Effects Of Proportion And Times Of Supplemental Fertilizer On Yield And Quality Of Burley Tobacco

Taking TN86 as tested cultivar, the effects of different supplemental proportion and top-dressing times on the growth, development and quality of burley tobacco were studied in Binchuan, Yunnan Province in 2009. Simultaneously, dynamic changes of soil nutrients, dry matter, total nitrogen, nicotine content of burley tobacco were investigated. The main results as follows:1.The contents of soil alkalytic nitrogen (AN), available phosphorous (AP) and available potassium (AK) increased rapidly at the 30th day after transplanting. During rapid growing stage, the content of AN decreased gradually, and then increased at the 60th day after transplanting. The increasing amplitudes were quite high in the treatments with higher top-dressing proportion and later top-dressing time. The contents of AP and AK decreased rapidly after transplanting 30d~60d, and decreased more rapidly with the increasing of top-dressing proportion. At the same supplemental proportion, the changes of the contents of AP and AK in soil were comparatively slight in the later top-dressing time treatment.2.Plant height, effective leaves and leaf area increased with the increment of top-dressing proportion and the delay of top-dressing time. At the same top-dressing time, the differences of the effective leaves were comparatively slight with the increment of top-dressing proportion. However, the leaf area increased with the increment of top-dressing proportion.3.The accumulation trend for dry matter presented the rule of"s"during the process of growth and development. The accumulation of dry matter speed of tobacco plant in high top-dressing proportion treatment was higher than that in low top-dressing proportion treatment in whole growth duration, and at the same top-dressing proportion, in 30days after transplanting, postponing top-dressing time was benefit to the accumulation of dry matter of tobacco plant.4.The content of total nitrogen in burley tobacco leaves decreased with the advancing of growth process, but the extent of decrement slowed down with increasing of top-dressing proportion and postponing top-dressing time. The content of nicotine increased with the advancing of growth process, presenting a maximum value at the 75days after transplanting, the content of nicotine increased with increasing of top-dressing proportion and postponing top-dressing time, which the content of nicotine in upper leaf of tobacco had the largest change range.5.The yield and output value of burly tobacco increased with the increment of top-dressing proportion, and at the same supplemental proportion, in 30days after transplanting, the yield and output value of burly tobacco increased with increasing the times of top-dressing and postponing top-dressing time.Supplemental proportion and top-dressing time had great effect on appearance quality, smoking quality and chemical components as well as mineral elements of tobacco leaves. The content of oil, body and luster of cured tobacco leaves gradually reinforced along with the increment of top-dressing proportion and the postponing of top-dressing time. With the raise of top-dressing proportion and the postponing of dressing time, the style of cured leaves was more significant, physiological strength, whereas the volume of aroma and taste concentration became strong, and at the same amount of top-dressing, increasing the times of top-dressing was benefit to increasing smoking quality.The chemical components in different stalk position tobacco leaves changed greatly, whele the content of total sugar and reducing sugar presented: cutter>upper leaves. The content of the total nitrogen and nicotine presented: upper > cutter leaves. With the increment of top-dressing level and the postponing of dressing time, the content of total sugar and reducing sugar decreased, while the content of total nitrogen and nicotine increased.Supplemental proportion and top-dressing time had great effect on mineral elements of tobacco leaves. The content of P,K,B,Mn in tobacco leaves increased with the increment of top-dressing proportion and the postponing of dressing time, but the content of Ca,Mg,Fe,Cu,Zn decreased.6. The contents of phenylalanine, products of browning reaction, carotenoids and neophytadiene in tobaccos were increased with the increment of top-dressing proportion and the postponing of dressing time. The content of all kinds of aroma-active components decreased when the ratios of base fertilizer to topdressing of 7:3. Postponing top-dressing increased the content of aroma-active components in tobaccos. The content of all kinds of aroma-active components increased when the ratios of base fertilizer to topdressing of 4:6. Also postponing top-dressing increased the content of aroma-active components.