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为有效控制大黄田赖草,减少对土壤水分、养分的消耗,对赖草的生物学特性、危害损失及其控制进行了调查研究。结果表明:赖草株高45～120cm,单生或丛生,具下伸土壤30～50cm耕层间有横走根群,每平方米内,深50cm耕层内赖草根茎总重量为1129.3g,根茎总长度为2783.3cm,根茎上的新芽589.7个,使土壤严重缺水,肥力下降;土壤水分在13.4%左右时,对出苗影响不大,对生长发育有很大的影响;气温在-6～6℃,根茎萌发出土,高峰期为4月上旬,平均单株结种量为468.4粒;每平方米内有赖草120～160株时,大黄产量损失达15.8%～17.8%;田间每平方米内有赖草1株时,采用人工或机械深耕捡出地下根茎,减轻翌年危害来源。赖草密度较大时,采用10%草甘瞵铵盐水剂22.5～30.0kg/hm2,将大黄苗用塑料薄膜遮盖,于赖草1～3叶期茎叶均匀喷施,防效达98%。田间无赖草时,应重视田埂赖草的防治,有效切断田埂赖草根茎传播于田间,且不污染农田土壤环境,有利于中藏药大黄的持续、稳定发展。
In order to effectively control the weeds in Dahuangtian, reduce the consumption of soil moisture and nutrients, the biological characteristics, damage and control of Leymus secalis were investigated. The results showed that the plant height of 45 ~ 120cm, single or clustered, with the extension of the soil 30 ~ 50cm tillage between the horizontal root group, per square meter, 50cm deep plow layer of the total grass root weight of 1129.3g, The total length of rhizome was 2783.3 cm, and the number of new shoots on rhizome was 589.7, which caused serious soil water shortage and fertility decline. When soil moisture was about 13.4%, it had little effect on emergence and had a great effect on growth and development. ~ 6 ℃, rhizome germinated and germinated, the peak was in early April, the average single-plant seedling was 468.4 grains per square meter; when there were 120-160 plants per square meter, rhubarb yield loss was 15.8% -17.8% Thanks to the grass 1, the use of artificial or mechanical plowing to find underground rhizomes to reduce the source of hazards the following year. Larix density, the use of 10% glycyrrhizic acid salt agent 22.5 ~ 30.0kg / hm2, the rhubarb seedlings covered with plastic film, the lei 1 to 3 leaf stage stems and leaves evenly sprayed, the control effect of 98% . In the field of rickety grass, attention should be paid to the prevention and treatment of Leymus latifolia, which effectively cut off the rhizome propagation of Lemna matsutake in the field and did not pollute the farmland soil environment, which is conducive to the sustained and stable development of the rhubarb in Tibetan medicine.