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Subject: Plant Pathology × Author: Adhikari, Suraj × End date: 2022 × Start date: 2020 × Type: Thesis × Thesis Type: M.Sc ×
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    ThesisItemOpen Access
    Eco-friendly management of black scurf of potato caused by Rhizoctonia solani Kuhn
    (G.B. Pant University of Agriculture and Technology, Pantnagar - 263145 (Uttarakhand), 2021-08) Adhikari, Suraj; Sharma, Shailbala
    Potato (Solanum tuberosum) is regarded as the most important non cereal crop which has the capacity to grow from sea level to snowline. However, it is susceptible to a number of bio stresses that hampers the production and cause significant economic losses. Among these bio stresses, black scurf disease of potato caused by Rhizoctonia solani Kuhn is one of the most important disease which is known to reduce the quality, yield and price of the tubers. The management of this disease by a single means is very difficult as the pathogen is both soil and seed borne in nature. So, efforts were made to develop an integrated disease management strategy by evaluating the efficacy and potential of various fungicides, plant extracts and liquid organic amendments. In the current study ten fungicides were evaluated among which pencycuron (contact fungicide) and penflufen (systemic fungicide) were found to be the best as they completely inhibiting the mycelial growth of R. solani at 150 and 20 μg/ml, respectively. Out of seven plant extracts evaluated Urtica dioica (stinging nettle) was the best, which recorded 83.54 per cent inhibition of R. solani mycelium at 20 per cent concentration under in vitro condition. Further five Vrikshayurveda based liquid fermented organic formulation were tested under in vitro condition, among which herbal kunapajala i.e. KJ2 (nettle + seasonal weeds based) completely inhibited the of R. solani mycelium growth at 10 per cent concentration. Under field conditions during the year 2020-21, penflufen was found superior in reducing the disease incidence as well as disease index over control while recording highest tuber yield and best benefit-cost ratio. Among the fourteen treatments of Vrikshayurveda based kunapajala, KJ2 at 1000 l/ha dose significantly reduced the disease incidence and disease index over the untreated check. Interestingly, all the treatment of kunapa jala despite zero fertilizer application were statistically at par in terms of germination per cent and tuber yield with the untreated check indicating that kunapa jala fulfilled the nutrient requirement of the potato crop along with significantly decreasing the disease incidence and disease index compared to the untreated control. Based on present investigation chemicals were found to be superior in short term control however, Urtica dioica (stinging nettle) under in vitro and Vrikshayurveda based kunapajala formulations under in vitro and in vivo conditions showed promising result which could be effective in the longer run and thus can reduce the dependency on chemicals.