Adubação nk no desenvolvimento e na concentração de macronutrientes no florescimento do feijoeiro

Abstract

Nitrogen and potassium are absorbed and transported more than any other element by bean plants. Fertilizer levels vary greatly among agriculturists and, therefor our aim was to study the effect of N levels (0, 60, 80, 100, 120 kg ha-1) and K2O levels (0, 60, 120 kg ha-1) on bean development, evaluating number of flowers, fresh weight, dry weight and macronutrients during flowering. The experiment was carried out at Botucatu, SP, Brazil, in plastic tunnels, with the bean cultivar Pérola. Two plants were grown for 50 days in 15L pots filled with an Haplorthox. The NK fertilizations were parceled 20 and 40 days after sowing. The parameters were influenced by N and K interactions. Soil N fertilization increases dry weight production without interfering on bean shoot N, K, Ca and Mg levels. Nitrogen omission reduces leaf chlorophyll content, decreasing dry weight, having no influence on flower number. K levels had no influence on plant Ca and Mg levels.