I was recently (as in earlier this week when visited by the County Apple Police) introduced to the Washington State University (aka WSU, the creators of 'Cosmic Crisp') Decision Aid System, aka WSUDAS- Science for Crop Management. Among many features are articles and this one entitled 'Leafroller and Codling Moth Movement During the Season' caught my eye. It ended with:
"Impact of kaolin on CM migration
Our studies showed that a border spray of 3 rows with kaolin can reduce CM migration significantly, even in the face of high population pressure, as long as the coverage is thorough and without gaps. Kaolin works as a deterrent as females do not lay their eggs on surfaces covered with kaolin. We suggest to treat only border rows as the kaolin can flare spider mites and interferes with natural enemies (they spend more time cleaning themselves than attacking pest insects and mites). CM migration into an orchard from outside decreases sharply after the first few rows. In sloped orchards, however, CM may be able to fly over the top of the orchard border rows (instead of from tree to tree), thus migrating further than in flat orchards."
Spraying the perimeter would be much easier on the wallet than doing the entire orchard. Thoughts?
Washington Okanogan Valley
Zone 6b
Edited 1 time(s). Last edit at 05/07/2021 03:59PM by Michael Phillips.