Formerly International Journal of Basic and Applied Agricultural Research

Management strategies under chemicals, liquid organic amendments and plant extracts against black scurf of potato caused by Rhizoctonia solani Kühn in tarai regions of Uttarakhand

SURAJ ADHIKARI, SHAILBALA SHARMA , R. P. SINGH , SUNITA T. PANDEY and VIVEK SINGH
Pantnagar Journal of Research, Volume - 19, Issue - 3 ( September-December, 2021)

Published: 2021-12-31

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Abstract


Black scurf is an important disease of potato caused by Rhizoctonia solani Kühn, which affects the quantitative and qualitative attributes of the crop. Chemicals are the quickest and most effective way providing varying degree of effectiveness to control this disease. Rising concerns over the ill effects of chemicals and increasing demand for organic potatoes have spurred researchers to look for organic alternatives. In this regard, various chemicals, plant extracts and organic amendments were tested under laboratory conditions. Urtica diocia at 25 per cent concentration was found to be the best among the five plant extracts tested under In vitro conditions inhibiting 83.54 per cent mycelial growth of the test pathogen followed by Pinus roxiburgii @ 25 per cent. In vitro evaluation of liquid organic amendments revealed that kunapajala (KJ) treatments were found to be better than jeevamrut and duspharni ark as KJ2 inhibited 100 per cent followed by KJ1 inhibiting 99.60 per cent mycelial growth of R. solani at 10 per cent concentration. Among the nine chemicals, the best results were depicted by penflufen as systemic fungicide and pencycuron as contact fungicide recording 94.11 and 91.02 per cent inhibition of R. solani mycelial growth at 10 and 100 µg ml1 concentration, respectively. The chemicals were further tested in the field on the crop variety Kufri Bahar during the rabi season of 2020-21 at Vegetable Research Centre, Pantnagar. Among them tuber treatment with penflufen @ 0.082 per cent was found best as it recorded 89.97 and 93.23 per cent reduction in disease incidence and disease index over control, highest yield (36.65 t/ha) and best B: C ratio (17.45). Although the chemicals were found better but U. diocia and Vrikshayurveda based kunapajala exhibited immense potential against Rhizoctonia solani the incitant of black scurf of potato which can be exploited to minimize our dependence on chemicals for its management.


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