Project Overview

Commodities

• Fruits: berries (strawberries)

Practices

• Crop Production: low tunnels

• Education and Training: decision support system, demonstration, on-farm/ranch research

• Farm Business Management: feasibility study

• Natural Resources/Environment: habitat enhancement

• Pest Management: biological control, cultural control, field monitoring/scouting, weed ecology

• Production Systems: agroecosystems

• Sustainable Communities: sustainability measures

Growing crops under plastic tunnels is an increasing trend in the northeastern U.S. due to the benefit of extending the growing season of high-value crops. Northeastern strawberry growers, in particular, are interested in low tunnel systems because strawberries are an important commodity in the region and extending their growing season poses substantial benefits. However, a major barrier to producing low tunnel strawberries that has yet to be addressed is the positive effect they have on some pests, including the two-spotted spider mite (Tetranychus urticae)(TSSM), which can reach especially high densities under plastic tunnels. Objectives of this project are to 1) quantify pest incidence on low tunnel strawberries, and 2) identify biological control options for TSSM that are effective under low tunnels. Addressing objective 1 will require interdisciplinary collaboration to quantify weeds, pathogens, and arthropod pests on low tunnel strawberry. TSSM is a major pest that is often problematic under plastic tunnels and is resistant to many miticides. Although TSSM biocontrol is available, control success is variable and efficacy under low tunnels is unknown. Objective 2 will evaluate which commercially available predators are effective under low tunnels and how often and at what rate to release them. Information on pest incidence and options for management are needed by low tunnel growers, especially as this system becomes common in the Northeast. The goal of this project is to provide this information and disseminate it to growers via stakeholder publications and YouTube videos demonstrating tunnel management and TSSM biocontrol under low tunnels.

1. Describe the incidence of strawberry pests under low tunnels with a focus on arthropods, pathogens, and weeds. There is currently little research devoted to pest surveys of protected culture crops although this production system is increasing in popularity among growers in the Northeast. By surveying common strawberry pests under low tunnels compared to other production systems, this objective aims to develop new information on pest barriers and challenges of low tunnel systems. Surveys will be conducted on low tunnel, conventional, and organically grown strawberries in central New York, both in research plots and at commercial strawberry farms. We predict that several pests of strawberry respond positively under plastic tunnels such that they reach higher densities on low tunnel strawberry. Past observations indicate that spider mites, slugs, tarnished plant bugs, long-necked seed bugs, creeping perennials, and some pathogens establish well under low tunnels, thus a special focus will be made on these particular pests. Weeds are likely less of an issue, though some species may present specific challenges. Dr. Kerik Cox, an associate professor in plant pathology at Cornell, has agreed to provide guidance on identifying disease incidence and severity as a collaborator on this project.

2. Develop biological control recommendations for two-spotted spider mite that are tailored for low tunnel strawberry systems. A major concern of strawberry growers is the effect low tunnels have on TSSM, as this species is pesticide resistant and reproduces well under plastic tunnels. A promising alternative for control of TSSM is biological control. Objective 2 is intended to develop specific biocontrol recommendations for TSSM on low tunnel strawberry by testing predator efficacy, optimal release rates, and the number of releases required to provide sustained control. Five predatory mite species will be tested that represent different prey and habitat preferences 19. Two are specialists of TSSM while the remainders are generalist predators. All are commercially available in the Northeast and marketed for TSSM control although they differ considerably in their ecology. Their ability to control TSSM under low tunnels will be evaluated in this objective including optimal release rates of predators and number of releases necessary for control success. We predict that combinations of specialist and generalist species, released several times during the season and at higher rates than recommended for conventional strawberries will provide the best control of TSSM under low tunnels.