In vitro evaluation of Carica papaya L. and Lantana camara L. extracts in the Control of Late blight of Potato caused by Phytophthora infestans (Mont.) De Bary

Abstract

In vitro study was conducted to evaluate the efficacy of two plant extracts of varying concentration in the control of late blight- causing fungal pathogen. Diseased leaves of Irish potato plants were collected from farms. The fungus was isolated from diseased potato leaf samples and identified using culture and morphological characteristics. The fungal species associated with the late blight of potato and subsequent rot was isolated and identified in this study as Phytophthora infestans Extracts of two plants namely: Carica papaya L. and Lantana camara L. were evaluated against Phytophthora infestans (Mont.) de Bary using three concentrations (20, 40 and 60g/l). Growth inhibition of the organisms varied with extract type and concentrations. Carica papaya extract was the most effective among the two extracts evaluated. It reduced the radial growth at 60g/l concentration to up to 75.29%. Lantana camara at 40g /l reduced the growth to the rate of 57.65%. There was significant difference in growth inhibition at (p<0.05) by the extract concentrations. The plant materials could serve as an alternative to synthetic fungicide in controlling late blight of potato and other rot inciting organisms.