Abstract
Factors influencing solanesol concentration in Burley tobacco have been investigated. A fivefold difference in solanesol concentration was found among genetic lines and the growing season effected a tenfold difference of this nonaprenol for certain tobacco genotypes. Soil-moisture deficits enhanced solanesol concentration at least fourfold. Irrigation of the stressed tobacco decreased the solanesol level. Data for the 1984 and 1985 growing seasons substantiated this observation and showed that solanesol may be a good indicator of small soil-moisture deficits. In 1984 and 1985 the solanesol concentration increased dramatically after topping for the top stalk position and there were smaller increases for the bottom and middle stalk positions. Nitrogen fertilization had only a minimal influence on solanesol concentration. The data show that it is possible to control solanesol concentration through genetic selection and, more importantly, through production practices.