(l)(G)] RRA98 added a five-year carryback for the net operating loss that would result if only income and deductions attributable to farming businesses were taken into account (i.e., "farming losses", reduced by the amount of profit, if any, from other businesses). [IRC § 172(b)(1)(G)] "Farming business" means the trade or business of farming, including operating a nursery or sod farm and raising or harvesting fruit trees and ornamental trees. [IRC §263A(e)(4)] If you want to make use of the net operating loss provisions to lower your taxes, the five-year carryback is now the default. If you want to use the regular net operating loss provisions you must elect to do so. Such election must be made by the due date (including extensions) for filing the return for the year with the loss. Once made, the election is irrevocable. [IRC §172(b)(3)] Regular net operating loss provisions have also changed. In 1 998 and future years losses can be carried back two years (instead of three) and carried forward 20 years (instead of 1 5). [TRA97; IRC § 1 72(b)( 1 )( A)] . Farmers in "Presidentially declared disaster areas" can use a three year carryback for disasters but not for "fanning losses" (i.e. not for losses incurred in the ordinary business), so this is of little use to most farmers. If you want to use these regular provisions you can elect to use only the carryforward provision. The same conditions apply to this election. You must make the election before the due date to file your return (including extensions) and once made the election is irrevocable. Net operating loss carryback and carryforward is most useful when set against income subject to high marginal tax rates. If you have low incomes and low marginal tax rates in prior years you may wish to use carryforward only. This is a decision that requires careful analysis of past years' incomes and formation of expectation about future net incomes. Form 1045 and its associated Schedules are used to make the complex adjustments to itemized deductions, to figure the allocation of losses and to calculate the amount of the tax reduction. As before, net operating losses are allocated chronologically, that is, to the earliest eligible year first. Massachusetts State Taxes Get Up to Date - Almost After being frozen at January 1, 1988, Massachusetts personal income tax law now follows the Internal Revenue Code in effect on January 1, 1998. Unless they are related to deductions for business expenses or one of the special federal tax provisions such as Roth and Education IRAs, any federal tax law changes that become part of the IRC as amended and in effect after January 1, 1998, will not be adopted by Massachusetts. One place where farmers might be affected is with depreciation. If you took different amounts of depreciation on a property for federal and State purposes, that difference will disappear on your 1998 returns. Example: The life for single purpose agricultural or horticultural buildings placed in service after 1989 is 10 years for federal purposes while it would remain at the 1988 life of 7 years Massachusetts purposes. Possibly amounts on purchased equipment taken as expenses (§179 expensing) might have been higher for federal than for State purposes. These differences would cause the amount of depreciation taken on federal returns to differ from that taken on State returns. Septic Credit Carryover Extended to Five Years The Massachusetts credit for the replacement or repair of failed cesspools or septic systems had been amended to extend the carryover for unused credit from three to five years. The current annual $1,500 maximum credit and $6,000 total maximum credit remains the same. If you claimed the credit in 1997 you have until 2002 to carryover any unused credit. Conversion to Roth IRA: What Did You Miss? If you convert from a traditional IRA to a Roth IRA by December 31, 1998, you meet a special rule that allows you (but does not require you) to spread the Fruit Notes, Volume 63 (Number 2), Spring, 1998 11 taxable income from the conversion over the next four years. This is not as big a deal as some advertising implies. You lose little by converting one fourth of the planned amount in each of the next four years. Most of the advertising by mutual funds or brokers is (or should be) directed at employees. Self-employed individuals have other possibilities (SEP-IRA and SIMPLE-IRA) that remove much of the attraction of the Roth IRA. A contribution to a Roth IRA is income after taxes have been paid while a contribution to a regular (deductible) IRA is before tax income. Both types of IRA accumulate earnings tax-free. Distributions from a Roth IRA are tax-free, while those from a regular IRA are taxable. The key issue appears to be whether the tax rate on contributions will be higher, the same or lower than the tax rate on distributions. If higher, the Roth is an advantage. If lower, it is not. Worksheets that do not employ any "smoke-and- mirrors" appear to show that conversion of a regular to a Roth IRA is advantageous, even when the tax rate during retirement is lower. That is, removing funds from a regular IRA, paying the tax on these funds (which are treated as ordinary income) and depositing the funds in a Roth IRA gives greater retirement income than not making the conversion. The money to pay taxes must come from somewhere, but the result occurs even after factoring in the lost earnings on that money. Why does the conversion "work" even if your tax rates fall after you retire? Because it allows you to shelter more interest and dividend income from taxes. If it is your goal to put a lot of money away for retirement, as an employee you are restricted to $2,000 of earned income each year (and usually less if you participate in another retirement plan). A Roth IRA conversion lets you increase this. Example: You withdraw $10,000 from a regular IRA. If you have sufficient other income to put you in the 28% tax bracket, the tax on this distribution is $2,800. Without any other source of money you only have $7,200 to put into a Roth IRA. If in retirement you are subject to a 28% percent tax rate it turns out that your after-tax retirement income is the same whether you converted or not. (Worse, the $2,800 is treated as a premature withdrawal and incurs a further 10% excise tax penalty.) But if you have other money to pay the $2,800 tax bill, you are effectively putting that same amount into your IRA (in addition to the $2,000 that you could put into a new Roth IRA). Footnotes: IRC. Internal Revenue Code; T.C., Court; Treas. Reg., Treasury Regulations. Tax ^f# %J# •Im mlm •A* 0^ ry» ry» ry» ry» 12 Fruit Notes, Volume 63 (Number 2), Spring, 1998 Preliminary Study of IPI\/I Options for Peaclies: i\/lajor Fruit-damaging Insects Karen I. Hauschild Department of Plant & Soil Sciences, University of Massachusetts Arthur T\ittle and Daniel R. Cooley Department of Microbiology, University of Massachusetts Ronald J. Prokopy Department of Entomology, University of Massachusetts At harvest, the most severe damage on peach fruit is caused by true bugs (primarily insects in the group Pentatomidae, stink bugs) and Japanese beetles. Fruit may show scarring or fresh feeding wounds accompa- nied by a gummy ooze. Often this injury is severe enough that damaged fruit must be culled or, at the very least, downgraded to processing quality. With the greatest profitability gained from fresh-quality peaches, growers need and want to keep insect-dam- aged fruit at the lowest level that is economically and environmentally feasible. There are three species of stink bugs that are known to attack peaches and cause cat-facing injury: the brown stink bug (Eiischistus sennis), the dusky stink bug [E. nisrigmus), and the green stink bug {Acrosternum hilare). These insects are all highly mobile, and usually remain in the orchard for only a short period of time. Stink bugs reproduce on the trees, laying eggs on the lower surface of peach leaves. These eggs are easily identified; they are barrel-shaped, shiny, and appear in clusters of about seven eggs each. After the eggs hatch, the young nymphs move into the or- chard groundcover. Nymphs do little feeding on peaches. Primary damage is the result of adult feed- ing. Numbers of brown and dusky stinkbugs are great- est within a month of shuck fall. Green stink bug num- bers tend to increase throughout the growing season. The most severe damage to peach fruit occurs between petal fall and the time when fmits are 0.5-0.75 inch in diameter. If fruit that is damaged during this time pe- riod fails to abscise, at maturity, it is heavily scarred or malformed (injury commonly referred to as "catfac- ing"). As the fruits enlarge, damage by stinkbugs is less dramatic. Injury results in holes with gummy exu- date or dry, corky areas just below the fruit surface. The Japanese beetle {Popillia japonica) is a seri- ous pest of ornamentals, grapes, and plants in the fam- ily Roseaceae. Adult beetles chew on leaves and fruit. Leaf damage ranges from minor tissue loss to com- plete skeletonization. Fruit damage is restricted to the fruit surface (surface damage), but can be extensive and contaminated with beetle frass. Damage caused by Japanese beetles often attracts other insects or dis- ease organisms. Because Japanese beetles tend to congregate, damage can occur very quickly and be- come quite severe in a short period of time. The objective of this study was to determine the incidence of damaged caused by these pests under re- duced-pesticide regimes. Brown rot incidence from the same study was reported [Fruit Notes 62(4)] . Materials & Methods Until pit hardening in early June, all treatment plots received standard calendar-based pesticide applications every 7 to 10 days. After pit hardening occurred, four different treatment protocols were employed. These treatments are outlined in Table 1 . Refer to Fruit Notes 62(4) for additional information on experimental de- Results & Discussion For Redhaven peaches (Table 2), the incidence of stink bug damage was twice that of Glohaven (Table 3), while the incidence of Japanese beetle damage was Fruit Notes, Volume 63 (Number 2), Spring, 1998 13 Tabic 1 . Insecticide and fungicide ircalmciiis on pcache.s after June 10 at the University of Massachusetts Horticultural Research Center, Bel chertown, MA, 1996 Treatment (rate /lOO gal. dilute spray) Date of application Full spray Imidan 70WP (0.75 lbs.) 17 June; 2, 14, 25 July Captan80WP(l lb.) 17 June, 2, 14 July Captan 80WP (1 lb.) + Benlate 50DF (6 11. oz.) 25 July, 2 Aug. Reduced spray Imidan 70WP (0.75 lbs.) 2, 14 July Captan 80WP (I lb.) 2, 14 July Captan 80WP (1 lb.) + Benlate 50DF (6 R. oz.) 2 Aug. Lo\^' spray Imidan 70WP (0.75 lbs.) 2, 14 July Captan80WP(Ilb.) 2 July Captan 80WP (1 lb.) + Benlate 50DF (6 n. oz.) Aug. No spray None none i substantially less than that on Glohaven. These differences most likely reflect the timing of activity of each of these two insect pests rela- tive to the timing of fruit development of the two cultivars and the last insecticide spray. The four treatment regimes resulted in similar levels of stink bug damage on Redhaven and Glohaven fruit(Tables 2 and 3). Because these were 3-tree plots, with different treat- ments applied to adjacent trees, it is possible that spray drift could account for at least some of the lack of effect. Timing of insecticide ap- plications could have affected results as well. Redhaven fruit under the reduced-spray regime had the greatest amount of Japanese beetle feeding, and those under the other treat- ments were similar (Table 2). Likewise, Glohaven fruit under the reduced-spray treat- ment had the most damage, but for Glohaven, the no-spray treatment had significantly less damage (Table 3). It is unclear why these re- sults occurred. It is likely, however, that real differ- ences did not occur in this experiment. High mean Table 2. Insect damage to Redhaven peaches under different pesticide treatment schedules. Fruit were harvested on August 15 and 21. Each treatment included three trees in each of three replications. For assessment, 100 peaches were harvested from each tree. '- Stink bug Japanese beetle Trcalmcnt damage (%) damage (%) IhiII s|ii"ay 28 a 2b Reduced spi ay 31 a 6a Low spray 29 a 4b No spray 22 a 3b 'Means within columns not followed by the same letter are significant at odds of 15:1. values were likely the result of very localized infesta- tions of Japanese beetles. 