Effect of varying maize intra-row spacing on intercropped yields of egusi melon (Citrullus lunatus Thunb.) and maize (Zea mays L.) at Makurdi, Nigeria

Abstract Field experiments were conducted from June to September during the 2010 and 2011 cropping seasons, at the Research Farm, University of Agriculture, Makurdi, Nigeria, to evaluate the effect of varying maize intra-row spacing on intercropped yields of egusi melon and maize and to assess the advantages of the intercropping system. The trial consisted of five treatments, replicated three times in a randomized complete block design. Three of the treatments consisted of three intra-row spacing (20 cm, 25 cm and 30 cm) into melon plots. Monocropped maize and melon, respectively sown at their recommended intra-row spacing of 25 cm and 35 cm constituted the fourth and fifth treatments, which also served as control plots. Results obtained showed that the greatest intercropped yields of egusi melon and maize were obtained when maize was sown at the intra-row spacing of 30 cm, significantly (P≤0.05) greater than the rest treatments. Maize sown at the intra-row spacing of 30 cm into egusi melon plots, not only recorded the lowest competitive pressure but gave the highest land equivalent ratio (LER) values of 1.80 and 1.76 respectively, in years 2010 and 2011, indicating that greater productivity per unit area was achieved by growing the two crops together than by growing them separately. With these LER values, 44.4 % and 43.2 % of land were saved respectively, in years 2010 and 2011, which could be used for other agricultural purposes. Both crops were found to be highly complementary and most suitable in mixture when maize was sown at the intra-row spacing of 30 cm. The implication of study showed that to maximize intercrop yields of egusi melon and maize, the optimal maize intra-row spacing would be 30 cm. This should therefore be recommended for Makurdi location, Nigeria.