Abstract:

To clarify main meteorological factors which affect the growth and development process of flue-cured tobacco in mountainous area, and to properly arrange field transplanting date, the field experiments of main tobacco variety ‘HN2146’ with different transplanting dates were carried out for three consecutive years, to analyze the changes of growth period, and define the relationship between sunlight, precipitation and temperature and the growth of flue-cured tobacco. The results showed that the plant height and stem girth were moderately correlated with the transplanting date of flue-cured tobacco, while the middle leaf length and middle leaf area were strongly correlated with the transplanting date. At the same time, the plant height, stem girth and leaf area of flue-cured tobacco transplanted at T1 (April 12, April 19 and April 26) were the largest, which increased by 6.14%±2.98%, 5.35%±1.69% and 19.38%±5.83%, respectively, compared with the average values of the other four transplanting dates. Simple correlation analysis showed that the effective accumulated temperature≥12℃, precipitation and sunshine duration were significantly positively correlated in pairs, and significantly positively correlated with most agronomic characters. The results of canonical correlation analysis showed that there was a very significant canonical correlation between agronomic characters and meteorological factors. Different transplanting dates of flue-cured tobacco mainly affected precipitation, effective accumulated temperature≥12℃, leaf number and middle leaf length. The results of principal component analysis showed that the first principal component indicated that adjusting different transplanting dates could improve the meteorological factors and agronomic characters of flue-cured tobacco at different transplanting dates, and the effects had similar characteristics. The second principal component indicated that the main differences in influencing meteorological factors and agronomic characters were the changes of upper leaf area, upper leaf length, middle leaf area, stem girth, plant height and effective accumulated temperature≥12℃. Therefore, from the perspective of agronomic characters, April 12, April 19 and April 26 are the best transplanting dates for flue-cured tobacco variety ‘HN2146’ in low, middle and high altitude areas in Xiangxi.

Key words: flue-cured tobacco, transplanting date, meteorological factor, agronomic characters