Screening of Turmeric Cultivars against the Alternaria Leaf Blight in Turmeric

Abstract

Turmeric (Curcuma longa L.) is an important commercial spice crop grown in India. The area is increasing year by year due to its culinary, medicinal and traditional usage. Although turmeric is considered to be a medicinal plant, it is susceptible to various diseases. Among the various diseases, leaf blight caused by Alternaria alternata (Fr.) Keissler, is one of the most serious foliar disease in all the turmeric growing regions of the world. The disease is recently gaining importance due to its severity causing considerable damage to the plant in almost all turmeric growing areas of Northern Karnataka. In Karnataka majority of the commercially grown varieties are susceptible to A. alternata. The field experiment was conducted to identify the resistance cultivars to leaf blight of turmeric. A total of 20 turmeric cultivars were screened for resistance against Alternaria blight during 2018-19 and 2019-20 under natural epiphytotic conditions. The overall disease reaction indicated that out of these 20 cultivars screened, majority (13) were categor as susceptible, while only seven viz., Kedaram, Co-2, Kranthi, BSK-2, Prathiba, Cudapa and CLI 325 expressed a moderately resistant reaction. They also recorded higher yields (23 to 24 q/ha) compared to the susceptible cultivars (17 to 18 q/ha). These results indicate variability in host response to Alternaria infection, with no cultivar exhibiting complete resistance.