Watering frequency and nitrogen fertilization in radish production in the Mato Grosso northeast region, Brazil

Abstract

Given the high temperatures in Mato Grosso northeast region, Brazil, the irrigation frequency and the amount of N supplied to the radish crop are highly relevant parameters, which can influence water saving, fertilizer and quality roots production. Thus, the aim this work was to evaluate the radish production as a function of the irrigation daily frequency and nitrogen rates in coverage. Seeds of the 'Crimson Gigante' radish cultivar were used, and the experiment was conducted in a medium texture Argisol, increasing the base saturation to 70%. The experimental design was a randomized complete block, with four replications in split plots, in the 2 x 6 scheme, being two irrigation frequencies in the plots and six nitrogen fertilization rates (0, 25, 50, 75, 100 and 125 kg ha^-1 of N) in the subplots. The frequencies consisted of irrigation once a day (in total time, in the morning, 6:15 - 7:15 am); and twice a day (50% of the time in each period, in the morning, and in the afternoon, 5:30 - 6:30 p.m.), respectively, restituting the crop daily evapotranspiration, obtained by weighing lysimeters. The harvest was accomplished at 30 days after ‘sowing. The increase of the nitrogen rates resulted in higher leaf area, dry matter of roots, aerial part and total plants. On average, the defects roots production (11105.4 kg ha^-1) was higher than the commercials roots productivity (1658.2 kg ha^-1). The irrigation twice a day (morning and afternoon) provided best answer to the radish.