Enhancement, Implementation - Evaluation of Biologically Based Pest Management Tactic for Three Key Pests in Production Nurseries

Enhancement, Implementation - Evaluation of Biologically Based Pest Management Tactic for Three Key Pests in Production Nurseries

Summary

The importance and production of ornamental plants has increased dramatically over the past decade. For example, production of nursery and greenhouse crops is first among all crops in 10 of the 12 states in the Northeast region. Pest management is a major component and challenge in ornamental plant production. This industry is heavily dependent on pesticides, which continue to be its primary pest control method (Hudson 1996). Nursery growers and Integrated Pest Management (IPM) scouts are looking for non-chemical pest management alternatives due to societal and regulatory (FQPA) pressures and their own desire. However, growers and scouts are unwilling to take the risks associated with new methods until they have been demonstrated to be economical, practical, and effective. This project aims to address these needs and reflects input solicited from IPM scouts and nursery growers in Maryland.

The 4 phases of the proposed 4 year project are: 1) research to evaluate the efficacy of, and refine techniques for using a biologically based pest management tactic, 2) a demonstration phase to integrate this and other tactics into a biologically based IPM program in commercial nurseries and evaluate their applicability (efficacy, ease of use, and profitability), 3) an education phase to extend results to end users and increase the likelihood of adoption of these biologically based tactics and IPM, and 4) perform an impact assessment to determine and document changes in practice, knowledge, and attitudes of beneficiaries. In addition, a committee of project beneficiaries (IPM scouts, nursery managers, and demonstration cooperators) will be formed from which feedback, in the form of discussions and emails with project investigators, will be solicited at key points in the project to assure the project stays on track.

Success of this project should lead to adoption of profitable, environmentally sound pest management practices, reduced health risks, bring ornamental plant production closer to sustainability, lead to a better management of resources, and have a positive influence on urban communities and the environment surrounding nurseries in the Northeast.

Objectives/Performance Targets

1. To refine and evaluate biologically based pest management tactics, habitat manipulations, for their feasibility (effectiveness, ease of use, and profitability) in increasing generalist predator populations, with a concomitant reduction in pest populations (Research).

2. We predict that 3 of the 4 commercial nurseries and all 3 of the 3 IPM scouts engaged in the demonstration phase of the project will continue to implement biologically based pest management tactics over chemical tactics (Demonstration).

3. We predict that 100 of the 250 nurseries in Maryland will increase their implementation of biologically based tactics, and that 25 of the 36 participating Extension personnel in the NE region will increase the number of times they train on biologically based control tactics for one year after participating in SARE education programs compared to the previous year (Education and Evaluation).

Accomplishments/Milestones

For 2002, our goal was to develop and evaluate biologically based pest management tactics by conducting an applied research project (Performance Target 1). More specifically we determined: 1) the effect of adding wood mulch to nursery beds with container plants of Cotoneaster dammeri compared to weed cloth beds and 2) the effect of plant / pot position (above ground compared to pot in pot) on arthropod (herbivore, alternative prey, natural enemy) taxa and abundance and herbivore (Hawthorn lace bug and black vine weevil) survival. This goal was accomplished.

In 2003, we identified 3 nursery cooperators. In 2003 and 2004, the demonstration phase of the project was implemented (Performance Target 2). This phase integrated biologically based tactics into commercial nurseries and evaluated their applicability. The goal was to increase the implementation and adoption of biologically based pest management tactics over chemical tactics (Performance Target 2). In one nursery, during 2003 and 2004, we implemented a program targeting the management of azaleas and their key pest, azalea lace bug. We examined biologically based tactics such as: two habitat manipulations (use of wood mulch ground cover, a pot-in-pot planting system), and augmentative release of predators (green lacewing). Additionally, we further examined the impact of habitat manipulations on ground active compared to foliar feeding pests. In a second nursery, in 2003 and 2004, we examined the use of augmentative releases of predatory mites to manage a key mite pest, southern red mite, on Ilex species. In a third nursery, during 2004, we examined the use of the pot-in-pot planting system and entomopathogenic nematodes to manage black vine weevil.

In 2003 and 2004, results of the research and demonstration projects were presented at educational programs throughout the Northeast region (Performance Target 3).

Impacts and Contributions/Outcomes

As part of the research phase of this project, we evaluated biologically based pest management tactic, habitat manipulations, for their feasibility in increasing generalist predator populations, with a concomitant reduction in pest populations and damage (Performance Target 1). In comparing the taxa and abundance of alternative prey and natural enemies in plant containers between ground cover types (mulch vs. weed cloth beds), and pot position (pot in pot vs. above ground pots) we found no effect of mulch. However, natural enemies were greater in pot-in-pot containers than in above ground containers. Individual predators, such as ants, rove beetles, ground beetles, and spiders, and a parasitoid (Scelionidae) were found to be more abundant within pot-in-pot containers than in containers above ground. Arthropods, such as Collembola that serve as alternative prey for beneficial insects, were also more common in the pot-in-pot position than the containers above ground.

We found that the mulch and weed cloth treatments rarely differed in their effect on survival of hawthorn lace bug nymphs or the eggs and larvae of black vine weevils. We also found that the pot position had a variable effect on hawthorn lace bug survival. However, pot position significantly affected black vine weevil egg and larvae survival. In all experiments, predation of eggs and larvae was dramatically higher in containers in the pot-in-pot versus above ground planting method.

As part of the demonstration phase of this project, we implemented biologically based pest management tactics in 3 nurseries. At nursery 1, treatments were based on results from the research study described above. We examined two habitat manipulations (ground cover type: use of wood mulch ground cover vs. weed cloth, and pot plnating system: pot-in-pot vs. above ground), and augmentative release of predators (green lacewing). Additionally, we further examined the impact of habitat manipulations on ground active compared to foliar feeding pest insects (herbivore on soil vs. herbivore on foliage). Data from 2003 have been analyzed, while data from 2004 are presently being analyzed. To date the data indicate that ground cover type and pot position had a significant effect on generalist predator and alternative prey abundance within the plant containers. Where abundance was greater in wood mulch compared to weed cloth plots, and greatest in the pot-in-pot than above ground planting method. However, there was no significant effect of ground cover type, and a slight effect of planting method on herbivore survival (a trend for lower survival in pot-in-pot). Herbivores active in the soil (at the soil line) were significantly more susceptible to predation compared to herbivores on the foliage. This effect was slightly enhanced in pot-in-pot plants and ground cover did not influence this effect. Cost and impact evaluations of this program are underway.

As part of the educational phase of this project, results of the research and demonstration projects were presented at several professional and end-user educational programs throughout the northeast region in 2003 and 2004. These included: 3 presentations at Entomological / IPM professional conferences; 3 University seminars; 8 green industry professional association meetings, Cooperative Extension short courses, and pesticide re-certification conferences; and 1 nursery field day held in MD. In 2004, an overview of this project was placed on line at http://shrewsburylab.umd.edu. A summary poster on the effect of habitat manipulations on pest insects and natural enemies on ornamental nurseries was developed and displayed for the Northeast SARE conference in Burlington Vermont during October 2004.

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