What destroyed my tomato plants in the fall of 2010?
Dr. Mark Black, Texas AgriLife Extension Service Plant Pathologist in Uvalde writes:
Most varieties in the San Antonio area have been damaged by the Tomato Yellow Leaf Curl Virus (TYLCV).
Tomato yellow leaf curl virus (TYLCV) is a Begomovirus (one genus in the gemini virus group) vectored by whiteflies. It has a broad host range including tomato, pepper, and green bean, and several weeds. All three of these vegetables this fall, 2010, in this area have at least one field with symptoms and lab confirmation to Begomovirus genus (tests to confirm species pending for tomato and bean samples with Judy Brown, Univ. Arizona). This virus has been damaging crops in the Rio Grande Valley and West of San Antonio (where cotton is grown since whiteflies multiply on cotton plants and disperse after cotton harvest (defoliation) in the early fall)
TYLCV is now the most important tomato virus in southern states where whitefly has become a big problem, especially in Florida and Texas. Disease incidence is higher in fall plantings than spring because whitefly populations dip in winter, build through spring and summer, peaking in August and September as the cotton crop matures and is defoliated.
Interesting facts: TYLCV can be passed from male to female whiteflies and vice versa. One study showed that two generations of progeny from an infected female whitefly also carry the virus. Once infected, an insect carries the virus for life.
Resistance is available in tomato and resistant parents have been identified in other vegetables.
Management suggestions include sanitation, no overlapping crops, site selection, insecticide use, and resistant varieties. See: