Newly Evolved Different Fungicide Combinations against Paddy Sheath Blight under Field Conditions in West Bengal

Abstract

Rice (Oryza sativa L.) is a vital global food crop, consumed by over half the world’s population. In India, it covers 43.5 M ha, yielding 112.9 Mt at a productivity of 2.56 t ha-1. In West Bengal, it spans 5.15 M ha, producing 15.09 Mt with a high productivity of 2933 kg ha-1. Rice sheath blight, caused by Rhizoctonia solani (also known as Thanatephorus cucumeris), is a highly destructive disease that has led to significant output losses in the last two decades. Reports suggest that production losses due to this disease can range from 5.2% to 50%, depending on factors like environmental conditions, crop growth stages, management practices, and rice cultivars used. This disease is called “sheath blight” because it initially infects the leaf sheath. To combat this disease, various fungicide compounds with diverse modes of action are available on the market. The research aimed to identify the most effective and cost-efficient fungicide combination for managing rice sheath blight. The experiment evaluated the efficacy and economics of Mancozeb 52.6% + Hexaconazole 2.4%, Hexaconazole 5% EC, and Hexaconazole 4% + Zineb 68%, as well as Mancozeb 75% WP under field conditions. The results showed that Mancozeb 52.6% + Hexaconazole 2.4% achieved the highest disease reduction over the control (46.10%), followed by Hexaconazole 5% EC (42.30%).