Influence of Machanical Harversting on Grow and Productivity of Sugarcane.

The adoption of mechanized harvesting of sugarcane has occurred unavoidably in Brazil, either for labor, environmental or economic reasons. However, this practice has caused some problems such as reduced productivity and longevity of sugarcane plantations and damage to ratoon.

The experiment was conducted in Lençóis Paulista - SP, Brazil, in a commercial area. Consisted in evaluating the damage caused on the sugarcane ratoon due to mechanized cutting and wear of the base cutting blades, over 5 hours of effective work of the harvester at two row spacings. The evaluations were made in each worked-hour by the machine.

Then, the developing and the productivity of next crop season was evaluated. In the first harvest were evaluated number of stems, percentage of failures in the planting line, average size of failures, cutting quality, shaken stumps and visible losses in the field. During the development of the crop, evaluations were made on three dates, consisted of stem height, number of tillers, percentage of failures, average size of failures.

At the end of the cycle, in the second harvest, were evaluated number of stems, percentage of failures, average size of failures, height and diameter of the stem and productivity. The experiment was conducted in a completely randomized design with four replications. Statistical analyzes were performed using the Friedman test, when the data did not follow a normal distribution, and the Tukey test, when they followed a normal distribution.

There was damage on the ratoon caused by mechanical harvesting, however, the wear of the base cutting blades did not increase the level of damage to the ratoon and did not impair the development and productivity of the crop, but caused inferior base cut quality. The quality of the cut did not reduce crop yield.