Author Archives: Katherine Jarvis-Shean

Winter Chill, Dormancy and Walnut Management

Walnuts are one of the highest chill requirement tree crops in California but recent winters have fallen short of the chill needed for a tight, economical walnut bloom. With funding from the California Walnut Board, dormancy breaking treatments are being tested in California’s conditions using products used to compensate for inadequate chill in other crops and countries. Continue reading

Late Winter to Early Spring is the Most Effective Time for Gopher Management

Late winter to early spring is the time of year that pocket gophers are usually cranking up their Barry White playlist. This reproductive pulse generally results in three to five young per litter, roughly doubling to tripling the population of gophers that feed on almond roots and crown. Reducing gopher populations ahead of this reproductive pulse is the most time-effective way to reduce gopher damage in your orchard. Continue reading

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