Development of Fungal Entomopathogens for Greenhouse IPM (ANE95-23)

Development of Fungal Entomopathogens for Greenhouse IPM (ANE95-23)

Summary

This three-state research and education initiative aims to encourage greenhouse growers to use IPM, including biological controls such as insect-killing fungi, for production of greenhouse ornamentals.

Accomplishments to date include:

The Tri-State IPM Advisory Committee was established in 1995 with grower, researcher and extension representatives from Maine, New Hampshire and Vermont to educate growers about IPM techniques in greenhouse production.

The committee conducted a survey in 1996, the results of which were used to develop a strategy for IPM education that is now being implemented. One workshop has already been held and two more are planned for 1998.

Preliminary laboratory tests suggest that fungal preparations are compatible with a variety of greenhouse beneficial organisms.

Plant regrowth regulators and biorational insecticides that are used in greenhouse production are commonly compatible with the use of fungal insecticides.

Some older insecticides were incompatible with fungal insecticides. Fungicides were the most inhibitory to the effectiveness of fungal insecticides.

Objectives
1. Establish a regional IPM Advisory Committee comprised of growers.
2. Initiate a three-year demonstration scouting program and Tri-state training workshops.
3. Assess compatibility of fungi with beneficial and biorational pesticides.

Method and Findings
Use of IPM is increasingly being advocated for ornamentals production. Presently, however, IPM is not widely practiced by growers in northern New England. Reasons for this include a general lack of knowledge of IPM techniques and a lack of opportunities to acquire an understanding of the techniques and necessary skills required to develop and implement an IPM program. Our goals have been to develop ways of increasing growers’ awareness of IPM practices by providing grower-oriented, hands-on educational workshops on some of the basic "how to’s" of IPM and to conduct research to address the integration of mycoinsecticides with other control tactics.

The Tri-State Advisory Committee, established in 1995, has met several times to discuss strategies for increasing IPM implementation in Maine, New Hampshire and Vermont. The first workshop proved very successful. Many of the growers who attended had never seen what an infected or parasitized insect looked or the different life stages of the common pests or beneficials.

One grower had said prior to the workshop that he never had thrips problems. Within one month of the workshops, he called to say he had a severe thrips problem and needed help developing a management strategy. He admitted that if he had not gone to the workshop, he would never have known they were thrips.

The committee is planning more workshops and a seminar in 1998 on the "Practical Application of Natural Enemies in Greenhouse IPM."

Fungi are not a "silver bullet" solution to all pest problems and will be more effectively utilized within an IPM program. Use with other IPM "basics" such as scouting will be essential for growers to decide on the optimal time to apply pest management techniques. In order to rationally utilize fungi in an IPM program, growers need information on the compatibility of fungi with chemicals and natural enemies used in greenhouse crop management. This sort of information is critical to facilitate the timely use of pesticide sprays or release of beneficials which will minimize any potentially negative interactions and maximize control effects.

In general, results of our in vitro trials suggest a high degree of compatibility between fungi and plant growth regulators and biorational insecticides (IGRs, soap, etc.); predictably, fungicides were most inhibitory.

Commercially, fungal products are formulated with materials such as emulsifiable oils, clays and other adjuvants, which are known to be toxic or repellant to certain beneficials. Current research is assessing the effects of commercially formulated myco-insecticides, focusing on survival of parasites in scales which are subsequently treated with fungi, and on parasitization rates when leaves have been treated with fungi prior to the parasitoids’ release. These trials, which are being carried out on poinsettia, will provide necessary practical information on the concurrent use of these two biocontrol agents. Results will be presented in the next report.

The different project components will serve to advance alternative approaches to pest management in ornamental crops, providing growers with the necessary tools to begin to use IPM techniques with confidence.

Reported December 1997.