ABSTRACT


Field and pot trials were conducted during the 2012 rainy season at the Research Farm of the Institute for Agricultural Research Samaru and in the Orchard of the Department of Agronomy, Ahmadu Bello University, Zaria to evaluate the effects of levels of NPK fertilizer (0, 50, 100 kg ha-1) and poultry manure (0, 2, 4 t ha-1) on the performance of two okra varieties (Clemson spineless and Ex-Samaru-4). The designs used were Randomized Complete Block Design (RCBD) and Complete Randomized Design for field and pot trials respectively, replicated and repeated three times in all possible factorial combinations. Results showed no significant difference in days to 50% flowering, 100-seeds weight, fruit length, fruit diameter and plant height when NPK fertilizer was varied from 0 to 100 kg ha-1, but at 7 WAS, significantly increased, and gave higher number of leaves per plant (9.0 and 7.0), number of primary branches per plant (5.0), shoot fresh weight (44.9 g), number of fruits per plant (5.0), number of seeds per pod (80) and fruit weight (17 g) from 0 to 50 kg NPK ha-1 in both trials. Other parameters were significantly at par. Application of poultry manure from 0 to 2 t ha-1 significantly increased plant height, number of leaves per plant, shoot fresh weight and days to 50% flowering, a further increase to 4 t ha-1 gave parameters that were at par. But varying poultry manure from 0 to 4 t ha-1 significantly increased number of primary branches per plant and fruit yield in both field and pot trials. Significant interactions were observed on variety and poultry manure on number of fruits per plant, variety and NPK fertilizer on shoot dry weight, NPK fertilizer and poultry manure on number of primary branches per plant and between poultry manure and variety on number of leaves per plant. Okra variety Clemson spineless significantly gave taller plants, longer fruits and fewer days to 50 % flowering than variety Ex-Samaru-4, however both varieties were statistically at par on fruit yield kg ha-1 in both trials. A highly significant and positive correlation were obtained between okra fruit yield and plant height, number of leaves per plant, number of fruits per plant, fruit length and fruit weight. Regression analysis carried out indicated that NPK fertilizer variation resulted to linear response and poultry manure had a quadratic response in both trials. Based on the result obtained in this study, it could be suggested that for good growth and yield of okra at Samaru application of 3.5 t ha-1 poultry manure in variety Clemson spineless should be recommended.