Maximizing Efficacy of Microsprinkler Chemigation
- Bioassays are a useful tool. They provide comparable information between products but underestimate actual field toxicity because they only take into account mortality as a result of dried residues during a 24 or 48-hour period and not droplet impact. In the field however, flies constantly inhabit a toxic environment, come in contact with both wet and dry residues and experience direct impact by droplets, as a result actual field efficacy is always higher than bioassay results.
- Efficacy, percent mortality of SWD, can be improved by manipulating the order of insecticides in a blueberry management program. This is also true for regular airblast applications.
- Leading off the season with a pyrethroid will provide a longer, protective layer that will boost efficacy of subsequent lesser residual insecticides!
Future of Microsprinkler Chemigation for SWD Control
Results of both our Washington and Oregon trials, even with different microsprinklers, indicate microsprinkler chemigation is an effective method of controlling SWD in blueberry. Interest in microsprinkler chemigation for SWD continues to expand in Oregon and interest is growing in Washington and British Columbia. The bottom line is no berry rejections caused by wormy fruit have been reported from cooperator fields in Oregon or Washington. Ongoing advances in irrigation technology will continue to increase speed and efficacy of microsprinkler chemigation for SWD control in blueberry. Irrigation companies should continue working to lower costs, making it economically feasible for all levels of blueberry production.