14 Fruit Notes, Volume 63 (Number 2), Spring, 1998 Tabic 3. Insect damiige Id Glohavcn peaches under differenl pesticide Ireatmenl schedules Fruil were harvested on September 3. Each treatment included three trees in each of lour replications. For assessment, 100 peaches were harvested from each tree. ' Treatment Slink hug damage (%) Japanese beetle damage (%) Full spray Reduced spray Low spray No spray 9a 12a 12a 12a 23 b 31 a 16 be 9c ^Means within columns not followed by the same letter are significant at odds of 15:1. Clearly Ihiscxpcriincnl shuuld be repeated, perhaps with closer attention paid to timing of insecticides. Weekly scouting of plots would help to determine more accurately when each insect pest is present, and whether timing of insecticide applications coincides with the tim- ing required for fungicide applications. Closer attention to pest status would also help to ex- plain how these pests enter and move within the orchard. It is obvious from this data, however, that both stink bugs and Japanese beetles can have a substantial effect on fruit quality at harvest. Better timing of insecticide treatments and al- ternative pesticides or methods of control could impact results in another year. «1^ %t^ m^A %!• %!• rj* #^ ry% rj% rj^ Fruit Notes, Volume 63 (Number 2), Spring, 1998 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, IMA 01002 1 SERIAL SECTION UNIV OF MASSACHUSETTS LIBRARY AMHERST MA 01003 Account No. 2-22914 vJorr Fruit Notes Prepared by the Department of Plant & Soil Sciences. UMass Extension, U. S. Department of Agriculture, and Massachusetts Counties Cooperating. Editors: Wesley R. Autio and William J. Bramlage blume 63, Number 3 SUMMER ISSUE, 1998 Table of Contents An Easy and Reliable Procedure for Predicting Scald and DPA Requirement for New England Delicious Apples Commercial-orchard Trial of Unbaited Traps for Monitoring Plum Curculio: 1998 Results Comparison of Six Different Types of Unbaited Traps for Monitoring Plum Curculios in Orchards Two Odor Compounds Hold Promise for Increasing Trap Effectiveness for Plum Curculio Fruit Notes Publication Information: Fruit Notes dSSN 0427-6906) is published the each January, April, July, and October by the Department of Plant & Soil Sciences, University of Massachusetts. The costs of subscriptions to Fruit Notes are $ 1 0.00 for United States addresses and $ 1 2.00 for foreign addresses. Each one-year subscription begins January 1 and ends December 3 1 . Some back issues are available for $3.00 (United States addresses) and $3.50 (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 UMASS EXTENSION 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, expres.sed or implied, concerning the use of these products. USER ASSUMES ALL RISKS FOR PERSONAL INJURY OR PROPERTY DAMAGE. Issued hv UMiiss Extension, Jclin (ierhcr. Direclor, in liirllwranie oj the acts of M(iy S tutd June ^0. 1 914. Utvtass Extension t'ffers equal njifun lunilv in piiii^itiiiis and eiiiplnynietit An Easy and Reliable Procedure for Predicting Scald and DPA Requirement for New England Delicious Apples Sarah A. Weis, William J. Bramlage, and William J. Lord Department of Plant and Soil Sciences, University of Massachusetts The processes which control scald susceptibility and development have been, and are being, studied by many researchers. While the exact causes of scald are not known, it has been observed that a) within a cultivar, late harvested fruit scalds less than early harvested fruit, b) other things being equal, the riper the fruit at harvest, the less they will scald, c) scald susceptibility varies from year to year among fruit, even from a given tree, and d) year to year variation is (at least partly) a function of weather. Cool, sunny weather favors scald reduction, while hot weather may increase scald susceptibility. We have been studying the effects of weather on scald variability, both at the University of Massachu- setts Horticultural Research Center (HRC) and at other New England locations in relation to effects recorded at various locations world-wide. Here we will report on recent findings from the New England studies. Our sites were in Ashfield, Belchertown (HRC), Shelbume, Warren, and Wilbraham, MA, Storrs, CT, Putney, VT, Durham, NH, and Monmouth ME. First, it must be recognized that many of the factors purported to influence scald are related to one another. For example, as the harvest season progresses, the fruit ripen, temperature falls, and the days become shorter. However, these factors relate somewhat differently to one another in different years, and in different locations. Our hope was that if we collected data for many years at the HRC, we could identify some of the specific factors influencing scald susceptibility, and then develop a workable general relationship of preharvest factors to scald susceptibility. The factors we have concentrated on are the following: 1) preharvest cool temperature as the number of days the apples are subjected to sub-50"F weather between August 1" and harvest; 2) a qualitative measure (sunny, partly cloudy, cloudy) of light to which fruit are subjected during the week prior to harvest; 3) fruit maturity at harvest as measured by a starch/iodine test, and 4) harvest date. Because we have been working primarily with Delicious, which are not harvested before late September, we did not experience enough hot (over 80"F) weather near harvest to evaluate that factor, even though we know it could be important. We also have not included a light factor in the reported equations because light measures were only available for the HRC. Development of Prediction Equations Between 1988 and 1993, we harvested 213 one- bushel samples of Delicious from HRC, stored them 20-25 weeks in 32"F air, and then removed the fruit to room temperature for a week before rating them for scald. Scald rating consisted of examining each apple in a box and recording the percent of apples developing scald in that box. A sample was considered very scald- susceptible if more than 60% of fruit in the box developed scald, and was considered scald-resistant if fewer than 20% of the fruit developed scald. It should be noted that any sign of scald was recorded, and some fruit in this latter category would not have been downgraded. The following equations, reported in Fruit Notes 61(4) were generated: Equation 1: If [8.36 - 0.320(harvest date as number of days after 8/31) + 0.0546(number of preharvest days < 50"F) - 0.0550(harvest starch score)] > 0, then fruit are very scald-susceptible. Equation 2: If [-11.8 + 0.414(harvest date as number of days after 8/31) - 0.0298(number of preharvest days < 50"F) - 0.708(harvest starch score)] > 0, then fruit are very scald-resistant. Fruit Notes, Volume 63 (Number 3), Summer, 1998 If a sample fits neither of these categories, it is considered to be of intermediate scald susceptibility. Please note: There was a typographic error in one equation in Fruit Notes 61(4). Those that we present here are the correct equations. The numbers you get from these calculations are called Indices. These Indices were tested in 1995, 1996, and 1997 a) for their ability to accurately place samples in the correct scald category and b) to see if they could be used as guides for application of the scald inhibitor, diphenylamine (DPA). We also are interested in relating the scald potential of controlled atmosphere (CA)-stored fruit to the scald Indices. In 1 996 and 1 997, we stored fruit from the HRC in C A, as well as in air storage. Scald symptoms on the CA fruit were roughly parallel to symptoms on air stored fruit, but affected a significantly higher percent of the fruit. It is possible that this is because CA fruit were stored for 28 to 29 weeks, while air-stored fruit were kept for 25 weeks. In CA, the specific atmosphere should influence scald potential. Our storage atmosphere was 2.8% 0„ <2% CO,. Lower oxygen concentrations ought to reduce scald, but we do not yet have adequate data to address specific questions regarding use of the scald Indices to determine DPA requirements for CA- stored fruit. Ability of Equations to Predict Scald Figure 1 shows how well the 1995, 1996. and 1997 samples fit the equations developed using the pre- 1 995 data. These samples included fruit from Storrs, CT, Putney, VT, Durham, NH, and Monmouth, ME, as well as the MA locations shown in Figure 2. In each category, observed scald was only slightly different from predicted scald, indicating successful application of the equations to estimate scald potential at the time of fruit harvest. Very Scald-susceptible Fruit Figure 2 shows the most scald susceptible samples from Massachusetts, which were those from the first harvest at each location. In all locations and years scald did develop on more than 60% of these fruit. However, responses to DPA varied by location. The n Fruit Predicted to Scald ■ Observed as Predicted 80% ■S 60% E 60% <60% <20% Number of Fruit Expected to Scald >20% Figure 1. Summary of results of scald forecasts: 237 samples, 9 orchards in Five states, 1995, 1996, 1997. Fruit developing any scald-like. Fruit Notes, Volume 63 (Number 3), Summer, 1998 100 nj u (/) < c ^1 5 3 to U. c 0) u a> a. DNo DP A DSOO ppm DP A 11000 ppm DP A 12000 ppm DP A Figure 2. Effects of DPA when more than 60% of fruit were predicted to scald. Percent of fruit showing any scald-like symptoms. highly scald susceptible fruit from the Warren MA site responded to 500 or 1000 ppm DPA to a much greater degree than did the corresponding fruit from other sites. (The only statistical comparison which could be made was with HRC and there the difference was significant at odds of 1:100). Yet overall, 2000 ppm DPA would have to be recommended for confidence that scald would be controlled in these highly scald susceptible fruit. Note that all the fruit samples represented in Figure 2 were harvested before 24 September, and Delicious are not normally harvested that early in New England. Results for samples harvested during the commercial harvest period will be represented below in Figure 3 and Tables 1 and 2. Intermediately Scald-susceptible Fruit When we moved on to consideration of the next category of fniit, those of intermediate scald- susceptibility, we began looking closely at scald severity, as well as whether any scald-like symptoms were evident. Most of the samples of "very scald- susceptible" and "intermediately scald-susceptible" included fruit displaying scald of varying degrees of severity. Scald would clearly render some of the fruit unsaleable in the fresh market. Other fruit, however, displayed scald, or scald-like symptoms, which would not be noticeable to the casual observer, and would not likely downgrade the fruit. The "very scald- susceptible" fruit tended to have enough severe scald that there was no question but that 2000 ppm DPA was needed if the fruit were to be stored for 25 weeks. In the fruit of intermediate scald susceptibility (or less), there often were few fruit with severe scald. In some cases we had difficulty determining if a given apple did or did not have scald. Therefore, we used a rating system which separated fruit showing any discolora- tion that might possibly be scald, from fruit with more Fruit Notes, Volume 63 (Number 3), Summer, 1998 D No DP A, Any Scald DSOO ppm DP A, Any Scald I No DP A, Distinct Scald 1500 ppm DP A, Distinct Scald HRC 1996 HRC 1997 Warren 1996 Warren 1997 Shelb. 1997 Figure 3. Effects of 500 ppm DPA when 20-60% of fruit were predicted to scald (Intermediate category). D Any Scald from Storage D Any Scald after 1 Week ■"Distinct Scald" after 1 Week Figure 4. Development of scald on 'Delicious' apples during one week at room temperature. All DPA treatments are included, and vary by year and location. These data do not relate to treatment; only to develop- ment of scald at room temperature. Fruit Notes, Volume 63 (Number 3), Summer, 1998 Table 1. Percent of fruit on which any scald-hkc symptoms occurred when fewer than 20% ol fruit had been predicted to scald. Percent of fruit with any scaid-hke symptoms if index is: Location Harvest year Number of samples 0-1 1-3 >3 HRC 1995 15 43 9 11 1996 20 / 23 11 1997 13 34 2 0 Ashfield 1996 10 15 12>' 2 Wilbraham 1995 10 - 10 10 Warren 1996 10 24 13 _ 1997 10 - 7 - Shelbume 1997 10 - 18 4 Storrs, CT 1995 5 - - 0 Putney, VT 1996 5 26 34" - Durham, NH 1996 12 31 2 - Monmouth, ME 1996 10 - 23 - Overall 130 30 12 6 ' A "-" indicates that no samples fell into this category. " Sample consists of Dniy one box. distinct external browning which would clearly reduce the grade of the fruit. In Figure 3, the term "distinct scald" is used. This scald was not always severely disfiguring, but it always was clearly noticeable. The term, "Any Scald" is used in Figure 3 (and Figure 4) to denote fruit which showed any scald-like external browning. We did observe differences in the appearance of scald on fruit from different sites. Scald on the HRC Redspur in particular was difficult to rate, because the early harvested fruit tended to have a brownish cast which was not necessarily scald, but did not occur when the higher concentrations of DPA were used; this brownish cast did not appear on fruit from the latest harvests. In contrast, the Sturdeespur from Warren showed scald very clearly if it was present at all. The appearance of scald was also variable among the different striped strains of Delicious we harvested in Ashfield in 1996. In fruit from some trees, the scald stood out, while in fruit from others, scald blended with the fruits' coloring, making it less noticeable. Figure 3 shows the effects of 500 ppm DPA on fruit predicted to be of intermediate scald susceptibil- ity. These fruit all were harvested from September 30 to October 3, when commercial Delicious harvest is expected to begin. From 0 to 3% of the 500 ppm DPA- treated fruit shown in Figure 3 clearly displayed scald. It should be noted for those who find 3% scald too much, that the 1996 HRC Delicious, which show 3% scald in Figure 3, also showed 3% scald following storage when 2000 ppm DPA was applied. Overall, 500 ppm DPA provided adequate .scald control; use of 1 000 to 2000 ppm DPA was not any more beneficial and constituted overu.se of the chemical on these intermediately susceptible fruit. Fruit With Low Scald Susceptibility The second equation presented earlier in this Fruit Notes, Volume 63 (Number 3), Summer, 1998 Tabic 2. Percent ol Iruit on which dislinc t scald ; >vmpl()ins occurred when lower than 207, ol Iruii had been predicted to scald. 