Nitrogen fertilization in rice cultivated in sandy soils of tropical floodplain

Abubación nitrogenada en arroz cultivado en suelos arenosos de várzea tropical arenosa que involucra control riguroso del nitrógeno aplicado, se objetivó identificar dosis más adecuadas a los cultivares Irga-424 y Epagri-116. El estudio fue conducido en suelo Hidromórfico de várzea irrigada en Formoso del Araguaia - TO, en la cosecha 2011/2012. El delineamiento experimental fue en bandas bajo esquema factorial 2x5, con cuatro repeticiones. Las dosis evaluadas fueron de 25, 50, 75, 100 y 125 kg ha-1 de N. Las características evaluadas fueron la altura de las plantas, el número de panículas, la productividad de granos, la masa de cien granos, el contenido de nitrógeno y el índice de clorofila total. Los datos fueron sometidos al análisis de varianza y de regresión al nivel del 5% de probabilidad por el test F. Productividades máximas fueron de 8.269 y 7.563 Kg ha-1 para Irga 424 y Epagri 116, respectivamente. La dosis máxima recomendada es de 103 kg ha-1 de N para Irga 424. Las dosis probadas no fueron suficientes para encontrar la máxima productividad del cultivar Epagri 116, ambos cultivares presentaron niveles adecuados de N a partir de la dosis de 50 Kg ha-1.A planta de arroz é bastante exigente em nutrientes, sendo o nitrogênio o segundo nutriente que a planta de arroz mais acumula. Dessa forma, visando atender a calibração de solos de textura arenosa que envolve controle rigoroso do nitrogênio aplicado, objetivou-se identificar doses mais adequadas aos cultivares Irga-424 e Epagri-116. O estudo foi conduzido em solo Hidromórfico de várzea irrigada em Formoso do Araguaia – TO, na safra 2011/2012. O delineamento experimental foi em faixas sob esquema fatorial 2x5, com quatro repetições. As doses avaliadas foram 25, 50, 75, 100 e 125 kg ha-1 de N. As características avaliadas foram altura de plantas, número de panículas, produtividade de grãos, massa de cem grãos, teor de nitrogênio e Índice de clorofila total. Os dados foram submetidos à análise de variância e de regressão ao nível de 5% de probabilidade pelo teste F. Produtividades máximas foram de 8.269 e 7.563 Kg ha-1 para Irga 424 e Epagri 116, respectivamente. A dose máxima recomendada é de 103 kg ha -1 de N para Irga 424. As doses testadas não foram suficientes para encontrar a máxima produtividade do cultivar Epagri 116, ambos os cultivares apresentaram teores de adequados de N a parti da dose de 50 Kg ha -1.The rice plant is very demanding in nutrients, being the nitrogen the second nutrient that the rice plant more accumulate. In this way, in order to meet the calibration of soils with a sandy texture that envolves rigorous control of the N applied, it was aimed identify doses more adequate of N to the cultivars Irga-424 e Epagri-116. The study was conducted in a hydromorphic soil of varzea at Formoso do Araguaia-TO, 2011/2012 harvest. The randomized block was in strips with a factorial treatment 2x5, with four replications. The doses varied there 25, 50, 75, 100 and 125 kg ha-1 of N. The characteristics evaluated were plant height, number of panicles, productivity of grains, mass of a hundred grains, the N content and total chlorophyll index. The data were submitted to analysis of variance and regression in 5% of probability on the test F. Maximum yields were 8,269 and 7,563 kg ha-1 for Irga Epagri 424 and 116, respectively. The maximum recommended dose is 103 kg ha -1 N for Irga 424. The doses tested were not sufficient to find the maximum productivity of farming Epagri 116, both cultivars showed adequate levels of N from dose of 50 kg ha-1

Biochemical quality of cowpea beans grown under water-deficit maintained with hydrogel

Investigations related to the effects of the hydrogel use in a water-deficit conditions on the biochemical composition of the harvested products are scarce. The aim of this study was to verify the influence of hydrogel on the biochemical response of cowpea beans produced under water-deficit in southern Tocantins. The experiment was a randomized complete block design with four replications. The treatments were obtained in a 2x5 factorial scheme, being: two sources of hydrogel (Hydroplan-EB HyC and Polim-Agri PP) and five concentrations (0, 5, 10, 15, and 20kg ha-1). After harvesting, the grains of cowpea, BRS Vinagre cultivar, were ground and chemically analyzed. The oil content of the seeds agreed with the reference values. The use of Polim-Agri PP promoted the best levels of amino acids (0.38mg g-1) and proteins (243.22mg g-1) of the grains. The carbohydrate content of them (Ȳ= 81.44mg g-1) was better using Hydroplan-EB HyC, regardless of the concentration applied. The application of 6.28kg ha-1 of Polim-Agri PP provided the highest starch content (842g mg-1). The use of hydrogel improves the biochemical quality of cowpea beans produced under water deficit in southern Tocantins

Kinetin and Nitrogen in Agronomic Characteristics of Soybean

The objective of this work was to evaluate the application of kinetin associated with nitrogen in coverage on the agronomic characteristics and soybean yield. In the 2016/2017 harvest, a 6x2 factorial scheme was used, six doses of kinetin (0; 0.30; 0.60; 0.90; 1.20; 1.50 g ha−1) and two doses of N (20 and 40 kg ha−1) and in the 2017/2018 harvest, factorial scheme 5x2 was used, five doses of kinetin   (0; 0.25; 0.75; 1.00; 1.25 g ha−1) and two doses of N (20 and 40 kg ha−1). Agronomic plant height characteristics, first pod insertion height, number of grains per plant, number of pods per plant, number of grains per pod, number of grains per pod, hundred-grain mass and grain yield were evaluated. The use of N alone and associated with kinetin increased the number of pods and grains in the 2016/2017 harvest. In the 2017/2018 crop, kinetin caused a reduction of 8.9% at plant height and N caused an increase in plant height and first pod insertion and reduced the number of pods and grains per plant, grains per pods and productivity