engleski

Effects of copper, zinc and boron on yield and quality of flue-cured tobacco

The effects of fertilization, at different rates of application of Cu, Zn and B, on yield and quality of flue-cured tobacco were investigated during 1989-1991. The field experiment was realized according to the block design method with four repetitions on sandy loam soils at the Tobacco Institute Zagreb. In all treatments, except for non-fertilized treatments, tobacco was fertilized with 20 kg/ha of nitrogen added to a fertilizing mixture NPK/5:20:30. According to the experimental design, some treatments were additionally fertilized with Cu, Zn and B. Soil application rates of Cu, Zn and B ranged from 2-8 kg/ha, 2-9 kg/ha, and 0.5-5 kg/ha, respectively. The nutrients were applied in two bands spaced 20 cm apart, with the tobacco row in the middle, and placed at a depth of around 10 cm. The Cu, Zn and B contents of the soil prior to treatments were 2.1 mg/ml, 1.0 mg/ml and 0, 37 mg/ml, respectively. Yield and content of nicotine were not affected by application of either Cu, Zn or B. The research results showed that in wet season positive effects of Zn and B application on the content of reducing sugars can be expected, whereas in dry season, an increased application of B can give better visual quality to cured leaf. The Zn and B contents of leaf tissues were significantly increased by increased application of Zn and B in the soil. Generally, additional applications of Cu, Zn and B nutrients do not appear necessary in flue-cured tobacco production on sandy loam soils, in Northwest Croatia.

flue-cured tobacco; yield; quality; Zn; Cu; B

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