Comparative Assessment of the Effect of Three Plant Spacing on the Performance of Maize (Zea mays L.) Varieties in the Humid Tropics of Port Harcourt, Rivers State, Nigeria

Experiments were conducted in the late (dry) season and early (wet) season to determine the comparative growth response of maize varieties using various plant densities (spacings) at the Rivers State University Teaching and Research Farm Port Harcourt. The treatments consisted of four maize varieties (Bendel white, Oba super 6, Oba super 98 and Provit A) and three plant densities/spacings (60cm x 15cm, 60cm x 30cm, 60cm x 45cm). Treatments were combined in a split plot arrangement with maize varieties fitted in a Randomized Complete Block Design (RCBD) replicated three times. Parameters evaluated were plant height, leaf area, and number of leaves at 4, 6, and 8 weeks after planting (WAP). Insect infestation and stem girth were determined 8 weeks after planting. Results show that Provit A produced highest performance (P<0.05) in early (wet) season cropping in terms of plant height (70.2cm), number of leaves (9.3), leaf area (304.9cm). Bendel white was high in stem girth (7.8cm). Comparing growth in late (dry) season and early (wet) season showed that growth was better in the early (wet) season cropping. However, there was more insect infestation in the late (dry) season cropping than in the early (wet) season cropping. Oba super 6 had the highest incidence of insect pest infestation in late (dry) season cropping with a mean of 7.3%. Also spacing of 60cm x 30cm produced highest growth performance. Thus, Provit A variety is recommended for cultivation by farmers in Port Harcourt agroecological zone. Spacing of 60cm x 30cm is recommended for maize production in Port Harcourt agroecological zone.