A field experiment was conducted in 1981 and 1982 on Fox loamy sand In Ontario to study the effects of number of harvested leaves on selected agronomic and chemical characteristics of flue-cured tobacco (Nicotiana tabacum L.). Tobacco (cv Delgold) was topped at 12, 15, and 18 leaves, and topped at 18 leaves with either three or six of the lower leaves removed. Reducing the number of harvested leaves had a negative impact on yield and returns regardless of whether the leaf number was reduced by lower topping or removing the bottom leaves. Differences in chemical composition among treatments for phytosterols, green pigments, fatty acids, polyphenols, organic acids, hexane extracts, duvatrienediols, reducing sugars, and total alkaloids followed changes of composition with stalk position although differences were typically smaller than were expected.

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