sample="quota" bates="2023894116" isource="pm" decade="1990" class="ui" date="19940503" PM USA CONFIDENTIAL - contains trade secrets Tobacco Crop Alkaloid History The attached charts show variation in tobacco alkaloid concentration for Burley, Bright (Flue Cured), and Oriental tobaccos purchased by Philip Morris between 1979 and 1992. The variation is due to: Growing conditions such as rain fall and temperature. Agronomic practices such as fertilizer usage, especially in the Mediterranean basin for Oriental tobacco. Dry weight basis.