Submitted to: National Meeting of Entomological Society Of America
Publication Type: Abstract Only
Publication Acceptance Date: 7/1/2008
Publication Date: 11/16/2008
Citation: Ranger, C.M., Luis, C., Derksen, R.C. 2008. Can Pesticide Delivery Methods Play a Role in Sustainable Pest Management?. National Meeting of Entomological Society Of America.Available: http://esa.confex.com/esa/2008/webprogram/Paper34170.html Interpretive Summary:
Technical Abstract: Conventional insecticides continue to play an important role in greenhouse pest management programs. Penetrating a dense plant canopy can be difficult with a handgun, and there is some evidence that boom sprayers or broadcast applications result in a more uniform deposition than handguns. A large-scale study was therefore undertaken to assess the ability of different insecticide delivery methods to penetrate a canopy, and to assess the efficacy associated with each delivery method. Deposition and efficacy were compared using four different insecticide delivery methods, namely, a handgun at 50 and 100 gallons per acre, a boom sprayer, and an air-assisted sprayer at 100 GPA. For efficacy purposes, the silverleaf whitefly was chosen because it feeds almost exclusively from the under surface of leaves. Nylon screens were also attached to the underside of leaves on the infested plants at upper and lower canopy elevations. The screens were then rinsed and analyzed by GC-MS for quantifying the insecticide pyridaben. Plants that were infested with whiteflies and also contained the target screens were randomly placed on a greenhouse bench. Deposition analysis documented a significant treatment by elevation interaction. For every treatment, except the boom application, there was significantly lower deposition on the lower canopy target vs. the upper canopy target. Furthermore, deposition on the lower leaf surface was significantly greater with the air-assisted application compared to the remaining delivery methods on the lower leaf surface. Therefore, the air-assisted application provided better penetration of the canopy. With respect to efficacy in the upper canopy, there was not a significant difference between treatments. In the lower canopy, control was also minimal, but the air-assisted application did provide significantly better control than the handgun at 50 GPA and the untreated control. Consequently, penetration of the canopy is not always better with boom or air assisted delivery methods compared to a hand gun. It is therefore important to choose the insecticide and delivery method best suited for a particular canopy and target insect.