Biopesticides Potential to Protect Tomato (Solanum lycopersicum L.) Production from Early Blight Disease (Alternaria solani) and Leaf Miners (Tuta absoluta)

Abstract

Early blight disease (Alternaria solani) and leaf miners (Tuta absoluta) pose significant biotic constraints to tomato production, causing 80 -100% yield loss. A study involving laboratory, screen house and field experiments evaluated the efficacy of plant and bio product pesticides including extracts of Azadirachta indica, Lantana camara , Cymbopogon citratus, Capsicum frutescens, Zingiber officinal and rabbit urine. We report significant inhibition of fungal mycelial growth ranging from 20% with a 5% rabbit urine to 98.25% by 10% hot pepper in the laboratory. Screen house trials showed a positive inhibitory effect of plant extracts on controlling leaf miners. The most effective extracts were 10% lantana (80%), 10% hot pepper (76.6%) and 10% ginger (72.6%).The most successful four extracts were used in field trials and resulted in an average 50% reduction in disease severity compared to the control. Also, 10% ginger, hot pepper (both 5% and 10%) and 10% lantana were effective in controlling Tuta absoluta and significantly reduced leaf damage. A cost benefit analysis showed that the 5% hot pepper treatment had the highest revenue benefit compared to the negative control and conventional tomato production methods. Further research is needed to integrate these biopesticides into crop management practices.