Vol. 12, Issue 6 (2023)

Author(s):
Tejashwini NK, RK Mesta, Manjunath Hubballi, Athani SI, Raveendra S Jawadagi and IB Biradar

Abstract:
Cultural and physiological studies on Colletotrichum gloeosporioides and Fusarium oxysporum were studied at the Laboratory of Department of Plant Pathology, College of Horticulture, Bagalkot during 2021-2022. Onion is one of the important oldest and widely grown bulbous vegetable crop among the genus Allium in India. Onion productivity is becoming quite low because of many fungal and bacterial diseases mainly twister disease which effect the yield of the crop. The Potato Dextrose Agar (PDA) medium was used to maintain the pure cultures isolated from twister disease infected onion plants and identified as C. gloeosporioides and F. oxysporum. The cultural studies were conducted to know the effect of growth and sporulation in different media among them both the pathogens gave maximum mycelial growth (87.92 and 88.00 respectively) on the 12^th day after incubation in a PDA medium with better sporulation. Among liquid media, potato dextrose broth was observed most supportive for its growth. The various response of C. gloeosporioides and F. oxysporum to different levels of temperature, pH and light showed that temperature of 25 °C, pH 6 and alternate cycles of 12 hours of light and 12 hours of darkness was found congenial under in vitro conditions.