Optimization of Operational Parameters of a Vacuum Single-Seed Planter for Sowing of Maize

The objective in study was to evaluate the performance of a vacuum single-seed planter in field conditions to optimize some operating parameters in maize production. The target seed spacing (effect of operational speed of the seed disc) and tractor forward speed were evaluated by examining the mean seed spacing, coefficient of precision in spacing, miss index, multiple index, quality of feed index, sowing depth, deviation from row (inter-row spacing), mean emergence time, emergence rate index and percentage emergence. A vacuum single-seed planter was used for sowing at three forward speeds (4.0, 5.4 and 7.9 km h-1) and five target seed spacings (102, 147, 195, 247 and 309 mm). The point dropped in furrow of seed, depth of seed placement, emergence rate and three indices of uniformity in seed spacing and precision coefficients of sowing quality were determined. The planter performed the best performance at the lowest forward speed and the highest target seed spacing. Increasing the forward speed resulted in a shallower sowing depth. The desired planting depth was also obtained at 4.0 km h-1 in all plots. Increasing target seed spacing increased the emergence rate by about 35%, while increasing forward speed decreased the emergence rate by 10%. Sowing at 4.0 km h-1 resulted in the lowest miss, multiple and precision indices (5.1% 2.9%, and 15.3%, respectively), and a quality of feed index as high as 92% was obtained in similar conditions. The results indicated that, with single-seed planters, success may be achieved in a conventional tillage maize production system at a target seed spacing of less than 100 mm and tractor forward speeds of less than 7.9 km h-1, thus satisfying farmers who carry out maize sowing by conventional tillage.