Efeito da aplicação preventiva de fungicida na produtividade do milho (Zea mays L.)

Abstract

The production potential of corn can be directly impaired by phytosanitary factors, such as fungal diseases. Such diseases cause losses in the development of the plant as well as for the economic sector, since the health of the plants basically defines the quality and quantity of the final product. These fungal diseases are responsible for the reduction of production on a small or large scale and therefore can create social problems, since maize culture is very important in the current scenario. Thus, the objective of this work was to evaluate the effect of application prevention of fungicides in corn productivity. Two field experiments were carried out in different agricultural years (2014/2015). The experiments were conducted in a randomized block design with four repetitions. The treatments were formed by a factorial (2x5), the first factor being composed of the fungicides pyraclostrobin + epoxiconazole (Abacus®) and azoxystrobin + cyproconazole (Priori Xtra®); the second factor was composed by the application times: V8 (eight fully expanded leaves), V8 + pre-piercing, prepiercing + post-piercing and V8 + pre-piercing + post-piercing, plus a treatment with no application of fungicides (control). Were used doses specified by the manufacturer. The evaluations were carried out at the end of the crop cycle, taking into account the severity and intensity of the leaf diseases of the plants that were at the end of the reproductive stage (R6) in December, with visual evaluation, observing the leaf area occupied by lesions of the leaf diseases , using a scale from 1 to 9, the higher the score the better the disease control. The result was significant in the application of Abacus at the time of pre and post weighing and 2 applications showed greater productivity.