Comparative Effects of Organic Manures and Npk Fertilizer on Growth and Yield of Okra (abelmoschus Esculentus (l.) Moench) on Ultisol

Experiments were conducted at the Teaching and Research Farm of the Federal College of Education (Technical), Omoku – Rivers State, in the humid tropics of South-South Nigeria to study effects of organic manures (poultry manure, cow dung and palm bunch ash) and nitrogen - phosphorus - potassium fertilizer (15-15-15) on plant height, number of leaves, number of branches, leaf area, pod weight and dry matter of okra (Abelmoschus esculentus (L) Moench) during the late planting season of 2012 and early planting season of 2013. Organic manures were applied at 0 and 6 t ha-1 while NPKF was applied at 250 Kg ha-1. Plant height and number of leaves were determined at 4 and 6 weeks after planting (WAP). Number of branches and leaf area were taken at 6WAP. Pod weight was determined at each harvest and cumulative taken at the eighth harvest while dry matter weight of plant was determined after harvest. Data obtained were subjected to ANOVA using the SPSS package. Organic manures and NPKF increased vegetative growth and pod yield relative to control. At 6 WAP in late planting season of 2012, NPKF had the highest height (40. 05 cm), followed by PM (35.18 cm), CD (27.88 cm), PBA (27.10 cm) and control (24.50 cm). The early planting season of 2013 also had NPKF (48.28 cm), PM (40.70 cm), CD (38.58 cm), PBA (30.88 cm) and control (26.85 cm). Pod weight indicated that CD (6.58 t ha-1) > NPKF (4.92 t ha-1) > PM (3.69 t ha-1) > PBA (3.58 t ha-1) and control (2.30 t ha-1). NPKF encourages more vegetative growth than yield while CD and PM support more pod yield than vegetative growth. Application of CD at 6 t ha-1 is recommended for optimum production of okra on Ultisols.