Blue Diamond Almond Facts March-April 2021

Vertebrate Control: Regular attention to rodent pests such as gophers, voles and ground squirrels is needed to effectively manage these damaging pests. Fumigation with phosphide gas (a restricted use material) is effective on gophers and ground squirrels in the spring. Once the soil begins to crack, the fumigant will “leak” out of the tunnels and control will be reduced or lost. Keep weeds controlled in the tree rows of young orchards to reduce vole habitat and damage. More information on gopher control is available at: ipm.ucanr.edu/pmg/ r1 0560021 1 .html and for ground squirrel control see: groundsquirrelbmp.com/biology.html. Weed Control: Controlling weeds saves water. This is especially true in young blocks where plenty of sunlight reaches the orchard floor. Preemergent herbicides, applied to bare soil, can help reduce the number of herbicide applications needed in young blocks. See information on young orchard weed management at: ucanr.edu/blogs/blogcore/postdetail. cfm ? postnum=39245. Visit ipm.ucanr.edu/agriculture/ almond/susceptibility-of-weeds-in-almond-to-herbicide- control/ for tables showing weed susceptibility to herbicides labeled in almond tables. Note: Paint does not protect trunks of young trees from herbicide damage, so preemergent herbicides applied ahead of carton removal delivers long lasting weed control without damaging trunks. Final Thoughts: As I write this, there is valley rain in the forecast and travel advisories for snow in the mountains. Perhaps the water situation will improve, even just a little. Franz Niederholzer, UCCE Farm Advisor, Colusa and Sutter/Yuba Counties 4 3 M A R C H – A P R I L 2 0 2 1