The Influence of Variety on Mechanical Harvesting Efficiency of Flue-cured Tobacco

Abstract

Mechanical harvesting of flue-cured tobacco is a widely used practice in North Carolina due to cost and labor savings compared to hand labor, acceptance of unaligned leaf by tobacco manufacturers, and accumulation of enough acreage by growers to justify the purchase of a mechanical harvester. Little research has been conducted to evaluate varietal effects on mechanical harvesting efficiency. Experiments evaluating current varieties were conducted at on-farm locations in North Carolina during 2003 and 2004 to investigate the influence of variety on mechanical harvesting efficiency. Ten varieties were selected to provide the widest possible range of growth characteristics. Treatments were replicated four times in a randomized complete block design. Tobacco was harvested four times. Measurements of leaf angle, leaf curvature, and internode spacing were taken before the final three harvests in order to establish differences among varieties in morphology. In addition, the number of leaves dropped on the ground behind the machine were counted after each harvest, and the fresh weight of non-harvested stem material left on the stalks within the fourth harvest position was recorded after the final harvest in order to establish differences in mechanical harvesting efficiency among varieties. Highly significant differences among varieties in leaf angle, leaf curvature, and internode spacing were found before every harvest. However, these differences did not result in highly significant differences in mechanical harvestability until the final harvest. At final harvest, significant differences in leaf and stem loss were found among varieties. Leaf angle and internode spacing were found to be significantly related to stem loss. As leaf angle and internode spacing increased, stem loss decreased. Therefore, some varieties are better suited for mechanical harvesting systems.