'erceni ol Iruit with distinct seal ll ll IIH ex is: Nu mbcr 0 Location Harvest date s implcs 0-1 1-3 >3 HRC 10/8/96 10/15/96 10/2/97 10/9/97 10/14/97 10 10 3 5 5 IB 18 0 0 6 0 Ashfield 10/3/96 10/14/96 5 5 3 1 0 Warren 9/30/96 10/7/96 10/6/97 10/16/97 2 8 5 5 17 1 2 0 Shelburne 10/8/97 10/15/97 5 5 - 11 3 Overall 73 13 7 3 ' A "-" indicates that no samples fell into this category. report identifies fmit of low scald susceptibility. This categoi^ should represent fnait with little or no need for DPA treatment. Identifying these fruit is of particular interest because 1 ) scald control treatment is expensive and inconvenient to apply, and 2) the materials used are not acceptable to an increasing number of markets. Clearly, if 20% of fruit in a lot develop scald, this is unacceptable. However, when we attempted to generate equations for forecasting small amounts, for example, less than 10% .scald, we were unsuccessful; there was simply too much variation in scald development in the vicinity of 10%. We therefore developed the equation to predict under 20% scald because it produced consistent results. If the Index for the "scald resistant" equation (Equation 2) is greater than zero for a given day, location, and starch score, then fewer than 207c of fruit harvested on that day will be predicted to scald after 25 weeks of storage. In addition, the higher the Index, the greater the likelihood that fewerthan 207p of fmit will scald. It also follows that the higher the Index, the less scald one would expect. Tables I and 2 show how many fruit developed any scald-like browning (Table 1) and how many developed "distinct scald" (Table 2). As the Index increased, the amount of scald did indeed decrease. There was some variability among orchards and years, but the trend was there. What this means is that an individual could base scald control measures on personal experience about how much scald had developed on fmit from this site in previous years, and on how much risk the grower was willing to accept, using the tables shown below as a guide. If the Index for Equation 2 is greater than zero, low susceptibility exists. As the number becomes increasingly greater than zero, the risk of scald becomes progressively smaller. A Simple Procedure for Using (he Prediction Equations The equations presented earlier in this article can be intimidating. However, they can be rearranged to produce an easy-to-use system for tracking scald susceptibility during the harvest .season. Fruit Notes, Vokime 63 (Number 3), Summer, 1998 Equation 1 ; Ti ) idenlify highly scald-sustcplihic Iruil (more than 60% likely to scald): 8.36 - In Seplember:[day ol month] x 0.320, or In Oclober:[30 + day of month] x 0.320 + (Number of times (overnights) the temperature was below 50"F] x 0.0546 - [Starch Score (measured on harvest date) of representative fruit] x 0.0550 = INDEX If greater than 0, then more than 60% of fruit likely to scald Equation 2: To identify scald resistant fruit (fewer than 20% likely to scald): -11.8 + In September: [day of month] x 0.414, or In October:[30 + day of month] x 0.414 - [Number of times (overnights) the temperature was below 50"F] x 0.0298 - [Starch Score (measured on harvest date) of representative fruit] x 0.708 = INDEX If greater than 0, then fewer than 20% of fruit likely to scald Example: Delicious were harvested on October 1, the temperature had gone below 50"F on 7 nights since August 1, and the starch score at harvest was 2.2. Using Equal ion I : 8.36 - 3 1 (0.320) + 7(0.0546) - 2.2(0.0550) = Index I so. Index 1 =-1.30 Since the Index is less than zero, less than 60% of the fruit are predicted to scald after storage if no DPA is applied. Using Equation 2: -1 1.8 + 31(0.414) - 7(0.0298) - 2.2(0.708) = Index 2 so. Index 2 = -0.73 Since this Index also is less than zero, then more than 20% of fruit are predicted to scald. Therefore, if these fruit are stored in air at 32"F for 20-25 weeks, between 20% and 60% of the fruit can be expected to scald if no DPA is applied. This scald can be controlled by application of 500 ppm DPA, as seen in Figure 3. Fruit Notes, Volume 63 (Number 3), Summer, 1998 Post-Storage Scald Development One of the concerns about scald is that while it may not appear on fruit on removal from storage or when packed, it may appear later, before fruit are consumed. We had not intended to address this issue, but we would like to report here that we did not see a great deal of scald developing during the week the fruit were kept at room temperature. In 1996 and 1997, we inspected some of the fruit at the time of removal from storage, as well as after 7 days at room temperature. Figure 4 shows that on air-stored Delicious, this post- storage increase in scald was not significant. Note that sometimes more scald was discernible at removal from storage than after a week at room temperature. This is an indication of the difficulty we sometimes had in determining if fruit discoloration was or was not scald. It should be made clear that not all cultivars are like Delicious in this regard. For example, we have observed repeatedly that Cortland may show little or no sign of scald at removal from storage, but after 7 days at room temperature, much scald is present. Conclusions We conclude from this research that forecasting scald susceptibility on air-stored New England Delicious is feasible, and we believe that use of these prediction models can lead to more efficient use of DPA. Results of 3 years of tests of the models developed from 6 previous years' data indicate that using a calendar, a min-max thermometer, and a starch test for maturity, one can use these equations to effectively predict high, intermediate, or low scald susceptibility of Delicious apples harvested at a given site on a given day anywhere in New England. Furthermore, the equations predict the need for DPA: highly susceptible fruit require 2000 ppm, intermedi- ately susceptible fruit require only 500 ppm, and low- susceptibility fruit, particularly those with an Index greater than 1 in Equation 2, have no need for DPA treatment. We offer a system for determining which fruit need 2000 ppm DPA, which will be protected by 500 ppm, and which may be stored without DPA treatment, and with a minimum of concern for post- storage scald development on air-stored fruit. As demonstrated by the data in Tables 1 and 2, it is possible to choose an Index higher than zero in Equation 2 as a demarcation between groups of fruit which receive 500 ppm DPA and those which receive none. This can be especially useful if experience has shown that the fruit from particular trees are especially scald susceptible, and allows flexibility in determining at what point to stop applying DPA. Acknowledgments The authors would like to thank the following people for their assistance in selection and provision of fruit and preharvest information for developing and testing scald prediction models: Dana Clark, Evan Darrow, David Kollas, William G. Lord, Wayne Rice, James Schupp, Joe Sincuk, Tim Smith, and Mark and Bob Tuttle. Technical assistance by Irene Clark and Laura Lee Jones is much appreciated. We would also like to thank the Massachusetts Fruit Growers' Association, the New England Tree Fruit Growers Research Committee, and the Washington Tree Fruit Research Commission for their financial support of this research. vl^ vL* vL* vt» *J> ^Y* 24 inches 3 inches Figure 1 . Trap designs used in the 1 998 field (rial: (a) unbaited trunk-mimicking pyramid trap, placed adjacent to the tree trunk and (b) unbaited tvvig-mimicking cylinder trap, positioned wiihiii ihe tree canopy and kept m a vertical position by a clipped upright twig. Fruit Notes, Volume 63 (Number 3), Summer, 1998 Tabic 1 Relationship between numbers of plum curculio adults captured by unbaited pyramid and twig-mimic traps and percent fruit showing injury by plum curculio across all 16 replicates of each tree size treatment m commercial orchards in 1998. Number of adults captured per sampling period Tree size Sampling period Pyramid Twig mimic Cumulative fruit injury (%) Small Before I'' spray 0.10 0.05 0.1 Between 1 "* and 2"'' spray 0.06 0.09 1.0 Between 2"^ and 3"* spray 0.03 0.02 2.2 After y' spray 0.00 0.00 3.5 Medium Before 1 " spray 0.14 0.10 0.1 Between i " and 2"'' spray 0.18 0.00 0.4 Between 2"^ and 3"* spray 0.02 0.00 0.7 After 3"* spray 0.00 0.00 0.5 Large Before 1 " spray 0.19 0.00 0.1 Between T and 2"'' spray 0.12 0.09 0.6 Between 2"'' and 3"" spray 0.00 0.00 0.7 After 3"' spray 0.00 0.00 0.8 1 positions in 48 blocks of trees in commercial orchards. In each block, one trap was placed immediately adja- cent to the tiTjnk of a perimeter tree, one trap was placed at the midway point between the perimeter tree and the first interior tree, and one trap was placed at the margin of the nearest woods. Data from this study extended our 1996 findings. Irrespective of trap posi- tion, captures of PC in unbaited pyramid traps did not reflect accurately the need for or proper timing of in- secticide spray. A second (preliminary) study was conducted m 1 997 intended to develop a trap to moni- tor PC abundance and activity within tree canopies. From this work, we developed a twig-mnnicking black cylinder trap as an alternative to trunk-mimicking black pyramid traps. In 1998, we repeated and expanded our trial of trap types in the same 48 commercial orchard blocks used in 1997. We compared the performance of black pyramid trunk traps with black cylinder canopy traps as indicators of the potential for PC injury. Materials & Methods As in 1997, traps were placed in six blocks of trees in each of eight commercial orchards. All blocks con- tained 49 trees (seven rows of seven trees each) of mixed cultivars. Of the six blocks in each orchard, two were considered high tree density (M.9 rootstock), two medium tree density (M.26 rootstock), and two low tree density (M.7 rootstock). Prior to bloom, we placed two unbaited black pyra- mid traps in each of the 48 blocks, each trap adjacent to the trunk of a perimeter tree (the most effective postion for traps of this type). We also placed two unbaited black hollow cylindrical (3 inches diameter x 12 inches height) twig-mimic traps in perimeter trees of each block, kept in a vertical position within the canopy by a clipped twig (Figure I ). In early May 1998, when all traps were placed, we knew of no at- tractive odor which could be used in conjunction with these traps (sec study of odors attractive to PC, this 10 Fruit Notes, Volume 63 (Number 3), Summer, 1998 Prior to 1st 1st to 2nd 2ncl to 3rd Insecticide Application After 3rd D Pyramid □ Cylinder ■ % Injury Figure 2. Captures of plum curculios per trap for two unbailed trap types and percent fruit injured by plum curculio before the first insecticide application, between the first and second applications, between the second and third issue). Evei7 3-4 days from petal fall until five weeks af- terward (the peiiod of fruit susceptibility to PC injury), we examined 15 fruit on each of the seven perimeter trees of each block. The number of PC egglaying scars was recorded, and scarred fruit were allowed to re- main on the tree. At each sample date, captures of PC were recorded for each trap, and all captured PCs were removed from traps and returned to the laboratory. All blocks were treated according to the growers' stan- dard orchard management practices, receiving two to three applications of Guthion or Imidan at 9- to 14-day intervals beginning at petal fall. Results We combined data for the two blocks of each plant- ing density for each orchard and categorized fmit in- jury and trap capture data according to spray interval. The