Performance of Okra (abelmoschus Esculentus (l.) Moench) as Affected by Nitrogen Fertilizer Application Rates in Mubi North, Adamawa State, Nigeria

The field experiment was conducted to examine the performance of okra (Abelmoschus esculentus (L.) Moench) as affected by nitrogen fertilizer application rates in Mubi North, Adamawa State, Nigeria, grown at the Teaching and Research Farm of Food and Agricultural Organization / Tree Crop Plantation (FAO/TCP), Faculty of Agriculture, Adamawa State University Mubi, during 2018 and 2019 rainy seasons. The experiments were laid out in a Complete Randomized Blocked Design (CRBD) with four (4) treatment levels of nitrogen: 0 kg N ha-1 , 50 kg N ha-1 , 100 kg N ha-1 and 150 kg N ha-1 replicated 3 times. Data collected on plant height, number of leaves/plant, stem diameter, days to first fruit setting, fruit length, fruit diameter, number of seeds/fruit, fresh and dried fruit yield/hectare. All the data collected were subjected to analysis of variance using Statistical Analysis System (SAS, 2010) and means that showed significant differences separated by F-test using Duncan Multiple Range Test. The results revealed that, at 9 WAS in 2018, 2019 and their combined effect, nitrogen fertilizer application rates significantly influenced plant height (34.960, 42.165 and 38.563 cm), number of leaves/plant (19.796, 19.680, 19.738), stem diameter (15.244, 14.076, 14.660 mm) recorded the highest values 150 kg N ha-1 . On the response of phonological traits and yield components of okra, to nitrogen fertilizer application rates, significant reduction in days to first fruit setting: 60.333 and 59.083 days 2018 and combined in the plots that received 150 kg N ha-1 compare with the shortest 58.00 days recorded in 2019 at 100 kg N ha- . 1 Furthermore, highest values of: 8.584, 9.088, 8.836 cm ( fruit length) and 9.731, 9.867, 9.799 cm (fruit diameter), 102.023, 102.484, 102.258 (number of seeds/fruit), 1238.38, 1293.42, 1265.90 kg ha-1 (dry fruit yield/hectare) and 615.33, 652.33, 633.83kg ha-1 (fresh fruit yield/hectare) were obtained from the plots that received 150 kg N ha-i accordingly. It was concluded that, plants from the plots received 150 kg N ha-i performed significantly higher than the rest of the treatments. The study therefore recommends the application of 150 kg N ha-1 at 3 and 6 WAS as suitable dose to okra farmers in Mubi and its environs for optimum fruit yield.