General situation
Winter rainfall accumulations and average temperatures in the Sacramento Valley this year are looking similar to the long-term averages. The drying wind and higher temperatures last week mean our first tomatoes are going into the ground this week.
Immediate outlook
Thrips are likely 1st-generation juveniles (1st-gen egg hatch peaked 2/23, and adults are predicted to peak 3/29). Currently 2nd-generation egg hatch and adults are predicted to peak at 4/22 and 5/8, and 3rd generation adults predicted to peak in early June. Thrips control is most effective in the 2nd and 3rd generations.
TSWV isn't transmitted to the eggs, and juveniles must acquire it while feeding on infected plant tissue. Infected adults then transmit the virus to new host plants during feeding. This generation of juveniles can acquire it by feeding on infected host winter weeds, winter crops, or cover crops. Many winter weeds can host the virus, including include prickly lettuce, little mallow (cheeseweed), and sow thistle. Fava bean is a common cover crop plant which can also host the virus. Controlling these weeds can help reduce thrips' ability to acquire and transmit the virus to newly planted tomatoes. This is especially important in old TSWV hotspots.
