Effect of different combinations of organic and inorganic nitrogen sources on growth and pod yield of Okra (Abelmoschus esculentus) in Minna, Niger State.

Abstract

A study was carried out at the Federal University of Technology Minna during the 2019 cropping season to evaluate different combinations of organic and inorganic nitrogen sources on growth and pod yield of Okra (Abelmoschus esculentus) in Minna, Niger State. Two varieties of Okra (NHAe47-4 and LD88) were treated to two different combination ratios (75:25 and 50:50) of inorganic and organic N sources, respectively, 100 % inorganic and control (No fertilizer). Nitrogen was sourced from urea (46 % N) and Cow dung. The nitrogen was applied at the rate of 80 kg ha-1 while Phosphorus and Potassium were applied as basal at 45 kg ha-1 each using Single Super Phosphate (18 % P2O5) and Muriate of Potash (60 % K2O) as sources. The experiment was laid out in a Randomized Complete Block Design with three replications, and data were subjected to Analysis of Variance using Minitab Version 17.0. Results showed that there were significant differences (P ˂ 0.05) among the treatments applied. The application of 75 % N from Urea + 25 % N from Cow dung produced the tallest okra plants of NHAe47-4 variety (103.27 cm) and LD88 (154.87 cm); highest number of leaves per plant, highest leaf area and stem girth per plant were also recorded with 75 % N +25% N (inorganic and organic sources respectively) as compared to other fertilizer plans. However, the two varieties' response to 100 % N from urea attained reproductive stage (days to first flower bud sight, first flower bud opening and 50% flowering) earlier than the other treatments. Application of 75 % N (Inorganic) + 25% N (Organic) produced the highest yield of 10 pods per plant with NHAe47-4 and 16 pods per plant with LD88. However, NHAe47-4 attained reproductive stage earlier than LD88, but best vegetative growth traits such as heights, leaf number/plant, leaf area and higher pod yield were recorded with LD88. Thus, it can be concluded from this study that the complementary application of 75 % N from Urea + 25 % N from cow dung resulted in significantly better performance and yield of the two okra varieties.