Behaviors of Some Soybean Cultivars (Glycine max L.) Yield to Planting Dates and Different Phosphorus Fertilizer Rates

Soybean production components such as planting date, cultivars and phosphorus fertilizer rates affected soybean yield. Two field experiments conducted in extensive field at El-Gahrbia district, Egypt during 2015 and 2016 seasons. The goal of this research was aimed to investigate the influence of sowing date at 1th May, 15th May and 31th May and three phosphorus fertilization rates, i.e. 0, 37.2 and 74.4 kg P2O5/ha on the performance of three soybean (Glycine max (L.) Merrl) cultivars i.e. Crawford, Giza 22 and Giza 111 on growth, yield and seed quality. The tallest plants, the thick stem, highest branches number/plant, pods number/plant, seed number/pod, weight of 1000 seed and seed yield/ha were recorded from sown early on first May in the both seasons. The tallest plants, the thick stems and highest number of branches/plant were recorded from sown Crawford cultivar. Whereas maximum number of pods/plant and number of seed/pod were found from sown Giza 111 cultivar in the both seasons. Increasing phosphorous fertilizer rates significantly increased all studied cultivars of seed yield and yield components. Tallest plant, the thick stem, the highest branches number/plant, pods number/plant, seed number/pod, weight of1000 seed and seed yield/ha were produced from phosphorous fertilizer at a rate of 74.4 kg P2O5/ha in the first and second seasons, respectively.