Northeast Region Sustainable Apple Project
Since 1988, project participants have conducted research and education programs providing growers and the public with practical information on scab-resistant cultivars and advanced integrated pest management (IPM) techniques for fresh market apple production.
The project conducted an extensive evaluation of how scab-resistant cultivars (SRCs) could contribute to more sustainable production systems. Many of the cultivars evaluated had serious flaws that limited their usefulness for commercial agriculture.
A World Wide Web site (www.orchard.uvm.edu) has been established for the dissemination of information concerning all aspects of sustainable apple production.
A publication titled Management Guide for Low-Input Sustainable Apple Production was authored by SARE-project participants and published in 1990.
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.
1.Develop sustainable apple production systems in the Northeast using scab-resistant apple cultivars and integrated pest management techniques.
2.Provide economic analyses of sustainable production systems and forecast the impact on the Northeast apple industry.
3.Expedite research and information transfer on sustainable apple production systems for the Northeast.
4.Compare potential impacts of conventional, agrochemical-intensive pest management with alternative IPM practices upon soil, water, wildlife, and beneficial fauna in the orchard agroecosystem and upon human resources.
Methods and Findings
Because of the breadth and diversity of the Northeast SARE Apple Production Project, it is difficult to succinctly summarize our accomplishments. Probably the most important achievement was the extensive evaluation of how SRCs could contribute to more sustainable production systems.
Using SRCs is one kind of pest management tactic (genetic resistance). Used in conjunction with other IPM strategies, SRCs have the potential for reducing, but not eliminating, the need for fungicides. Several impediments to fungicide reduction exist in SRC-based systems, including potential for damage from important diseases other than scab, marginal cost savings relative to increased costs for alternative management methods, and increased risks for some alternative methods.
Project participants have also shown that the current production methods are largely defined by the free-market system that forces growers to compete on a world market to supply consumers with a blemish-free product. SRCs that are currently available should be promoted for home garden use and for niche-market sales. Fruit quality and storage life of named SRCs are not yet good enough to warrant large commercial plantings for fresh market sales. Like any other new cultivar of apples, SRCs face formidable barriers in gaining recognition and market acceptance in fresh-market channels.
Research on IPM strategies applicable to scab-susceptible cultivars provided information that was immediately integrated into state apple IPM programs. For example, in Massachusetts, the SARE Apple Project created part of an overall apple program focused on developing and implementing advanced IPM control strategies for sooty blotch and flyspeck. Research on a computer-based predictive model for timing summer fungicides was also initiated and is being continued with other funding sources. In New York, fungicide timing studies showed that flyspeck on apple can usually be controlled by fungicides applied on a three-week interval rather than the 14-day interval that was previously recommended for this disease. In New Jersey, SARE funds enabled Rutgers Cooperative Extension to expand delivery of IPM scouting and information to an increasing number of growers.
The Management Guide for Low-Input Sustainable Apple Production, targeted for both large and small apple producers, was published. It included comprehensive chapters on economics, horticulture, and disease and insect management, with easy-to-understand information on the best reduced-input approaches for managing orchards. In 1993 the project organized a comprehensive conference/symposium titled “Disease-Resistant Apple Cultivars: An Update on Horticulture, Pests, and Marketing.” SARE project participants authored hundreds of articles and thousands of contacts were made via mass media and through presentations at grower, industry, and professional meetings.
A complex environmental question emerged from our project after several years. We had shown that SRCs enabled 50 to 100 percent reductions in fungicide. But from a broader perspective, what were the off-site and long-term savings involved when the environmental impacts of pesticides in orchard ecosystems or regional food systems were considered? We conducted a thorough review of current methodologies and databases for assessing environmental impacts of different pest-control practices. Major obstacles to meaningful, holistic impact assessment were identified_especially the lack of comparable or complete databases for pesticide effects on key processes, species, and components of agroecosystems.
By 1992, project participants were working with more than 5,000 trees of SRCs in various commercial and experimental plantings. At least 30 cultivars and numbered selections were evaluated. The greatest disappointment was that most of the cultivars evaluated had serious flaws that limited their usefulness for commercial agriculture. Two of the four SRCs included in the reference planting showed a high incidence of fruit defects and have since been removed from consideration as selections that become named cultivars, thereby reducing the usefulness of the reference planting.
