Disease resistance to tomato yellow leaf curl virus (TYLCV) enhanced by natural plant growth regulators and biopesticide

Over the last three decades, tomato yellow leaf curl virus (TYLCV), causing yellow leaf curl disease in tomatoes, has become one of the most destructive pathogens of tomatoes (Solanum lycopersicum L.), especially in tropical and subtropical regions worldwide. Despite the diverse climatic conditions in Pakistan, this disease is prevalent throughout the country. This virus is transmitted through Bemisia tabici (white fly) and causes heavy yield losses. Botanical pesticides and natural growth regulators are encouraged to manage plant viral diseases due to their environment-friendliness and low cost. Potted tomato plants were exposed to whiteflies for natural viral infection 14 days after exogenous application of MeJA (0.1μΜ), SA (0.05 mM), and neem extract (NE) (2%) alone and in combinations to assess their effect against TYLCV and growth of tomato plants under controlled greenhouse conditions. The results of this study show that exogenous application of MeJA, SA, and NE significantly reduced TYLCV disease by 75.00% at 35 days post-infection (dpi) compared with positive control. Moreover, methyl jasmonate (MeJA), salicylic acid (SA), and neem extract (NE) combined application enhanced plant growth and resistance against TYLCV disease. The results could be helpful for future environment-friendly biopesticide development programs.