Effects of Plant Densities and Row Orientation on the Seed and Forage Yield of Grass Sorghum in Bam

To study the effects of plant densities and planting orientation on the seed and forage yield of sorghum, an experiment was conducted at Hossein- Abad – Shahcal village –90 kilometers south of Bam-in 2002. The experiment was a factorial with randomized complete block deisgn and three replications. The treatments were: orientation with three levels (South-North, East – West, Northeast – Southwest) and plant densities with four levels (50000, 70000, 90000, 110000 plants per hectare). Results of analysis of variance showed that planting orientation had significant effects on seed yield, weight of 1000 seeds, number of tillers, dry matter yield, length and diameter of shoot. Mean comparisons, showed that the maximum and minimum amount of the above mentioned traits except for shoot length was obtained under the North-South and East-West orientations, respectively. Significant differences were also found among densities in terms of all the mentioned traits. Results showed that increasing density decreased seed yield, weight of 1000 seeds, number of tillers and shoot diameter. The highest and lowest values (except of seed yield) were recorded for 50000 and 110000 plants/per hectare, respectively. Dry matter yield and the shoot length increased with increasing density. Based on the results of this experiment, the best plant densities to obtain the highest forage and seed yield are 70000 and 110000 plant per hectare, respectively and the best planting orientation is North-South.