Natural pest management in New York high tunnel and greenhouse vegetables

2007 Annual Report for LNE07-262

Project Type: Research and Education
Funds awarded in 2007: $108,905.00
Projected End Date: 12/31/2010
Region: Northeast
State: New York
Project Leader:
Judson Reid
Cornell Vegetable Program

Natural pest management in New York high tunnel and greenhouse vegetables


High tunnels and greenhouses offer high returns and season long market capture for Northeast fresh market vegetable farmers. However, the enclosed environment of a high tunnel/ greenhouse creates a separate pest complex from field production.

This project is an example of Integrate Pest Management (IPM) within the season extension technology. Our focus is on biological control of pests and diseases. In this project we consider biological control to include classic arthropod control with predatory and parasitic beneficials, microbial fungicides and plant resistance.

The use of biological control in protected culture has a long history and widespread adoption in areas such as Europe, Canada and the Mediterranean. Large-scale U.S. vegetable greenhouses also now use biological control. However, adoption by small-scale operations in the Northeast is currently low.

This project will increase the adoption of biological pest management among greenhouse and high tunnel vegetable growers in New York. We aim also to decrease pesticide use and increase yields. This will be accomplished through on-farm demonstrations, one-on-one contacts and other education events. Participating farmers will gain an understanding of the proper use of natural controls through a well-rounded understanding of the biology of both the pests and diseases to be controlled and the natural enemies to be deployed.

In year 1, nearly 30 surveys were completed by farmers throughout New York indicating pests and diseases of major concern in high tunnel and greenhouse vegetables. Our first field season found us focused on spider mites, aphids, thrips, leaf mold and powdery mildew on crops such as cucumbers, peppers, and tomatoes.

We accomplished several milestones towards the goal of increased adoption of biological control. These include the recruitment of 4 farms to host trials, 1 on-farm demonstration and several winter meetings focused on biological control. A part-time technician was hired to monitor pest populations, document the impact of biological control measures, and input data. These results were shared in our winter meetings.

At our year 1 demonstration farm we implemented a successful biological control program for thrips on greenhouse cucumbers. We were able to bring the thrip population down to zero without pesticides. Fortunately this coincided with the date of our on-farm field day, with over 40 farmers in attendance.

Farmer interest the summer field meeting and winter educational events has been strong. In year two we will continue our work by hosting more on-farm trials and inviting neighboring farmers to visit our demonstrations. The major crops will be tomatoes and cucumbers, but we also have an opportunity to include aphid management in early season high tunnel lettuce production.

Objectives/Performance Targets

About 30 greenhouse/high tunnel vegetable growers completed pest/disease surveys, ranking issues of greatest relevance.

2 farms hosted research/demonstration trials.

40 growers attended an 1 on-farm demonstration meeting.

40 growers attended a winter meeting presenting results from 1 on-farm demonstration and basics of biological control in greenhouse/high tunnel vegetables.

4 farms committed to hosting on-farm trials in year 2.



1 on-farm trial was a convincing success. We achieved control of thrips in greenhouse cucumbers with the release of predators (Amblysueis cucumeris). Populations dropped from block counts nearly 400 thrips (12 leafs per block, 4 randomized blocks)to 0 within a month of an aggressive release program.

A 2nd on-farm trial resulted in partial crop loss. We were not able to completely control a high population of spider mites on greenhouse tomatoes. A non-sprayed, untreated block of plants had to be removed from the greenhouse because of the intense pest pressure.

A summer technician collected data on a regular basis at these 2 farms as well as candidates for year 2 demo sites. Data was entered and analyzed in the fall of 07.

Impacts and Contributions/Outcomes

The successful trial of thrips control in greenhouse cucumbers provided an excellent opportunity for demonstration. We hosted about 40 farmers at this site.

However, we did have one farm where we were unsuccessful in controlling two-spotted spider mites on greenhouse tomatoes. In this situation we were likely too late with our control measures. We learned a valuable lesson on intense scouting and early releases of predatory mites.

We also compared control costs to the crop value to illustrate the economic benefit of this approach. Slightly higher costs when compared to chemical controls should be considered in the context of decreased environmental impacts and improved working conditions. As we fine-tune our skills in biological pest management, we will likely continue to decrease the cost with precise, well-timed releases.

Our experience with disease resistant plants was very positive. For example, by only planting resistant cucumber varieties, we kept powdery mildew out of our tunnels.

Adoption is to be measured in year 3.


Kathryn Klotzbach
Program Assistant
Cornell Vegetable Program
12690 Route 31
Albion, NY 14411
Office Phone: 5857984265