Apr 29, 2015
Over the past few months there have been many small grain fields infested with aphids, primarily the bird cherry-oat aphid, which vectors barley yellow dwarf virus. Economic thresholds for chemical control are quite high, and most of the agronomists I've conferred with have indicated that spaying for aphids has generally limited efficacy. The best defense against aphids vectoring BYDV is selecting a resistant variety. Rachael Long, a UCCE farm advisor in the Sacramento Valley, recently posted some information about the susceptibility of some oat varieties here. In addition, BYDV ratings are available for all the statewide small grain variety trials, which can be found at smallgrains.ucdavis.edu.