POTATO TUBER ROTS AND ASSOCIATED INCITANTS

Abstract

During an extensive study of 112 samples of potato tuber rots at Gwalior, Madhya Pradesh, some new symptoms of luber rots and/or pathogens were found associated With potato tuber rots New potato diseases observed were; Low temperature or freezing inury - a physiological disorder, semi soft rot by Fusarium oxysporum and F. pallidoroseum at high humidity and high temperature and hollow tuber soft rot. Thumb impressions caused by Fusuium oxysporum and partly mummified tubers due to Rhizopus sioiomferwere also observed. Five new fungal species to cause ruber rots were Fusarium chlamydosporum, Chaetomium nigricolor, Altemarid aiternaria, Phoma humicola and Penicillium janthinellum Four new fungal species causing dry rots were Fusarium pallidoroseum. Aspergillus flavus, Vertiallium sp and Acremonium sp. Sirmlarly four new fungal species associated with mouldy rot were Penicllium crysogenum, Aspergillus niger. Alternaria altemata and Trichothecium roseum.