烟稻复种区烤烟K326中部烟叶采收成熟度研究OACSTPCD

In order to determine the appropriate maturity of the middle tobacco leaf of K326 variety in the multi-planting area of tobacco-rice,three harvest maturity treatments of M1(low maturity),M2(medium maturity,delayed 8 d harvest)and M3(high maturity,delayed 16 d harvest)were designed to carry out sampling and roasting experiments in Hunan Shaoyang tobacco region.The results showed that SPAD value of fresh tobacco leaf decreased with the increase of leaf ma-turity,and starch content of fresh tobacco leaf increased first and then decreased.The proportion of microstrip green and va-riegated tobacco leaves decreased first and then increased after roasting.The proportion of total sugar and reducing sugar in tobacco leaves increased first and then decreased.Compared with M1 and M3,the high-grade smoke rate of M2 treatment increased by 7.84 and 7.88 percentage point respectively,the average price increased by 28.52%and 18.42%respective-ly,and the appearance quality index increased by 3.46%and 1.77%respectively.There was no significant difference be-tween M2 treatment and M3 treatment,but it was significantly higher than M1 treatment.According to the comprehensive a-nalysis,in the tobacco area of Shaoyang,Hunan,M2 is suitable for the harvest maturity of the middle leaves of K326,and its fresh tobacco leaves are characterized by yellow-green leaf base,yellow leaf tip,less hairs falling off,sticky feel on the leaf surface,white main and branch veins about 1/2,and leaf margin slightly curled.