Mark Gleason, Professor, Iowa State University Department of Plant Pathology, Entomology, and Microbiology in the U.S., describes the pesticide problem and in this vein, why testing new options is needed to sustain apple production.
2021 was a dry year for Iowa, which caused conditions of low relative humidity through most of the spring and summer. In each on-farm trial, the SBFS warning system saved 3 fungicide sprays compared to the standard calendar-based spray program, with no loss of control of any disease.
Getting an airblast sprayer ready to use in an apple orchard involves a fair amount of tweaking. Sprayer pressure, nozzle size, and travel speed may need to be adjusted to spray for insect pests and diseases in the upcoming growing season. The goal is to get adequate coverage. But how can you make pesticide spraying more efficient?
Conventional airblast sprayers operate in continuous spray mode, so they can’t adjust sprayer flow rate in real time to match canopy conditions. For apple growers, this familiar type of sprayer can do a good job of controlling diseases and insect pests, but it wastes pesticide because much of what goes out the nozzles never hits the target.
When apple growers plan their pesticide spray programs, they may think about a couple of important factors: spray coverage and spray drift. What’s the difference? How do we measure spray coverage? How do we manage spray drift?