ORCHARD SYSTEMS PROJECT
Apples have been grown and consumed for over two thousand years. Seeds and grafted trees from European cultivars were brought to North America and planted by the earliest settlers in the late 1600s. In colonial days, apples were mainly used for making cider and applejack and for feeding livestock. Today we enjoy apples year round—both fresh and in a variety of processed products.
Orchards are a beautiful part of our regional landscape. But, apples also represent many of the issues facing food production today. Pesticide usage per acre in commercial apple orchards is greater than most other food crop systems; and in our present economy, orchards often turn into housing developments. The challenge for growers and consumers is to create environmentally and economically sustainable fruit production systems.
More than 40 insect and mite pests and 10 or more diseases threaten apple crops in the Northeast each season. Coupled with consumer demand for blemish-free, perfectly shaped fruit and heavy pest pressure, growers traditionally have relied on intensive spraying programs to keep insect and disease problems under control. Recently, there has been an increased interest from growers to reduce the risk of pesticide exposure and find alternative ways to manage pests and diseases. Public awareness of chemical use on apples has also increased, especially since the highly publicized ALAR scare in the early 90s. Since 1986, Rodale Institute’s Orchard Systems Project has been evaluating biological and cultural pest management alternatives to conventional spraying programs and has provided information on the efficacy of these techniques to growers and backyard orchardists. The Orchard Project has been working to:
- To reduce pesticide use in apple production by developing management options for key orchard pests
- To better understand the insect population dynamics of a bio-intensively managed system.
In 1988, the orchard at the Research Center became part of the Northeast Sustainable Apple Production Project, funded by a USDA Sustainable Agriculture Research and Education grant. Other institutions involved with the project are the University of Vermont, the University of Massachusetts, Rutgers University, and Cornell University. One major component of this project is to evaluate new scab-resistant cultivars. The new cultivars are grown at each of the five sites, allowing the researchers to monitor the trees’ performance (e.g. horticultural performance and susceptibility to insects and diseases) in different regions.
In addition to our new cultivar evaluation work, an Advanced Integrated Pest Management (IPM) Trial was initiated in 1993 with Pennsylvania State University. Advanced IPM focuses on minimizing pesticide use as much as possible, while producing an economically viable crop. Orchards managed with new biological technologies and minimum pesticide inputs require extensive evaluation before growers can adapt these systems with a fair degree of confidence.
The past two years of the Advanced IPM project have produced complex and interesting results. The pest/beneficial insect complex inhabiting the RIRC orchards is markedly different from that of conventional commercial orchards. Because most commercial orchards are managed using 12 -14 spray applications each growing season, both pest and beneficial insects are eliminated. Although the RIRC orchards were sprayed two times in 1993 and 1994, the timing of these two sprays had less of an effect on beneficial insects, especially predatory mites. The two early season insecticide applications were used to control plum curculio, a troublesome fruit pest in the Northeast that has no effective biological or cultural control at this time.
Parasitism (when an insect completes its larval development within the body of another insect, eventually killing it) of various leafroller species, which are major pests in Pennsylvania, was at high levels in 1993 and 1994, with correspondingly low levels of leafroller fruit damage. However, due to our minimal use of pesticides, several uncommon insect pests were also observed. One major fruit pest codling moth was responsible for fruit damage over economic threshold levels. In 1995, we address alternate controls for codling moth in the Advanced IPM trial.
No fungicides were used to control apple scab or any other diseases in this orchard, because we are monitoring the scab-resistant cultivars. We monitored trees for other diseases, such as sooty blotch, flyspeck, cedar apple rust, and powdery mildew, that may be problematic when no fungicides are used.
1995 Research Activities
In 1995, we will be conducting the Advanced IPM trial for the third year.
This year our work will focus on codling moth control. The entire orchard will be treated with pheromone-based mating disruption for codling moth, a new bio-control product that uses a synthesized female insect pheromone (a scent produced by the female insect to attract the male for mating). The synthetic pheromone is encased in small plastic dispensers that are placed in trees throughout the orchard. The product slowly dissipates from the dispensers and saturates the orchard air with pheromone, confusing the male moths as they unsuccessfully try to locate the females to mate.
Along with pheromone-based mating disruption, some orchards may need to use some supplemental measures to effectively control codling moth due to orchard design, geographical factors, or specific pest pressures. The RIRC orchard will use an additional biological control because of the long and narrow design of the orchard. A small parasitic wasp (Trichogramma minutum) will be released at four
different rates in a replicated trial within the Advanced IPM orchard.
The management system for the orchard other than codling moth will consist of:
- Scab-resistant cultivars - no fungicides are needed for scab and none will be used for other diseases
- Red spheres coated with Tanglefoot (a sticky substance) placed around the perimeter to trap apple maggot flies
- Application of 2-3 insecticide sprays from April to the end of May to control plum curculio, tarnished plant bug, and European apple sawfly
- Removal of apple drops after harvest to reduce overwintering insect and disease pest organisms
- Tree-row weed management with a rotary tine cultivator in lieu of herbicides
- Horticultural management that include trickles irrigation, tree training, and hand thinning of fruit.
Terry Schettini, P.h.D., Program Coordinator
Sarah Wolfgang Heffner, Project Leader
Ed Lachowski, Researcher
Don Jantzi, Field Operations Foreman
Project Status: initiated 1986
Advanced IPM Trial: 1993
Management Guide for Low-Input Sustainable Apple Production (USDA/SARE, 1990)
Organic Apple Pest Management Observations 1991-1992
Additional support for this
project is provided by:
USDA Sustainable Agriculture Research and Education Program (SARE) AND
Sustaining Agriculture and Natural Resources in Urbanizing Environments (SANRUE)