Yield Responses of Four Maize Varieties to Two Plant Densities in the Humid Tropics of Rivers State, Nigeria

Study on yield responses of four maize (Zea mays) varieties was carried out in the late (dry) season and early (wet) season using two plant densities (spacings) at the Rivers State University Teaching and Research Farm, Port Harcourt. The treatments comprise of four maize varieties (Bendel white, Oba super 6, Oba super 98 and Provitamin A) and two plant densities (60cm 15cm and 60cm 30cm). Treatments were arranged in a split plot combination fitted in a Randomized Complete Block Design (RCBD) and replicated three times. Parameters assessed were stover yield, cob length, cob weight, cob circumference, number of grains/cob and 1000 grains/weight. Results showed that Provitamin A had highest mean in cob length (24.5cm), cob circumference (13.2cm), cob weight (898.8gm) and number of grains/cob (260.9), OBA super 98 had high 1000 grains/weight (160.3gm) and OBA super 6 in stover yield (3.4kg). Yield response showed that early (wet) season had the highest performance (p < 0.05) than late (dry) season. Also, 60cm 30cm was high in cob weight (852.7gm), no of grains/cob (223.6) and 1000 grains/weight (159.3gm) but was not significantly different from 60cm 15cm in stover yield, cob length and cob circumference. Provitamin A variety spaced with 60cm 30cm (V4 + P2) had high mean (p < 0.05) in cob weight, number of grains/cobs, cob circumference. The least in yield performance was Bendel white spaced 60cm 15cm (V1 + P2) in cob length, cob weight and cob circumference. Therefore, Provitamin A is recommended by farmers for ideal for optimum maize yield in Rivers State. Farmers in this agroecological zone are advised to adopt plant density of 60cm 30cm for maize production.