Corn (Zea mays L.) seed treatment with insecticide to control soil pests alters the surface roughness, difficulting seed to slide from the seed reservoir to the soil, affecting the performance of the seeder. The objectives of this work were to determine the effect of seed treatment with insecticides or graphite on the angle of repose of maize seed and to evaluate the effect of seeder velocity, chemical treatment, seed size and shape on the performance of two seed distribution systems: disc and fingers. The tests were performed in a laboratory, by using maize seeds of the cultivar BR 201, with different classifications, submitted to six chemical treatments, tested at two velocities, with two types of seed distribution system. The experiment was designed in randomized complete blocks, with three replications. All isolated factors and interactions were significant at 5% probability level. The use of the insecticides Furadan and Semevin made the performance of the seeder become better for the finger system and worse for the disc system. Adding graphite, at the dose of 4 g/kg of seed, improved performance to the levels before the chemical treatment, when using Semevin, and to levels slightly slower with Furadan.
Zea mays; maize; insecticide; repose angle; graphite
