Influência do uso de produtos fitossanitários e adjuvantes na formação de espigas de milho, aplicados em diferentes estádios fenológicos.

Abstract

Corn is one of the main cereals grown in Brazil and the world, and because of the phytopathogens that reduce the photosynthetically active area of the plant, we often have to make use of chemicals in the crop. However, there were reports of poor ear formation that has been attributed to the application of fungicides in association with several products in the culture. Thus, the objective of this work was to analyze the influence of the combined application of phytosanitary products and adjuvants in different phenological stages in the poor formation of spikes. Three field trials were carried out where the application was carried out at different stages: either in pre-plowing in V18, in R1, or in R3. The experimental design was a randomized complete block design with five treatments and ten replications. One of the trials had an additional treatment, where three sequential sequential applications of three days each were done. The treatments were: combination of fungicide (triazole + strobilurin + carboxamide) and mineral oil; fungicide, mineral oil, insecticides and spreader adhesive; the same before, but with the dose of folded mineral oil; and the control treatment, where no application was made. It was evaluated percentage of poorly developed ears, a thousand grain mass and productivity. There was no bad ear formation. Even with normal ear development, there is a tendency for earlier applications to generate lower productivity. It is necessary to conduct new studies to prove the hypothesis that the cause of the phenomenon occurs in the earliest stages of the crop, especially when the spike is differentiating between V12 and V15, and that this is due only to the applications of the products.