Sementes de feijão-caupi com alto conteúdo de molibdênio originam plantas mais produtivas em solos com baixa fertilidade natural na Amazônia Oriental

Abstract

Cowpea is one of the most consumed foods in the North and Northeast of Brazil, and one of the main sources of income for family farmers. Our objective was to study the effects of Mo content of combined or uninoculated seed (rhizobia) on nitrogen nutrition and cowpea production in soils with low natural fertility in the Eastern Amazon. For this, two experiments were conducted. In the first, in Coimbra-MG seeds were produced with three Mo contents. In this experiment, the plants were sprayed with 0, 250 and 850 g ha-1 of Mo and the seeds harvested were evaluated for Mo content. With these seeds, an experiment was in São Luís-MA in the 3 x 2 factorial scheme: three Mo contents of the seed (0.014 ± 0.005; 0,674 ± 0,151 and 1,987 ± 0,278 μg Seed-1) and the use of rhizobia with Bradyrhizobium strains (BR 3262). A randomized complete block design was used, with four replicates. There was low nodulation, and inoculation with rhizobium did not (P = 0.107), although the N content in the leaf increased by 17%. in relation to the treatment that did not receive inoculant. The Mo content of the seed of 1,987 ± 0,278 μg increased the N content in the leaf by 36% and by 35% the seeds compared to 0.014 ± 0.005 μg. Our results suggest that rich seed in Mo increases the production of cowpea seeds in the Eastern Amazon region, regardless of inoculation. The use of Mo-rich seeds may yield benefits to the farmer, even to those who do not use inoculant.