Zmiany składu chemicznego liści tytoniu i ich jakości pod wpływem nawożenia miedzią i molibdenem
AbstractThere is not much research reported on the effects of microelement treatment measured with the yield and quality of tobacco leaves in Poland. The present study was, therefore, aimed to develop knowledge in this field by determining the following: 1. the effect of fertilisation with selected microelements on the yield and chemical composition of tobacco leaves, 2. the relationships between the nutrient and heavy metal level in leaves and the raw tobacco quality assessed organoleptically, and between the nutrient and heavy metal level in leaves and the nicotine and sugar contents of leaves. in a preliminary study (1988-1990) of the chemical composition of tobacco grown in a strict pot experiment and under field conditions it was found that: 1. Cu and Mo had a positive effect on tobacco growth and yield structure, 2. the chemical composition of tobacco depended on the location of the plantation and the quality grades of ]eaves, 3. the sugar and nicotine contents were correlated with the level of mineral constituents in raw tobacco. Following this, in 1991-1995 field experiments were carried out to further investigate the effect of Cu and Mo on the yield and chemical composition of the raw tobacco material. Total N content of the plant material was determined using Kjeldahl's method, protein N by Bernstein's method, the sum of water-soluble reducing carbohydrates by Bertrand's method and the level of alkaloids expressed as nicotine by means of the spectrophotometric method. Following dry mineralisation and ash dilution in HNO3, the level of P was assayed calorimetrically with ammonium molybdate and ammonium vanadate, Ca, Mg, microelement and heavy metal contents were determined using ASA (absorption measurement), and K by the FES method (emission measurement). The results can be summarised as follows: 1. The yields of leaves gathered in the experiments depended primarily on the conditions under which the tobacco plants grew and developed in individual experimental years, and were only slighty affected by topping. 2. Cu and Mo treatment usually increased the yield of leaves, its effect being similar to, or better, than that of nitrogen top dressing. 3. Under the influence of Cu and Mo the quality of leaves usually improved. The effect of these elements was more beneficial than that of nitrogen; it also alleviated the negative impact of nitrogen fertilisation on raw material quality. 4. The levels of most mineral components in the analysed tobacco leaves did not differ substantially from their average contents determined by other authors, except the Fe and Cd levels which considerably exceeded mean values reported in other studies. 5. The mineral component contents depended on the date of priming, being for most components higher in leaves of worse quality, The level of nicotine and sugars in leaves also varied between successive primings. The greatest amount of sugars was contained in leaves from upper stalk positions and of better quality. In contrast, the levels of nicotine were higher in leaves from earlier priming and of worse quality. However, they were also dependent on weather conditions during the vegetation of tobacco in successive years. 6. Plant topping slightly altered the mineral element contents of plants, increased the nicotine content and decreased the sugar level. 7. Microelement treatment increased the levels of the majority of metallic components of the tobacco plant. Special consideration should be given to the increased Cd content since this metal aggravates harmful effects of tobacco on smokers' health as it accumulates in soft tissues: lungs, liver and kidneys. 8. Cu and Mo fertilisation increased the nicotine and sugar contents of leaves with Cu having a more pronounced effect on nicotine content and Mo stronger influencing sugar level. The levels of both components tended to become similar in leaves of successive primings and individual quality grades. 9, The tobacco quality indexes improved but sometimes their values indicated an excessive sugar level in the raw material, especially with a large amount of precipitation at the beginning of field vegetation of plants that caused nitrogen leaching. 10. The nicotine content of tobacco was positively correlated with total N, P and most of metalic elements in leaves, whereas the level of sugars was negatively correlated both with the mineral and nicotine contents of leaves. Strong correlations were found between the levels of individual metalic elements in tobacco, which were also positively correlated with the P content of leaves. Most of the correlations were significant at p = 0.001 or 0.01. 11. The sugars : crude protein ratio may be successfully applied as an indicator of tobacco quality since it is strictly correlated with Szniuk's number and does not require time-consuming and expensive analyses either of nicotine or protein contents. On the basis of multiple regression analysis, equations for the sugar and nicotine contents and for the sugars : crude protein index were formulated in which the levels of the investigated components in tobacco leaves were included (K, total N, nicotine and sugar contents expressed in %, and Fe and Mn in mg•kg-1): sugars = 39.7018 - 0.0064 • Fe - 3.7621 • nicotine - 2.263 K - - 3.7248 • Total N R2 = 0.76 nicotine = 0.48852 • N - 0.00033 Fe + 0.0055 • Mn - 0.0389 • sugars + + 0.3464 R2 = 0.84 sugars : crude protein = 0.0392 nicotine + 0.0739 • sugars - - 0.5765 Total N + 1.3074 R2 = 0.97
|Other language title versions||Changes in chemical composition and quality of tobacco leaves as influenced by copper and molybdenum fertilisation|
|Publisher||Uniwersytet Rolniczy im. Hugona Kołłątaja w Krakowie, MNiSW |
|Publishing place (Publisher address)||Kraków|
|Book series /Journal (in case of Journal special issue)||Zeszyty Naukowe Akademii Rolniczej im. H. Kołłątaja w Krakowie. Rozprawy, ISSN 1233-4189, (0 pkt)|
|Publication size in sheets||8|
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