Economic evaluation and determination of the most suitable Plant Density of promised forage sorghum varieties

Density of promised forage sorghum varieties Achieving to the forage crops with high performance, water deficiet resistance and resistance to hot weather conditions such as sorghum (sorghum bicolor L.) is one of the main purposes in researchs in recent years. In order to consider this matter, an experiment was coducted in 2002, and 2003 in the fields of fars Agricultural Research center, Zarghan. The purposes of this experiment were to determine the appropriate density and the best promosing variety in Fars provience. This experiment was carried out in factoriol experiment arrenged in a Randomized complete block Design (RCBD) with three replicatin and two factors, i.e. Three variety selected from Breeding prograns (KFS1., KFS2, KFS3)and four density levels (167, 208, 287 and 417 thousends plants per hectar). Every treatment was planted in four rows with sevenmeter- length by current methods. Inorder to omit nested effects, 25 cm of the first and of the end of each row was cut out. Sampling and data recording was done from two middle rows. According to the results, the power and rate of growth had significant discripancy between different varieties and noticiablely climbed up by increasing density. By increasing density at first cut in two year, Power and rate growth of varieties increased. However at second cut had no significaut differences between densities. The highest nwmber of tillers was obtmin from lowest density (167000 p/ha). The highest fresh froage yield was obtained from KFS1 and KFS3 varities. The results also showed that by increasing densities, fresh forage yield increased. At this experiment. had no significant differences beetween varieties for dry forage yield. At first cut in two years, by increasing densities dry forage yield increased singnfimcantly. At first cut, by increanig densities, proteins content decreased sigificantly. At second cut in tow years, the lowest protien content was obtained from the highest density (417000 p/ha).