Effect of boron and molybdenum applied to seed coatings of beans (Phaseolus vulgaris)

Abstract

The effect of adding boron and molybdenum to seed coating of beans (Phaseolus vulgaris L.) under field conditions at Instituto de Pesquisas e Experimentação Agropecuárias do Centro-Sul, Rio de Janeiro, is reported. Specifically studied were effects on nodulation, nitrogen fixation and seed production. Four coating types were used: a) calcium carbonate; b) rock phosphate; c) 50% rock phosphate and 50% calcium carbonate; d) 50% rock phosphate, 25% calcium carbonate and 25% magnesium carbonate. Boron and molybdenum were added individually and together to each. Among the coatings, plain rock phosphate was significantly lower for dry weight of nodules, nitrogen fixation and bean production. Neither micronutrient increased nodulation although the addition of molybdenum to rock phosphate increased dry nodular weight. Boron significantly increased total nitrogen, plant growth (at flowering) and bean production. When molybdenum as well as boron was added, nitrogen percentage, total nitrogen and nodular weight were significantly increased only when rock phosphate was also present. When both micronutrients were used with rock phosphate and calcium carbonate there was a significant increase in bean production.