Based on extensive evaluation of SRCs over an eight-year period, project participants compiled a list of potential benefits and limitations of using SRCs.
Benefits of Scab-Resistant Cultivars
1. SRCs need less fungicide. In northern growing regions where diseases other than apple scab are relatively unimportant, high-quality SRCs can be grown without fungicides in many sites and in most years. Even in more southerly regions, where SRCs may require three to five fungicide applications annually, fungicide use would still be reduced by at least 50 percent.
2. SRCs have fewer problems with mites. Fungicides have an adverse impact on mite predators. When SRCs were grown either without fungicides or with only a few summer fungicide sprays in our tests, they generally required no miticides other than the delayed-dormant oil spray each year.
3. SRCs provide new options for niche markets. Scab-resistant cultivars may gain market share if there is significant growth in demand for “ecologically-grown” produce.
4. SRCs provide quality fruit for home gardeners and small-scale farmers, groups that frequently struggle to control apple scab on conventional cultivars.
5. SRCs may have potential for commercial processing. More than half of the apples grown in the eastern U.S. are currently destined for processing, so the use of SRCs for processing could lead to a significant reduction in fungicide use. Within the last three years, breeders and processors have begun screening advanced selections of SRCs for their potential as processing apples. Factors such as fruit color, appearance, and minor surface defects are less critical for processing than for fresh-market fruit. A few large processors willing to buy SRCs could provide an immediate outlet for thousands of tons of fruit. By comparison, getting a new cultivar established in fresh market channels requires that thousands of individual produce buyers at both the wholesale and retail levels must be convinced to change cultivars or “brand loyalty.”
Limitations of Scab-Resistant Cultivars
1. SRCs are limited by market economics. Studies revealed a major barrier to grower acceptance of SRCs. They showed that a net yearly savings of $200 per acre could be achieved if no fungicides were needed to produce SRCs. However, the high market value and productivity of orchards (crop values exceeding $10,000 per acre are readily attainable) means that a mere 2 percent loss in either production or sales price for SRCs relative to proven conventional cultivars would offset the savings in fungicide costs. Thus, SRCs would be profitable only if they are as productive and as marketable as proven varieties like McIntosh, Delicious, or Granny Smith. The higher prices that were anticipated for eco-labeling and reduced pesticide use in the wake of the Alar scare generally failed to materialize except in a few niche markets.
Planting new varieties is very risky for eastern apple growers wholesaling their fruit through brokers because fresh-market apples are sold and recognized by their varietal names. Under current conditions, it is very unlikely that any new apple cultivars (SRCs or scab-susceptible) can be introduced in supermarkets and achieve a measurable market share unless the introduction is supported and heavily promoted by large apple marketing groups.
2. SRCs have fruit quality limitations. None of the SRCs that we evaluated have distinctive and desirable fruit quality attributes such as those found in other recent introductions like Gala (unique flavor and appearance) or Ginger Gold (early-maturing, high-quality summer apple). Some SRCs have gained acceptance in local markets, but the perfect fresh-market SRC has yet to be developed.
3. SRCs cannot be grown without fungicides in most locations. Several diseases affect fruit during summer and must be controlled with fungicides applied during mid to late summer. As a result, the level of fungicide residues on SRC fruit at harvest will likely remain comparable to fungicide residues found on scab-susceptible cultivars because most residues come from late-summer sprays.
4. SRCs lose their resistance to apple scab if new scab strains are introduced. Scab-resistance in SRCs has a narrow genetic basis. If the SRCs were widely planted in the Northeast, they might require occasional applications of broad spectrum fungicides to forestall selection of races of Venturia inaequalis able to overcome the Vf and Vm resistance genes.
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. A dynamic model of the U.S. 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.
Growing SRCs with no fungicides, or with inadequate fungicide protection, can result in costly losses because summer diseases can reduce fruit quality.
For some cultivars, the increased crop value from mulched trees may justify the greater costs for the mulches.
Pesticide-use after mid-June may be substantially reduced, but at a significant cost in terms of increased management and, over three to four years, increased insect damage.
Reported October 1997.