Effects of different magnesium, zinc and boron levels on yield and quality of flue-cured tobacco in Tengchong volcanic ash soil

Abstract

To improve quality of tobacco in the region of volcanic ash soil, field experiment of nine treatments of three factors and three levels, which were composed with magnesium sulfate(0, 57.75, and 115.5 kg/hm2), zinc sulfate(0, 6.60, 13.2 kg/hm2) and borax(0, 8.25, and 16.5 kg/hm2) was designed to research the effect of adding extra magnesium, zinc and boron on agricultural character, economic character and chemical components of flue-cured tobacco in Tengchong county. The results showed that treatment one(T1,with magnesium free and low zinc and boron level), treatment two(T2, with magnesium free and moderate zinc and boron level), treatment four(T4, with moderate boron and low magnesium and zinc level), and treatment eight(T8, with moderate magnesium, zinc and low boron level) could result in a better tobacco growth and good economic character compared with that of CK. Among the mentioned treatments, the yield value of treatment 1 was 66.8 thousand Yuan per hectare, with a 96.3% of middle and first class tobacco. The usability index of top, middle-stalk and lower leave was 0.69, 0.73 and 0.80, respectively. It could promote the growth of tobacco plant, improve the economic character and availability of chemical composition of flue-cured tobacco, and increase the content of plastid pigment degradation products and other volatile aroma substances in tobacco leaves by increasing extra zinc sulfate and borax in volcanic ash soil.