nov-dec-2020

to a dormant spray. However, with below average rainfall forecast, be careful with horticultural oil in dry (soil and/or trees) orchards to avoid oil burn. Consult with an experienced PCA regarding rates, materials and timing when planning a dormant spray. Reducing navel orangeworm (NOW) damage at harvest begins now, with orchard sanitation before bloom. There is no effective dormant spray for navel orangeworm control as the pest is protected from spray inside the mummy nut. NOW survive in the orchard in mummy nuts from the previous crop. These nuts are also food and housing for the first NOW generation in the coming spring. Getting rid of as many mummy nuts as possible this winter is critical to keeping NOW numbers (and nut damage) down next year. There are four steps to effective sanitation: monitoring, shaking/ poling, windrowing/shredding and monitoring after sanitation. Before January 15, check 20 trees per acre across an orchard, counting mummy nuts still in the trees and those on the ground. Include all varieties in the orchard in the survey as NOW can use all varieties for shelter, including hardshells where they survive between the hull and the shell. If there are more than two mummies per tree, on average, then the recommendation is to sanitize the orchard — shake/pole, windrow and shred all nuts with a flail mower. The trees should be shaken by the end of January, perhaps stretching into early February in a normal year, and the nuts shredded by March 1. The shredding must be slow and deliberate so that no nuts survive intact. Monitor the orchard after sanitation to confirm that there are less than two mummies per tree. In the southern and central San Joaquin Valley, the TRUST. IT'S IN OUR ROOTSTOCK. order now! № 1-844-DWN-TREE DWNTREES.COM l f @davewilson Blue Diamond Growers does not endorse or verify statements made by advertisers within this publication. 4 5 N O V E M B E R – D E C E M B E R 2 0 2 0