Growth and yield of forage sorghum cultivars as affected by different planting dates.

摘要

A possible strategy to increase sorghum forage production could be the use of appropriate planting dates and cultivars. To investigate the effects of planting dates on yield components and protein percentage of sorghum cultivars, an experiment was conducted at Research Farm of Isfahan University in 2008. A split plot design in the layout completely randomized block design with three replications was used. The main plots included 15th and 30th June, and sub-plots were four cultivars, namely, Sarasai, Speedfeed, Pegah and Sofera. The effect of planting dates was significant on the number of days from plantation until ear emergence stage, the number of days from plantation until flowering stage, the number of days from plantation until milk seed development and total fresh yield. Planting dates did not significantly influence total dry yield. The number of days from plantation until ear emergence stage, the number of days from plantation until flowering stage, the number of days from plantation until milk seed development, the number of days from plantation until ripening, total fresh yield and total dry yield were significantly affected by cultivars. The interaction between cultivars and planting dates effect on all experimental characteristics was significant. In this experiment, the maximum number of days from plantation until ear emergence stage, flowering stage, milk seed development stage, soft dough seed stage and hard dough seed stage were obtained on 30th June. Plantation on 15th June also obtained the maximum total fresh and dry yield. Speedfeed cultivar having appropriate growth time and suitable number of days in flowering and seed development stage can obtain the highest total fresh and dry yield.