Fertilization with boron in corn, sesame and wheat in soils of different textures

Abstract

Boron is a metabolically and structurally indispensable element in the growth of a crop, whose availability depends on physical and chemical factors of the soil. The objective of this work was to evaluate the effect of applying doses of boron on agronomic characteristics of corn, sesame and wheat crops in two soils with different textures. The experiment was carried out using 5 kg pots of soil in the greenhouse of the Soil and Territorial Planning Area of the Faculty of Agrarian Sciences of the National University of Asunción, San Lorenzo, Central Department, in the period between November 2018 and July of 2019. A completely randomized design was implemented with a bifactor scheme, where factor 1 corresponded to soils of different textures (sandy loam and sandy clay loam) and factor 2 to boron doses (0, 5, 10, 15 and 20 mg kg^-1), with 5 repetitions. The average of the variables was subjected to analysis of variance, then evaluated using the Tukey test at 5% probability of error and regression analysis. The corn crop presented significant differences in terms of plant height, being higher in the sandy clay loam texture soil with an average of 70,1 cm, while the aerial dry mass showed a decrease with increasing doses of B. The crop of sesame presented an interaction between the factors dose and soil texture for the height and dry matter variables, the maximum height for the sandy clay loam texture was 87,73 cm with an optimal dose of 2,25 mg of B, while the texture sandy loam decreased 2,7 cm for each mg of boron applied, due to toxicity effects with doses greater than 5 mg kg^-1. The wheat crop presented an interaction between dose and texture for the height of the plant, with a decrease in the sandy clay loam soil being noted depending on the doses due to the toxicity effect, while on the contrary the sandy loam texture was increasing, the dry matter was not presented statistically significant differences, with the recommended dose of B for corn being minimum doses lower than 5 mg kg^-1; sesame 5 mg kg^-1 while for wheat cultivation 10 mg kg^-1.