DIFFERENT PLANTING DISC TECHNOLOGIES UNDER THREE ADVANCE SPEEDS

Abstract

THERE ARE DIFFERENT DISCS AND TECHNOLOGIES IN THE BRAZILIAN MARKET FOR SEED DISTRIBUTION IN THE FIELD, SO IT IS ESSENTIAL TO EVALUATE THEM AT DIFFERENT SPEEDS TO IDENTIFY THEIR PLANTABILITY CAPACITY. THEREFORE, THE OBJECTIVE WAS TO EVALUATE TWO TYPES OF DISCS (CONVENTIONAL AND GROUPED) FOR PLANTING UNDER THREE WORKING SPEEDS 4,3, 5.5 AND 7.2 KM H^-1. THE DISTRIBUTION OF 16 SEEDS PER LINEAR METER WAS REGULATED, THAT IS, 16 SEEDS SPACED AT 0.0625 M FOR THE EQUIDISTANT SOWING DISC (90 HOLES - CONVENTIONAL) AND 16 SEEDS SPACED AT 0.25 M FOR THE GROUPED SOWING DISC (24 HOLES). IN A TOTAL DISTANCE OF 50 M IN LENGTH, ONLY THE CENTRAL 10 METERS OF EACH EXPERIMENTAL UNIT WERE CONSIDERED AS USEFUL PLOTS. THE DATA WERE ANALYZED, ACCORDING TO ABNT (1994), IN ACCEPTABLE, FLAWED AND MULTIPLE DISTRIBUTION. THE RESULTS REFERRING TO DISTRIBUTION REGULARITY (AVERAGE NUMBER OF SEEDS EVERY 10 METERS) FOR THE TWO TYPES OF DISKS EVALUATED WERE ALSO COUNTED. THE RESULTS OF THE ANALYSIS OF VARIANCE INDICATED A SIGNIFICANT DIFFERENCE FOR THE INTERACTION OF THE FACTORS: DISKS AND VELOCITIES, IN ALL ANALYZED VARIABLES. REGARDLESS OF THE TYPE OF DISK USED IN SOWING, 4.3 KM H^-1 WAS THE SPEED THAT PRESENTED THE BEST TECHNICAL FEASIBILITY, GIVEN BY THE SMALLER DISTRIBUTION OF FLAWS AND MULTIPLES, ASSOCIATED WITH THE HIGHEST ACCEPTABLE DISTRIBUTION, RESULTING IN 16 SEEDS DISTRIBUTED PER LINEAR METER. HOWEVER, AT SPEEDS OF 5.5 AND 7.2 KM H^-1, ONLY THE 90-HOLE DISC SHOWED A DISTRIBUTION CLOSE TO THE REGULATED ONE. IT IS CONCLUDED THAT WITH THE INCREASE IN THE SPEED OF THE MECHANIZED TRACTOR-SEEDER SET, THERE WAS A REDUCTION IN ACCEPTABLE SPACES, INCREASING THE NUMBER OF FLAWS AND MULTIPLES, AS WELL AS A REDUCTION IN THE NUMBER OF SEEDS PER LINEAR METER.