Studies on Alternaria leaf spot of cotton with special reference to disease management by use of chemicals and botanicals

Abstract

Cotton is one of the most important fiber cash crop of the world as well as India which belongs to the botanical family “Malvaceae”. Alternaria alternata is an economically important pathogen on numerous crops worldwide. The experiments were conducted at Guru Kashi University, Talwandi sabo (Punjab) under the field and laboratory conditions to study the Alternaria leaf spot of cotton during season 2019-2020. The disease severity elevated in cotton crop with delay in sowing between D1, D2 and D3. American cotton varieties recorded highest disease severity than desi cotton variety in all sowing dates. Hence, American cotton varieties were more susceptible than desi cotton variety. Mancozeb show the maximum diameter of zone of inhibition at different concentrations (125, 250, 500, 1000 ppm) followed by Ridomil. In botanical management, Allium sativum was performed better than Azadirachta indica. Use of botanicals is the alternative approach for the disease management that is eco-friendly.