Growth, Yield and Storability Response of Two Okro Varieties to Integrated Nutrient Management.

Abstract

Field trials were conducted during the 2021 and 2022 cropping seasons at the University of Skills Training and Entrepreneurial Development (USTED) Research Farm. The objective of the study was to determine the growth and yield performance and post-harvest qualities of two okro varieties (a local and an exotic variety) in response to the integrated application of organic and inorganic fertilizers. The experiment contained six treatments: (i) 650 kg/ha NPK (full NPK), (ii) 20 t/ha Poultry Manure (full PM), (iii) 487.5 kg/ha NPK+5 t/ha PM (¾ NPK + ¼ PM), (iv) 325 kg/ha NPK +10 t/ha PM (½ NPK + ½ PM), (v) 162.5 kg/ha NPK + 15 t/ha PM (¼ NPK + ¾ PM), and (vi) No Fertilizer (control). The experimental design used for the field experiment was laid out in a 2 x 6 factorial experiment arranged in a Randomized Complete Block Design (RCBD) with four (4) replications. The storability experimental design used was a 4 x 12 factorial arranged in a Completely Randomized Design (CRD) with 3 replications. On the average, Asontem, a local okro variety in the 2021 and 2022 cropping seasons, produced the tallest plant of 126.25 cm and 123 cm in plots where 487.5 kg/ha NPK+5 t/ha PM and 20 t/ha Poultry Manure were applied respectively, while Clemson, an exotic okro variety produced the maximum plant height of 125.65 cm and 122.98 cm where full PM was applied. Asontem okro variety produced the highest fruit yield of 10.03 t//ha and 4.73 t/ha in 2021 and 2022, respectively, under the 162.5 kg/ha NPK + 15 t/ha PM fertilizer combination. The control treatment recorded the least yield of 8.76 t/ha and 3.68 t/ha in both cropping seasons, respectively. Similarly, the Clemson okro variety produced, the highest fruit yield of 8.18 t/ha and 2.95 t/ha under the 325 kg/ha NPK +10 t/ha PM fertilizer treatment in both 2021 and 2022 cropping seasons. The control treatment had the lowest yields of 7.51 t/ha and 2.29 t/ha in both cropping seasons, respectively. The integrated management of poultry manure and NPK (15:15:15) fertilizer application significantly increased all growth and yield attributes of okro crops under rainfed conditions of the study area. It is recommended that okro farmers should adopt integrated nutrient management strategies. For higher yields, Asontem with 162.5 kg/ha NPK + 15 t/ha PM and Clemson with 325 kg/ha NPK +10 t/ha PM could be considered for adoption. The nutritional analysis results indicated that both the sun-drying and freezing methods of okro after two months of storage period did not show any significant decrease in some nutrient content. The study showed that both sun-drying and freezing okro samples consistently yielded greater okro nutritional qualities during preservation over time. The freezing process on average preserved the nutrient content quality better when compared to the sun drying method. Hence sun drying and freezing methods could be adopted by okro farmers and value-chain actors in Ghana depending on the resources available to them.