Regional survey, isolation, and morphotypes diversity of Fusarium Wilt pathogen in chilli from Andhra Pradesh and Tamil Nadu

Abstract

Fusarium wilt, caused by various species of Fusarium, is a severe disease affecting chilli (Capsicum annuum) crops, leading to significant yield losses in major chilli-growing regions. This study aimed to assess the incidence of Fusarium wilt in Andhra Pradesh and Tamil Nadu during the 2021 rabi season. A systematic survey was conducted across chilli-growing districts, including Guntur, Kadapa, Cuddalore, Trichy, and Dindigul, to determine disease prevalence and severity. The highest percent disease incidence (PDI) was recorded in Peesapadu (38.96%), followed by Karambilipatti (35.57%), while lower incidence levels were observed in other locations. Isolation and identification of the wilt pathogen were performed using the tissue segment method, with morphological characterization revealing the presence of Fusarium sp. as the primary causal agents. The isolates exhibited significant variability in colony morphology, conidial dimensions, and growth patterns, suggesting diverse Fusarium populations in the surveyed regions. These findings highlight the need for continuous monitoring, precise pathogen identification, and the development of integrated management strategies, including breeding for resistance, to mitigate the impact of Fusarium wilt on chilli production.