EFFECTS OF CROP SPACING ON WEED COMPETITION AND SEED YIELD IN COWPEA, VIGNA UNGUICULATE (L.) WALP C.V. IFE BROWN

Abstract

When cowpea (Vigna unguiculata (L.) Walp c.v. Ife Brown) was planted at spacings of 50cm x 25cm and 50cm. 31 and 15 percent yield increases were obtained over that of the conventional (100cm x 30cm spacing respectively. Optimum yield was obtained under the 50cm x 25cm spacing with 4 weeks of weed-free maintenance, whereas 6 weeks of weed-free maintenance were required for the same under the 50cm x 50cm and 100cm x 30cm spacings. When weeds were allowed to compete with the crop for more than 4 weeks, yields decreased under the 50cm x 50cm and 100cm x 30cm spacings but yield reductions were not observed under the 50cm x 25cm spacing even with up to 6 weeks of weed competition.