Low-volume sprayer rodeos

Authors: Hoffmann, Wesley; Fritz, Bradley - Brad; Martin, Daniel - Dan

Submitted to: Florida Grower
Publication Type: Popular Publication
Publication Acceptance Date: 12/15/2009
Publication Date: 12/20/2009
Citation: Hoffmann, W.C., Fritz, B.K., Martin, D.E. 2009. Low-volume sprayer rodeos. Florida Grower. p. 12-13.

Interpretive Summary: Citrus greening is a disease that threatens the survival and economic viability of the Florida citrus industry due to the disease's ability to kill an infected tree. An insect called the Asian citrus psyllid is a carrier of the bacteria that causes citrus greening; therefore, citrus growers are using several insecticides and sprayers to find the most effective method to control the insect. Studies involving numerous citrus sprayers and active ingredients were conducted to determine the droplet size generated by the different sprayers and to adjust the sprayers to meet a droplet size requirement that is on many insecticide labels. In the sprayer tests, reductions in engine speed or increases in flowrate were required to increase droplet sizes to meet the product label-required droplet size. As the equipment tested here represents the most typical application equipment used in Florida for psyllid control, these results will provide applicators, growers, and extension agents with general guidelines to insure that spray systems are operated in a manner that complies with label restrictions.

Technical Abstract: Citrus producers have found that many pesticides, when applied properly, are very effective at suppressing or eliminating citrus psyllids, which are a vector of citrus greening. Due to threat that greening, several pesticides have been granted special local needs registration for use in the State of Florida if the product is sprayed with a volume median diameter of 90 microns or greater. A number of studies involving numerous citrus sprayers and active ingredients were conducted to determine the droplet size generated by the different sprayers and how to adjust the sprayers to meet the 90 micron requirement. In the sprayer tests, it was found that reductions in engine speed or increases in flowrate were required to increase droplet sizes to meet the product label required droplet size. As the equipment tested here represent the most typical application equipment used in Florida for psyllid control, these results will provide applicators, growers, and extension agents with general guidelines to insure that spray systems are operated in a manner that complies to label restrictions.