Flyspeck and alternate hosts
Fungicides could be applied more judiciously if growers knew when and where flyspeck fungal spores would be released and deposited. The proximity of trees to blackberries, a major source of inoculum, influenced flyspeck incidence in commercial orchards, suggesting that trees closer to blackberries are at greater risk (MA). Mature fungal ascospores were released during a five-week period beginning about two weeks after petal fall (MA). In controlled studies, ascospores matured when blackberry canes were held under high relative humidity (RH) at 21C and 14C, but not at 7C. Ascospores failed to develop on canes held at low RH, indicating that both temperature and RH are important for ascospore development (MA). This could explain why flyspeck is less severe in seasons with dry weather in late May and early June.
Reduced spray programs for SRCs
Under NY and NJ conditions, three to six fungicide applications for controlling summer diseases are required to produce SRC fruit that meets current market quality standards. In an IPM trial with SRCs in NJ, over 50% of fruit from trees that received no fungicide had summer diseases at harvest. SRCs receiving only 1/2 the fungicide of conventional spray programs produced fruit free of summer diseases (NJ). In 13 NY tests with six cultivars (five SRCs), trees receiving three to six fungicide sprays during summer produced more marketable fruit, and total fruit value was a dollar value 2.6 times greater than that for trees receiving no summer fungicides. The lower dollar value for fruit from untreated trees was attributable to decays and fungal blemishes on the fruit (NY).
Late-maturing cultivars are at greater risk for flyspeck and therefore may require more fungicide protection than early-maturing cultivars. In a block of SRCs in Pennsylvania that received no fungicide sprays in 1994, the proportion of fruit out of grade (USDA Fancy/Extra Fancy pack) because of sooty blotch and flyspeck was 7% for 'NY 74828-12' harvested August 24 and 17-18% for 'Liberty' and 'NY 75441-67' harvested in late September (PA).
A single summer fungicide application may suffice in VT, but SRCs in more southern locations may need a spring fungicide during bloom or at petal fall to protect fruit from rust infections. In VT, one summer fungicide application resulted in 99% disease-free fruit for the SRC 'Liberty'. However, 1% of 'NY 74828-12' had cedar apple rust, 2% had quince rust, and 7% of 'NY 75414-1' had moldy core (VT). Since moldy core cannot be controlled with fungicides, this trait, along with other undesirable characteristics of 'NY 75414-1', may decrease the probability that it would become a named cultivar.
In NY, flyspeck can be effectively controlled only by applying fungicides at regular intervals through summer (NY). Benomyl (Benlate 50W) applied only in August did not compensate for earlier gaps in summer spray programs that allowed flyspeck to become established on fruit.
In NY, three to five fungicide sprays will control summer diseases on 'Liberty' and produce the same marketable yield as the 9-15 fungicide applications generally required on scab-susceptible cultivars. In a four-year study, summer diseases on 'Liberty' apples could not be controlled by cultural methods, but fungicides applied only three or four times from June to August reduced losses by 82%. Each dollar spent on applying fungicides returned $17.50 in increased crop value. Failure to control flyspeck on 'Liberty' apples in southeastern NY resulted in an average loss of $2,330 per acre per year (NY).
Disease control with alternative compounds
Ziram and sulfur applied together provided excellent residual activity against sooty blotch and flyspeck and could provide apple growers with an alternative to the commonly-used fungicides that have been listed as potential carcinogens. The incidence of sooty blotch remained low on fruit treated with ziram/sulfur, indicating that this treatment provided residual protection against sooty blotch throughout the 47-day pre-harvest interval, despite the 7.6 inches of rain that occurred from mid-August to harvest. However, growers resist using ziram/sulfur combinations because the treatment leaves fruit with unsightly white residues and because of fears that sulfur applied during summer could "burn" fruit (NY).
Copper (Tenncop 5E) applied during summer failed to control summer diseases in a New Jersey evaluation of pest control systems for organic apple orchards. More than 50% of the fruit was damaged by disease at the end of the season (NJ).
Potassium bicarbonate failed to provide cost-effective control of flyspeck. Four applications were less effective for controlling flyspeck than two applications of Captan plus Benlate (MA). This research is being continued under a newly funded SARE project.
b2. Pest Management - Arthropod (Project Objective 1)
Overall goals are to develop IPM systems that further reduce apple growers' reliance on traditional synthetic pesticides, while increasing grower awareness of new pest management methods. Efforts have focused on various means of refining integrated pest management (IPM) techniques that include bio-intensive orchard management, use of insect trapping methods, mating disruption, use of new Bacillus thuringiensis (B.t.) insecticides, botanical insecticides, tree row volume spray delivery, host plant resistance, and investigating the non-target effects of certain pesticides, particularly fungicides. Much of what we have learned is being applied in advanced IPM systems (called second-level IPM in MA) utilizing SRCs (MA, PA, VT, NJ). Work has compared IPM in various SRCs with and without fungicides and with reduced fungicide use. Both target and non-target effects of pesticides on pest density and fruit quality have been examined.
