Effect of irrigation intervals and plant density on yield, yield components and some physiological traits in sorghum

To consider density and application of various levels of irrigation intervals and plant density on yield and yield components and some physiological traits of forage sorghum Speedfeed cv.، this research was done in the research farm of Arak Islamic Azad University in 2008. This test was executed as a factorial based on CRBD with four replications. Treatments were selected as different density and rates of irrigation interval. An application treatment of irrigation of three levels 9، 13 and 17 days، and the treatment of crop densities on three levels consisted of 200، 300، and 400 thousands bushes per hectare. Traits such as plant height، stem height، panicle height، number of tiller، tiller height، number leaf of tiller، number of leaf، number of node، stem diameter، dry forage yield، wet forage yield، wet stem weight، dry stem weight، wet leaf weight، dry leaf weight، dry weight، wet weight، dry weight to wet weight، dry leaf weight to dry stem weight، LAI، TDW، CGR، RGR، NAR، LAR، LAD، LAID، BMD، SLA and LWR were studied. Results indicated that an effect of irrigation of the bush on plant height، stem height، panicle height، number of tiller، tiller height، number leaf of tiller، number of leaf، number of node، stem diameter، dry forage yield، wet forage yield، wet stem weight، dry stem weight، wet leaf weight، dry leaf weight، dry weight، wet weight، dry weight to wet weight، dry leaf weight to dry stem weight had a meaningful distinction. Also، the effect of different densities on plant height، stem height، panicle height، number of tiller، tiller height، number leaf of tiller، stem diameter، dry forage yield، wet forage yield، wet stem weight، dry stem weight، wet leaf weight، dry leaf weight، dry weight، wet weight، dry leaf weight to dry stem weight had a meaningful distinction. Interactions of the treatments on the plant height، stem height، number of tiller، tiller height، number leaf of tiller، stem diameter، dry forage yield، wet forage yield، wet stem weight، dry stem weight، dry weight، wet weight، dry leaf weight to dry stem weight became meaningful. The most forage yield gained per hectare was 74 ton/ha in an irrigation of 9 days once، and an application of density of 300،000 bushes.