April 16th update

Submitted by nmcrober on

Weather outlook  The next 10 days will see consistent warm, dry weather in the upper San Joaquin Valley. Highs in the upper 70's or low 80's and overnight lows in the mid to low 50's will allow steady thrips development, and we should see numbers starting to build up.

Generation peak timings  since our last update a couple of weeks ago our predicted peak date for generation 3 has moved forward by three days to June 5th, and generation 4 has advanced by 2 days to June 29th.  If you are concerned about TSWV risk these are the two generations where control will have the biggest impact.  Knocking thrips numbers down while the populations are still relatively small and while the crop is still small enough to allow good penetration of sprays is a good tactic.  Keeping thrips under control at this stage also allows the crop to grow past the really vulnerable stage before and during flowering before there is much TSWV around and helps to reduce the yield impact if the virus does show up.  The UC IPM guidelines for thrips control can be found by following this link.  Further advice on treatments is available from your local UCCE adviser.


Source URL: https://oc4h.ucanr.edu/blog/thrips/tswv-eastern-san-joaquin-co/article/april-16th-update