Responses of flue-cured tobacco to harvesting and curing variables
Two flue-cured tobacco varieties (Nicotiana tabacum L.) and eight harvesting and curing methods were simultaneously evaluated. Harvesting variables involved the removal of different leaf numbers on different schedules. Curing methods included single or separate barn conventional curing and a bulk curing method. Certain agronomic, physical, and chemical factors were measured.
The modified harvesting methods in which the leaves were removed in less than the conventional number of harvests caused a reduction in yield and value, but not in price. Bulk curing also resulted in lower yield and value per acre as well as dollars per hundredweight than conventionally cured leaves, but there were no differences associated with curing leaves from different stalk positions in separate barns.
When considering stalk positions, modification of the harvesting methods from the normal method caused a reduction in yield and an increase in filling value for the lower leaves from each harvest section. Bulk curing caused an increase in filling value in comparison to conventionally cured leaves.
Leaves from the modified harvest treatments were higher in amino nitrogen and lower in nicotine concentration than normally harvested tobacco. Leaf extracts were less acidic for leaves which were harvested in one day than for normally harvested leaves.
With increases in stalk position, the nitrogenous factors and water soluble acids increased, while the pH value decreased. Reducing sugars were highest for midstalk tobacco and decreased in leaves from the extremities.
Plants that were harvested three times were not greatly altered in agronomic, physical, or chemical factors from those harvested conventionally, but the bulk curing of the leaves (as operated in 1970) did alter these factors.