data (Table 1, Figure 2) show that PC egglaying injury was very light in all blocks prior to the first in- secticide application. Injury to fruit increa.sed sharply between the first and second spray, and increased fur- ther between the second and third spray. Interestingly, PC damage to fruit subsided in most blocks after the third spray, but in a few blocks of high density trees, there was a flurry of PC egglaying activity in mid-June, after the final spray. Captures of PCs by unbaited black pyramid traps were greatest prior to the first insecticide application, decreased moderately between the first and second spray, and decreased substantially after the second spray (Table I, Figure 2). In fact, in several blocks which continued to accumulate substantial PC damage after the second insecticide application, not a single PC was captured during this interval by unbaited pyramid traps. A similar trend occurred for captures within the tree canopies by unbaited black cylinder traps (Table I , Figure 2). Conclusions Results of the 1998 field trial of unbaited PC traps confirm our findings of 1 996 and 1 997. For commer- cial use, captures of PC in unbaited trunk-mimic or twig- mimic traps are not accurate indicators of the need for or timing of insecticide applications. If development of traps for other species related to PC (such as cotton boll weevil and sugar cane weevil) can be used as a guide, then the most effective trap for PCs should be Fruit Notes, Volume 63 (Number 3), Sui 1998 11 baited with a combination of attractive pheromone and host odor (neither of which was available at the start of the 1998 season). For 1999, we intend to maximize the visual attractiveness of traps, and incorporate use of attractive odor lures. Acknowledgments This work was supported by State/Federal IPM Funds, the New England Tree Fruit Growers Research Committtee and SARE Grant #97 LNE 97-90 (USDA 96-COOP- 1-2700). We are grateful to the eight grow- ers that participated in this study: Bill Broderick, Dana Clark, Dave Chandler, Dave Cheney, Dave Shearer, Joe Sincuk, Tim Smith and Mo Tougas. vL* vL* vl* »X* vj> •T* -T* •?• -T* -T* Comparison of Six Different Types of Unbaited Traps for Monitoring Plum Curculios in Orchards Ronald Prokopy, Shawn Mclntire, Jonathan Black, Max Prokopy, and Tracy Leskey Department of Entomology, University of Massachusetts We can conceive of at least four approaches to monitoring entry of plum curculio (PC) adults into or- chards and orchard trees that might be useful in pre- dicting need and time to spray for PC control. These approaches are: (1) monitoring flights of PCs exiting from overwintering sites in areas bordering orchards, (2) monitoring flights of overwintering PCs into orchard trees, (3) monitoring PCs entering orchard trees via climbing tree trunks, and (4) monitoring PCs present in orchard tree canopies. In 1998, we evaluated each of these four approaches using unbaited traps placed near or in four small blocks of apple trees. Materials & Methods Two of the four blocks of trees (one at the Univer- sity of Massachusetts Horticultural Research Center and one in Deerfield, MA) received no insecticide to control PC. Each of the other two blocks one at the Horticultural Research Center and one in Conway, MA) received two sprays of Imidan: one at petal fall and the other two weeks later. All trees were on either M.7 or M.26 rootstock. To monitor exit flights of PCs from overwintering sites, we positioned unbaited Tangletrap-coated clear Plexiglas traps (2 feet by 2 feet), intended to represent empty space, 6 feet from edges of foliage of woods that bordered each block. Each of the four traps per block was fastened vertically to a wooden pole. The center of each trap was 3 feet above ground. The sticky-coated side faced the woods. To monitor flights of overwintered PCs into orchard trees, we positioned three different types of unbaited Tangletrap-coated traps 1 8 inches away from edges of canopies of orchard trees and facing woods. The three trap types were: a 2 foot by 2 foot square of clear Plexiglas, a 2 foot by 2 foot square of plywood painted green to mimic tree foliage, and a 1 foot by 4 foot tall 12 Fruit Notes, Volume 63 (Number 3), Summer, 1998 Tabic I, Numbers ol plum cuaulios captured by each type ol Irap m blocks ol unsprayed and sprayed apple trees May I- June 19, 199X Trap type Number ol replicates Unsprayed Sprayed Number ol curculios per trap* Unsprayed Sprayed Sticky clear traps at edge of woods Sticky clear traps at edge ot apple trees Sticky green traps at edge of apple trees Sticky black traps at edge of apple trees Black pyramid traps at apple tree trunks Black cylinder traps in apple tree canopies 8 8 0.5 c 1.6 a 8 8 2.6 b 1.0 a 8 8 1.9 b 0.8 a 8 8 0.3 c 0.4 a 16 16 26.3 a 1.5 a 16 16 2.2 b 0.5 a Numbers in the same column followed by a different letter are significantly different at odds of 19:1. rectangle of plywood painted black to mimic a tree trunk. Each trap was attached vertically to a wooden pole, with trap center 3 feet above ground. The sticky- coated side faced the woods. Each block contained four traps of each type, arranged so that traps alter- nated in type. To monitor PCs entering orchard trees by climbing tree trunks, we placed one unbaited black pyramid trunk-mimicking trap (described in the preceding ar- ticle) next to the trunk of each of eight perimeter apple trees bordering woods in each block. To monitor PCs present in orchard tree canopies, we placed one unbaited hollow black cylinder twig-mim- icking trap (described in the preceding article) in the canopy of each of the eight other perimeter apple trees (not the same trees having pyramid traps) bordering woods in each block. The black cylinder traps were maintained in vertical position by placing each one over a clipped vertical branchlet about mid-way between the edge and center of the tree canopy and at mid- height of the canopy. All traps were emplaced during the pink stage of apple bud development and were monitored twice weekly for eight weeks for captured PCs. On each monitoring day, beginning at petal fall, 1 2 fruit on each of 12 perimeter trees per block were examined for evidence of PC damage. Damaged fruit were allowed to remain on the tree. Results In the unsprayed blocks of apple trees, significantly more PCs (at least 10 times more) were captured by black pyramid traps next to apple tree trunks than by any other type of trap (Table 1 ). Sticky clear traps and sticky green traps at edges of apple tree canopies, along with black cylinder traps in apple tree canopies, cap- tured about the same number of PCs and significantly more than the sticky clear traps at edges of the woods or sticky black traps at edges of apple tree canopies (Table I ). Despite the large number of PCs captured by the pyramid traps, captures by these traps were not useful in predicting occurrence of PC injury to fruit. Thus, increases in captures by sticky clear traps and sticky green traps at edges of apple tree canopies, but not increases in captures by any other types of traps, were positively correlated with increases in fmit dain- age caused by PCs during the monitoring period. In the sprayed blocks of apple trees, there were no significant differences among any of the trap types in numbers of PCs captured, although sticky clear traps at edges of woods and black pyramid traps next to apple tree trunks captured the most PCs numerically, and sticky black traps at edges of apple tree canopies and black cylinder traps in apple tree canopies captured the fewest PCs numerically (Table I). Increases in captures by any of the trap types did not correlate sig- Fruit Notes, Volume 63 (Number 3), Summer, 1998 nificantly with increases in fruit damage caused by PCs during the monitoring period. Compared to captures of PCs by traps in unsprayed blocks, captures in sprayed blocks were ( 1 ) just as great for PCs caught by sticky clear traps at edges of woods (this is an expected finding because orchard sprays should not interfere with emigration of PCs from woods), (2) fewer by an average of about 50% for PCs caught by all three types of sticky traps (combined) at edges of apple tree canopies, (3) fewer by about 80% for PCs caught by black cylinder traps in apple tree cano- pies, and (4) fewer by about 95% for PCs caught by black pyramid traps at apple tree trunks. We do not know why orchard sprays apparently interfered more with captures of PCs by pyramid traps at tree trunks than captures by cylinder traps in tree canopies. apple tree canopies better coincided with periods of increase in fruit injury than did periods of increase in captures of PCs by black pyramid traps at tree trunks. Disappointingly, in the sprayed blocks, in no case did periods of increase in captures of PCs by any of the trap types tested in 1 998 correlate positively with peri- ods of increase in fruit injury. We believe that a more user-friendly form of a sticky trap placed at the edge of an apple tree canopy to capture PCs flying into apple trees and/or a modi- fied form of a cylinder trap placed in an apple tree to capture PCs active within the canopy hold the most promise as effective monitoring devices. We further believe that neither of these trap types can succeed in monitoring accurately the presence of PCs in sprayed orchards unless they are baited with attractive odor. Conclusions Acknowledgments The findings from these studies in unsprayed blocks of apple trees in 1998 are similar to findings reported in Fruit Notes 63(1) on studies in an unsprayed block of apple trees in 1997. In both studies, periods of increase in captures of PCs by sticky clear traps at edges of This work was supported by USDA Hatch funds and the New England Tree Fruit Growers Research Committee. We thank Jim Hardigg for allowing us to use his orchard for part of this work. vl^ *X* *X* *^ *X* 0^ 0^ *Y* *X* *T* 14 Fruit Notes, Volume 63 (Number 3), Summer, 1998 Two Odor Compounds Hold Promise for Increasing Trap Effectiveness for Plum Curculio Tracy Leskey, Max Prokopy, Anthea Yanopolous, Margaret Young, Brian Hogg, Fidelma Boyd, and Ronald Prokopy Department of Entomology, University of Massachusetts Larry Phelan Department of Entomology, Ohio State University There has been no trap developed for plum curculios (PCs) that successfully detects the beginning of PC activity in orchards each spring. Traps for other species of weevils such as the cotton boll weevil and the sugar cane weevil use a combination of attractive compounds present in host plant odors and weevil-pro- duced pheromones to increase trap effectiveness. PCs are attracted to odors produced by their host fruit over short distances as reported in the 1 996, 1 997, and 1 998 Winter Issues of Fruit Notes. Under field conditions, PCs are attracted to host fruit odors at distances up to 3 yards. Eller and Bartelt of Illinois found that male PCs produce an aggregation pheromone called grandisoic acid. Therefore, we decided to screen 18 of the 19 compounds present in plum odor that were identified by Larry Phelan's lab at Ohio State Univer- sity in hopes of finding attractive compounds that could be used in combination with grandisoic acid to improve trap performance. Compounds were tested in the labo- ratory and in the field to identify those that were most attractive to PCs. Materials & Methods A profile of volatile compounds that comprises the odor of freshly picked plum fruit (2 weeks after bloom) was completed in the laboratory of Larry Phelan using a gas chromatograph and mass spectrometer. The compounds listed in Table 1 plus phenol were identified as comprising plum odor. All compounds were evalu- ated as potential attractants for PCs in laboratory and field experiments with the exception of phenol, which is highly toxic to mammals. Compounds were tested in the laboratory at three concentrations (1, 0.1, and 0.01%) and in the field at two concentrations (5 and 0.5%). PCs used in laboratory bioassays were collected from unsprayed wild plum and apple trees. For all labo- ratory tests, PCs were starved 24 hours prior to test- ing. Tests were conducted at the beginning of dark- ness. A 75 ul aliquot of the compound (the treatment) was pipetted onto a small cotton wick placed next to one of the two pipette tips that served as ports into a Petri dish test chamber. Either 75 ul of hexane or wa- ter (depending on the solubility of the compound) was used as a solvent control and was pipetted onto a sec- ond cotton square placed next to the other pipette port. Handling of PCs was kept to a minimum. A single PC was placed gently in the center of each Petri dish test chamber. Each time a specific compound was tested, 12 PCs were tested singly in individual dishes and kept together on a tray. Dishes were then moved immedi- ately to the testing room. All bioassays lasted 2 hours, and all compounds were tested at least four times at each concentration ( 1 2 individual PC per tray x 4 trays = 48 individual PCs tested per compound and concen- tration). To measure the level of attraction to a par- ticular compound (the treatment), we used a Response Index (RI). The RI was calculated by subtracting the number of PCs responding to the control (C) from the number responding to the treatment (T), dividing this amount by the total number of PCs tested each time, and multiplying by one hundred. Thus RI = [(T - C) / 12] x 100. The greater the RI value, the more attrac- Fruit Notes, Volume 63 (Number 3), Summer, 1998 15 Tabic I. Laboratory response indices (RIs) ol plum curculio ailulls lo individual odor compounds al three concentrations in solvent Compound 1% 0. 