Study of genotype on response ability of tobacco potassium nutrition and selection

tobacco varieties were selected randomly for studying different types of tobacco potassium nutrition under different potash rates. The variability in potassium level was as high as 2.34%, with variation coefficient of 24.6% among different genotypes. The leaf potassium contents of the three treatments with high, conventional and low potash rates were significantly correlated, with coefficients of 0.980, 0.941, and 0.937 respectively, but are not significantly correlated with the treatment of none potash rate. The critical values of potassium levels were 2.50% and 1.80% at the conventional potash rate, 2.06% and 2.05% at the high potash rate, and 1.90% and 1.45% at the low potash rate respectively. Tobacco genotypes for potassium nutrition could be divided into three categories of rich, high and low, corresponding to the natural conditions including soil, climate etc. in Guizhou Province. The results showed that selecting tobacco varieties with high capability of potash absorption and accumulation are the most effective measure to increase potassium content in tobacco leaves. The optimum selection of potassium-sufficient genotypes are recommended among genotypes with potassium level over 2.5 percent under conventional potash rate.