揭膜时期对烟株生长及烟叶产质量的影响

对地膜覆盖栽培的揭膜时期进行了研究。结果表明 ,在生育中期揭膜有利于成熟期烟株根系的生长 ,移栽后 30d揭膜处理的烟株根干重是全生育期盖膜处理的 1.72倍 ;盖膜导致了碱解氮、水溶性硼、速效钾、交换性镁等移动性强的养分在畦土表层富集。全生育期盖膜处理烟叶采收结束时 ,畦土表层 1.5cm深处土壤的碱解氮、水溶性硼、速效钾和交换性镁含量分别为 937.5 8mg/kg、1.60mg/kg、2 136.0 6mg/kg和 143.96mg/kg。试验还表明烟株生育中期揭膜 ,对提高烟叶产质量有一定效果 ,但上部烟叶烟碱含量较高

Effects of the Duration of Film-covering on Growing, Yield and Quality of Flue-cured Tobacco

The time of film-covering was studied, the results showed that removing film in middle growth period was conducive to the growth of tobacco plant roots. If film was removed in 30 days after transplanting, the dry weight of root was 1.72 times as that of root covered by film in whole growth period. The nitrogen, potassium, magnesium and boron moved up and rich in the top of ridge with film-covering. The contents of alkaloid nitrogen, soluble boron, rapidly available potassium, and exchangeable magnesium in the top layer of ridge (1.5cm below surface) at the end of growth period were 937.58mg/kg, 1.60mg/kg, 2136.06mg/kg, and 143.96mg/kg, respectively. The nicotine contents in upper leaves were higher with removing film in middle growth period.