| Selenium is an essential nutrient element for human beings and animals as well as a useful trace element for plant growth.At present,many studies about enrichment of selenium in flue-cured tobacco and the effects of selenium on the growth and quality of flue-cured tobacco under the condition of selenium rich soil were reported,Yuyan 10 is the main popularized variety in Henan,the quality of Yuyan 10 tobacco leaves can be improved,but there were few studies about how foliar application of selenium affected the growth and quality under low selenium soil conditions of Yuyan 10,the main tobacco variety in Henan.On the one hand,the effects of foliar application of organic and inorganic selenium fertilizer in different concentrations(5 μg/m L and 10 μg/m L)on dry matter accumulation and the content of selenium in tobacco leaves of Yuyan 10 were studied with field experiment in this paper,indicating that spraying 10 g/m L of sodium selenite,as the best source of selenium compound selenium fertilizer,improved the dry matter accumulation and selenium content in flue-cured tobacco most significantly of Yuyan 10.On the other hand,the effect of foliar application of traditional selenium fertilizer(60%Na2Se O3 10mg/L)and new type of selenium compound fertilizer(sodium dodecyl sulfate 10mg/L,Dodecyl Sulfonate Sodium 13mg/L,DA-6 10mg/L,fulvic acid 250mg/L)on Yuyan 10 agronomic and physical charateristics,chemical and aroma components,physiological characteristics,selenium content,tobacco smoke components and economic charateristics were studied with field experiment,providing theoretical basis and guidance for the production of selenium-enriched tobacco leaves under low soil selenium conditions.The main conclusions are as follows:1.The effects of foliar application of organic and inorganic selenium fertilizer in different concentrations(5μg/m L and 10μg/m L)on dry matter accumulation nad the content of selenium in tobacco leaves of Yuyan 10 were studied.Foliar spraying of different selenium fertilizer could promote dry matter accumulation and selenium content of Yuyan 10.The total weight of dry matter(total dry weight of leaves,roots and stems)and dry matter accumulation of Yuyan 10 increased with the increase of selenium concentrations.The total weight of dry matter and dry matter accumulation in tobacco leaves with inorganic selenium fertilizer was higher than that with organic selenium fertilizer with the same spraying amount.The content of selenium in leaves increased with the increase of selenium concentrations.The inorganic selenium fertilizer could improve the selenium content of leaves more efficiently;The dry matter accumulation and selenium content of Yuyan 10 was highest with the concentration of 10 g/m L of sodium selenite.2.The effects of foliar application of new type of selenium compound fertilizer on the growth and economic characteristics of Yuyan 10 were studied.Foliar spraying of different selenium fertilizer(traditional selenium fertilizer and new type of selenium compound fertilizer)could promote the growth and development of tobacco plants in low selenium soil conditions,the plant height,stem girth,leaf number and maximum leaf length increased.Spraying new type of selenium compound fertilizer had the most significant improvement on plant height,stem girth and leaf number of Yuyan 10.Foliar spraying of different selenium fertilizer could increase the output value of tobacco,the proportion of high-grade tobacco and the average price.And the economic characteristics of the new type of selenium compound fertilizer was the best,which significantly increased the proportion of high-grade tobacco.3.The effects of foliar application of new type of selenium compound fertilizer on quality of Yuyan 10 were studied.Under the condition of low selenium soil,spraying different selenium fertilizer(traditional selenium fertilizer and new type of selenium compound fertilizer)could increase the leaf length,tension resistance,single leaf weight and filling value of flue-cured tobacco.The application of new type of selenium compound fertilizer could maximize the improvement of the physical properties and the usability of flue-cured tobacco.Foliar application of different selenium fertilizer could reduce the content of total sugar and reducing sugar,increase the content of nicotine,total nitrogen and protein,reduce the ration of sugar to nicotine,increase the ratio of potassium to chlorine,and the ratio of nitrogen to alkali was closer to 1;Spraying new type of selenium compound fertilizer could also increase the content of potassium,the chemical composition became more coordinated,and met the requirement of high quality tobacco.Foliar spraying of different selenium fertilizer could increase the content of aroma components including carotenoid degradation products,Maillard reaction products,phenylalanine degradation products and Solanone;Spraying new type of selenium compound fertilizer could improve the content of neoplytadiene,increase the concentration of aroma and improve the aroma quality.4.The effects of foliar application of new type of selenium compound fertilizer on physiological characteristics of Yuyan 10 were studied Under the condition of low selenium soil,spraying different selenium fertilizer(traditional selenium fertilizer and new type of selenium compound fertilizer)could decrease the content of MDA.The earlier the fertilizer was sprayed,the more obviously the content of MDA would decrease;Foliar application of different selenium fertilizer could improve the activity of GSH-Px.Spraying Selenium in 40 d after transplanting significantly improved the activity of GSH-Px;The promotionon of antioxidant ability of tobacco with spraying the new type of selenium compound fertilizer was the biggest.5.The effects of foliar application of new type of selenium compound fertilizer on the selenium content and smoke of Yuyan 10 were studied.Under the condition of low selenium soil,foliar spraying of different selenium fertilizer(traditional selenium fertilizer and new type of selenium compound fertilizer)could increase the selenium content in different organs,which increased the selenium content in leaves most.Foliar spraying of different selenium could increase the selenium content in middle and upper leaves,which increased the selenium content in middle leaves most.Foliar spraying of different selenium fertilizer could decrease the the content of carbon monoxide,total particulate matter and tar in smoke.The selenium content in different organs and leaf positions was highest with the spraying of the new type of selenium compound fertilizer,which could maximize the reduction of the harmful components. |
