Changes in seed yield and yield components of two cultivars of sweet sorghum in different plant populations

Sweet sorghum belongs to the same species as grain sorghum. Sweet sorghum has a potential source to use as multi purpose industrial crop. In order to evaluate changes in seed yield and yield components of two cultivars of sweet sorghum in different plant populations, two sweet sorghum cultivars (Rio and Keller) and six plant densities (100000, 200000, 300000, 400000, 500000 and 600000 plants per ha), were evaluated in a split plot layout within a randomized complete block design with three replications at the Isfahan University Research Station, Isfahan, Iran in 2009. Plant density had significant effect on panicle length, the number of panicle per m2, the number of seed per panicle, seed yield and biological yield. Pancile length, the number of seed per panicle, seed yield, biological yield and harvest index was significantly affected by cultivar. Sorghum cultivars did not differ significantly between themselves in yield attributing characters viz., the number of panicle per m2 and one hundred seed weight. Sweet sorghum has the highest dry matter accumulation rate when considered on a day basis. On the basis of the results, 600000 plants per ha, had obtained the highest seed yield, biological yield and appropriate one hundred seed weight. So, cultivation of Rio with 600000 plants per ha, was recommended for this semi arid region.