Productivity of sugarcane on narrow rows, as affected by mechanical harvesting

Abstract

The growth-and-yield response of the six major commercial sugarcane ( Saccharum interspecific hybrids) cultivars to mechanical culture and harvesting on row-spacings of 0.9, 1.2 or 1.8 m (conventional) was investigated in Louisiana. In the plant-cane crop, millable stalk populations for all cultivars were 32% and 17% greater at the 0.9- and 1.2-m spacings, respectively, compared with the 1.8-m spacing. Differences in stalk populations among row-spacings decreased with successive harvests of the stubble crops. By the second-stubble crop, only the cultivar CP 70–330 continued to show a significant increase in stalk populations at the 0.9-m row-spacing. Whole-stalk mechanical harvesters adapted to the narrower spacings minimized stubble destruction observed in earlier studies, but appeared to be less efficient in gathering and piling stalks for weighing. As a result, standing cane yield (tonnage) responses were similar for all cultivars, and were significantly higher at the 0.9- and 1.2-m spacings only in the plant-cane crop. When standing cane yields were averaged over the crop cycle, significant increases in yield occurred only for CP 65–357 (0.9-m), CP 70–321 (1.2 m), and CP 70–330 (0.9 m) when the row spacing was narrowed, indicating that cultivar selection may also affect row-spacing responses under mechanical culture and harvesting conditions.