- Author: Neil McRoberts
Weather outlook: After further atypical cool, showery weather over the last week or so, the forecast for the next ten days shows a more settled period of dry weather with partial cloud cover and daytime highs gradually increasing towards the low 90'sF. Thrips population development can be expected to be steady over this period.
Thrips population timings: In our last update on 4/16 we projected Generation 3 adults to peak on June 7th and Generation 4 to peak on June 30th. The period of cool weather has slowed development further, delaying the projected generation times by a few days. The projected peak date for Generation 3 is now June 9th, with Generation 4 now projected to peak on July 2nd. We are still not hearing reports of any TSWV in the area, and together with the delay in thrips development, the overall risk level in the upper San Joaquin Valley is low. Depending on crop development stage we recommend targeting either Generation 3 or Generation 4 for any intended thrips treatments. Later planted crops may still be at early, vulnerable growth stages as Generations 3 and 4 emerge; stay on top of the situation and check in with your UCCE adviser to find out if TSWV is being reported as the season progresses.