Mfects of Sowing Time on Biological Yield of Forage Sorghum Sorghum bicolor ( L. ) Moench in Autumn Idle Land

摘要

［Objective］ This study was performed to explore the correlation between sowing time and biological yield of forage sorghum in autumn. ［Method］ In field trials, forage sorghum was sown on six different dates (July 23, July 29, August 6, August 14, August 22 and August 30). Then, seedling emergence stage, jointing stage, booting stage, heading stage, filling stage, fresh weight and dry weight in each plot were observed or measured. Finally, linear regression analysis on these data was carried out to deduce the correlation between sowing date and biological yield of forage sorghum. ［Result］ Sowing time showed a significant influence on biological yield of forage sorghum in idle land, and the biological yield of forage sorghum linearly decreased with the postponement of sowing time. The relationship between sowing time and biological yield of forage sorghum can be represented by the regression equations fresh=196.646-4.625x and dry =58.253-1.423x, wherein, x is sowing date, fresh and dry are the fresh weight and dry weight of forage sorghum. On average, the fresh weight of forage sorghum was reduced by 4.625 kg/20m2, and dry weight by 1.423 kg/20m2, when the sowing date was delayed by one day from July 23 to August 30. ［Conclusion］ The regression models built in this study will provide a theoretical basis for improving the yield of forage sorghum in autumn idle land.