DAMAGE ASSESSMENT OF THE CORN BORER ON PLANTS, YIELD AND CHEMICAL COPOSITION OF THE SEEDS OF SOME SORGHUM CULTIVARS

Abstract

A field study was conducted at the College of Agriculture, Abu-Ghraib during ‎the autumn season 2011, to evaluate the susceptibility of 4 local varieties of sorghum ‎‎(Ishtar, Babylon, al-Warkaa and Lillo) against the infestation by the corn stem borer‎‏,‏‎‎Sesamia cretica Led., Compared with‎ variety Inkhad, and to study the effect of infestation on the ratio the loss in protein and carbohydrates in Rosses. Results showed that Lillo was the most preferred grain for oviposition, and also distinguished by the highest infection rate and dead heart after 3-4 weeks from emergence amounted to 13.62% and 7.19% respectively, while the lowest percentage was on Babylon (3.87% and 2 .01%) respectively.At harvest infestation rates on Al-Warkaa (41.77%), and the the lowest on Babylon (26.91%).There were not significant differences in the number of holes/plant and the total area of stem tunneled/plant, the lowest number of 1.85 hole/plant and 4.79% of stem tunneled were on Ishtar respectively, while Al-Warkaawas 3.15 hole/plant and 13.62% respectively. There was no effect of the infestation on plant height and loss ratios ranged between least percentage of 7.9%on Al-Warkaa and the highest percentage of 12% for Inkhad. Plant yield loss has ranged in different varities between 20% for Ishtar and the highest percentage of 25% for Lillo.There were not significant differences in the rates of loss in grain protein, the lowest percentage of 11.19% for Al-Warkaa, while it ranged between 14.47%-21.41% for the rest varities. There were not significant differences in the rates of loss in carbohydrates between sorghum varitiestested , and the lowest percentage of loss of 2.69% was recorded for variety Lillo and the highest of 9.44% for Inkhad.