1. Effect of temperature on the development, yield and quality of flue-cured tobacco after transplanting
1.The boundary temperature of flue-cured tobacco growth was 10 35, the optimal temperature was 25 28, the growth was restricted below 17, the tobacco leaves produced by 20 26 were of the best quality, and the average temperature of high-quality flue-cured tobacco during the growth period was above 20.
Low temperature after transplanting is the most important reason for "early flowering", the tobacco plant begins to differentiate flower buds and directly enters reproductive development, the leaf development slows down and the yield decreases, the number decreases, and the coordination of chemical components decreases.
In low temperature areas such as higher latitudes and higher altitudes, low temperature and other adversity stresses can also stimulate the early reproductive development of flue-cured tobacco, and the internal carbon and nitrogen metabolism of early-flowering individuals has an enhanced trend after topping, and the positive feedback of endogenous hormones in the plant is given during the physiological period, such as the increase of zearalenone and oligosaccharides, and the early flowering plants end their nutritional development and turn to reproductive development, and the tobacco plants are short in the mature stage, with few leaves, small leaves and large thickness, and a significant decrease in the number of leaves, resulting in low tobacco availability.
Temperature plays an important role in tobacco leaf ripening, and the contents of total sugar and reducing sugar in flue-cured tobacco with low maturity in the Northeast tobacco area with insufficient accumulated temperature were higher, while the tobacco plants with field temperature higher than 35 grew slowly, had limited development, and even wilted and dehydrated.
The development of flue-cured tobacco leaves is very sensitive to rainfall, and too much or too little precipitation will affect the yield and quality of leaves. The average water demand of tobacco fields in many provinces in China showed a trend of more in the south and less in the north, more in the east and less in the west, and the average of root extension stage, flourishing period and maturity stage was mm. Generally speaking, the average monthly rainfall suitable for the growth of flue-cured tobacco is 100 130 mm, the monthly rainfall required is 80 100 mm, the maximum monthly rainfall requirement is 100 200 mm, and the average monthly rainfall is 100 mm, and the average monthly rainfall is 100 mm after the maturity stage [29-30].
IIEffect of rainwater on the development, yield and quality of flue-cured tobacco after transplanting
When the rainfall is small, it can cause the osmotic balance of the cell protoplast structure to be destroyed, and the tobacco plant will wilt due to lack of water.
The severe lack of water at the root extension stage hindered the root development of tobacco seedlings, increased the proportion of bound water in the body, wilted the lower leaves, small and thick leaves, few openings, tight cell tissue, uncoordinated endogenous hormones in plants, and even early flowering.
In the early stage of vigorous growth, it is quite sensitive to water stress, and mild water deficiency can cause the reduction of the number of leaves left in tobacco plants, and the restriction of growth and development, which has a great impact on the yield of tobacco leaves.