Abstract
This experiment was carried out at the experimental station of the Coll. of Agric., in Abu-Ghraib, Univ. of Baghdad during spring and autumn seasons of 2012. The main objective was to find out the effect of boron concentration (0, 50, 100, 150 and 200) mg.l(-1) and three times of foliar application (vegetative growth, 25% flowering and 75% flowering) on grain yield and its major components of Sorghum cv. Abu Sabeen. Layout of the experiment was a split plot in a randomized complete block design with three replications. Boron concentrations were used as main plot, while times of foliar application of boron were used as a sub-plot. Result showed that addition of boron at a conc. More than 50 mg.l(-1) (100, 150 and 200) resulted in a significant increment in mean of plant height, leaf area, No. of grain.head(-1), weight of 1000 grain, grain yield, biological yield and harvest index, while No. of heads per hectare was not significantly influenced by boron conc. in spring and autumn seasons. Highest grain yield (4.57 and 5.02) t.ha(-1) was obtained when plants sprayed with 150 mg.l(-1). Foliar application at time of vegetative growth gave highest No. of grain.head(-1) and weight of 1000 grain, while foliar application at time of 25% flowering gave highest leaf area. There were no significant effect of time of foliar application on plant height, No. of head per hectare, grain yield, biological yield and harvest index. The higher grain yield in spring and autumn seasons (4.74 and 5.24) t.ha(-1) respectively were obtained when plants of sorghum sprayed with boron at conc. of 150 mg.l(-1) at 25% of flowering.