Effect of Boron (B) and lime on production of watermelon in dystrophic yellow latosol soil

Abstract

The low concentration of boron in the soil is one of the main challenges for the cultivation of watermelon in regions of the Cerrado biome, due to the appearance of rot apical which may occur due to the lack of boron in the soil or due to boron toxicity by the use of fertilizers without recommendation. There is a narrow range between the appropriate and toxic level pf boron. Therefore, the objective of this study was to evaluate the effect of boron doses on watermelon production in the soils with and without liming. The experiment was carried out in a dystrophic yellow latosol soil, in a randomized block design in subdivide plots: plots (i) liming or without liming and subplots: (ii) boron (0, 2, 4 and 5 kg.ha-1), with 8 treatments and 5 replicates. The data were analyzed by regression analysis. The maximum point of the equation was estimated by equating the first derivative of the equation to zero. The diameter, length, weight, number of commercial fruits, bark thickness, percentage of fruits with apical rot, commercial fruits, female flowers, total soluble solids, productivity and profitability were evaluated. The use of boron provided positive effects on the analyzed variables. However, in concentrations higher than 4 kg ha-1 its behavior was fitted with a quadratic model (R2: 0.77 to 0.99). The range was equivalent to 2 to 4 kg ha-1 of boron with a specific level of 2.4 kg.ha-1, whereas the base saturation rose to 70%, promoted greater productivity for watermelon cultivated in dystrophic yellow latosol under conditions of the closed biome.