Velvet Bean (Mucuna pruriens L.) as an Alternative to Failed Fallow Farming: Impacts on Okra [Abelmoschus esculentus (L.) Moench] Production in Ibadan, Nigeria

Crop production continues to decline as a result of the failed fallow farming. The inclusion of nodulating leguminous low-growing plants such as Mucuna pruriens in the cropping systems can improve soil health for increased crop performance. Mucuna pruriens is underutilized in Nigeria despite its acknowledged values in agriculture. Therefore, the stand density of M. pruriens and its green manure potential on the performance of okra (Abelmoschus esculentus) were investigated in Ibadan, Nigeria. The experiment was laid out in a randomized complete block design with five treatments (stand density) replicated three times. The treatments were 0 (MP0), 20,000 (MP20), 62,500 (MP62.5), 137,500 (MP137.5), and 262,500 (MP262.5) stands/ha of M. pruriens. At 42 days after sowing, the ground cover of M. pruriens was determined and the plants were incorporated into the soil, allowing three weeks for decomposition. Okra seeds were sown on each of the prepared plots at a 50 × 50 cm spacing. At seven weeks after sowing data were obtained on dry weight (g), number of flowers and fruit weight (g) of okra and dry weight (g) of weeds. Data were analyzed using ANOVA at α0.05. With the increasing density of M. pruriens, its cover increased, the field cover of other weed species decreased and the fruit weight of okra increased. The cover of M. pruriens under only MP262.5 (4.07 hits) was significantly higher than the control (0.00 hits). The dry weight of weeds in MP20 (200.8), MP62.5 (154.1), MP137.5 (86.1), and MP262.5 (49.2) treatments were significantly lower than control (429.0). The fruit weight of okra in MP137.5 (15.50) and MP262.5 (18.8) treatments was significantly higher than control (3.99). Mucuna pruriens stands at a density of 262,500 stands/ha is the appropriate density to attain optimal cover for weed management on the field. Additionally, M. pruriens can be used as green manure to increase okra fruit yield.