Öz
In this study, the cutting force and energy requirement of corn (Zea mays L.) stalk at different internodes (diameter), from the bottom to the top internode positions for Pionner 2105, Pioner 1570, KWS and MAY 75 varieties, were determined. The mean diameter of internodes varied between 11.28-19.00 mm from top to bottom. Also, cob breakout force and energy requirements were determined for these varieties. According to test results, the cutting force requirement of the varieties were found statistically different. While the highest cutting force requirement was found in MAY75 variaty as 504.79 N and Pioneer 2105 as 537.80 N, the lowest values were obtained in the KWS variety as 409.50 N. Similar results were found for cutting energy values. While, there were no found difference between MAY 75 and Pioneer 2105 varieties, cutting energy requirements were found statistically different (p<0.01) among the other varieties. The highest cutting energy requirements has been found in Pioneer 2105 and MAY75 varieties, followed by Pioneer 1570 and KWS variaty, respectively. The lowest value was obtained in the KWS variety as 3.83 J. The difference between internodes was found statistically significant. The cutting force values varied between 806.00 N and 203.00 N, the cutting energy varied between 7.91 Joules and 1.56 Joules depend on internodes. The highest cutting force and cutting energy values were obtained at the first node as 806.00 N and 7.91 Joules, these values decreased as the diameter decreased from the bottom to the top. Tukey test results showed that there were no significant differences among the varieties in terms of both breakout force and breakout energy. However, the highest values were obtained as 382.7 N and 15.50 J in Pioneer1570 variety, while the lowest values were obtained as 319.0 N and 9.830 J in Pionner 2105 variety.