Influence of fertilizer application and cropping system on growth, dry matter accumulation and yield of okra (Abelmoschus esculentus L. Moench)

Abstract

Reduction in agricultural land with increasing population has led to a need for multiple cropping to maximize limited land resources and thus require an improvement. A field experiment was conducted during the growing seasons of 2019 in two locations (Ikenne and Ibadan) in Southwest Nigeria to assess the effects of cropping system and fertilizer application on the yield of okra intercropped with Jatropha. The experiment was a split-plot arrangement in a Randomized Complete Block design, replicated three times. Fertilizer types (NPK; Organic; Organic + NPK (50:50) and control were the main plots while cropping systems of sole okra; sole Jatropha and Jatropha/okra intercrop were sub-plots. Data collected to determine okra growth includes: plant height, number of leaves/ plant, leaf area and dry matter accumulation. Yield components assessed were: number of days to 50 % flowering, number of fruits/ ha, fruit yield and fruiting duration. Jatropha growth parameters taken include: plant height (cm) and number of leaves/plant. Okra can be intercropped with Jatropha with no significant reduction in okra yield as the number of fruits/ha, 172.25 in sole crop and 147.23 in intercrop, and fruit yield/ha in both intercrop, 2.79 t/ha, 1.06 t/ha and monocrop, 3.31 t/ha, 1.35 t/ha in Ikenne and Ibadan sites respectively were not different significantly. Growth, dry matter accumulation and yield were similar to sole cropping. Growth of Jatropha as well as okra yield was significantly 0.05) better in fertilized plots than the unfertilized plots. Complementary use of organic and inorganic fertilizer (50:50) produced the highest number of fruits/ha and fruit yield/ha than other nutrient sources. Intercropping of okra with Jatropha should be encouraged with the combine use of organic and inorganic fertilizer to enhance productivity at reduced cost for sustainable agriculture.