Apple Maggot
Red sticky spheres for control of apple maggot flies were developed for use in second level IPM orchards, but the sticky spheres were difficult to maintain. The development of a more efficient low maintenance sphere addresses this concern (MA). A feeding stimulant (sucrose), insecticide (dimethoate), and a residue extending agent (red latex paint) were combined, and used at a density of 25 traps/ac in a commercial orchard while achieving 99.7% maggot control. However, because traps had to be recharged after each rain period, further development is needed and will continue under a newly funded SARE project.
Several commercial growers in VT have used an insecticide-free combination yellow board/red hemisphere with adhesive (Ladd Trap) for maggot fly control and have successfully controlled them during each of the past two years.
Cultivar Effects
Some SRCs will need less insecticide treatments than others because of differences in their attractiveness/susceptibility to various pests. In Vermont, tarnished plant bug injury was greatest on 'Empire' and 'NY 74828-12'. In a six cultivar trial in New Jersey, spotted tentiform leafminer populations were affected by cultivar (NJ). High mine counts were present at the end of the season, but in the SRCs fruit drop was least in 'Enterprise,' suggesting that fewer leafminer sprays are needed for that cultivar. In a vigorous 'M.111' planting, aphid populations were highest on 'Enterprise' and lowest on 'Liberty'.
Plum Curculio
Plum curculio (PC) is a key pest in the Northeast. It can be especially problematic in 'Liberty', where greater levels of PC injury were observed than on other cultivars. An adaptation of the Tedders trap, originally developed for pecan growers in southern states, was used to monitor PC throughout the season in VT. While the trap does attract PC adults, it was not effective enough to serve as an monitoring aide. Development of a PC attractant could increase the value of this trap. In a system using reduced amounts of Imidan® (plus mating disruption and various formulations of B.t. for controlling other pests), second generation larvae of PC developed as a key pest. This generation was previously thought not to occur in PA and the northeast (PA). The fact that the pest can occur late in the season points to the importance of a full season monitoring and IPM program.
Botanical Insecticides
Control of certain pests with botanical insecticides can equal synthetic organophosphate insecticides, but at a higher cost. In a two year study in VT, rotenone 5% (11.3 lb/100 gal in yr 1 and 20 lb/100 gal in yr 2) were compared to Imidan® 50W. Imidan® was better than the low rate of rotenone for controlling plum curculio, green fruitworm, codling moth and leafrollers, but the two were equally effective against tarnished plant bug and European apple sawfly. Rotenone treated trees showed less foliar injury by leafminers. There was a significant difference in insecticide costs for the season: $50 for Imidan®, and $765 for rotenone (VT). In a NJ test, a liquid formulation of rotenone 1.1% plus pyrethrins 0.8% (6 lb/ac) used in a season long program resulted in fruit injury levels that were too high to be commercially acceptable (NJ).
Other Strategies
Pest management strategies that included mating disruption, increased use of advanced B.t. insecticides, and tree row volume pesticide application met with various degrees of success. Mating disruption for codling moth (CM) and tufted apple budmoth/leafrollers (TABM/LR), combined with B.t. applications yielded up to 7.7% CM injured fruit, but only minimal TABM/LR injury. The low levels of TABM/LR injury may have been in part due to extremely high parasitism of those pests by as many as 10 species of parasitoids (PA). Since TABM is a key pest in the mid Atlantic area this high degree of successful biological control merits further investigation. When combined with an IPM program, calculating tree row volume requirements for pesticides in dwarf trellised trees led to further reductions in pesticide use (NJ). Pesticide use was about 25% of the total normally used in NJ apple orchards.
