Sep 26, 2018 | We are currently detecting a variety of whitefly-vectored viral diseases in vegetable crops. The two of greatest concern are cucurbit leaf crumple virus and tomato yellow leaf curl virus. Both have been detected in multiple counties in southern Georgia but are generally at low levels to date; unfortunately, this could change rapidly. Current levels of virus infection are similar to late spring (in normal years) but with the obvious difference of large whitefly populations to spread these viruses. The only good news with this is that infection is occurring much later in the season than the last two years and will have less impact on overall yield.
In test on station, I noted obvious leaf crumple virus in less than 5 percent of young squash plants but terminal growth with questionable symptoms was likely in the 25 to 50 percent range. Again, with the relatively high whitefly population we have in Tifton, even a low level of virus can spread rapidly.
Tomato yellow leaf curl virus has also been detected, but generally at lower levels (with the exception of one field reported to be near 100 percent). Again, under conditions with high whitefly populations, any whitefly-vectored virus can spread rapidly.