Circulation, accumulation and distribution of potassium in flue-cured tobacco with different potassium levels

The solution culture experiment was carried out to study the effect of potassium supply levels on circulation, accumulation and distribution of potassium in flue-cured tobacco. The results showed that there were large amounts of potassium flowing from shoot back to root in flue-cured tobacco. The flowing amount of potassium in phloem was more than about 50% of the amount in xylem. The potassium circling amount between root and shoot increased as potassium supply levels increased. The difference of dry weight of flue-cured tobacco among potassium supply levels was not significant. The potassium contents of leaf, stem and root of flue-cured tobacco increased significantly as the potassium supply levels increased. The leaf potassium content could be quite high if there were large amounts of potassium ion supplied. The highest K2O content of leaf in this experiment was 8.8%. The potassium distribution proportion in organs of flue-cured tobacco was highest in leaf, lower in stem and root under different potassium supply levels. After topping, potassium distribution proportion decreased in leaf and increased in root.