1 % 0.01% Bcnzaldehyde -28 -13 0 Benzonitrile -29 -10 12 Biphenyl -33 -10 -4 Diphenyl methane -6 -8 19 Ethyl acetate 6 -6 13 Ethyl butyrate 15 6 8 Ethyl isovalerate -4 13* 24* 2-Hexenal -21 -17 -13 2-Hexanol -4 8 8 3-Hexanol 0 0 -2 2-Hexanone 2 10 0 3-Hexanone 17 -10 -10 3-Hydroxy-2-butanone -17 -6 -17 Isopropyl acetate -13 -4 4 Limonene -7 4 18* Linalool -27 -6 13 2-PentanoI -2 13 0 2-PropanoI 0 0 -4 * Significantly different from zero at odds of 19 to 1 . live was the stimulus. Ifi the field, green boll weevil traps were placed on the ground beneath the canopy of unsprayed apple trees approximately one yard from the trunk at each cardi- nal point. Compounds being tested were diluted in min- eral oil to a 5% concentration and applied to a 3-inch piece of cylindrical cotton wick that was wrapped in aluminum foil and attached by a wire to a boll weevil cone-shaped trap top. One end of the wrapped foil cylinder was clipped to permit dissemination of odor. For each tree, two traps were baited with an individual compound and placed at north and south positions, and two traps baited with mineral oil only (the control) were placed at east and west positions. After 48 hours, the number of PCs captured in each of the traps was counted, traps were baited with fresh wicks, and posi- tions of traps were rotated around the tree so that com- pound-baited traps were in east-west positions and control-baited traps were in north-south positions. This procedure was repeated 12 times. A .second experi- ment was conducted using only the most and least at- tractive compounds at two concentrations: 5 and 0.5%. In this experiment, procedures were nearly the same as in the first experiment except this procedure lasted only 24 rather than 48 hours, and was repeated only 10 times. To measure the attractiveness of a particular compound, a Field Response Index was created by subtracting the number of PCs responding to the con- trol (C) from the number responding to the treatment (T), dividing by the total number of PCs captured in the treatment and control traps, and then multiplying by 100. Thus, RI = 1(T - C )/ (T + O] X 100. The greater the RI, the more attractive the compound. Results Laboratory Results. For compounds at 1 %, none of the RI values were significantly (Table I). AtO. I'^f, ethyl isovalerate jiiovided a positive and significant RI. Other compounds did not result in significant RIs at 16 Fruit Notes, Volume 6.^ (Number 3), Summer, 1998 Tabic 2 I'lc'ld response indices (KIsj ol plum cuiciilio adulls lo (iilor cumpouruls :il conccnlralions ol 5 "/< . anil ().5'/f in mineral oil. Compound Experiment (5%) Expcrimcnl 2 5% 0.5% Benzaldchyde 13 Benzonitriie 33 Biphenyl -27 Diphenyl methane 0 Ethyl acetate 9 Ethyl butyrate 14 Ethyl isovalerate 71* 2-Hexenal 8 2-Hexanol -13 3-Hexanol -67 2-Hexanone -18 3-Hexanone -39 3-Hydroxy-2-butanone 26 Isopropyl acetate -13 Limonene 38* Linalool 10 2-Pentanol -25 2-Propanol -31 80* 25 50 20 100* 26 Significantly different from zero at odds of 19 to 1. 0.1%. At 0.01%, ethyl isovalerate and limonene re- sulted in positive and significant RIs, and all others re- sulted in nonsignficant RIs. Field Results. In the first field experiment, the only significant RIs were recorded for 5% solutions of ethyl isovalerate and limonene (Table 2). In a second set of experiments testing ethyl isovalerate and limonene (the most attractive compounds from the first field ex- periment) and 3-hexanol (the least attractive compound from the first field experiment), significant RIs were recorded for 5% solutions of ethyl isovalerate and li- monene, but not 3-hexanol at 5% or any of the three at 0.5% (Table 2). Conclusions Data obtained from our laboratory and field ex- periments are in agreement. Two compounds, ethyl isovalerate and limonene, proved significantly attrac- tive to PCs under the test conditions described here. For the future, we plan lo test these two attractive com- pounds alone or in combination with male-produced pheromone as baits for the pyramid traps described in 1997 and 1998 Winter Issues of Fruit Notes, and also for alternative trap designs including a circle trap and a twig-mimicking black cylinder trap to see if trap effi- cacy is increased, A ckn ow ledge m ents This work was supported by USDA Hatch funds and by the New England Tree Fruit Growers Research Committee. We thank Jim Hardigg for allowing us to use his orchard for part of this work. vt* vl> *!>* vl>* vT>* y^ *^ *^ #^ #^ Fruit Notes, Volume 63 (Number 3), Summer, 1998 17 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 1 SERIAL SECTION UNIV OF MASSACHUSETTS LIBRARY AMHERST MA 01003 Account No. 2-22914 Morr Fruit Notes Prepared by the Department of Plant & Soil Sciences. UMass Extension, U. S. Department of Agriculture, and Massachusetts Counties Cooperating. Editors: Wesley R. Autio and William J. Bramlage iiMIW AC lAACC u i * I V . w r iv 1 /\ o ^ . Volume 63, Number 4 FALL ISSUE, 1998 Table of Contents Structural Refinement of Spheres for Controlling Apple Maggot Evaluation of Varying Doses of Different Toxicants for Use on Spheres to Control Apple Maggot Flies Fate of Apple Maggot Flies Alighting on Pesticide-treated Spheres in a Commercial Apple Orchard Evaluation of Scab on Fruit of New Apple Cultivars Testing Various Methods of Timing Summer Fungicides On-farm 1PM Education: Displays and Self-guided Tours Fruit Notes Publication Information: Fruit Notes (ISSN 0427-6906) is published the each January, April, July, and October by the Department of Plant & Soil Sciences, University of Massachusetts. The costs of subscriptions to Fruit Notes are $10.00 for United States addresses and $12.00 for foreign addresses. Each one-year subscription begins January 1 and ends December 3 1 . Some back issues are available for $3.00 (United States addresses) and $3.50 (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 UMASS EXTENSION 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. 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Fruit Notes, Volume 63 (Number 4), Fall, 1998 1 Send this form and your check by July 15, 1999. Make check payable to: UNZVERSHY OF MASSACHUSETTS. Send this form along with payment to: Fruit Notes 205 Bowditch HaU University of Massachusetts Amherst, MA 01003 Fruit Notes, Volume 63 (Number 4), Fall, 1998 Structural Refinement of Spheres for Controlling Apple Maggot Starker Wright, Ronald Prokopy, and Xing Ping Hu Department of Entomology, University of Massachusetts Currently, there is no clear indication of the extent to which organophosphate insecticides will continue to be labeled for use in commercial apple production. If recent state and federal decision- making trends can be used as a guide for future action, then we should prepare ourselves for the possibility that the pre-harvest interval for orga- nophosphate insecticides (particularly azinphosmethyl) may be lengthened considerably, possibly to 60 days or more. The purpose for do- ing this would be to eliminate all detectable resi- due on fruit at harvest, a principal aim of the Food Quality Protection Act (FQPA). This same sce- nario could well apply to permissible use patterns of carbamate insecticides, the only other class of labeled materials known to be at least moderately effective against apple maggot. For many years (as reported in Fruit Notes), we have conducted studies aimed at development of behavioral control of apple maggot using traps as a substitute for insecticide applications. These studies have led to the development of pesticide- treated spheres as a potential alternative in com- mercial apple production. Such spheres are in- tended to be inexpensive, easy to use, safe to handle, and to offer reliable control of apple maggot. In 1997, we began an extensive comparison of odor-baited sticky coated spheres, pesticide-treated wooden spheres, and biodegradable pesticide- treated spheres for direct control of apple maggot flies (AMF) in commercial orchards. This study was conducted in eight commercial apple orchards, each containing four blocks of 49 trees each. In each orchard, one block received three insecticide sprays for AMF control, one block was surrounded by sticky-coated wooden spheres, one block was surrounded by pesticide-treated wooden spheres, and one block was surrounded by biodegradable pesticide-treated spheres. The results [Fruit Notes 62(4)] showed that pesticide-treated biodegradable spheres performed as well as sticky spheres and considerably better than pesticide-treated wooden spheres on which we were unable to preserve an effective level of feeding stimulant. None of the three trap types provided quite the level of AMF control as 3 insecticide sprays did. In the case of biodegradable pesticide-treated spheres, compro- mising factors were that some spheres cracked pre- maturely, some were eaten by birds and/or rodents, and some were overgrown by fungi, reducing the number of effective spheres comprising the barrier to fly immigration into some blocks. Despite short- comings, our 1997 findings were encouraging, as all sphere types performed well under high pest pressure in commercial orchards. Our goal for 1998 was to conduct experiments leading to improved versions of pesticide-treated spheres and to evaluate these for direct control of AMF. Here we report on structural refinements of both pesticide-treated biodegradable spheres and pesticide-treated wooden spheres. Materials & Methods To maximize effectiveness and durability of bio- degradable spheres, we addressed each of the short- comings of such spheres experienced in 1997: 1 ) To combat premature breakdown of biodegrad- able sphere bodies, we evaluated seven differ- ent structural compositions. We assessed each body type for drying ti-ne, hardness, and resis- tance to humidity. 2) To ease deployment, we replaced the trouble- some string hangers with wire hooks, and used a metal disc beneath each sphere to support the weight of the sphere body. 3) To prevent consumption of spheres by rodents, Fruit Notes, Volume 63 (Number 4), Fall, 1998 we evaluated five different fornuilations of hot pepper additive, whose active ingredient (cap- saicin) is known to deter rodent feeding. 4) To reduce damage caused by birds, we evalu- ated black spheres versus red spheres. 