Discos dosadores de milho operando em diferentes densidades de semeadura

Abstract

In corn cultivation it is important that the seeds are distributed satisfactorily to obtain a correct plant stand. The problem of poor distribution is verified in the absence of graphite in the seeds, the inadequate choice as well as the increase of the peripheral velocity of the metering disc. Considering that the increase in sowing density and, consequently, the peripheral velocity of the metering disc directly affects the seed distribution in the sowing groove, the present work had the objective of analyzing the performance of four different horizontal disks (DB, DC, DS , DR), in three different densities 63,600; 84,800; 1 06,000 haˉ¹ seeds. The work was developed during the year 2017 in the experimental area of the Frontier South Federal University - Campus Cerro Largo - RS. The design was a randomized block design in a 4 factorial (disks) x 3 (sowing densities) scheme with 4 replications, totaling 48 plots. The evaluation of the longitudinal distribution of seeds was performed by opening the groove manually until finding the existing seeds in a range of 84 meters and measuring the spacing between at least 250 seeds in the groove of each plot. To measure the acceptable spacings, the deposition configuration according to the reference spacing for each density was characterized, where the acceptable spacing measures from 0.5 to 1.5 times, the double deposition with spacing less than 0.5 times and the deposition fails with spacing greater than 1.5 times the reference spacing. It was possible to notice that the increase in the peripheral velocity of the metering disc caused by the increase of the density used resulted in a decrease in the percentage of acceptable spacings, and there was no significant difference between the metering discs.