Seeds enriched with phosphorus and molybdenum as a strategy for improving grain yield of common bean crop.

摘要

Sowing seeds with high concentrations of P or Mo can improve growth and nodulation of common bean (Phaseolus vulgaris) plants. However, the performance of the bean crop originating from seeds enriched with P and Mo has not yet been assessed under field conditions. This study aimed to evaluate the effect of sowing seeds enriched with P and Mo, harvested from plants that received foliar sprayings of P or Mo or both, on growth and yield of common bean crop. Seeds with contrasting concentrations of P and Mo were sown in three field experiments in Brazil (in 2006 and 2008 in Rio de Janeiro State, and in 2009 in Goias State) with different N sources (control without N, seed with rhizobia inoculation, rhizobia inoculation plus 40 kg N ha-1 side-dressed, mineral N with 60 kg N ha-1). In 2006, seeds enriched with P and Mo increased nodule mass at 32 days after emergence (DAE), shoot N and biomass at 48 DAE, and grain yield and N content, for most combinations of the three cultivars and N sources evaluated. In 2008, the highest shoot growth at 57 DAE and grain yield were obtained with low-P high-Mo seeds, which was partially due to the higher Mo concentration of these seeds. In 2009, seeds enriched with P and Mo increased nodule mass at 34 DAE and grain yield but only for plants receiving inoculation plus side-dressed N. The results demonstrate the benefits of seeds with high concentrations of P and Mo for improving bean yield, although such yield increases were more effective for plants inoculated with rhizobia than amended with N. Sowing enriched seeds, associated with rhizobia inoculation and side-dressed N, provided grain yields much higher than the average common bean yields in Brazil.