Incidence and severity of fungal diseases of safflower in India

Abstract

Field surveys were conducted in two major safflower growing states of India for two consecutive cropping seasons (2015-16 and 2016–17). A total of 872 fields spanning 22 districts of Karnataka and Maharashtra were examined to determine the occurrence and distribution of various fungal diseases on safflower. Safflower fields were found to be infested by four fungal diseases, namely Alternaria leaf spot, Fusarium wilt, Cercospora and Ramularia leaf spot. Among these, Alternaria leaf spot and Fusarium wilt were most widespread and found in all the districts investigated, while Ramularia leaf spot was confined to the districts of Karnataka. The disease prevalence, incidence and severity varied among districts, cropping seasons, with sowing periods and cropping patterns. The first survey recorded higher disease in both states. In both cropping seasons, Karnataka showed higher disease parameters compared to Maharashtra. District Dharwad (Karnataka) exhibited the maximum mean disease incidence for both Alternaria leaf spot and Fusarium wilt (55.41% and 41.42%) among all the districts. The disease prevalence was less in fields with late as compared to early sown crops. Intercropping with chickpea, cotton, sorghum alone and chickpea and sorghum together decreased disease prevalence in comparison to monocrop fields of safflower. This is the first comprehensive survey reporting the distribution of fungal diseases on safflower in India. The study encourages agriculturalists to adopt cultural practices such as late sowing and intercropping with chickpea and sorghum as an effective management strategy for reducing disease in safflower.