Effect of water stress on growth and chemical quality during the different growth period of flue-cured tobacco

Rainproof and water controlling was studied for the research on effect of water stress on growth and chemical quality during the different growth period of flue-cured tobacco.The result indicated that,during each stage of flue-cured tobacco growth,the height and leaf area of tobacco increased obviously along with the elevation of the soil relative water content.The soil was dry or the water was excessive,the root system volume,the root system surface area and the root system vigor will all drop,the most suitable relative water of soil in the resettling stage,vigorous growing stage,budding stage and mature stage respectively were 65%,80%,80%,65%.In the mature period of flue-cured tobacco,under the different water processing condition,protein in the middle and the upside leaf,the smoke alkali and the total nitrogen increased.The total sugar,the reducing sugar reduced.Moreover,it reduced when the soil was drought more than when the water was excessive,which caused the quality of tobacco leaf to reduce;the sugar alkali,NIT/NIC and SUR/NIT of flue-cured tobacco was more reasonable when it was processed by mild drought(65% processed).