Effect of flag smut caused by Urocystis agropyri on yield components of popular wheat cultivars in Rajasthan

Flag smut caused by U. agropyri is an important disease of wheat. The seed and soil-borne nature of the disease leads to gradual built up of the inoculum in the soil. Further, the persistent nature of the pathogen and the cultivation of susceptible varieties, flag smut may become a serious threat to wheat cultivation particularly in northern parts of the country. Losses upto 80 per cent have been reported in some endemic areas of Rajasthan. A survey conducted during Rabi, 2001–02 to 2003–04 (3 years) revealed that all popular wheat cultivars are susceptible to the disease. Attempts were therefore made to determine the effect of diesase on yield and yield attributing components of popular wheat cultivars grown in Rajasthan viz. Raj 1482, Raj 3077, Raj 3765, Raj 3777, C-306, WH 47, PBW 343 and Lok-1 in sick plot under artificial seed inoculation conditions at Agricultural Research Station, Durgapura, Jaipur. A significant reduction in number of tillers, plant height, length of ear-head and test weight was noted in smutted plants over healthy plants. Maximum disease was recorded in Raj 1482 (47.2%) followed by PBW 343 (45.8%), C-306 (43.9%), Raj. 3765 (41.8%), Raj 3077 (39.6%), Raj 3777 (37.3%), WH 147 (36.7%) and Lok-1 (10.8%). Highest yield reduction was noted in PBW 343 (49.0%), whereas, in Raj 1482, C-306, Raj 3765, WH 147, Raj 3077 and Raj 3777 yield losses upto 46.5, 38.9, 35.7, 35.2, 28.2, and 26.7 per cent, respectively were observed. In Lok-1, least losses (6.9%) were observed.