Associations Among Disease Resistance, Agronomic Characteristics, and Chemical Constituents in Flue-Cured Tobacco1
- James F. Chaplin2
Four hundred and sixty-six Fb breeding limes of fluecured tobacco were evaluated for associations among disease resistance, agronomic characteristics, and chemical constituents. These lines were derived from a cross between ‘NC 95’ and ‘MR Coker 139.’ Resistance to the following diseases were evaluated: tobacco mosaic virus (TMV), root-knot, black shank, bacterial and fusarium wilt. Considerable yield decreases were associated with mosaic and fusarium wilt resistance. Yield decreases were greater when resistance to .these two diseases was combined in the same line. Value per 45.4 kg was reduced slightly in all disease resistant lines when compared with susceptible ones. Further reductions in value per 45.4 kg were associated with lines resistant to more than one disease. Slight associations between resistance to some of the diseases and other characteristics such as percent sugars, total alkaloids, plant height, length and width of leaves were also noted. Narrow leaf type plants were associated with reduced yield and value er 45.4 kg. Black shank resistance was also associated with plant type, the narrow leaf types being slightly more resistant. Yield was highly correlated with value per hectare, value per 45.4 kg, width of leaves, days to flower, and percent sugars. Value per hectare was also correlated with value per 45.4 kg, wigth of leaves, height of plant, days to flower, and sugars. In addition, value per 45.4 kg was positively correlated with percent sugars.Please view the pdf by using the Full Text (PDF) link under 'View' to the left.
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