Nodulation and growth of soybean plants as a function of coating the seeds with phosphorous

Abstract

The increase of phosphorous concentration in soybean seed enhances the subsequent potential plant yield. The objective was to evaluate the effect of coating the seeds with phosphorous on the nodulation and growth of soybean plants. Seeds from two lots of cultivar Pioneer - P98R31 were treated with monobasic phosphate sodium in doses of 0.0; 0.2; 0.4; 0.8 and 1.2 g hg-1 of seeds and, with the inoculant 'turfoso Microxisto' using 3.0 millions cells of bacteria (Bradyrhizobium japonicum) by seed. The experiment was carried out in a totally randomized block design with five replications in a factorial scheme of 2x2x5+4, consisting of seeds with different phosphorus content, two levels of phosphorus fertilizer in the soil, five levels of P used in the coating of seeds, and four controls. After treatments, the seeds were sowed in pots with 3.0 dm3 of red yellow Latosol, which received P doses of 200 and 400 mg kg-1 having triple superphosphate as the source. In the stage R2 of plant development, the P and N concentration in the third trifoliate was evaluated. In the initial stage of strings formation (R3), the plant height, whole shoot, root and the dry matter of viable nodules were evaluated. Independently of the endogenous P concentration in the seed, coating soybean seeds with P did not increase nodulation and growth of plants in soil with higher high P availability, whereas in soil with less P available, the coating of seeds increased the nodulation and growth of soybean plants.