EFFECTS OF DIFFERENT GROWTH STAGES OF MUNG BEAN (Vigna radiata) USED AS GREEN MANURE IN THE GROWTH AND YIELD OF SWEET CORN (Zea mays)

Green manure is a term used to describe grasses and legumes that are grown and plowed into the soil to provide nutrients such as nitrogen. Hence, this study was conducted to determine the growth and yield response of corn to different growth stages of mung bean as green manure. Specifically, to determine the effect of green manure to the growth and yield of corn, to know the appropriate time of plowing the green manure into the soil and to know the effectiveness of mung bean as green manure. This study used randomized complete block design having four treatments with three replications. The treatments were T1-Control (no application), T2-green manure at vegetative stage, T3-at flowering stage and T4-green manure after harvest. The mung bean was planted successively with 15 days interval so green manuring of mungbean and planting of corn was done at the same time for all treatments. Data gathered were soil condition, tasseling period, silking period, plant height, number of car per plant, car length, average weight of high and low quality corn and yield. A cost and return analysis was also done. There were no significant differences among treatments for tasseling period, plant height, number of ears per plant, average weight of high and low quality corn and yield. However, the silking period and ear length were significant among treatments where green manures were applied. Green manuring mung bean after harvest had the shortest period to silk emergence and had the longest corn ears. Green manuring mung bean after its harvest yielded the highest return of investment (ROI) percentage of 199.63% for corn. This is because the harvested mung bean seeds contributed to the income. Therefore, green manuring mung beans are recommended for plowing after harvest rather than at the flowering stage.