Abstract

Author:
Akash Gupta, Roshan Kumar Yadav, Rajan Sah and Dhaniraj Kohar

Doi: 10.26480/sfna.01.2025.46.51

This is an open access article distributed under the Creative Commons Attribution License CC BY 4.0, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited

The Alternaria leaf blight disease is one of the most severe diseases in Radish. It is responsible for up to 45% loss in case of Radish in Nepal. Various fungicides have been used by farmers for the management of this disease without the knowledge of their efficacy in the management of this disease. Therefore, this research was carried out to test the efficacy of various chemical & biological fungicides used by farmers in the management of Alternaria leaf blight disease of radish. The experiment comprised of seven treatments; among which six were commercially available fungicides viz. T1, Delma (Azoxystrobin 8.3% + Mancozeb 66.7% WG) @ 0.5 gm/l; T2, Allistin (Carbendazim 50%WP) @ 2.5gm/l; T3, Turnus (Hexaconazole 5%EC) @ 0.5ml/l; T4, All M-45 (Mancozeb 75%WP) @ 2.5gm/l; T5, Tilt (Propiconazole 25% EC) @ 0.5ml/l; T6, Biocide Trivi (Trichoderma viridae 1×109 cfu/ml) @ 6ml/l & T7, control which did not involve the use of any fungicides. The experiment design was Randomized Complete Block Design with three replications. The fungicides were sprayed thrice i.e. on 35th, 45th & 55th days after sowing (DAS) and the data was recorded on the 45th, 55th and 65th DAS. The disease severity data was recorded on a scale of 0-5 based on disease severity chart used given by Shrestha, Munk, & Mathur, 2005. The data was utilized to compute percent disease index (PDI) using formula given by Ayyangar, 1928. At 45 DAS (after first spray), T1 to T6 remained statistically similar to each other. At 55 DAS (after second spray), T1 treated plot showed least PDI i.e. least infection by Alternaria leaf blight disease, which was statistically similar to T4. At 65 DAS (after third spray) T1 showed least PDI, and T1 was statistically similar with T4 & T5. The root weight was not significantly affected by different disease management approaches. However, considering the seed borne nature of this disease, for the purpose of disease-free seed production, the management of Alternaria leaf blight disease using T1 (Azoxystrobin 8.3% + Mancozeb 66.7% WG@0.5gm/liter) can be effective.