Influence of Seed physical properties and speed on the external mechanical damage index and in-row spacing uniformity in an automatic potato planter

In this study, a new fully automatic potato planter was used in which the planting metering mechanism consists of cups and hold pins attached to the circumference of a vertical disc. In order to evaluate performance of the planting metering mechanism, in-row spacing uniformity and external mechanical damage index were determined (P<0.01). Also skips and doubles that caused deterioration of in-row spacing uniformity were investigated. In experiment, two potato varieties (Marfona and Agria) and two potato sizes (25-45 and 45-65 mm) were used. The ground speeds of potato planter were chosen as 3.5, 5.4 and 7.3 km h. The results obtained from the experiment indicated that the ground speeds and tuber physical properties significantly influenced tuber spacing accuracy and external mechanical damage index (P<0.01). While the ground speed increased, accuracy of tuber spacing decreased. The highest coefficient of variation (CV%) values were obtained from ground speed of 7.3 km h, Marfona variety, and tubers between 25-45 mm, with 26.80%, 25.58% and 26.27%, respectively. The highest damage index values were obtained from ground speed of 7.3 km h, Agria variety, and tubers between 45-65 mm, with 1.34, 1.18 and 1.23, respectively.