Integrated Pest Management 



POTENTIAL FOR GREENHOUSE PRODUCTION 



GAIL D. MCWILLIAM 



The concept of dealing with pests has changed over the years. 

 Today we more commonly manage pests at tolerable levels, 

 rather than eradicate them. This concept is called Integrated 

 Pest Management, or IPM. 



IPM, as the name implies, is a system of managing pests 

 with a variety of different methods 



including cultural, biological and ^H 



chemical. The emphasis is on 

 procedures that are environmentally 

 compatible, economically feasible 

 and socially acceptable. 



The components of an IPM 

 system can be grouped into four 

 major steps: 



1) Prevent pest build up. 

 Practices are implemented before a 

 full-blown pest problem develops. 

 Once pest populations explode, they 

 are very difficult to control, even 

 with chemical pesticides. 



2) Monitor pests. 

 Monitoring means regular checking 

 and early detection of pests and 

 determining if any natural controls 

 Cmsect predators, etc.) are present 



3) Assess pest situation. 



Determine the potential for pest 

 populations to reach intolerable 

 levels. 



4) Determine best action to 

 take. Decide what, if any, is the best 

 course of action in this situation. 

 Chemicals are always a last resort. 



In New Hampshire, IPM 

 practices have been used histori- ^H 



cally and most successfully in apple 

 production. New Hampshire apple growers have been able to 

 dramatically reduce pesticide use in their orchards over the 

 last 15 to 20 years, while maintaining quality product 



This success has led to research in IPM methods for other 

 areas of crop production. A New Hampshire Extension IPM 

 team has recently been established to coordmate IPM 

 research projects in other crop commodity areas. The team 

 has identified a number of potential projects, including some 

 involving greenhouse production. If funding for IPM projects 

 is approved, pilot projects may be implemented by the team 



NON-CHEMICAL 



PEST MANAGEMENT OPTIONS 



INCLUDE: 



CULTURAL COI^ROLS 



practices that disrupt the environment 



of the pest such as crop rotation, equipment 



sanitation, etc. 



BIOLOGICAL COrJTROLS 



using natural enemies to control pests like 



insect predators, species-specific diseases, etc. 



PHYSICAL BARRIERS 



Materials \\k6 netting or plant covering that 



physically prevent pests from reaching the plants 



PHEROMONES TRAPS 



Pheromones are natural Insect scents that can 



be used to confuse Insects, lure them Into traps, 



or away from crops. In addition to pheromone 



traps, color-cued traps are also effective. 



INDICATOR PLANTS, TRAP CROPS: 



Indicator plants are plants that are more 



attractive to pests than the main crop. 



Placed among the main crop these are 



monitored for signs of infestations. Trap crops 



are similar to Indicator plants, but they have 



been treated with a pesticide. 



PEST-RESISTANT VARIETIES: 



Plant crop varieties that have shown resistance 



to damage by certain insects and diseases. 



this year. Major areas of interest are whitefly and disease 

 management in poinsettia production. An initial project may 

 focus on this topic. Stay tuned! 



IPM has been a key interest of a number of greenhouse 

 operators, but concern about risks to a high value crop has 



prevented many from adopting these 

 BB practices. A recent IPM demonstra- 



^™ tion conducted by UNH Cooperative 



Extension, Merrimack County, 

 focused on whitefly management in a 

 greenhouse at the Merrimack County 

 Jail. The project looked specifically at 

 whitefly management on tomatoes. 

 Emphasis was on biological control 

 with timely release of Encarsia 

 fomwsa, a tiny parasitic wasp that 

 attacks whiteflies. Whitefly popula- 

 tions were monitored weekly with 

 sticky traps placed throughout the 

 greenhouse. 



Encarsia releases were made at 

 regular intervals and no pesticides 

 were used during the growing 

 season. The combination of careful 

 monitoring and biological control 

 were found to be effective in manag- 

 ing the whitefly population at a 

 tolerable level. 



In another example of IPM work, 

 Merrimack County Cooperative 

 Extension seeded endophytic grasses 

 around a greenhouse at Pleasant 

 View Gardens, Pittsfield, to reduce 

 populations of insect pests that could 

 migrate from turf through vents into 

 the greenhouse. Endophytes are 

 ^H fungi found in certain grasses that 



produce chemicals that either kill or 

 repel several sucking insects. The project has shown signifi- 

 cant reductions of insect populations. 



A project similar to that in Merrimack County with 

 Encarsia formosa is planned for the 1993 season in Sullivan 

 County. Kathan Gardens, Newport, has agreed to work with 

 Sullivan County Cooperative Extension in a local demonstra- 

 tion program looking at whitefly and/or thrips management 

 through the release of parasites and predators. A spring 

 project is planned beginning with the placement of sticky 

 traps to monitor pests in the greenhouse. Research has 



April & May 1993 

 17 



