Management systems for flue-cured tobacco (Nicotiana tabacum L.) involving variations in topping height, number of harvests, planting date, and cultivars with different ripening patterns were compared with a conventional system of topping and harvesting to evaluate their influence on yield and quality of flue-cured tobacco. With the conventional system (18/6), tobacco was topped at 18 leaves and harvested six times. The reduced systems consisted of an 18-leaf topping harvested three times (18/3), a 15- leaf topping with two harvests (15/2) and a 12-leaf topping with a once-over harvest (12/1). In each of the systems, the number of leaves per unit area was kept constant by modification of plant population. In addition, systems with increased leaf number and N fertilization were used for the 12-leaf (12/1(+)) and 15-leaf (15/2(+)) systems. Evaluation of the systems involved yields by stalk positions, harvests, and the complete plant. Other measurements taken included dollars/quintal and analysis of the USDA grade distribution for group, quality, and color categories, and the tobacco companies’ usability evaluation. Data were also collected on the relation between the date of planting and the date of harvest. The 12-leaf topping with one harvest produced substantially lower yields and subtle quality alterations of the tobacco. These yield losses were primarily due to overripeness and loss of lower leaves. Quality alterations in the tobacco from once-over systems were characterized by changes in the USDA grade distribution. The intermediate systems 15/2(+) and 18/3 produced yields and quality equal to that of the conventional system. These advantages plus the potential labor savings and economic gains make the 15/2(+) and 18/3 feasible systems. Date of planting-date of harvest relationships were evaluated by using two planting dates to lengthen the harvest season. However, prediction of the harvest interval from the planting interval is virtually impossible.

(Full article published with kind permission from "Tobacco International")