Study On Suitable Harvest Period Of Upper Six Tobacco Leaves In Typical Strong-aroma Flue-cured Tobacco Area Of Henan Province

In order to clarify the relationship between the suitable mature harvest characteristics,maturity and tobacco production quality of six slices of flue-cured tobacco in Henan tobacco area,explore the best harvest period of upper tobacco leaves,achieve the purpose of improving quality and efficiency,clarify the changes in the maturation process of upper tobacco leaves and determine the most favorable maturity standard for quality improvement,different harvest gradients were set up with Zhongyan 100 and Yunyan 87 as experimental materials.The maturation characteristics and SPAD values of tobacco leaf were described and determined in the field.1.During the delay of 10-and 11 days,the upper six tobacco leaves were orange to deep orange.The thickness of tobacco leaves was moderate,the structure was loose,the maturity was good,the oil was sufficient,the gloss was strong,the evaluation.The field maturation characteristics of the upper six tobacco leaves were that the veins were basically white,the leaf color was light yellow,the mature spots were more,and the corresponding SPAD values of the upper three and the lower three were 5.4～5.7 and 6.4～6.9,respectively.Therefore,the harvest of six tobacco leaves in Yuzhong tobacco area should be delayed by 10～11 d,and the high quality upper tobacco leaves with good quality can be obtained at this time.2.The leaf color of tobacco leaf was orange,the oil was sufficient,the structure of tobacco leaf was loose,the thickness was medium,and the residual area was not more than 15.The mature characteristics of the field were as follows:the leaf veins were about 6%and 70%white,the leaf color was pale yellow,the angle between leaf surface and stem was 70°～80°,the SPAD value of the upper three leaves was 9.4～10.5,and the suitable SPAD value of the next three leaves was 8.0～8.6.At this time,the physical properties of the tobacco leaves after six slices were good,the chemical composition and coordination were suitable,the economic properties were good,the total aroma was the highest,and the sensory evaluation quality of the tobacco leaves was the highest.3.The results showed that the harvest maturity of six slices in Henan tobacco area had great influence on physical,chemical,appearance,economic,aroma and sensory evaluation,etc.The quality,yield and quality of tobacco leaf could be improved effectively...