Author Archives: Katherine Jarvis-Shean

Photos from the Field: Identifying Damage from Deer Mice in Almond Orchards

Deer mice are rarely a problem in orchards in California, but when present they can cause damage to irrigation lines and nuts in almond trees, as we found on a recent farm call. The mice were taking advantage of cracks in the shrink-swell soil to more easily create their burrows, which we may see more of in the future as more orchards with drip irrigation come into bear on these shrink-swell soils. Continue reading

What new research into carbohydrates is teaching us about California orchards

Orchards up and down the Central Valley sit bare and leafless during winter. But just because we can’t see active growth with our eyes, doesn’t mean the trees themselves aren’t active. Recent years of research by the Zwieniecki lab (the Z Lab) at UC Davis, including the Carbohydrate Observatory, have been shedding light on what is happening in orchard trees during their yearly cycles, including during this dormant period. This research has been used to better explain how trees may be counting winter chill and spring heat. Continue reading

Ethephon in a Straggled Leaf-Out, Lean Price Year

Given this spring’s prolonged leaf-out window, it is likely that there will also be a wide window in the timing of hull split and a need for two shakes in some varieties. Ethephon is a commonly used tool for advancing hull split and harvest-readiness in walnuts. Remember that there are two potential timings of ethephon, based on different goals. Continue reading

Rootstock Trial for Boron Tolerance – 2019 Update

Excessive boron in soil or irrigation water is not widespread in the Central Valley, but where present, it can be a substantial obstacle to almond production. A rootstock trial in Yolo County was designed to find which almond rootstocks do better or worse under high boron conditions. What follows is a summary of findings to date. What follows is a summary of findings to date. Continue reading