地表温度日较差对湖北烟区烤烟化学成分的影响

利用湖北烟区16个国家气象观测站1960—2020年0 cm地表温度数据和16个产烟县2005—2020年烤烟化学成分数据,通过数理统计分析了湖北烤烟生育期地表温度日较差（简称地温差）变化对烤烟化学成分的影响。结果表明：地温差对湖北烤烟化学成分影响显著。除伸根—团棵期外,湖北烤烟生育期的地温差呈现明显下降趋势,其中鄂西南的兴山和秭归,鄂西北的竹山和南漳下降趋势最显著。相较于湖北烤烟的上部叶和中部叶,下部叶各化学成分的离散程度最大,空间差异显著。湖北烤烟地温差大田期、旺长期和成熟期的突变年份分别为1974年、1973年和1979年,突变之后的地温差的下降趋势更为显著,且未来进一步缩小的地温差将引起烟叶的烟碱、还原糖和总氮含量减少,总糖、钾、氯、钾氯比、氮碱比、糖碱比和两糖比含量增加。

Effects of Surface Diurnal Temperature Range on Chemical Constituents of Flue-cured Tobacco in Hubei Tobacco-growing Areas

In this paper, the surface temperature data from 16 national meteorological observing stations during 1960—2020 and the chemical constituents data of flue-cured tobacco from 2005 to 2020 in Hubei tobacco-growing areas were used to analyze the effects of the surface diurnal temperature range (surface temperature difference in short) variation on chemical constituents of flue-cured tobacco at different growth stages by mathematical statistics. The results showed that the effects of surface temperature difference on chemical constituents of flue-cured tobacco were obvious. The tendency of surface temperature difference at tobacco growth stages in Hubei tobacco-growing areas had a declining trend except in the root extending and rosette stage, which could be remarkably seen in Xingshan, Zigui, Zhushan and Nanzhang. Compared with the upper and middle leaves of Hubei flue-cured tobacco, the dispersion degree of chemical constituents of the lower leaves was the largest, which had significant spatial difference. The mutation year of the field stage, the vigorous growth stage and the mature stage of Hubei flue-cured tobacco was 1974, 1973 and 1979 respectively, and the decreasing trend of surface temperature difference was more significant after the mutation. Meanwhile, further decrease of the surface temperature difference in the future would lead to the decrease of the content of nicotine, reducing sugar and total nitrogen in tobacco leaves, and the increase of the content of total sugar, potassium and chlorine, and the ratio of potassium to chlorine, the ratio of nitrogen to nicotine, the ratio of total sugar to nicotine, and the ratio of total sugar to reducing sugar.