Impact of NPS Fertilizer Rates on Okra Growth, Yield, and Quality

Okra (Abelmoscus esculentus (L) Moench) is widely known and utilized vegetable crop in tropical and sub-tropical parts of the world. In Ethiopia, including Gambella, okra production and yield improvement have not been attained due to a lack of appropriate production practices, including fertilizer use recommendations. Hence, this experiment was conducted to evaluate the effect of NPS fertilizer rates on growth, yield, yield components, and quality of okra. The treatments were laid out in a randomized complete block design (RCBD) with three replications with eight levels of NPS fertilizer application rates. Data collection and measurement was done according to scientific recommendation for each parameter; data analysis was done using statistical analysis software version 9.3 (SAS, 2008). Results indicated that the NPS fertilizer had a significant influence on the growth, yield, yield components, and quality parameters of okra. The maximum number of branches (4.2), leaf area (890 cm2), number of pods per plant (7.6), pod length (30.9 cm), individual pod weight (18.0 g), fresh biomass yield (814.2 g), dry biomass yield (248.7 g), number of seeds per pod (96.3), total soluble solute (4.9), and pod yield per hectare (15.9t ha-1) were obtained from the NPS rate of (75-90-16.5) kg ha-1. The highest pod diameter (2.7cm) was obtained from NPS fertilizer rate of 50–60–11 kg ha-1 which was statistically similar with (2.4cm) at NPS rate of 75–90–16.5 kg ha-1. Similarly, the maximum pod dry matter content (27.1) was obtained from NPS fertilizer rate of 100–120–22 kg ha-1 which was also statistically on par with (25.9) at NPS rate of 75–90–16.5 kg ha-1. The economic feasibility analysis showed that the maximum net benefit (Birr 232740.4 ha-1) with highest MRR (3625.53%) was obtained from application of 75kgN-90kgP2O5-16.5kgS per hectare, whereas the lowest (Birr 118500 ha-1) was obtained from the unfertilized. Application of NPS fertilizer resulted to gain (114240.4 Birr ha-1) more compared unfertilized. Therefore, NPS fertilizer rate of 75–90–16.5 kg ha-1 appears to be the optimum practice for higher yield and is economically feasible with maximum net benefit (Birr 232740.4 ha- 1) and the highest MRR (3625.53%) of the local cultivar okra in the Abobo area. Further increase in NPS rate above (75-90-16.5) kg ha-1 did not bring about significant changes in yield, suggesting that NPS (75-90-16.5) kg ha-1 is the optimum rate to obtain the highest green pod yield of okra.