The survival of Rhizobium japonicum on the surface of inoculated soybean seed

Abstract

The objective of this work was to study the possibility of recommending inoculation of soybean seeds before the planting time. For this purpose, the effect of inoculum formulation (water, sucrose solution (25%) and diesel oil as binders) and storage time (0, 1, 2, 4, 6 and 8 days) on the survival of Rhizobium on the surface of inoculated soybean seed was evaluated. Four experiments were carried out: two in the glasshouse and two in the field in Dark-Red and Yellow-Red Latossols at the Centro de Pesquisa Agropecuária dos Cerrados (CPAC) of EMBRAPA. In general, storage time did not affect Rhizobium survival. However, in the glasshouse experiments, nodulation in treatments with sucrose and water even with no storage period, were significantly greater than treatments with diesel oil. Although good nodulation was obtained with water alone, it was poorer than with sucrose. Results obtained under field conditions confirmed those from the glasshouse, indicating that if kept at an ambient temperature, inoculated soybean seeds can be stored for up to four days without affecting nodulation or grain production.