Desempenho fisiológico do amaranto BRS ALEGRIA sob diferentes densidades de plantio

Abstract

Amaranth is an ancient grain that has gained popularity due to its nutritional benefits and unique properties, having several uses, both in human and animal food. The objective was to evaluate the development and physiological performance of Amaranthus cruentus BRS Alegria under different planting densities. The experiment was conducted in the experimental area of the UFC agriculture sector, from July to September 2021. The adopted experimental design was in randomized blocks, with five treatments and three replications. The treatments consisted of five planting densities (62,500; 83,333; 111,111; 125,000 and 166,666 plants ha-1). The development, growth, and physiological characteristics of the plants were evaluated. The growth variables were: plant height, stem diameter, number of leaves, leaf area, dry matter content of stem, leaves, root and inflorescences. The variables related to physiology were: net photosynthetic rate, transpiration rate, stomatal conductance, internal CO2 concentration, carboxylation efficiency, intrinsic water use efficiency, instantaneous water use efficiency and ratio between internal and external CO2 concentration , PSII effective quantum yield, electron transport rate, photochemical quenching and non-photochemical quenching. Regarding the BRS Alegria amaranth growth analysis, the following variables varied significantly in relation to the different densities tested: number of leaves and stem diameter. Where the best result came from densities, 83,333 and 62,500 plants ha-1, respectively. Regarding the physiological analysis of BRS Alegria amaranth, the best result of all the variables analyzed came from the density 111.111 plants ha-¹, except those related to water use: instantaneous efficiency of water use and intrinsic efficiency of water use, where the density of 83,333 plants ha-1 obtained the best result.