(Faculty of Agriculture, University of Ife, 1981) Osiname, O. A.
Trials were conducted at three locations on Alfisols in southwestern Nigeria to study the optimum phosphorus - zinc balance in the soil for field grown maize (Zea mays L.) and cowpea (Vigna unguiculata s.sp. ungzciculata L. Walp). The incidence of P induced Zn deficiency in maize was observed to be more probable in the sandy soils of the savanna zone than in the sandy loam soils of the forest zone. Correcting P deficiency without correcting Zn deficiency resulted in lower maize yields. In soils with Bray-1 P test of >7.0 ppm and 0.1N HCL extractable Zn of G 1.0 ppm, further addition of P. was observed to induce Zn deficiency in maize. Cowpea was less sensitive to either the deficiencies of P and Zn or to the incidence of P induced Zn deficiency.
(Faculty of Agriculture, University of Ife, 1984) Adelana, B. O.
Maize (Zea mays L.) and okra (Abelmoxhus esculentus L. Moench) were grown in pure and mixed stands with the mixtures having the same plant density as the pure stands. The sole crops gave higher yields than in mixtures. There was competition for growth factors between the two species with their relative yield total (RYT) slightly above unity. The taller maize was at an advantage in the mixture and its yield was only slightly reduced compared with the pure stand, while the shorter okra plants were heavily shaded and the yield greatly reduced. Planting both crops together was more efficient as their land equivalent ratio was above unity.