Abstract

---

Megagreen is a bio stimulant, containing micronized calcite whose particles act quickly on the vegetal metabolism via foliar surface. Therefore experiment was carried out at the screen house of the College of Plant Science and Crop Production at the Federal Univer sity of Agriculture, Abeokuta, Ogun State, Southwestern Nigeria to investigate the effect of different rates of single super phosphate and frequency of megagreen on nodulation, nitrogen fixation and yield of cowpea Vigna unguiculata L). The experiment was a Complete Randomized Design (CRD) arranged in split split plot with application of megagreen at the rates of 1.5 and 3 (kg/ha per 500 litres of water) used and applied at two frequencies and application of SSP (0 kg/ha P 2 O 5 ) and recommended rate (40 kg/h a P 2 O 5 ) applied at planting. Plant growth and reproductive parameters were measured. The soil physical and chemical properties; and analysis of ureides N and nitrates N were determined. The results showed that cowpea gave no significant response to the two treatments of SSP and megagreen in terms of the growth parameters, yield obtained, level of nitrogen retained in the soil and the ammonium nitrate in the plant sap and plant tissue. However, application of SSP and megagreen at the rate of 3 kg/ha per 500 litres of water at 2, and 3 WAP (S 1 M 2 R 1 ) also recorded more than 200 % increase in yield. The findings indicate that application of SSP and megagreen at the rate of 3 kg/ha are the preferred option to improve soil fertility and quality, and increase cowp ea yield

Keywords: Cowpea yield, megagreen, nitrogen fixation, nodulation, single superphosphate