Franz Niederholzer, UCCE Farm Advisor, Colusa, Sutter and Yuba Counties
Luke Milliron, UCCE Farm Advisor, Butte, Glenn and Tehama Counties
Katherine Jarvis-Shean, UCCE Farm Advisor Sacramento, Solano & Yolo Counties
Please note that the following are general recommendations intended to help you keep track of regular practices in a busy time; the optimal timing for management practices may vary based on specific location and conditions.
- Pest & Disease Monitoring: Continue monitoring for aphids and rust.
- Spider mites: Begin scouting by checking two different sections of the orchard each week. Spend about five minutes in each section, checking 2-3 leaves (some inside and outside of the canopy) on 10 trees. Look for spider mites and predators (predaceous mites and sixspotted thrips). Treatment decisions should be based on population levels of both mites and predators. If more than 20% of leaves have mites, but less than 50% of the leaves have predators, treat for mites. If more than 60% of leaves have mites, treat even if most leaves have predators. For more on mites, see the UC IPM Page on Webspinning Spider Mites.
- Irrigation Management: To avoid excessive vegetative growth and associated pruning costs, maintaining a mild to moderate tree water stress with the pressure chamber from late June, through early August reduces shoot growth without slowing fruit sizing. Learn more from our article on Pre- and Post- Harvest Irrigation Management in Prunes.