Growth and dry matter yield responses of cowpea to different sowing depths

摘要

The depth of sowing has an important impact on the seedling emergence, growth and yield of crops. Uniform seeding depth is essential toward achieving higher crop yields. The objective of this study was to compare the effect of different depths of sowing on cowpea (Vigna unguiculata (L.) Walp.) Seedling emergence, plant height, stems girth, number of leaves per plant, and dry matter yield. Asontem cowpea variety was sown in a loamy sand soil at five different sowing depths (20, 30, 50, 70 and 90mm) replicated three times in a randomised complete block design at two seeds per hill in 1.8x 1.8m plots with spacing between plants and rows of 20 and 60cm, respectively. Plant stand was counted daily on each plot after the first seedling emerged until a stable count was obtained to determine the percentage emergence. Plant height, stem girth, and number of leaves were measured once a week for 7 weeks after the first plant emerged. The dry matter yield was determined 65 days after planting. Sowing depth effects were generally not significant. However, sowing at 50mm produced the highest percentage cowpea seedling emergence, plant height, stem girth, number of leaves and dry matter yield compared with sowing at 20, 30, 70 and 90mm. The study showed that for optimum growth and yield of cowpea, sowing should be done at a depth of 50mm.