To clarify the suitable harvest maturity of Xiangyan 7 of the lower leaves of paddy-tobacco,the curing test of lower tobacco leaves with different maturities was carried out in Guiyang tobacco area of Hunan in China.T...To clarify the suitable harvest maturity of Xiangyan 7 of the lower leaves of paddy-tobacco,the curing test of lower tobacco leaves with different maturities was carried out in Guiyang tobacco area of Hunan in China.The results showed that the SPAD value of fresh tobacco and proportion of normal group decreased,the proportion of mottle tobacco increased,the appearance quality of tobacco leaves became worse,the level of total sugar,reducing sugar,nicotine and reducing sugar/total sugar increased,and the total nitrogen/nicotine decreased with increased harvest maturity of lower tobacco leaves.It could cause lower smoking quality,lower proportion of high-class tobacco leaves and lower average price if the harvest of lower tobacco leaves was delayed.Therefore,the lower leaves of Xiangyan 7 in Guiyang tobacco area of Hunan should be harvested early.Suitable harvest maturity required light green leaf blade,light green midrib,and curl leaf margin.When the SPAD value of fresh tobacco was 26.26~30.33,it could be used as a reference for guiding the appropriate harvest maturity of lower paddy-tobacco leaves of Xiangyan 7.展开更多
文摘To clarify the suitable harvest maturity of Xiangyan 7 of the lower leaves of paddy-tobacco,the curing test of lower tobacco leaves with different maturities was carried out in Guiyang tobacco area of Hunan in China.The results showed that the SPAD value of fresh tobacco and proportion of normal group decreased,the proportion of mottle tobacco increased,the appearance quality of tobacco leaves became worse,the level of total sugar,reducing sugar,nicotine and reducing sugar/total sugar increased,and the total nitrogen/nicotine decreased with increased harvest maturity of lower tobacco leaves.It could cause lower smoking quality,lower proportion of high-class tobacco leaves and lower average price if the harvest of lower tobacco leaves was delayed.Therefore,the lower leaves of Xiangyan 7 in Guiyang tobacco area of Hunan should be harvested early.Suitable harvest maturity required light green leaf blade,light green midrib,and curl leaf margin.When the SPAD value of fresh tobacco was 26.26~30.33,it could be used as a reference for guiding the appropriate harvest maturity of lower paddy-tobacco leaves of Xiangyan 7.