Management of Tomato yellow leaf curl virus: US and Israel Perspectives

Over the last 15 years, TYLCV has been a serious problem for tomato production in many parts of the world. The virus has been known in Israel for over 40 years and in Florida since 1997 (Cohen & Nitzany, 1966; Polston et al., 1997). In Israel, tomato crops are severely affected by epidemics of TYLCV and despite almost daily spraying with insecticides, 100% yield losses have often been recorded in cases where the whitefly populations were high (Cohen & Antignus, 1994). In Florida, there have been numerous crop failures due to TYLCV and costs of production have risen. TYLCV is considered the most important pathogen of tomato in Israel and in Florida (Lapidot & Friedmann, 2002). The management of TYLCV in tomato is difficult and expensive both in protected and open field production. Often management techniques are not sufficient and economic losses are incurred. Many approaches have been used to try to decrease losses due to TYLCV although only a few are frequently effective and some cannot be used in all climates and locations. In general, no single approach is effective to manage TYLCV. Combinations of chemical and cultural techniques are employed to (1) reduce the number and movement of the whitefly vector, and (2) minimize or eliminate inoculum sources of TYLCV.

Management of TYLCV is often expensive and difficult but not always successful. In both Florida and Israel, multiple techniques are employed simultaneously to reduce incidences of TYLCV-infected plants. In Israel, TYLCV is managed primarily through the use of resistant cultivars, pesticides, cultural practices, and exclusion through the use of 50 mesh screens, and regular or UV absorbing plastics in the case of protected production. In Florida, where the majority of tomatoes are produced in open fields, the virus is managed through cultural practices and a heavy reliance on insecticides (Cohen & Antignus, 1994; Lapidot & Friedmann, 2002). The development of pesticide resistance and the loss of natural predators and parasites after repeated insecticide applications contribute to control problems and environmental concerns. The most practical control of TYLCV is the use of resistant cultivars. These unfortunately are limited and not available for all production conditions, climates and market preferences. Growers are forced to rely on other approaches to minimize yield losses.