Non-Target Issues
The non-target effects of fungicides were noted where Captan and Benlate were applied. In one test, European red mite populations were 77% higher under a standard fungicide program than in a second-level IPM program (MA). Mite populations were similarly affected in VT and NJ, where fungicide use suppressed predaceous mites either directly or by suppression of alternative food sources (e.g. rust mites). Leafhopper populations were suppressed by fungicide use in NJ, but not in MA trials. In a study in VT, all fungicide-treated cultivars had aphid levels above threshold, while 'Liberty' and 'Empire' trees receiving no fungicides had aphid populations below treatment levels . A VT study tested rotenone efficacy for insect control while using Captan in maintenance sprays for disease management (VT). Rotenone had both beneficial and injurious non-target effects. Rotenone treated 'McIntosh' had less foliar and fruit scab, and 'Redfree' trees had less quince rust than Imidan® treated trees. Rotenone treatments increased overall fruit russeting. Captan reduced apple maggot injury in the second year of the study.
c. Environmental Impact Assessment (Project Objective IV)
In recognizing the need to have objective assessments of the environmental impacts of various production practices, this project supported a two-year pilot project to review currently available models. This pilot project has expanded to involve apple workers, as well as ecologists, entomologists, and toxicologists from research and regulatory agencies throughout North America and Europe (NY). A network of scientists has been developed, and the basic computational and conceptual framework for modeling and comparing environmental impacts has been established. Major gaps and limitations in the coverage, reliability, and availability of essential ecological and toxicological data have been determined, and progress is being made to redress these problems. A "bottom line" comparison of conventional and alternative systems developed and tested in our projects will be completed soon. For the next two years, the USDA-National Research Initiative Program will support completion of the environmental impact model, making it available to other researchers and fruit growers, and linking it with complementary impact assessment systems such as PLANETOR in Minnesota, and the Stemilt rating system in Washington.
3B. Dissemination of Findings (Project Objective III)
The project members have widely disseminated the information and knowledge generated by this project. Target audiences include farmers, Extension personnel, other researchers, and the general public, both children and adults. Based on recommendations from growers participating in the former NE SARE Farmer-to-Farmer Information Exchange Project, a decision was made in early 1995 to create a Grower Coordinator position. The Coordinator's role is to further enhance our ability to develop, communicate, disseminate, and incorporate Project generated information into Northeast apple grower's production habits. Several meetings have been held to define roles and responsibilities, and these are discussed in the request for continued funding.
Over thirty articles reporting project results appeared in Extension and industry publications including Fruit Notes, The Apple Press, Scaffolds Fruit Journal, New York Fruit Quarterly, Proceedings of the New England Fruit Meeting, and the Annual Report of the State Horticultural Society of Michigan. These publications are important sources of information read by thousands of commercial and hobby growers, Extension personnel, and researchers throughout the Northeast and beyond the region.
The NE SARE Sustainable Apple Production Newsletter is the only periodical devoted to distributing the latest information on SRCs and advanced IPM strategies to growers and researchers. Two issues were produced last year that were distributed world-wide to a total circulation of over 1,000. Subscribers come from at least 35 States and the District of Columbia, five Canadian provinces, and five foreign countries. Additionally, over 200 more copies of the Management Guide for Low-Input Sustainable Apple Production were sold or distributed.
Project results continue to receive significant national coverage by the press. For example, the article titled 'New-Era Apples' in the Nov/Dec 1994 issue of National Gardening magazine (with over 235,000 subscribers) focused on SRCs, and contained information and illustrations supplied or reviewed by project members. This coverage follows an article that appeared last year in USA Today that illustrated an apple maggot trap and mating pheromone disrupters, two techniques being employed and researched by project participants and grower cooperators (see 1994 Annual Report).
Fourteen research articles based on project results were published in scientific journals having national and international circulation such as Environmental Entomology, Journal of Economic Entomology, Plant Disease, HortScience, and Agriculture, Ecosystems & Environment.
Over 4,000 growers and the general public attended Field Days and On-Farm Demonstrations sponsored and/or hosted by Project members.
Over 45 presentations were made at meetings having an attendance totaling over 2,000 growers in the Northeast and Midwest regions, and at professional society meetings before scientists, agribusiness professionals and governmental policy makers.
Computer technology is being used to disseminate information to a wide audience. The UVM Apple Orchard World Wide Web page features information on SRCs and other sustainable apple production information, and was featured during an Internet presentation at the Annual Meeting of the National Association of County Agricultural Agents this past August. The 'Orchard' has had over one hundred 'visits' (including commercial growers) since its debut in late 1994. The 'Orchard' is available to anyone with Internet/WWW access (http://apple.uvm.edu), and we expect to continue using the WWW for Project information dissemination.
Youth and young adults were also recipients of project efforts. Over 3,000 students from third through twelfth grade (both in the classroom and during special events) received information on sustainable apple production, SRCs, and IPM in VT and NJ. In PA, the apple project was part of the in-service training of K-12 teachers. In addition, Cornell and Rutgers Universities introduced aspects of sustainable apple production into lectures in numerous courses, and project personnel acted as mentors to undergraduate and graduate students.
