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Spread of tomato yellow leaf curl in California tomatoes arrested

The Issue

Tomato yellow leaf curl virus (TYLCV) is the most recent whitefly-transmitted virus disease to appear in Imperial County. The disease caused by TYLCV in tomato crops is the most destructive whitefly-transmitted virus disease of tomatoes worldwide. TYLCV threatens commercial tomato production in California, transplant production of peppers and tomatoes in Imperial County, and home garden tomato production. TYLCV is transmitted by adult silverleaf whiteflies and can spread rapidly, but TYLCV is not seed borne or transmitted mechanically. The presence of silverleaf whitefly host plants, both cultivated (such as peppers and tomatoes) or wild hosts (such as sowthistle, cheeseweed and nightshade) during spring and summer may lead to whitefly migration and spread of TYLCV.

Immediate action was needed to inform tomato growers of the new threat to their industry and to attempt eradication of TYLCV from California.

What Has ANR Done?

Eric Natwick, Imperial County Cooperative Extension director, collected tomato plants with TYLCV-like virus symptoms from a greenhouse in Brawley, Calif., in March 2007. Dr. Robert Gilbertson at UC Davis determined that TYLCV was the cause of the virus-like symptoms in the tomato plants.

ANR immediately notified the Imperial County Agricultural Commissioner’s office and California Department of Agriculture. We worked with the Agricultural Commissioner and CDFA to attempt eradication of all sources of TYLCV in the county. Further, educational presentations were given to growers in Imperial County, Calif., and Yuma County, Ariz., newsletter articles were published by Imperial County Cooperative Extension, and a TYLCV educational flyer was published through the UC Integrated Pest Management Program, both print and on-line, to inform and educate tomato growers, tomato and pepper transplant producers and pest control advisers statewide of the threat of TYLCV to California tomato production.

The Payoff

Spread of TYLCV stopped

Although it is not yet possible to say that TYLCV has been eradicated from California, we can say that the spread from Brawely to other parts of the state has been arrested. This was due to the combined efforts of UC ANR, CDFA and the Imperial County Agricultural Commissioner's Office to rapidly define the geographic area with TYLCV-infected tomato plants and to get voluntary destruction of all infected plants in commercial and home garden tomato production.

Through UC ANR educational efforts, growers and allied industries were informed of methods to stop the spread of TYLCV infected plants and whiteflies that carry the virus.


Supporting Unit: Imperial County

, UC ANR Cooperative Extension and UC Davis Plant Pathology - CAES
Eric Natwick, (760) 352-9474, etnatwick@ucdavis.edu