Development, Physiology and Productivity of the Common Bean Under Different Nitrogen Doses

João Everthon Da Silva Ribeiro,Arliston Pereira Leite,Fábio Mielezrski,José Eldo Costa,Manoel Bandeira De Albuquerque

doi:10.5539/jas.v10n6p171

Abstract

Among nutrients, nitrogen is required in the greatest quantities by bean culture. The objective of this work was to evaluate growth, physiological responses and productivity of the common bean cultivar, ‘IAC Imperador’ under varying nitrogen doses in Brejo Paraibano. The experiment was carried out at Fazenda Experimental Chã-de-Jardim (Chã-de-Jardim Experimental Farm), of the Centro de Ciências Agrárias of the Universidade Federal da Paraíba, in the municipality of Areia, state of Paraíba. The treatments comprised 0, 50, 100, 150 and 200 kg of nitrogen ha-1, applied in coverage at 35 days after sowing. To assess growth, plant height, stem diameter and number of leaves were evaluated. For gas exchange, photosynthesis rate, internal CO2 concentration, transpiration, stomatal conductance, instantaneous water use efficiency and instantaneous carboxylation efficiency were evaluated. For chlorophyll “a” fluorescence, minimum leaf fluorescence, maximum leaf fluorescence, variable maximum fluorescence, potential quantum efficiency of PSII (Photosystem II) and ratio (Fv/F0) were evaluated. For the components of primary productivity, the height of insertion of the first pod, number of pods per plant and the number of grains per pod were evaluated. Nitrogen fertilization in coverage significantly affected most of the growth, gas exchange and productivity variables, with the dose of 200 kg ha-1 being responsible for the highest values (p < 0.05). Chlorophyll fluorescence showed no significant differences among the nitrogen doses. The nitrogen doses influenced the growth, gas exchange and productivity of the common bean in the region of Brejo Paraibano.

Highlights

Beans (Phaseolus vulgaris L.) are one of the most economically important crops for Brazil (FAO, 2017), generating employment and income, and are an important source of protein for the population
This macronutrient is of great importance to the physiology of bean plants because it acts on the composition of the chlorophyll molecule by transforming photoassimilates into grain, thereby increasing productivity (Soratto et al, 2006)
Height did not differ significantly among nitrogen doses, but maximum heights were obtained at doses of 0 and 200 kg ha-1 for both evaluation periods, with it being 8.3 cm at 45 days and 18.4 cm at 60 days

Summary

Introduction

Beans (Phaseolus vulgaris L.) are one of the most economically important crops for Brazil (FAO, 2017), generating employment and income, and are an important source of protein for the population. The management of fertilization is considered fundamental to achieving better grain yields (Arf et al, 2011), with nitrogen (N) being the most influential nutrient for bean crops. This macronutrient is of great importance to the physiology of bean plants because it acts on the composition of the chlorophyll molecule by transforming photoassimilates into grain, thereby increasing productivity (Soratto et al, 2006). Growth assessment is essential for analyzing the effects of management systems on plants by providing information on plant productivity as a function of time, which is impossible to obtain from only grain yield (Urchei et al, 2000)

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Conclusion