【作者】 张银军；

【导师】 周冀衡； 张晓海；

【作者基本信息】 湖南农业大学 ， 作物学， 2008， 硕士

【摘要】 烟叶生产会受到多种生物和非生物逆境作用,烟叶的产质量和可用性也会受到巨大影响。云南保山陇川江沿岸的部分烟区,90年代末出现较大规模的灰色烤烟,严重的灰色烟初烤后呈灰褐色,完全失去经济价值。由于云南保山陇川江沿岸的部分烟区发病原因不明,有效防治措施缺乏,造成发病面积和发病率逐年上升,致使灰色烟受灾面积高达万亩以上,发病严重田块烤烟甚至绝收。为寻找对灰色烟叶的有效防治措施,我们对烤烟灰色烟叶发生的原因及形成机理进行了系统的分析研究。同时,结合烤烟栽培技术,笔者试图从改善土壤通透性、调节土壤pH值、揭膜培土、配方施肥等方面开展了示范研究。现将结果汇报给同行,为发生此类病害的烟区在进行有效防治时提供参考,研究结果如下:1、通过田间生态环境调查和盆栽试验,以及对土壤、烤烟生理生化指标及烟叶品质指标的分析,系统研究了形成灰色烤烟的原因及影响品质的机理。结果表明,灰色烟叶的发生与土壤pH偏低、根层土壤含水量过高、土壤通透性差密切相关,而影响灰色烟叶发生和严重程度的直接原因是土壤和烟叶内Fe²⁺、Mn²⁺等离子含量过高所致。2、烤烟出现灰色烟叶是由于植烟土壤的Fe²⁺、Mn²⁺离子含量偏高,在土壤pH值偏低,土壤含水量过高,根层土壤通透性差的条件下,Fe、Mn由不易被吸收的高价态转化成容易被植物吸收的低价态,造成烟株体内吸收积累Fe²⁺、Mn⁺²过多,造成营养平衡失调,而引起的烟草出现生理性中毒所至。3、为了消除灰色烤烟发生,探讨了利用高墒高培土排水、调节土壤pH值、揭膜培土、配方施肥等农田管理措施对灰色烤烟的防治效果。结果表明,无论是通过高墒高培土排水改善土壤通透性、施用石灰提高土壤pH值、不盖地膜或移栽后及早揭膜高培土,还是通过配方施肥提高P素比例而降低K素比例,均能降低烟草对Fe²⁺和Mn⁺²的吸收,减少灰色烟叶的发生。更多还原

【Abstract】 Growth of tobacco is subject to a variety of biological and non-biological effects of stress on the quality of tobacco production and availability of a dramatic impact. There have been appeared a great deal of flue-cured tobacco of grey disorder leaves of in Yunnan Baoshan in the late 1990s.Gray severe flue-cured tobacco was cured in the early dust-color,which is of less value.Those leaves even were grey-black,and of less usability.However,Because without knowing the reason and lack of effectively prevention measure.The pathogenesis areas and incidence rate increase year by year. Some tobacco-growing areas even have no harvest.In order to search for prevention measure of grey disorder leaves,the cause and mechanism of those have been studied. The results are as follows.1、Base on field experiment and potted plant test,physiologic and biochemical indexes of grey tobacco leaves and the soils occurring grey disorder were measured, the cause and mechanism of occurrence of grey disorder leaves were discussed.The results showed that the occurrence of grey disorder leaves correlate with the low soil pH,high water content of root layer soil,its occurrence and severity degree positive correlate with the Fe2+ and Mn2+ content of soil and tobacco leaf。2、In that condition,charged ions of tobacco leaves from higher oxidation state to lower oxidation state,which leading to uptake accumulation excessly and distribution of Fe²⁺ and Mn²⁺ in flue-cured tobacco.These caused nutrition equilibrium maladjustment,finally,flue-cured tobacco leaves were intoxication.3、Plot trials were carried to explore the effects of some agricultural practices on the prevention of grey flue-cured tobacco.The results showed that the occurrence of grey flue-cured tobacco was mainly due to the excessive uptake of Fe2+ and Mn2+ by tobacco plant.However,the agricultural practices,such as plowing high ridge in the field to improve soil drainage ability,applying lime to increase soil pH,no plastic film covering or uncovering film in season,or increasing P and decreasing K fertilizer,had obvious effect to decrease the uptake of Fe²⁺ and Mn²⁺ by tobacco plant and controlled the occurrence of grey flue-cured tobacco.更多还原