Submitted to: New York State Vegetable Conference & New York Stateberry Growers Meeting
Publication Type: Proceedings
Publication Acceptance Date: February 10, 1998
Publication Date: N/A
Interpretive Summary: This manuscript is intended to provide vegetable growers with the latest information regarding the most efficient application techniques for treating vegetable crops. Basics of good applications, such as calibration, proper nozzle selection, and nozzle placement, are critical to ensure effective application of pesticides. Particular emphasis must be placed on methods for increasing spray coverage which is important to ensuring the effectiveness of most insecticides and fungicides used on vegetable crops. Increasing nozzle pressure has been shown to be a less desirable technique for increasing coverage and canopy penetration. New technology as well as existing equipment can be used to increase on-target placement of pesticides. Recent vegetable sprayer research demonstrates the potential benefits of air-assist and electrostatic sprayer technology. Better quality fruit and cleaner crops have been produced in crops treated with these new technologies.
Technical Abstract: Proper distribution and deposition of pesticides are crucial to ensuring their effectiveness. Application needs vary depending on the pesticide, crop, and the pest problem. The little application research that has been conducted in vegetable crops has shown that equipment set-up, matching equipment to the crop canopy and pesticide, and air assistance can improve pest management. Much of the improvement can be attributed to increased spray coverage. However, increasing nozzle pressure to increase canopy penetration will probably not increase penetration because smaller droplets have been shown to slow more quickly to terminal velocity. In 1995, researchers in Arizona found that an air-assist sprayer and a sprayer using both air assistance and electrostatics provided better whitefly control in cantaloupe grown on raised beds. The electrostatic sprayer also produced more higher market value fruit. The air-assist sprayer used in the Arizona studies also produced higher spray deposits on the soil outside of the test plots. Recent potato sprayer evaluations conducted in New York found that an air-assist sprayer and a sprayer utilizing both air assistance and electrostatics produced higher underleaf spray deposits than conventional sprayers. These treatments also provided better protection against late blight infection. While there were no significant differences in mean deposits between traditional sprayer treatments, there were significant differences in the degree of late blight protection provided by these treatments. This suggests that perhaps spray coverage, a factor that was not evaluated in these studies, could be important in providing protection against foliar infections.