5) To inhibit growth of fungi on the surface and in the body of the spheres, we incorporated 1.0% sorbic acid mto the ingredients of each sphere body as a preservative. In an attempt to extend the residual activity of sucrose as the necessary feeding stimulant on pes- ticide-treated wooden spheres, each sphere was fit- ted with a 1.25-inch plastic dish containing 15 grams of molten sucrose, which cooled and hard- ened after pouring. In concept, as these spheres are exposed to rainfall, the sphere surface is re- treated with a dilute sucrose solution from the res- ervoir atop the sphere. If there was a constant release of sugar to the sphere surface under condi- tions of rainfall, then ideally each sphere would have enough sucrose to replenish the active supply through several inches of rainfall. In addition to structural modifications of pes- ticide-treated spheres, we increased the level of imidacloprid (Merit formulation, 75 WP) from 1.5% to 2.0% active ingredient to extend late-sea- son effectiveness of the spheres (see following ar- ticle), l-'or all pesticidc-treated spheres, the toxi- cant (iniKiacloprid) was applied to the spheres at 2.0% a.i. in Glidden Latex Gloss Enamel paint. In 1998, we evaluated odor-baited sticky spheres, modified wooden pesticide-treated spheres, and im- proved biodegradable pesticide-treated spheres in 32 commercial orchard blocks. Blocks used in 1998 were the same blocks used in 1997; spheres were emplaced in eight commercial orchards, each con- taining four blocks of 49 trees. Each block receiv- ing spheres was surrounded by 26 spheres of the same type at a 5-meter interval, and each sphere was baited with a vial of butyl hexanoate. Results In laboratory tests under conditions of artifi- cial rainfall, the following body composition proved the most durable for biodegradable spheres: 16% wheat flour, 16% pre-gelatinized corn flour, 5% corn starch, 20% powdered sugar, 13% granu- lated sugar, 7% corn syrup, 8% glycerol, and 9% water. Spheres of this composition were found to harden very quickly and were much more resis- tant to premature breakdown than the body style used in 1997. Of materials tested to deter rodent feeding, the best product was African cayenne pepper powder, Table 1. Control of apple maggot flies by odor-baited sticky-coated wooden spheres, wooden pesticide-treated spheres (PTS), biodegradable pesticide-treated spheres, or three applications of azinphosmethyl in 32 blocks of medium-size apple trees in eight commercial orchards in 1998. Mean no flies captured per block Mean 0/ /o Treatment Perimeter tra ps Interior monitoring traps injured fruit per block* Sticky spheres Wooden PTS Biodegradable PTS Insecticide sprays (3) 1702.5 137.3 210.8 272.4 123.6 0.70 2.93 0.77 0.59 * Values here represent injury during five sampling periods (every 2 weeks from mid-July tiirough harvest), during which 100 fruit per block were sampled on each sampling date. Fruit Notes, Volume 63 (Number 4), Fall, 1998 mixed at 5% with sphere body ingredients. Sub- sequent lab and field tests indicated that AMF were completely unaffected by the pepper additive, whereas damage to spheres by rodents was greatly reduced or eliminated. Field assays revealed that bird damage to biodegradable spheres was substan- tially reduced by painting spheres black, thus mak- ing them less visually attractive to foraging birds. Fortunately, AMF are equally attracted to black and red spheres. Given this early-season progress, we were confident in the potential of biodegrad- able pesticide-treated spheres to offer AMF con- trol comparable to sticky-coated wooden spheres. Data trends established in the 1997 comparison of sphere types held true in 1998. Results for 1998 (Table 1) showed that biodegradable pesticide- treated spheres performed about as well as sticky spheres (0.77% and 0.70% injured fruit, respec- tively) and nearly as well as three insecticide appli- cations (0.59% injured fruit). As in 1997, wooden pesticide-treated spheres released the entire sucrose supply too quickly, and did not perform as well (2.93% injured fruit). Unfortunately, many bio- degradable spheres required replacement after about a month of field exposure due to softening and bursting of the sphere bodies. Conclusions Pest pressure in commercial orchards in 1998 was even higher than in 1997 (an average of 1702 AMF per block captured by the 26 sticky spheres per block). Despite shortcomings of biodegrad- able and wooden pesticide-treated spheres, we are nonetheless encouraged by the 1998 results, par- ticularly by the performance of biodegradable spheres under very high pest pressure. With fur- ther structural modifications and pending commer- cial production of biodegradable sphere bodies, we are becoming increasingly confident in recommend- ing use of sphere traps in place of insecticide sprays for control of AMF in commercial orchards. As discussed m the Introduction, development of al- ternatives for control of AMF is gaining emphasis given the implications of FQPA implementation. For the 1999 field season, we will again com- pare the efficacy of sticky-coated wooden spheres, pesticide-treated wooden spheres, and pesticide- treated biodegradable spheres for direct control of AMF. In 1999 field trials, pesticide-treated wooden spheres will be augmented with a new sucrose-re- lease mechanism, and biodegradable spheres used in 1999 will be commercially-made prototypes, produced by a private corporation under USDA supervision. Acknowledgments This work was supported by state/federal IPM funds, a grant from the Washington Tree Fruit Re- search Commission, a USDA SEA CSREES grant (# 97-34365-5043), and a SARE grant (USDA 96- COOP-1-2700). As always, we are grateful to the seven growers who participated in this study: Bill Broderick, Dana Clark, Dave Chandler, Tony Lin- coln, Wayne Rice, Dave Shearer, and Tim Smith; and to our field technicians: Jon Black, Joel Benton, Anthony Minalga, Stephen Lavallee, Eric Gemborys, and Max Prokopy. \f^ Kf^ Kf^ \r %f •"k ^C *C ^C *'k Fruit Notes, Volume 63 (Number 4). Fall. 1998 Evaluation of Varying Doses of Different Toxicants for Use on Spheres to Control Apple Maggot Flies Ronald Prokopy, Starker Wright, Brad Chandler and Xingping Hu Department of Entomology, University of Massachusetts In the 1997 Fall issue of Fruit Notes, we re- ported that imidacloprid was a promising alterna- tive to dimethoate as a toxicant for application to pesticide-treated spheres for controlling apple mag- got flies (AMF). We also reported that imidacloprid at 1.5% active ingredient (a.i.) in paint afforded longer residual activity than imidacloprid at 0.5% a.i. in paint, and that a Merit 75 WP formulation of imidacloprid in paint was more effective than a Provado 1.6 F formulation in paint at 0.5% a.i., though not at 1.5% a.i. The unusually large numbers of AMF in some Massachusetts commercial apple orchards in 1998 allowed early-season direct observations of the behavior of AMF after alighting on imidacloprid- treated spheres. These observations suggested to us that by increasing the dose of imidacloprid on spheres beyond the 1.5% active ingredient used heretofore, we might be able to capitalize on con- tact-type toxicity of imidacloprid, thus diminish- ing the need to maintain feeding stimulant (sucrose) on the sphere surface. Such a high-dose approach was thought previously to be impractical, owing to the handling risk associated with higher doses of our originally-adopted toxicant, dimethoate. Here, we report on 1998 studies of AMF re- sponses to four different doses of imdacloprid in latex paint, with and without the addition of su- crose as feeding stimulant. We also report on AMF responses to three new candidate toxicants: spinosad, sugar ester, and fipronil. All three, like imidacloprid, are considered to be comparatively safe for handling by humans. Materials & Methods In our first test, we painted the inside surface of small plastic cups with a mixture of Glidden Red Latex Gloss Enamel paint and either 0.1, 0.5, 1.0, or 5.0% a.i. of one of the following potential toxicants: imidacloprid (Merit 75 WP), spinosad (SpinTor 22.8 F), sugar ester (SCO 3483, 100%), or fipronil (Regent 80 WG). No sugar was added to any mixture. After the mixture dried, 10 AMF were confined in each of two cups of the same treat- ment type for 10 minutes, following which AMF were transferred to clean cups supplied with food and water. Mortality was assessed after 72 hours. For our second test, we focused on the two toxicants that showed the most promise in the first test: imidacloprid and fipronil. Each of these toxi- cants was evaluated at 2, 4, 8, and 16% a.i. in Glidden Red Latex Gloss Enamel paint (no sugar added) applied to wooden spheres. After drying, spheres were hung in orchard trees and returned to the laboratory after 3, 6, 9, or 12 weeks for evaluation of toxicity to AMF. For evaluation, 30 AMF were placed individually on a sphere of each treatment type and allowed to remain 10 minutes, following which AMF were transferred to small, clean cups supplied with food and water. Mortal- ity was assessed after 24 hours. Half of the spheres of each treatment type received a 20% sucrose so- lution just prior to testing. The other half received no sucrose. For our third test, we again focused on imidacloprid and fipronil, but in this experiment, we evaluated the behavior of sphere-exposed AMF shortly after removal from spheres. Spheres were treated with 2.0% a.i. imidacloprid or fipronil in Glidden Red Latex Gloss Enamel paint and exposed for 3 weeks in orchard trees. Just before testing, all spheres received a 20% sucrose solution. For each treatment, 32 AMF were placed individually on a sphere and allowed to feed for up to 10 min- utes. One hour after feeding, each fly was trans- Fruit Notes, Volume 63 (Number 4), Fail, 1998 fcrred to a leaf nc.ir the center of the canopy of a small non-frinting fig tree and allowed to forage freely for 15 muiutes. The niinibcr of leaves vis- ited was recorded. Immediately thereafter, each fly was placed on a ripe hawthorn fruit, and pro- pensity to lay an egg was observed. Results In our first test, conducted with no sugar added, 20, 80, and 100% of AMF died by contact toxic- ity alone when confined in plastic cups treated with 0.5, 1.0, and 5.0% a.i., respectively, of imidacloprid in paint (Table 1). None died at 0.1% a.i. of imidacloprid. The only other toxicant causing AMF mortality was fipronil, where 107o of AMF died by contact toxicity alone after exposure to 5.0% a.i. of this material. Even though both spinosad and sugar ester conceivably might be somewhat toxic to AMF if ingested together with sugar or when applied alone to foliage, neither material caused any toxicity by contact alone when mixed in latex paint. In our second test, results showed that in the presence of sucrose, mortality of AMF was consis- tently high (70% or more) on spheres treated with imidacloprid, even after 12 weeks of sphere expo- sure to outdoor weather in orchard trees (Figure 1). Provided that sugar was present, the dose of imidacloprid had little effect on AMF toxicity, with 2% a.i. being about as toxic as 16% a.i. at all evalu- ation periods (3, 6, 9, and 12 weeks). In contrast, in the absence of sucrose, toxicity of imidaclcjprid- treated spheres to AMF did not exceed 15% at 12 weeks of orchard exposure, even at the highest dose tested (16% a.i.). Results for fipronil roughly par- alleled those for imidacloprid at 3, 6, and 9 weeks of orchard exposure. However, at 12 weeks, even in the presence of sucrose, lower doses of fipronil (2 and 4% a.i.) yielded no more than 40% mortal- ity of AMF. A dose of 8% fipronil was required before toxicity approached that of 2% imidacloprid at 12 weeks. In the absence of sucrose, toxicity from contact with fipronil, as with imidacloprid, was virtually nil at 12 weeks, irrespective of dose. In our third test, results showed that only a minority of AMF exposed to spheres treated with 2% a.i. imidacloprid and sucrose were capable of foraging within a plant canopy after exposure, and of those that could forage, an average of only one leaf was visited for every three flies tested (Table 2). Moreover, only 6% of assayed AMF attempted to oviposit in a hawthorn fruit. In contrast, al- most all AMF exposed to spheres treated with 2% a.i. fipronil were capable of foraging within a plant canopy, with the average number of leaves visited nearly equaling the number visited by AMF that were exposed to spheres lacking pesticide. Also, Table 1. Fate after 72 hours of apple maggot flies confined for 10 minutes in plastic cv with insecticide in latex paint (no sugar added). ps coated Insecticide Active ingredient (a.i.) concentration (%)* 0.1% a.i 0.5% a.i. 1.0% a.i. 5.0% a.i. Imidacloprid (Merit 75 WP) Fipronil (Regent 80 WG) Spinosad (Spintor 22.8 F) Sugar Ester (SC03483 100% a.i.) 0 0 0 0 Mortality (%) 20 80 0 0 0 0 0 0 100 10 0 0 For each dose of each insecticide, ten flies were confine d in each ot two cups for 10 minutes. Fruit Notes, Volume 63 (Number 4), Fall, 1998 I'lguic I rerCL'Ml iiiDilalilv nl .ipplc in.iggol llics cxpuscil Id wooiicn pcsliculc-lrcalcd spheres siili|ccle(l lo ^, (). ') or 12 weeks dI liekl exposure aller UealnienI w rlli varying conceiilralrons ol insectieide. I'Ires were lesled on spheres with and without suizar added lo llic surface prror lo lestinc. 100 c 60 o E >- 40 20 3 weeks exposure % active ingredient 16 100 ' ^ 80- ? 60 o E >■ 40 ^ 20 0 6 weeks exposure H 4- 1 ' ' ' 1 -"■'•■*■ + " +' =^^ , - - ' ^^^^ -^--rrrrr _.. 2 4 8 % active Ingredient 16 100 - >- 80- 1 60 E >. 40 ■ ^ 20- 0 - 9 weeks exposure _.--*' 4- - + t I - ■ ' . " ■\ '■ ■ ■ 1 — h 77^ ^-^^^ -^^jj - - ^^ -— — 2 4 % active ingredient 8 16 100 >- 80 ? 60 E ^ 40 °- 20 0 12 weeks exposure . .... _ . ■ ■! ^ — ■ — ' 1-^ ^ , - - ■ +--■'"■ -..----'--+'' __...+-■" \r .-■■' 1 — \ 4 8 % actrve rngredlent 16 Imidacloprid Fipronil + + + + in line indiealcs that spheres were treated with 20% sucrose solution prior to testing. Fruit Notes, Volume 6.3 (Number 4), Fall, 1998 Tnble 2. f-'ornging behavior of .ipplc maggot fly females, subsequent egglaying propensity and percent mortality following feeding on untreated, fipronil-treated or nnidacloprid-treated red wooden spheres. Foraging and cgglaynig behaviors were evaluated I hour after exposure to spheres. Females tested Sphere treatment per treatement Parameter measured (no.) Untreated F ipronil Im dacloprid Mean feedmg time on spheres (sec.) 32 596 579 363 Flies capable of foraging on tree (%) 32 100 91 44 Mean foraging tune (sec.) -- 844 760 585 Mean number of leaves visited 32 2.3 1.6 0.3 Flies laymg an egg (%) 32 61 16 6 Mortality: 24 hours (%) 32 3 28 71 72 hours (%) 32 10 82 83 Treated spheres contained 2% active ingredient of insecticide in latex paint. All spheres were subjected to 3 weeks field exposure and then were re-treated with 20% sucrose solution just prior to testing. Maximum permited feeding time = 600 seconds. Flies were placed individually on a small, caged tree. Numbers represent mean foraging time of flies capable of foraging. Maximum permitted canopy foragmg time = 900 seconds. Immediately after foraging, each fly was exposed to a hawthorn fruit. Maximum permitted time on fruit = 600 seconds. 