3D. Economic Analysis (Project Objective II)
Economic studies of the profitability of instituting sustainable practices on apple orchards in the Northeast have focused on micro level analyses and an industry wide analysis. The industry-level analysis centered on using econometric models to evaluate the impacts of changes in the apple industry and to determine the transmission of prices between the grower, shipping point, wholesale, and retail market levels. A dynamic model of the US apple industry, including relationships for bearing acres, production, utilization, and allocation to the fresh, canned, frozen, juice, dried and other markets, was developed and results from the model were published.
Micro-economic studies showed that growers can significantly reduce pesticide costs without compromising fruit quality by growing SRCs and using size-controlling rootstocks. For SRCs on 'M.7' rootstock (mid-size trees), total pesticide use, including fungicides applied for summer diseases, was 40 lb. of product costing $113/Ac. This represents a 50% reduction in pesticide use compared to commercial practices with standard cultivars. On dwarf trees, the total cost was only $55/A (NJ).
Growing SRCs with no fungicides, or with inadequate fungicide protection, can result in costly losses because summer diseases can reduce fruit quality. In a four-year study with 'Liberty' apple trees in southeastern New York, the estimated gross return (in dollars per acre) was 50% greater for fungicide-treated than for untreated plots (NY). The mean value of fruit per tree for 13 tests was $2.93 for trees receiving no fungicides during summer compared to $7.76 for trees receiving summer fungicides. The summer fungicides applied in the sprayed plots failed to provide complete control of sooty blotch and flyspeck. If fungicides had provided complete control of these diseases, the mean value per tree would have been $9.93 (NY).
For some cultivars, the increased crop value from mulched trees may justify the greater costs for the mulches. Natural and synthetic mulches were compared with mechanical tillage and herbicides as orchard ground cover management systems (GMS). Substantial differences in fruit size, color, blemishes, and pre-harvest drop among the eight apple genotypes and 10 GMS treatments resulted in a broad range of fruit packout values, from $3.48 to $7.45 per 42 pound bushel. Cumulative crop market-value estimates based on yields and proportional packouts from 1992 to 1994 also varied greatly, from $3,323 to $7,386/Ac, assuming a planting density of 270 trees/Ac. Some of the most expensive treatments were the least profitable, while trees in several low-cost mulches (white polypropylene, polyester fabric, and hay mulches) produced the most profitable crops (NY). Voles caused more serious damage to trees under synthetic and hay mulches, despite the use of mesh trunk guards and rodenticide baits.
Participating growers and retail sales reports confirm that the best immediate market potential for SRCs may exist in the low-volume direct marketing niche that constitutes an important and profitable sales outlet for many fruit growers in the Northeast.
4. POTENTIAL CONTRIBUTIONS AND PRACTICAL APPLICATIONS (additions to previous reports)
Successful use of SRCs will involve significant modification of conventional pest management techniques, including conventional IPM. Such IPM systems will also be useful to the vast majority of growers who are producing scab-susceptible cultivars. It will be increasingly important that NE growers be able to use such ecologically-sound systems if they are to compete with other apple production areas, which have already begun to institute reduced pesticide standards. This project's grower-based research is designed to develop and test these IPM systems.
Reducing Summer Pesticide Applications
Reducing summer pesticide applications is the next key step to advanced IPM for apples in the Northeast. This includes the following key components:
A low-maintenance sphere to manage apple maggot.
Monitoring systems and cultural controls to reduce the need for summer fungicide sprays.

There are several potential benefits of reducing or eliminating summer pesticides:
Enhanced natural biocontrol of arthropods and reduced non-target pesticide effects.
Reduced pesticide expenses.
Reduced chances of pesticide residue on fruit.

Using Compost from Urban Sources
Another area of ecological concern, waste management, is being linked with apple production. Project members are studying whether municipal yard waste and commercial food processing waste can be diverted from landfills to benefit soil quality and apple production.
Horticultural Performance of Scab-Resistant Cultivars
'Liberty,' 'Enterprise,' and 'Coop 36', perform well in the southern-Northeast to mid-Atlantic area. Yield and tree vigor for these cultivars has been equal to or superior to 'Empire'. 'Liberty' out-performs 'Empire' in more northern climates.
Pest Management of Scab-Resistant Cultivars
Significantly less fungicide is required to produce this fruit compared to scab-susceptible cultivars. SRCs require 50% or less of the normal fungicide use seen in New Jersey apple production. When SRCs are grown on dwarfing rootstocks and combined with grower use of tree row volume sprayer calibration and dose delivery, as much as 70% savings can be realized.
