Aplicação foliar de Níquel no milho

Abstract

Nickel (Ni) is considered a micronutrient and was one of the most recent elements to be studied and added to the list of nutrients in the plant production cycle. The need for nutrition and the toxicity of Ni is understood by a very small variation in the presence of the element, which implies a demand for adequate management and use. In view of this, the aim was to evaluate doses of Ni in maize in order to find adequate amounts that can increase gas exchange capacity. The design used was a Randomized Block Design (DBC) and involved the application of five doses of nickel (Ni): 0, 20, 40, 80, 160 g ha-1 of Ni, divided into two moments during the crop cycle, and four replications which totaled 20 experimental plots. The variables analyzed were photosynthesis, transpiration, stomatal conductance and instantaneous water use efficiency. By means of regression analysis, the data was adjusted to the quadratic model with the increase in Ni doses, and the results obtained were significant. All the analyses showed an improvement in the indices evaluated when compared to the control effect, since this increase was most significant for stomatal conductance (gs), with an increase of up to 47.28%. The dose of 80 g ha-1 of Ni contributed the most to the development of the maize crop, since the application of Ni via foliar application favored photosynthesis, transpiration, stomatal conductance and instantaneous water use efficiency. The 160 g ha-1 dose showed a decline in yield in all the variables analyzed.