16% of AMP that were exposed to fipronil-treated spheres attempted to lay an egg. Together, the re- sults of the behavior tests reflect the fact that fipronil is a much slower-acting compound than imidacloprid. AMF mortality following ingestion of fipronil was only about a third the amount at 24 hours after exposure as at 72 hours afterward, whereas with imidacloprid, mortality at 24 hours was nearly equal to that at 72 hours (Table 2). Conclusions Our combined findings show that imidacloprid performed better as an AMF toxicant on pesticide- treated spheres than did any of three other candi- date toxicants tested here: fipronil, spinosad and sugar ester. Imidacloprid at 2% a.i. in Glidden Red Latex Gloss Enamel paint gave excellent sea- son-long ( 1 2 weeks) AMF control provided that it was ingested with a feeding stimulant (sucrose). It gave very poor control, as did fipronil, in the ab- sence of sucrose, irrespective of dose used (16% a.i. was the highest dose tested). A low dose of imidacloprid, such as 2% a.i., not only is less ex- pensive than a higher dose but is safer for those handling pesticide-treated spheres. Imidacloprid rapidly immobilized AMF that ingested it, result- ing in very little or no subsequent foraging and egglaying activity of exposed AMF. Because imidacloprid seems to be an ideal toxicant for use in conjunction with sucrose on pesticide-treated spheres for controlling AMF, we are hopeful that the registrant (Bayer Corporation) will see fit to officially register its use for this purpose. Fruit Notes, Volume 63 (Number 4), Fall, 1998 Acknowledgments This work was supported by a grant from the Washington Tree Fruit Research Commission and USDA SEA CSREES grant # 97-34365-5043. We thank Gary Puterka of the USDA Regional Fruit lab in Kearneysville, WV for providing the sugar ester. ^C •'k *C *C *C Fate of Apple Maggot Flies Alighting on Pesticide-treated Spheres in a Commercial Apple Orchard Xingping Hu, Eric Gemborys, Max Prokopy, and Ronald Prokopy Department of Entomology, University of Massachusetts As mentioned in the preceding article, unusu- ally large numbers of apple maggot flies (AMF) invaded certain commercial apple orchards in Massachusetts in 1998. In most cases, invasion was attributable to a combination of large num- bers of AMF emerging from overwintered pupae beneath unmanaged apple trees nearby commer- cial orchards and to near or total absence of any fruit on such unmanaged trees, leading to AMF abandonment of unmanaged trees and movement to fruiting trees in commercial orchards. We took advantage of this situation in a cooperating orchard and studied the fate of AMF that were observed to alight on pesticide-treated red spheres. Methods & Materials Eight wooden spheres, 3 inches in diameter, were coated with a mixture containing 2% active ingredient of imidacloprid (Merit 75 WP), 20% sucrose, and 78% Glidden Red Latex Gloss Enamel paint. Four similar spheres, serving as non-toxi- cant checks, received only the sucrose and paint. All of the spheres were exposed outdoors for 3 weeks before testing (but no rain fell during this period). On three sunny days (July 21, 27, and 29), each of three observers hung two pesticide- treated and one check sphere about 2 feet apart in an apple tree and watched each sphere continu- ously for alighting AMF for a period of about 6 hours per day. An attempt was made to capture each AMF after it departed or fell from a sphere. Captured AMF were placed singly in small clean cups, supplied with food and water, and observed 1, 24, and 72 hours later for mortality. Results In all, 36 AMF were observed alighting on pes- ticide-treated spheres and 19 AMF on untreated check spheres. Of the 36 alighting on pesticide- treated spheres, the median duration of stay was about 3 minutes and 25 died while still on a sphere or within 1 hour after having fallen from a sphere. 10 Fruit Notes, Volume 63 (Number 4), Fall, 1998 All remaining 1 1 AMF flew from a pesticide-treated sphere to nearby foliage. Of these, six were cap- tured. All six died within 24 hours. The other five AMF evaded capture. Of the 19 AMF alighting on untreated check spheres, the median duration of stay was about 4 minutes and none died while on a sphere. Unfortunately, none could be cap- tured after departing an untreated sphere, as flight was too fast and far to permit capture. Conclusions Results of this study of responses of wild-popu- lation AMF in a commercial orchard to wooden spheres treated with imidacloprid, sucrose and la- tex paint confirm results of a study reported in the preceding article conducted using laboratory-main- Acknowledgments tained AMF. Among all wild-population AMF observed here to alight on pesticide-treated spheres, 86% (31 of 36) died within 24 hours and most died within 1 hour. The fate of the 14% that were not captured after alighting is unknown. Some of these also may have died. In the preceding article, data showed that pesticide-treated spheres com- parable both in type (2% a.i. imidacloprid) and field-exposure before testing (3 weeks) to those used here yielded 75% mortality of tested AMF. It is thus reassuring to know from this study of wild- population AMF that we can use response patterns of laboratory-maintained AMF placed directly on pesticide-treated spheres as an accurate guide to the performance of pesticide-treated spheres in commercial orchards. It is also reassuring to know that pesticide-treated spheres treated with 2% a.i. imidacloprid and sucrose are highly effective against AMF. This work was supported by a grant from the Washington Tree Fruit Research Commission and a USDA SEA CSRESS grant (#97-34365-5043). ^C *C ^C ^C *C Fruit Notes, Volume 63 (Number 4), Fall, 1998 11 Evaluation of Scab on Fruit of New Apple Cultivars Daniel R, Cooley, Arthur Tuttle, James Hall Department of Microbiology, University of Massachusetts Duane Greene Department of Plant and Soil Sciences While scab resistance has not proven to be the most important characteristic of new apple culti- vars, it is still useful to know how susceptible new cultivars are to scab. A grower is probably wisest to choose a new cultivar based on marketability and production, but then treat it for scab ac- cording to susceptibility to the disease. It was difficult to control scab in 1998, and a test block of new cultivars at the Horticul- tural Research Center in Belchertown, MA developed significant foliar and fruit scab over the growing season even though fungicides were applied. These cultivars were planted in five replicated blocks, and we decided to evalu- ate scab incidence to determine if there were differences. All the trees were on M.9 root- stock, except two that also were on Mark (Golden Delicious and Yataka). On Septem- ber 3, 1998, scab on the fruit was evaluated, and incidence was calculated as a percent of total fruit per tree. The only cultivar in the planting that is al- ready widely planted commercially in Massa- chusetts is Golden Delicious. Golden Delicious is generally reported as not very susceptible to scab, and this evaluation supported that as- sumption. While Golden Delicious had about 10% scab incidence, scab incidence over the whole planting ranged from 0 to 49%. Gala Supreme was quite resistant to scab, with 0% incidence. Similarly, Sansa, a Gala x Akane cross, also had 0% scab. As might be expected, two scab-resistant cultivars from the Purdue/ Rutgers/Illinois program, Enterprise and Goldrush, and one from the New York pro- gram, NY-75414-1, also did not show any scab. Suncrisp, progeny of a Golden Delicious cross, had very little scab (6%). Unfortunately, two cultivars that would have been very interesting to evaluate, Honeycrisp and Ginger Gold, did not produce fruit in 1998. Table 1. Evaluation of fruit scab in a variety block (NE 183) at the Horticulture Research Center, Belchertown, MA, September 3, 1998. Cultivar/Rootstock Apples wi thscab(%) Enterprise 0 c Gala Supreme 0 c Sansa 0 c NY 75414-1 0 c Goldrush 0 c BC8M 15-10 4 c Suncrisp 6 c Golden Delicious 10 c Golden Delicious/Mark 11 c Shizuka 20 be Cameo 28 abc Fuji 32 a be Orin 33 abc Braeburn 39 ab Golden Supreme 42 ab Yataka 44 ab Arlet 45 ab Yataka/Mark 49 a NY 429 49 a Means followed by the same letter are not significantly different at odds of 19:1. 12 Fruit Notes. Volume 63 (Number 4), Fall, 1998 Braeburn and Fuji were both quite susceptible to apple scab. Results of this test were similar to those in for- mal disease analyses done in Connecticut, Michi- gan, New York, Virginia, and West Virginia All apple cultivars do not get scab to the same degree. The key question, for which we do not yet have an answer, is how much less can we spray the less susceptible cultivars? That will have to be re- searched. %r ^r \r ^r ^r *^i ^C •'k •'k •'k Testing Various Methods of Timing Summer Fungicides Kathleen Leahy Polaris Orchard Management, Colrain, Massachusetts Thomas Clark Clarkdale Fruit Farm, Deerfield, Massachusetts Ezekiel Goodband Alyson's Apple Orchard, Walpole, New Hampshire The summer diseases, sooty blotch and flyspeck are the cause of most of the fungicide use after June in New England orchards. Using an improved understanding of the biology of these diseases, and specifically the wetness-hour model developed by Turner Sutton and his colleagues , has allowed growers to reduce fungicide usage in North Caro- lina and other mid-Atlantic states. We wanted to test this model to see whether it is viable in New England conditions. In a nutshell, the method developed by Brown and Sutton in North Carolina is based on the biol- ogy of the sooty blotch and flyspeck fungi. It al- lows the first summer fungicide to be delayed until 200-250 hours of wetness (counting only wetting periods of 4 hours or more) after the last scab fun- gicide. With our relatively dry summers, we gen- erally reach this threshold in early to mid-August. Thus, using this method, we could, in most years, save a couple of fungicide applications and have greater flexibility in timing summer fungicides with respect to insecticides and miticides/summer oils. We also decided to try a somewhat less radical method, based on work by David Rosenberger in New York, showing that fungicide retention dur- ing the summer is such that fungicides need not be re-applied until 150 hours of wetness (no mini- mum threshold) having occurred since the previ- ous fungicide. This would still provide a measure of flexibility in summer fungicide use. Materials & Methods The two cooperating orchards were located in the Connecticut Valley, one in Walpole, NH and the other in Deerfield, MA. In these orchards, the test blocks were divided into three Vi acre plots, and each plot was treated according to one of three summer fungicide programs: 1) the 'standard' pro- gram of a fungicide application every three weeks Fruit Notes, Volume 63 (Number 4), Fall, 1998 13 Table 1. The percent of fruit wi th flyspeck in a 50-fruit sample from each tree evaluated weekly from mid July and at harvest in 1998. Clarkdale Alyson's Standard NY NC Standard NY NC Check 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 4 0 0 2 2 2 0 8 0 0 2 18 6 6 14 2 2 8 20 10 0 14 10 2 8 22 1 00- fruit sample taken at Mcintosh harvest, 9/11/98 15 10 13 43 - ~ - 1 through June, July, and August; 2) the 'New York' program of waiting until 150 hours of wetness had accumulated since the most recent fungicide appli- cation; and 3) the 'North Carolina' model of wait- ing until 200-250 hours of wetness had accumu- lated after the primary infection period for these diseases. A modified hygrothermograph unit was used to measure the wetting periods in both orchards. The weather units were set out prior to blossom. The time of petal fall was noted (May 10 at Clarkdale Orchards; May 1 1 at Alyson's Apple Orchard) and wetness-hours were accumulated beginning 10 days after petal fall (May 20 and May 21, respectively). Trees in both blocks are on M.7 rootstock. The Clarkdale block consisted of Golden Delicious and Mcintosh, about 15 years old, with rows running east-west, and the Alyson's block was Mcintosh and Empire, about 12 years old, with rows running north-south. This was an unusually wet year in the North- east. In a more typical year we would not reach the 'North Carolina' threshold until early August, but in 1998, we reached this threshold by early July. Over 100 hours of wetness occurred during a single