Control of the Bemisia tabaci/Tomato yellow leaf curl virus complex on protected tomato crops in Algarve (Portugal)*

Abstract

The whitefly Bemisia tabaci has been a serious pest in protected tomato crops since 1995 in the south of Portugal (Algarve), causing severe losses mainly resulting from Tomato yellow leaf curl virus (TYLCV), first reported in the autumn/winter season. In order to manage and control the B. tabaci/TYLCV complex, experimental field trials were carried out between 1997 and 2000. Several control methods were tested, such as the application of white screen nets to windows and doors, chemical treatments against B. tabaci and the use of cucumber as a trap crop. The results show that the percentage of plants with TYLCV symptoms mainly reflects B. tabaci infestation level in the first 6 weeks. Screen net protection was the control method that clearly provided a low incidence of plants with TYLCV symptoms in the autumn/winter season. Additionally, insecticide treatments, made weekly in the first 6 weeks, may give improved protection. In the winter/spring season, the B. tabaci/TYLCV complex is a minor problem because of the low populations of B. tabaci and the climatic conditions. Information about the work in progress and results was given to growers through visits to the experimental fields and oral presentations.

Incidences and progression of tomato chlorosis virus disease and tomato yellow leaf curl virus disease in tomato under different greenhouse covers in southeast Spain

“…1). The greenhouses were selected and classified based on their efficiency to prevent insect entry, particularly of aleurodids, according to literature and common observations by field agronomists in the Mediterranean area (Arsénio et al , 2002). Selected covers in greenhouses/nethouses ranged from very low mesh nets to polycarbonate film.…”

Insect‐screened cultivation to reduce the invasion of tomato crops by Bemisia tabaci: modelling the impact on virus disease and vector

“…Polyhouses are used extensively in Mediterranean countries and are frequently associated with reports of begomovirus disease problems. Screen nets on windows and doors were reported to be effective in reducing incidence of TYLCV but, additionally, weekly insecticide treatments for the first 6 weeks may have had an effect (Arsenio et al , 2002). Similarly, in spite of the fact that screens limited the entry of B. tabaci , numerous insecticide treatments were also required (Polizzi & Asero, 1994).…”

Mejora genética para la resistencia a los geminivirus tomato yellow leaf curl virus (TYLCV) y tomato yellow leaf curl sardinia virus (TYLCSV) en tomate

“…En este sentido los tratamientos insecticidas no suelen resultar efectivos si no se combinan con otras medidas, dado que la eficacia de la transmisión es elevada y un número pequeño de individuos es capaz de iniciar una epidemia. Otras alternativas útiles consisten en la utilización de trampas cromotrópicas (Chu et al, 2000) o la protección de los cultivos con redes de malla densa (Arsénio et al, 2002). El control biológico con enemigos naturales es otra de las medidas empleadas, fundamentalmente con parasitoides de los géneros Eretmocerus (Urbaneja et al, 2007) o Encarsia (Gerling et al, 2001).…”