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Leaf Number at Topping and Yield, Grade Index, and Leaf Chemistry of a Mammoth‐Type Tobacco 1
Author(s) -
King Mark J.
Publication year - 1986
Publication title -
agronomy journal
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.752
H-Index - 131
eISSN - 1435-0645
pISSN - 0002-1962
DOI - 10.2134/agronj1986.00021962007800050033x
Subject(s) - topping , cultivar , yield (engineering) , horticulture , nicotiana tabacum , biology , curing of tobacco , nicotiana , agronomy , botany , chemistry , solanaceae , materials science , biochemistry , metallurgy , gene
Tobacco ( Nicotiana tabacum L.) cultivars containing a mammoth gene have not been evaluated at leaf numbers greater than 18 to 20 leaves per plant. In addition, they have not been evaluated with respect to potential for mechanical topping. Flue‐cured tobacco cultivar NC 22NF containing the mammoth gene, was grown in 1982, 1983, and 1984 at Blackstone, VA. Plants were topped (apical meristem removed) to determine the effect of leaf number per plant on yield, grade index, and leaf chemistry at constant soil fertility. Leaves remaining on the plant after topping were 14, 18, 22, and 26 per plant. Yield increased with leaf number. This study demonstrated that the accepted practice of topping at 18 to 20 leaves may be extended to 26 leaves, increasing yield and value with no detrimental alteration in leaf chemistry or decline in leaf grade index. The lack of difference in grade index compared to earlier studies may be due to the different genomes. In a duplicate set of treatments, four additional leaves per plant were allowed to develop before being removed to study the effects on yield, grade index, and leaf chemistry at 14, 18, 22, and 26 leaves per plant. The delay in topping until four additional leaves were produced did not significantly decrease yield, grade index, or leaf chemistry and may be advantageous for mechanical topping.