灌溉水氯含量与灌溉次数对烤烟叶片氯含量的影响

为明确灌溉水氯含量与灌溉次数对烤烟叶片氯含量的影响，采用低氯(7.7 mg/L)、中氯(24.6 mg/L)、高氯(43.2 mg/L)含量的灌溉水，进行灌溉1次、2次、3次（每次灌水量按照525 m3/hm2）9个处理田间试验。结果表明，成熟期、烤后叶片氯含量随灌溉水氯含量与灌溉次数增加而增加，其对叶片氯含量的影响均达到显著水平。低氯水灌溉3次成熟期、烤后中部与上部叶片氯含量仅为0.43%~0.49%。中氯水灌溉1次叶片氯含量相对较低，成熟期、烤后中部与上部叶片氯含量0.51%~0.55%，灌溉2次成熟期、烤后中部与上部叶片氯含量0.61%~0.72%，灌溉3次叶片氯含量0.8%左右；高氯水灌溉1次叶片氯含量0.59%~0.64%，灌溉2次叶片氯含量超过0.85%，灌溉3次超过1.1%。中氯水增加1次灌溉对叶片氯含量相对贡献率19.2%~30.9%，增加2次灌溉对叶片氯含量相对贡献率达到31.3%~54.5%；高氯水增加1次灌溉对叶片氯含量的相对贡献率超过44.1%，增加2次灌溉相对贡献率超过86.4%。综上所述，灌溉水氯含量与灌溉次数对烤烟叶片氯含量影响显著，尤其高氯水灌溉对氯含量影响较大，要控制烟叶氯含量在0.3%~0.8%适宜范围内，应选用低氯水灌溉，合理限制中氯水灌溉，控制高氯水灌溉。

Effect of Irrigation Water Chlorine Content and Irrigation Times on Chlorine Content of Flue-cured Tobacco Leaves

To clarify the effect of irrigation water chlorine content and irrigation times on chlorine content in flue-cured tobacco leaves, irrigation water with low (7.7 mg/L), medium (24.6 mg/L) and high (43.2 mg/L) chlorine content were used to irrigate tobacco plant once, twice, and three times (each irrigation volume was 525 m3/hm2), 9 treatments field trials in total. The results showed that: increase in both irrigation water chlorine content and irrigation times can significantly increase the chlorine content of mature and roasted leaves.chlorine content in mature and roasted leaves of middle and upper part of tobacco. which were irrigated three times by low-chlorine water, were only 0.43%-0.49%,However, under the condition of medium-chlorine water irrigation, the mature and roasted leaves of the middle and upper part of tobacco, which were irrigated once, twice and three times, contained the lowest (0.51%-0.55%); medium (0.61%-0.72%) and highest (0.8%) chlorine content respectively; under the condition of high-chlorine water irrigation, the chlorine content in leaves of tobacco, which were also irrigated once, twice and three times were 0.59%-0.64%, more than 0.85%, and more than 1.1% respectively. The relative contribution rate of one and two more times of irrigation by medium chlorine water to the leaf chlorine content were 19.2%-30.9% and 31.3%-54.5% respectively, while, the relative contribution rate of one and two more times of irrigation by high chlorine water to the leaf chlorine content were 44.1% and 86.4% respectively. In summary, irrigation water chlorine content and irrigation times can affect the chlorine content of flue-cured tobacco leaves significantly, and the high chlorine water irrigation has the greatest impact. So, to control the chlorine content of tobacco leaves within the appropriate range of 0.3%-0.8%, tobacco plant should be irrigated by low chlorine water, medium-chlorine water irrigation should be rationally limited, and high-chlorine water irrigation should be controlled.