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

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 CO 2 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 (F v /F 0 ) 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.

Growth Rate of Eggplant Under Nitrogen and Phosphate Fertilization and Irrigated With Wastewater

“…Proper mineral nutrition is essential for plant growth, as observed by the nitrogen supply in the growth of bean plants (Ribeiro et al, 2018), okra (Medeiros et al, 2018a) and eggplant Souza et al, 2017). Phosphorus levels also promoted adequate growth in rice plants (Veronica et al, 2017), strawberry (Medeiros et al, 2015) and wheat (Rodríguez, Keltjens, & Goudriaan, 1998).…”

“…However, there are no reports of phosphorous addition associated with wastewater in the literature. Different nitrogen doses are recommended for other cultures, for example, 135 kg ha -1 for sunflower (Ali & Noorka, 2013) and 200 kg ha -1 for common bean (Ribeiro, Leite, Costa, Albuquerque, & Mielezrski, 2018) and okra (Medeiros et al, 2018a(Medeiros et al, , 2018b. It is needed, however, to quantify the ideal phosphorus doses because its deficiency affects the physiological metabolism of plants, such as gas exchange and, consequently, growth and production (Hernández & Munné-Bosch, 2015;Veronica et al, 2017).…”