Effects Of Phosphorus Supply On Growth, Development, Yield And Quality Of Flue-Cured Tobacco In Nanyang Area

Taking Yunyan 87 as tested cultivar, field experiment was carried out to study the effects of phosphorus supply on intrinsic chemical quality of flue-cured tobacco, phosphorus accumulation in tobacco organs and typical leaf position, and biochemical and economic index of rhizosphere soil in nanyang fangcheng town from 2007 to 2008, the flue-cured tobacco were planted in yellow cinnamon soil with high, middle and low fertility (taking phosphorus content <10mg/kg as low, 10～20mg/kg as middle and >20mg/kg as high). The main results as follows:1. Effect of phosphorus supply on chemical component and aroma material content of flue-cured tobaccoIn low phosphorus soil, phosphorus supply could promote the absorption to potassium and calcium of tobacco plant, to phosphorus of middle and lower leaves, and to magnesium of middle leaves. It could also decrease the contents of total sugar, reducing suger and starch, reduce the total nitrogen differences among different position leaves and increase obviously the content of aroma material and organic acid in tobacco leaves.In middle phosphorus soil, the effect of phosphorus supply on the absorption to mineral nutrients was little. It promoted the synthesis of nicotine, the conversion of reducing suger in middle upper leaves, the degradtion of starch and increased obviously the total content of aroma material , but the changes of organic acid content was not obvious.In high phosphorus soil, phosphorus supply could promote the absorption to potassium and phosphorus of tobacco plant, decrease the content of total sugar, reducing sugar, nicotine and total nitrogen in upper leaves, but the effect on contents of starch and organic acid was not obvious. It could improve the content of total aroma material in tobacco leaves in different degrees.2. Effect of phosphorus supply on biochemical index of rhizosphere soil of flue-cured tobaccoIn low phosphorus soil, the pH value of rhizosphere soil was lower than that of non- rhizosphere soil, with the growth of tabacco plant, it showed decreasing trend, and the effect on pH value of soil was little in different treatments. The available phosphorus content of rhizosphere soil was higher than that of non-rhizosphere soil, the differences of available phosphorus content of non-rhizosphere soil in different treatments was little, but what in rhizosphere soil was large, so phosphorus supply could increase the available phosphorus content of rhizosphere soil obviously. The organic matter content of rhizosphere soil was higher than that of non-rhizosphere soil in different degrees, the differences in treatments between rhizosphere soil and non-rhizosphere soil was little, so phosphorus supply had little influence on content of organic matter. With the growth of tobacco plant, the content of acid phosphatase, neutral phosphatase and the total phosphatase increased obviously, the content of alkaline phosphatase increased in prophase, but the regularity was not obvious in the late, so, phosphorus supply could improve the content of various phorphatase in different degrees.In middle phosphorus soil, the pH value of rhizosphere soil was lower than that of non- rhizosphere soil, the pH value of rhizosphere soil and non- rhizosphere soil were lower in high applied phosphorus treatment than that of other treatments. The available phosphorus content of rhizosphere soil was higher than thant of non- rhizosphere soil and phosphorus supply could increase the available phosphorus content of rhizosphere soil and non- rhizosphere soil in different degrees. The change rules of organic matter content of rhizosphere soil and non- rhizosphere soil was not obvious. With the growth of tabacco plant, the acid and neutral phosphatase decreased first and then increased. The content of alkaline phosphatase was almost invariant except CK. Comparing with non- rhizosphere soil, the total content of phosphatase of rhizosphere soil slightly increased.In high phosphorus soil, the pH value of rhizosphere soil was lower than that of non- rhizosphere soil. The available phosphorus content of rhizosphere soil was higher than that of non- rhizosphere soil and phosphorus supply could increase the available phosphorus content of rhizosphere soil and non-rhizosphere soil in different degrees. The organic matter content of rhizosphere soil was higher than that of non-rhizosphere soil in different degrees. The regularity of various phosphatase and total phosphorus content were not obvious.3. Effect of phosphorus supply on phosphorus content of different organs in tobacco plantIn low phophorus soil, phosphorus supply could increase the phosphorus content in each organs obviously, among which was leaf> stalk> root. The phosphorus content of each organs showed high level in the early development stage, but decreased rapidly in the late and the more phosphorus supply was, the more differences of phosphorus content among root, stalk and leaf was. The regularity of phosphorus content in root, stalk and leaf in the middle phosphorus soil was the same as in the low phosphorus soil.4. Effect of phosphorus supply on phosphorus content of typical leaf position of tobacco plantIn low phosphorus soil, phosphorus supply could improve the phosphorus content of middle and lower leaves. In the whole development stage, phosphorus supply could promote the absorption of phosphorus. In the early development stage, the phosphorus content of each position maintained in high level, as the growth of tobacco plant, the phosphorus content of lower leaves decreased rapidly and increased in different degrees in the late. The middle leaves also decreased rapidly first and then increased, and still showed downward trend in the late. The change trend of upper leaves was similar to the lower leaves.In middle phosphorus soil, phosphorus supply could aslo improve the phosphorus content of each leaf position. In the whole development stage, phosphorus supply could promote the absorption of phosphorus. In the early development stage, the phosphorus content of middle and upper leaves showed high level. As the growth of tobacco plant, the phosphorus content of lower leaves slightly increased and then decreased, in late growth stage it maintained low level. The phosphorus content of middle leaves nearly unchanged in prophase and then decreased rapidly, in late growth stage it increased. The phosphorus content of upper leaves increased in prophase and then decreased rapidly and rose a bit again at last.In high phosphorus soil, phosphorus supply could improve the phosphorus content of each leaf position. In the whole development stage, phosphorus supply could promote the absorption of phosphorus. As the growth of tobacco plant, the phosphorus content of lower leaves always decreased rapidly, after down to low point there was a little rally and the two treatments with high applied phosphorus showed higher amplification in the late. The phosphorus content of middle leaves maintained higher level in prophase, but decreased rapidly at last. The phosphorus content of upper leaves showed a little rally in prophase and then decreased rapidly and showed a little rally at last.5. Effect of phosphorus supply on economic characters of tobacco plantPhosphorus supply could improve the yield, average price, upper and middle leaves proportion and output value per mu. In low phosphorus soil, the P120 treatment showed higher average price and output value. In middle phosphorus soil, the P90 treatment showed higher average price and output value and in high phosphorus soil, the P60 treatment showed average price and output value.