Influence of cultivar, topping height, and harvest treatment on physical and chemical characteristics of flue-cured tobacco

There has been an increased interest among the tobacco industry in the production of tip leaves in flue-cured tobacco. Different harvest treatments of flue-cured tobacco were compared across six cultivars and two topping heights with the objective of identifying tip grade tobacco. Agronomic and cured leaf chemistry data were collected. Cultivar had significant influences on yield, average price, grade index, and value in three growing seasons. NC 71 and RG H51 were the highest yielding cultivars, with grade indices among the highest as well. Increasing topping height increased tobacco yield in two of three years. As topping height increased there was a significant increase in the percentage of tobacco receiving a tip grade. The four harvest treatments focused on the ten uppermost leaves of the plant. Harvest treatments that allowed proper separation of stalk positions (5&5L and 7&3L treatments) resulted in increased yields and tip grades. Harvest treatments that separate upper stalk position tobacco resulted in a higher percentage of tip grades from a tobacco company grader. Chemical analysis identified differences between stalk positions at the top of the plant. In order for cigarette manufacturers to properly blend the tobacco used to make American blend cigarettes, this separation of stalk positions is important. Harvest treatments that combined stalk positions resulted in the loss of these chemical differences. By topping flue-cured tobacco four to five leaves higher than current extension recommendations and separating stalk positions correctly, tobacco growers can meet the crop throw requirements of tobacco marketing contracts.