INFLUENCE OF THE USE OF GRAPHITE ON THE QUALITY OF SWEET CORN SOWING

The propagation process of sweet corn (Zea mays L. saccharata group) is carried out through seeding. For good quality in this process, the operating speed and graphite dosage must be assertive for a greater plant stand and seed distribution and depth. Given the above, this research aimed to analyze three different operating speeds and the influence of graphite dose to evaluate the effects on plantability in sweet corn. A John Deere 4 x 2 TDA tractor with a nominal power of 78 kW (106 hp) and a Netz model PDN 6000 seeder were used to carry out the sowing. The area was part of an 18-hectare central pivot. Three operating speeds (5.0, 7.7, and 10.7 km h-1) and three amounts of graphite (4.0, 8.0, and 12.0 g for each kg of seed) used in mechanical seeders were evaluated. The experiment was carried out in a 3 x 3 factorial design in subdivided plots with 12 replications. The results were subjected to analysis of variance (ANOVA) using the “F” test, and subsequently, the means of the variables in the different treatments were analyzed using the Tukey test. Statistical process control was also analyzed using control charts with upper and lower limits drawn based on the ideal sowing spacing. In conclusion, the greatest uniformity of sowing was achieved with a speed of 5.0 km h-1, and a graphite dose of 12.0 g kg-1 provided the greatest uniformity of sowing. Higher operating speeds and lower graphite doses resulted in a higher number of failed or double germinations. The lowest seed spacing VC was when there was a higher dosage of graphite and a lower operating speed.