Changes of Pigment and Water Contents during Ripeness and Post-harvest Stage for Several Flue-cured Tobacco Varieties

In order to understand the changes of postharvest tobacco quality before entering cured house and the difficult flue-cured reasons for Hongda, pigment and water contents in fresh tobacco leaf were tested. The results showed that the rather high contents of chlorophyll a and b in Hongda tobacco leaf caused that it was difficult to completely turn yellow in wilting stage. Basing on the higher contents of free water and total water and the lower contents of bound water, Hongda tobacco leaf easily retained green for excessive loss of water or easily turned black for little loss of water in flue-curing process, while it was difficult to fix yellow after wilting stage. The reduction of tobacco quality precursor was mainly caused by sharply adverse biological response.