Sugarcane Chopper Harvester Extractor Fan and Ground Speed Effects on Yield and Quality

Operational settings on chopper harvesters are extremely important in green-cane harvesting since one is relying solely on the harvester to remove extraneous matter instead of the traditional pre-harvest burn method. The objective of this research was to determine the combined effect of selected ground and fan speeds on sugar yield, cane quality, and field losses using a commercial chopper harvester. In both 2003 and 2004, a split-plot experiment was performed at harvest with the main plots having ground speeds of 4.0, 4.8, and 5.6 km h-1 and subplots having primary extractor fan speeds of 650, 850, and 1050 rpm of the 1.5-m diameter fan. Under the optimal conditions (low leaf and soil moisture), the 1050 rpm fan speed increased theoretical recoverable sugar (TRS) by 10% but decreased cane yield by 15% compared to the two lower fan speeds resulting in similar sugar yields for all fan settings. Under poor conditions (high leaf and soil moisture), the 1050-rpm fan speed decreased cane yield by 13% without an increase in TRS, resulting in lower sugar yields than the low or medium fan settings. Ground speed, under both conditions, did not affect cane yield or quality. The chopper harvester performed well under ideal conditions with a primary fan speed of 1050 rpm but had decreasing performance under poor conditions regardless of fan speed.