We have documented differences in insect susceptibility by various SRCs that will have a direct impact on how much pesticide growers need to use for certain cultivars. For example, 'Enterprise' and 'Coop 36' do not seem to drop fruit in response to spotted tentiform leafminer infestation and can tolerate this pest better than other cultivars. Therefore, fewer insecticides are needed for leafminer control. However, 'Liberty' seems to be very susceptible to plum curculio injury, thereby requiring a vigorous insecticide program just after petal fall.
Non-Target Effects
As we reduce overall pesticide use in the orchard, the effects of the remaining pesticides on non-target pests will become increasingly important in order to optimize the advanced IPM systems. For example, we have determined that Captan/Benlate (or Topsin) programs suppress white apple leafhopper damage, and Captan alone suppressed apple maggot injury.
Rotenone lowered the incidence of foliar apple scab on the scab-susceptible cultivar 'McIntosh'. This is of interest to organic growers who have difficulty controlling apple scab with sulfur; if they use rotenone in their pest management program, they may be able to better manage the disease. Unfortunately, rotenone may not be reregistered for use.
Consumer Acceptance
Consumer education displays and studies have shown that, when given the opportunity, consumers prefer the taste of several of the SRCs over the standard 'Red Delicious'. These studies have also shown that while extreme reductions in fungicide use have led to some visible sooty blotch and fly speck on the fruit, it has not always had a negative impact on marketability.
Alternative Controls
Information concerning the enhanced activity of ziram-sulfur combinations for controlling flyspeck as compared to either material used alone gives farmers a new option for summer sprays and allows them to avoid other fungicides that have been listed as potential carcinogens.
Economic Impacts
Failure to control flyspeck on 'Liberty' apples in southeastern New York cost $2,330 per acre per year in a three-year study. Knowing the economic importance of this disease will help farmers prioritize pest control efforts and highlights the importance of additional research on this disease.
5. FARMER ADOPTION AND DIRECT IMPACT (additions to previous reports)
5A. Changes in Practice
During the last two years, participation in a NJ fruit IPM program has exceeded 100 commercial growers.
In cooperation with the New Jersey Agricultural Society and the New Jersey Horticultural Society, growers organized taste testing activities in commercial markets which are featuring scab resistant apple cultivars from this project.
Seven growers have established plantings of scab resistant apple cultivars in New Jersey.
In Vermont, over one dozen growers (over 10% of the state's commercial apple growers) have dedicated some of their orchard plantings to scab-resistant apples.
Some farmers in New York and Michigan are switching to ziram, or ziram plus sulfur, to control summer diseases instead of using benomyl and Captan. They are thus able to avoid using fungicides listed as potential carcinogens and reduce worker exposure to Captan.
Based on work begun with this project, USDA Regional Research Project NE-183 was organized to evaluate both horticultural qualities of new cultivars (including SRCs) and their responses to the most commonly-occurring pests. The new project has more than 50 cooperating scientists in 18 different states. Results from the NE-183 project will be used to inform growers about cultivar traits, and their responses to pests.

5B. Pesticide Reduction Potential
An extensive appendix on this topic was included in the 1994 Progress Report.

5C. Farmer Evaluations
In addition to comments below, please see grower letters that follow the project cover letter.
Commercial orchardists who responded to the 1994 Annual Apple Press survey [See Vermont Appendix] clearly support the necessary research to reduce their reliance on pesticides. In fact, their concern for 1) environmental contamination, 2) the potential loss of pesticides, and 3) food safety issues, were mentioned along with labor and marketing as some of the most critical problems/issues facing apple growers. Integrated pest management, reduction of apple scab sprays, and alternative (better) methods of insect and disease control were also recurring responses when asked what areas of research were important to the future of apple growers.

6. PRODUCER INVOLVEMENT
Workshops 682 Field Days 767
Conferences 1068 Other Events 984
7. ADDITIONAL AREAS OF STUDY (new since last report)
Breeding new apple cultivars for multiple disease resistance and suitable for processing.
Screening current and new cultivars for arthropod susceptibility.
Effects of pesticides on non-target pests.
Fruit thinning recommendations for new cultivars.
Mechanisms of soil conservation and sustainable fertility enhancement in perennial crop systems such as orchards.
Determine why ziram-sulfur combination sprays provide such exceptional control of sooty blotch and flyspeck, and determine if ziram-sulfur will also control bitter rot and black rot.
Effects of specific horticultural management practices (i.e. nutrition, pruning, rootstock selection, and thinning) on commercial fruit quality of SRCs.