week in June. The specific threshold dates were: at Clarkdale Orchards, the New York thresh- old of 150 hours from the last apple scab fungi- cide was reached on June 22, and the North Caro- lina threshold of 200 hours was reached on July 3. At Alyson's Apple Orchard, the New York thresh- old was reached on June 24, and the North Caro- lina threshold on July 2. Because the New York threshold at Clark's was reached at the same time that he was planning a 'standard' spray, both the 'standard' and 'New York' plots were treated on the same date. The first summer fungicide applications were made on June 22, June 22, and July 9 at Clarkdale for the standard program, NY program, and NC program, respectively. The first summer fungicide applications were made on June 24, July 2, and July 16 at Alyson's for the standard program, NY program, and NC program, respectively. At Alyson's, Mr. Goodband decided to test a yet more radical approach than what we had origi- nally proposed. The fungicide application on June 24 actually coincided with the NY threshold, and the July 2 date was when the 200-hour NC thresh- old was reached. The application on July 16 was 14 Fruit Notes, Volume 63 (Number 4), Fall, 1998 Table 2. The percent of Mcintosh fr Lilt With fivs pec k m a 50-fruit sample from each tree eval lated weekly from mid Se ptember throL gh early October in 1998 Clarkdale Alyson's Standard NY NC Standard NY NC Check 10 6 28 6 6 10 34 56 46 52 4 6 10 26 58 62 62 10 18 10 30 68 72 72 — — - — 1 at 336 wetness-hours from 10 days after petal fall, and 262 wetness-hours from the previous fungi- cide. Once the first summer fungicide was applied in each section, that section thereafter continued to receive a regular fungicide program. Results Because of the early accumulation of the thresh- old level of leaf wetness hours, sampling (50 fruit per section per week) began in mid-July instead of early August as planned, but no symptoms were seen even in check trees until mid-August. When flyspeck symptoms began to appear (virtually all the summer disease seen this year was flyspeck), they appeared first in the most lightly-sprayed plots. Despite the early wetness, there was not a signifi- cant level of flyspeck except in the check trees un- til mid-September. As can be seen from Table 1, there were few significant differences in summer disease occurrence except between the treated and check trees, but there was a trend toward somewhat higher disease in the 'radical' plot at Alyson's. When Mcintosh fruit were harvested in this plot, a random survey of fruit showed over 40% with flyspeck, which is not commercially acceptable. It was clear that this 'radical' option did not provide acceptable control of flyspeck. Because of the advanced season and the dry conditions in August, the fruit in the other two plots were harvested before a proper survey could be done, but it was evident that control was satisfactory in these two plots. At Clarkdale, there was very little difference between treated plots (the intended check trees were sprayed so the data were not included), and a har- vest survey of 100 Mcintosh per plot showed no significant difference nor any trend between treat- ments. Once the Mcintosh had been harvested, it be- came evident that there were differences in flyspeck occurrence between varieties in both orchards. This effect had been masked by the random zigzag pat- tern through the plot adopted when sampling fruit in the regular weekly sessions. At Alyson's, the Empires had much less flyspeck than the Mcin- tosh, whereas at Clarkdale, the Golden Delicious had much more flyspeck than the Mcintosh. These differences were presumably not owing to varietal susceptibility, since the literature indicates that apple varieties are essentially identical in their sus- ceptibility to flyspeck. We believe that the differ- ences were owing to the more open growth habit of Empires vs. Mcintosh at Alyson's, generating a less favorable (lower humidity) environment for the organism, whereas at Clarkdale the strikingly high level of flyspeck throughout all three treat- ments indicates that this entire row did not receive a summer fungicide application - perhaps the last scab fungicide on June 9. Mite sampling in the test plots did not show any difference in either pest or predator mite num- Fruit Notes, Volume 63 (Number 4), Fall, 1998 15 bers. This was as we expected, since the first year of reducing fungicide is unhkely to produce a dra- matic effect on the mite population. Discussion In general both the New York and North Caro- lina methods of timing fungicide applications seemed to work very well, under unusually chal- lenging conditions for this region. It is clear, though, that extending the number of wetness- hours beyond the 250 recommended by the North Carolina model poses an unacceptable risk to the crop. The economic savings from reduced sprays overall were less than $10 per acre, but even this amount could be significant, given the slim profit margins in apple-growing at this time. The major benefit of adopting a reduced summer fungicide program, however, is more likely to be increased flexibility in time management and the ability to incorporate summer oils into the spray program without risking phytotoxicity from fungicide/oil in- teractions. In addition, it is possible that this prac- tice might be helpful for beneficial organisms in the orchard. ^L ^U ^L •^L ^L 16 Fruit Notes, Volume 63 (Number 4), Fall, 1998 On-farm IPM Education: Displays and Self-guided Tours Craig HoUingsworth, William Coli, and Ronald Prokopy Department of Entomology, University of Massachusetts Karen Hauschild Department of Plant & Soil Sciences, University of Massachusetts Returning from a 1995 international scientific conference, two of us toured the fruit growing re- gion of Switzerland. Among the techniques for educating the Swiss consumer about Integrated Fruit Production (the European version of IPM) that we observed were self-guided tours within vineyards. These tours consisted of signs and pic- tures which explained a variety of agricultural tech- niques in use in the vineyard. This spawned the idea of educating Massachusetts apple customers about IPM through similar orchard tours. Apple growers were solicited to participate in the project through announcements in extension publications and by phone. The nineteen growers VISUAL TRAPS attract early season pests such as apple sawtlies and leafininers by mimicking the attractive parts of the apple tree. Using these traps, a farmer can detennine whether pesticide applications are needed, eliminating unnecessary pesticide use. and often resulting in better quality fruit. Sawflies are attracted to apple blossoms, mimicked by white traps. Leafminers are attracted to reddish tree bark, mimicked bv red traps. Apple sawfly adult Sawfly damufie Leafminer adult Leafminer damage Trap for apple saw/ly Trap for leafminer adult Figure 1. A photograph of one of the signs in the self-guided tour. Fruit Notes, Volume 63 (Number 4), Fall, 1998 17 who responded provided assistance in determin- ing the content and design of the education dis- plays and contributed matching funds for a grant by the Massachusetts Department of Food &c Ag- ricuhure. It was determined that self-guided tours would the most appropriate for pick-your-own operations but that static sign-boards would be more useful for farmstands and farmers markets. Self-guided Tour trol, biological control and pesticide use, as well as the biology of primary apple pests. A colorful 8-x-l 0-inch sign to advertise the tour was also in- cluded. At each orchard,, the grower determined how the signs were placed. Most were arranged through part of the orchard. In some cases, a path was marked by mowing or with plastic tape. It was suggested that IPM tools such as insect traps and scare-eye balloons be placed in association with appropriate signs. Each tour consisted of eight signs, 18 x 24 inches, on laminated paper, mounted on 0.5-inch Apple IPM Displays plywood, covered with Plexiglas and sealed with plastic. Figure 1 is an example of one of these eight signs. Each sign was mounted on a 7-foot, 3- x-5-inch pressure-treated post. The signs describe aspects of IPM, including monitoring, cultural con- Self-standing displays were developed and dis- tributed to eleven Massachusetts farms for use at farmstands and farmers markets. Figure 2 is a photograph of one of the displays. Displays con- i NTr-C^iiTEO PEST MANAGEMENT ,.ombi;iti di(fL-(ciu in(:tt,vds of [x-u rntrot to produce qn.ility fruit in an n onmcntaily rwponsiblc m,li>nc' ■ [I'O fitJ'^.Tged tlirougli .1 cot'ibination , . mg, natural enemies, cuUtml , actices aod chemical coniroi riHTiJftAt AliVJ/lGf MrNT l« l^ M ► L(ur.!ll/-0^..u'Hn>; iv.tJmo. >•!: i Figure 2. A photograph of the self-standing display. 18 Fruit Notes, Volume 63 (Number 4), Fall, 1998 sisted of a three hinged panels of vinyl lattice mea- suring 4x8 feet. For strength and stability, each panel was framed with vinyl edging. Four lami- nated posters describing and illustrating apple IPM through the four seasons were hung on the frame- work. The displays could be folded for transport and were light enough to be carried by one person. Evaluation The self-guided tour was evaluated by a ques- tionnaire mailed to participating growers. Seven of the ten growers returned the questionnaire. Most growers (5 of 7) arranged the signs as tours within their orchards. Two growers placed all the signs in one place. Five of the seven grow- ers told their customers about the tour. No grow- ers provided extra signs to direct their customers to the tour. Four growers added traps and other IPM equipment to the tour. Positive comments from customers about the tour were received by four of the growers. Five growers reported their intentions to use the tour as part of their educa- tion program for school children. Growers reported that between 1% and 40% of their customers took the "tour". Two growers (with participation of 1% and 40%) rated this as "unsatisfactory." All growers reported that the message and information presented, presentation and workmanship were good to excellent. The over-all success of the project was rated good to excellent on six farms and poor on one farm. Both educational projects were also evaluated by a brief customer survey. Twenty-nine custom- ers at two farmstands with self-guided tours were surveyed, 30 at a farmstand with an IPM display, and 40 at two farmstands with neither educational program. Twenty-four percent of all customers professed to having heard of IPM before coming to any of the orchards. Where a self-guided tour was located. 14% of customers interviewed had taken the tour, whereas, 60% of customers looked at available IPM displays. When asked to describe what they learned from a farmstand display, the most frequent response (37%) was that IPM uses less pesticide. Ninety-five percent (20 of 21 responses) of the re- spondents agreed that seeing this information af- fected their attitude about farming. Of these, 85% said that their attitude became more positive. Three individuals traveling together said that their atti- tude was more negative after viewing the display. We also evaluated the program by visiting farms where the tours and displays were used. It was apparent tours were less successful where custom- ers were not adequately informed that the tours existed, or where the start of the tour was too far from the farmstand. Conclusions Public education on farms can be especially effective in a pick-your-own setting. As customers indicated, families pick apples, in part, as a recre- ational activity, but once the apples are picked, they are looking for other things to do. These educational products were successful for some growers, but not for others. As with most educational or marketing products, they are tools and must be used in an appropriate manner to pro- duce the best results. Self-guided tours are best placed in a convenient, conspicuous location and promoted by the grower through welcoming signage, talking to customers, and other methods. Tours can become another reason for customers to come a particular farm. In this project, press re- leases attracted a number of customers. Static dis- plays are much simpler for the grower to use, and while they did not have the novelty or recreational value of the tours, it was clear that the message from simple signs reached a greater percentage of customers. *,L Kf^ ^L *.L *>?. Fruit Notes, Volume 63 (Number 4), Fall, 1998 19 X X L^xi^ x^vycv^vj University of Massachusetts Department of Plant & Soil Sciences 205 Bowditch Hall Amherst, MA 01003 nunproTii urganizaiion U.S. Postage Paid Permit No. 2 Amherst, MA 01002 SERIAL SECTION UNIV OF MASSACHUSETTS LIBRARY AMHERST MA 01003 Account No. 2-22914 ^'l-) ACME BOOKBINDING CO., INC OCT n 9 t999i" lOOCAdfflWG&SifflBr CHARitST'OWN.WWSS.