Crop Loss Estimation and Management of Sorghum Shoot bug

Natural infestation of shoot bug, Peregrinus maidis (Ashmead) resulted in the yield loss of 11.16, 21.11 and 2.97 per cent in grain yield, fodder yield and 1000-grain weight, respectively across different dates of sowing. The unprotected plot recorded significantly higher sorghum stripe disease incidence (18.72%) as compared to protected ones (9.51%). Under graded level of infestation, the yield reduction ranged from 7.1 to 51.3 per cent and 9.1 to 49.7 per cent in grain and fodder yield with release of 5 to 30 first instar nymphs per plant, respectively. The economic injury level of shoot bug was worked out to be 3.13 bugs per plant. Among the 80 genotypes screened against shoot bug the lines viz., 61611, 61612, CK 60B, Swati, and RS-29 were promising by recording lower population (2 shoot bugs/plant). The seed treatment with thiamethoxam 70 WS @ 3 g per kg seeds resulted in higher net profit of Rs. 15902 per hectare which was on par with the seed treatment by carbosulfan 25 DS @ 20 g per kg seeds (Rs. 15772/ha), imidacloprid 70 WS @ 5 g per kg seeds (Rs. 15437/ha), imidacloprid 70 WS @ 2 g per kg seeds (Rs. 14663/ha) and thiamethoxam 70 WS @ 2 g per kg seeds (Rs. 14573/ha).

Autorentext

Raju Anaji is presently serving as Assistant Manager in Syndicate Bank at Belthangady, South Canara, Karnataka, India. He completed his M.Sc. (Agri.) in Agricultural Entomology during 2005 under the guidance of Dr. R. A. Balikai, Professor of Agril. Entomology, College of Agriculture, University of Agricultural Sciences, Dharwad, Karnataka, India.