Study and Determination of the most Suitable Plant Density in Row of Promised forage Sorghum Lines

In this study three sorghum ( Sorghum bicolor (L.) Moench ) Lines named KFS12 ' KFS17 and KFS18 were conducted to determination of the most suitable plant density ' in factorial experiment based on a randomized complete block design in three replications at Karaj for two years in 2010 – 2011 . Studied plant densities were 166 ' 208 ' 278 and 417 thousands plants pear hectare on row spacing of 60 cm. The plots deep plowing in autumn and 250 kg / ha Ammonium phosphate was applied. Other treatments preparing the seed bed was done in the spring after the weather was favorable. Nitrogen Fertilizer (Urea) was given 100 kg per hectare before planting, the same amount as a roads and after each cutting operation. Each line in each replications were planted of the 4 rows with 7 meters in length in early-May. Irrigation was carried out 7-10 days. Two cuttings forage were harvested from all treatments each year. Five traits including plant height, Stem diameter, tiller number, green fodder and dry matter were measured each cuttings . Harvesting was done from the two central rows of 7.8 m2 area. The fresh weight was done and a random sample of two kg was taken for determination of hay. Each years data were analyzed in combined analysis and the means comprised with Duncan multi rang testing method. Results showed significant differences between cuttings for all traits, years ( except for tiller number) ' varieties ( except for tiller number and dry matter ) 'Plant Density( except for tiller number) at 1% level of probability . mostly interaction of year *variety ' year*plant density ' variety* plant density and year*variety*plant density interaction showed significant differences at 5% and 1% level of probability. There was also non significant difference to other traits. The means comprised with Duncan multi rang testing showed, totally KFS18 with 216 cm plant height, 13.89 mm Stem diameter, total yield of green fodder and dry matter 117.6 and 24.3 t/ha/year respectively; plant density 208 and 278 thousands plant pear hectare were determined the most Suitable treatment