Effect of plant density and planting pattern on yield, yield components and morphological traits of forage sorghum in second cultivation

In order to determine the effects of plant density and planting pattern on yield, yield components and morphological traits of forage sorghum, an experiment was conducted at Agricultural Research Station of Azad University, Birjand Branch, Iran in 2003. The experiment was a factorial based on RCBD with three replications and eight treatments. Factors were plant density with 4 levels (20, 30, 40 and 50 plant/m2) and planting pattern with 2 levels (one row above furrow and two rows within furrow). The results obtained from the statistical analysis showed that the effects of plant density, planting pattern and their interactions were not significant on yield and yield components of forage sorghum but the effect of plant density was significant on the number of tiller per plant and main stem diameter. The total produced fresh forage in the plant densities of 20, 30, 40 and 50 plants/m2 was 25.8, 25.7, 25.6 and 28.6 ton/ha, respectively and the total produced dry forage in the above plant densities was 5.28, 5.35, 5.26 and 5.83 ton/ha, respectively. Increase in plant density decreased number of tillers/plant and stem diameter. In the density of 20 plants/m2 with an average of 2.3 tillers/plant the maximum and in the density of 50 plants/m2 with an average of 0.27 tillers/plant the minimum tillering were observed. The results of the research indicated that for optimum use of the short growth period of forage sorghum dense cultivation in the second cultivation in Birjand region is recommended.