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A response in yield and chemical composition of flue-cured tobacco leaves to soil acidification was investigated in field experiments carried out on two soils with granulometrical composition of slightly clayey sand, which differed in their chemical composition, particularly the degree of acidification and the share of exchangeable aluminium in exchangeable soil acidity. Complete organic and mineral NPK fertilization (variant a) was applied and nitrogenous top dressing on its background (variant b). Similar yields of leaves were achieved on both soils, which confirms weak sensitivity of tobacco to soil acidification. Applied top dressing only slightly influenced the amount of yield. The level of majority of mineral components depended on soil acidification. The content of calcium, potassium, magnesium and total nitrogen in leaves from both experiments was similar. On very acid soil the leaves contained much less iron, copper and phosphorus, which results from lower availability in this environment or reciprocal retardation. In the same conditions the leaves contained decidedly more manganese and aluminium which effects from a higher leaching of these elements in very acid soils, and to minor degree of sodium and zinc. In most cases, top dressing with nitrogen decreased the level of mineral components in tobacco leaves, which was particularly clear for iron, sodium and potassium in both experiments, for aluminium and calcium on acid soil, and for manganese and magnesium on very acid soil.
Hydrogels used in gardening increase the water-capacity of soil. The preliminary field and pot experiments carried out in Tobacco Research Station at Zamość in the years of 1995-1997, aimed to study the influence of hydrogel on growth, development and yielding of light cigarette tobbacco. In pot experiment the biggest increase in mass and volume of the roots was observed at 10 g hydrogel added to 8 1 light soil (medium sand). Biometrical features of the plants were largely modified by the type of soil, although it was also observed that the plants growing in pots with addition of hydrogel tended to increase in the area and number of leaves as well as in their height. In field experiment the hydrogel was applied in two doses of 3 and 10 g, mixed with the soil at the depth of down to 15 cm in 15 cm radius around the plant. The percentage of seedlings which took roots amounted 83% on control plots and 96-97% on the plots with hydrogel addition. The plants growing on plots with applied hydrogel were also characterized by considerably increased mass and volume of the root system. Another factor which increased considerably the yield and quality of the material was supplementary watering applied during vegetation season. Watering caused 23.3% rise in the mass of leaves but at simultaneous 12.5% drop in the proportion of high grade leaves (I—III). The effects of watering were found to be better on the plots with no hydrogel addition. Therefore, it may be concluded that the addition of hydrogel guarantees better conditions for the growth of tobacco plants. Although the addition of hydrogel caused a drop in the leaf quality, it brought about a considerable increase of yield. Finally, the commercial value of tobacco leaves, characterized either by the crop’s yield and quality, was higher after hydrogel application.
The effects of a differentiated row spacing as well as topping and lateral bud pruning on the yield and quality of light cigarette type of tobacco were tested on a 3-year field experiment. It was noticed that topping and lateral bud pruning had positive effects on yield level. A wider row spacing as well as the pruning of inflorescence and side buds lad to positive changes in tobacco's product quality as a results of an increase in the carbohydrate content of leaves.
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