The effect of plant density on yield, yield components and protein content in four grain sorghum varieties

In order to study the effects of plant density on yield, yield components protein in four grain sorghum varieties an experiment was conducted as factorial based on compeletely randomized block design with three replications in Research Field of Birjand Azad University at year 2003. In this study four varieties including “ Sepideh, Saravan local, Payam and Kimia ,, and 3 plant densities 100000 , 180000 and 260000 plant / ha were investigated. The results indicated that varieties were significantly different for grain yield, protein yield, biological yield, number of seeds per panicle, 1000 kernel weight, harvest index and protein percentage. The highest grain yield, protein yield, biological yield, number of seeds per panicle and 1000 kernel weight were observed in Saravan local and the highest harvest index was belong to Sepideh and the highest protein percentage was in Kimia. Characteristics such as grain yield, protein yield, biological yield and number of seeds per panicle were affected by density. By increaseing of plant density grian yield, protein yield, biological yield increased but seed number per panicle decreased 1000 kernel weigth, harvest index and protein percentage did not affect by density. Also interaction between variety and density was significant on seed number per panicle. According to the results of this experiment, Saravan in 260000 plant / ha density is recommended for maximum grain yield and protein yield.