Singh, A.K.Sharma, Saurabh2023-10-312023-10-312023-10-13Sharma, S. 2023. STATUS AND MANAGEMENT OF LATE BLIGHT OF POTATO [Phytophthora infestans (Mont.) de Bary] IN JAMMU REGION, M.Sc. thesis37075https://krishikosh.egranth.ac.in/handle/1/5810199992The present investigation onthe status and management of late blight of potato in Jammu regioncaused by Phytophthora infestanswere undertaken to study the status, epidemiology and management of the disease. Survey of potato fields conducted during Rabi season 2022-23, revealed that disease was prevalent in four districts of Jammu region, viz., Jammu, Kathua, Samba and Udhampur where in disease intensity varied from 14.56to 28.57percent with an overall mean of 21.31percent. Role of abiotic factorsin the development of disease, such asthe minimumtemperature, maximum relative humidity and rainfall showed highly significant andpositive correlation with the disease development,whereas maximum temperature hadsignificantlynegative correlation.In cultural practices, different dates of sowing at ten days interval viz., 31th October, 10th November, 20th November and 30th Novemberhad great impact on the disease severity. Earlyplanted cropexhibited less disease severity(31.97 %) of late blight. Identification of host plant resistance was assessed through screening of 21 potato germplasm against late blight. KufriSangam, KufriKiran, Kufri Mohan, KufriJyoti was found resistant, while KufriPukhraj, P-38, KufriBaharwere highly susceptible.Chemical management withnine fungicides evaluated under fieldconditions revealed thatCymoxanil 8% +Mancozeb 64% WPwas most effective recording minimum disease severity (26.46%) followed byMetalaxyl 8%+Mancozeb 64% WP (30.19%), and Carbendazim50% WP wasleast effective fungicide with maximum disease severity (48.67%).The cost-benefit ratio was highest in cymoxanil + mancozeb(1:2.5) followed by metalaxyl + mancozeb(1:2.0).EnglishThesis