Evaluation of foliar and stem susceptibility of three cultivated Solanaceous crops to Phytophthora infestans

Late blight of potato, tomato and some members of Solanaceae is of wide occurrence in many parts of the world leading to crop damages and yield losses. Caused by Phytophthora infestans which has a wide host range, late blight disease offers severe challenges to the crop growers in geographic localities where climatic conditions favor spread of the disease. In this study, we evaluated the susceptibility of potato (Solanum tuberosum L.), tomato (Solanum lycopersicum L.) and eggplant (Solanum melongena L.) to P. infestans. The foliar resistance of intact leaves and detached stems of three species were determined by the disease severity, incubation period and lesion area caused by the pathogen. The three crops significantly varied in response to late blight infection; potato and tomato showed severe disease symptoms, lesion area and lower incubation period. Foliage sensitivity was more evident than stems. Among the evaluated crops, eggplant was the most resistant to foliar and stem late blight disease suggesting its role in potential breeding for resistance purposes.