Effect of inter-row spacing on some selected Cowpea (Vigna unguiculata (L) Walp) varieties in Yola, Adamawa State, Nigeria

Abstract

Nigeria is a leading producer of cowpea. However, average yield as obtained by local farmers is far below the yield capacity of the crop. Some of the reasons for this low yield could be attributed to cultivation of low yielding varieties and lack of optimum spacing of specific varieties. Field experiments were conducted during the 2009 and 2010 cropping seasons at the Teaching and Research Farm of the Department of Crop Production and Horticulture, Modibbo Adama University of Technology, Yola (9 0 10'N, 11 0 14'E and 158,5 above sea level), to evaluate the effects of inter-row spacing on some selected cowpea varieties. The experiment consisted of three row spacing (45 x 25cm, 60 x 25cm and 75 x 25cm) three varieties (IT89KD-288, IT89KD-391 and IT97K-499-35), and were replicated three times with plot size of 4m x 3m. Data collected include number of pods per plant, pod length and pod weight, number seeds per pod, number of seeds per plant, 1000 seed weight, seed yield per plot. The result showed that increasing spacing from 45cm x 35cm to 75cm x 25cm significantly increased number of pods per plant from 12.77 to 15.74 in both 2009 and 2010 rainy seasons. Similarly, number of seeds per pod increased from 10.91 to 12.74. On the other hand, seed yield per plot was higher in spacing of 45cm x 25cm with 1227.9 kg/ha. With respect to the varieties, IT89KD-391 had higher seed yield of 1240.54 kg/ha. Yield increased with decrease in row spacing and hence it is suggested that closer spacing of 45cm x 25cm should be adopted for the erect varieties IT89KD-391 and IT97K-499-35 in the studied area.