Franz Niederholzer, UCCE Orchards Advisor, Colusa, Sutter-Yuba Counties

Early bloom and a warm March contributed to rapid almond crop development this year, with kernel fill and first hull split at least a week ahead of past years. Please consider the following suggestions when planning for preharvest pest management.

• Harvest timing: While harvest timing varies with orchard location and management, an earlier than usual harvest timing is expected. From what I can tell, many growers may start shaking in mid to late July. Shake date, not pickup date, should be used with pesticide preharvest Intervals to comply with label requirements.
• Hull split spraying reminders:
• First hull split sprays were early, with many sprayers going the week of June 15.
• Based on current heat unit (degree day) accumulations, the third generation of NOW should start 7 to 10 days ahead of last year. If timely Nonpareil harvest can be ahead of that generation, worm damage should be reduced. Test shakes are critical to balancing shake timing for best product quality and trunk health (no bark damage) with pest management (avoiding NOW).
• Slow sprayer speeds (for example, 2 MPH) and higher spray volumes (150-200 gallons per acre) deliver better pest management compared to higher sprayer speeds and less spray volume (for example, 3 MPH;100 GPA).
• Spraying when relative humidity drops below 40% can reduce spray coverage through evaporation. For better spray coverage, apply foliar sprays in the late evening into early morning under high heat and low humidity conditions.

If planning to use ant bait this season, consider advancing your ant bait spreading timing to match up with projected earlier harvest. If we have a poor almond drying year (smoke, higher humidity, etc.) it will be important to have good ant control where treatment is needed.