The impact of climate, soil and their interactions on reducing-sugar, nicotine and total nitrogen contents of flue-cured tobacco in Hunan high-quality tobacco region
Abstract:The impact of climate, soil and their interactions on reducing-sugar, nicotine and total nitrogen contents of flue-cured tobacco leaf were investigated through pot experiments in Hunan high-quality tobacco regions of Yongzhou, Liuyang and Sangzhi from 2006 to 2007. The experiments disclose the following results: First, the variation coefficients of reducing-sugar, nicotine and total nitrogen of tobacco leaves are of medium intensity and the intensity decreases in the order of reducing-sugar, nicotine and total nitrogen. Furthermore, climate, soil and their interactions impact reducing-sugar, nicotine and total nitrogen contents of tobacco leaves in different ways, i.e. climate has strong impact on all of the three while soil′s impact is insignificant; the impact of the interactions between climate and soil vary from year to year with climate, soil and their interactions each contributing 51.42%,19.78% and 28.79% respectively to the total impact. Above all, climate is the main ecological factor that affects the abovementioned chemical components contents of tobacco leaves. Thirdly, sunshine hours, diurnal temperature variance and quantity of evaporation in tobacco rooting stage, relative humidity, average air temperature and cloud coverage in tobacco vigorous growth stage, average air temperature, diurnal temperature variance and sunshine hours in tobacco mature stage were the top three climate factors that relate closely to the contents of reducing-sugar, nicotine and total nitrogen of tobacco leaves during their growth periods. Overall, average air temperature,relative humidity and diurnal temperature variance are the main factors that relate closely to the contents of abovementioned tobacco chemical components during the whole tobacco growth periods.