Abstract:

The experiment was conducted to study the effects of different magnesium application level on growth,yield and nutrient absorption of flue-cured tobacco in Yuxi city, Yunnan province. Field experiment was randomly divided different small field, which was setup five levels of magnesium 0, 56.25、112.50、168.75、225.00 kg/hm2. The results showed that magnesium application level could increase yield, output value and ratio of first grade of leaves and CK was statistically significant. When magnesium application level was168.75 kg/hm2, the highest yield, output value and proportion of superior grade of leaves could be gotten.The quality was improved with Mg application level being 56.25～112.5kg/hm2. magnesium application increased the Mg content in tobacco leaves. The order of Mg contents in leaves at different positions was lower>middle>upper. Mg expedited the absorption of N、P、K in tobacco leaves. when the Mg application level was either scarcity or too high(≧225.00 kg/hm2）there was no benefit for the Cl nutrient absorption. The Ca content in tobacco leaves decreased with the increasing of magnesium application levels. Comprehensively considering agronomic characters, economic characters,quality and nutrient absorption, the optimum Mg application level should be 56.25~112.5 kg/hm2 for high-quality flue-cured tobacco growth in Yuxi city, Yunnan province.