【作者】 韦家书；

【导师】 曾东强；

【作者基本信息】 广西大学 ， 农业昆虫与害虫防治， 2008， 硕士

【摘要】 银胶菊,为菊科银胶菊属,是一种原产于中美洲的外来有害杂草。该杂草已经在东南亚地区对人类健康、生态环境和农业生产造成了严重的危害,目前广泛分布于我国的热带和亚热带地区。本文对银胶菊的生物生态学特性进行了系统研究,以探明其入侵为害机制,为科学有效地防除银胶菊提供生物生态学理论依据;筛选防除银胶菊的有效药剂,摸索出一套银胶菊的化学防除技术。主要结果如下:1.该杂草具有强大的繁殖能力和传播能力。主要表现在:种子数量多,单株种子产量为7500-10000粒;成熟种子具有休眠性和脱落性;种子小,长为1.0-1.5mm,重量轻,千粒重为0.74-0.76g。2.种子在土壤中的不同深度对出苗率有较大的影响。种子埋深为0时(种子处于土表),出苗率最高,达36.40%;种子埋深0.5cm时,出苗率为14.00%;种子埋深1.0cm时,出苗率仅为0.67%;种子埋深超过1.5cm时不能出苗。银胶菊种子的这种特性可能是其在农田发生为害轻的主要原因。3.银胶菊极易在其入侵地形成群落优势种,对本地物种具有排斥作用,可导致生物多样性下降。在银胶菊定殖的生境中,物种丰富程度指数(Shannon-Wiener index)较低,仅为1.91-2.31;表示物种优势度与均匀度的Simpson和Evenness指数也较低,分别为0.54-0.63、0.56-0.62,说明群落中物种分布极不均匀,优势度集中在银胶菊等少数物种上。4.银胶菊对其他植物具有化感作用,这可能是其成功入侵本地的一个重要机制。试验结果表明,银胶菊植株水浸提液对萝卜、黄瓜、三叶鬼针草和马唐种子的萌发、幼苗生长发育有不同程度的化感作用;银胶菊根系分泌物对三叶鬼针草和马唐种子的萌发及幼苗生长具有抑制作用。5.筛选出对银胶菊具有良好防除效果的除草剂品种。土壤处理剂为苄嘧磺隆、莠去津和莠灭净;茎叶处理剂为二甲四氯、莠去津和莠灭净。6.提出有效的化学防治方法和关键防治时期。在作物播后苗前土壤处理和银胶菊生育早期(3-4叶)茎叶处理为佳。土壤处理施用苄嘧磺隆30-40 g·ai╱ha、乙草胺+苄嘧磺隆(500-600+21 g·ai/ha)和乙草胺+莠去津(405+150-450 g·ai/ha)等药剂均可取得较好的防除效果。茎叶处理施用二甲四氯840-1260 g·ai/ha、莠灭净1200-1920 g·ai/ha和乙草胺+莠去津(405+150-450 g·ai/ha)对银胶菊的防效最为理想。更多还原

【Abstract】 Parthenium hysterophorus L. of the family Asteraceae is an exotic noxious weed from Central America. It has caused serious health, environmental and agricultural hazards in Southeast Asia, and now widely distributed in the tropical and subtropical regions in China. In this paper, the main biology and ecology of the weed were examined systematically in order to explore the invasion mechanism of the plant, which could provided some reference for scientific and effective control on P. hysterophorus, and a set of techniques of chemical control on P. hysterophorus were established. The main results were summarized as follows:1. P. hysterophorus had epidemic spread and strong reproductive potential. The weed could produce 7500-10000 seeds during its lifetime. The mature seeds had the characteristics of abscission and dormancy. The length of the seed was 1.0-1.5mm and the thousand-grain weight was 0.74-0.76g only.2. The seedlings emergence rate of P. hysterophorus had a close relationship with the burial depth of the seeds. The seeds which laid at the soil surface had the highest seedlings emergence rate, and the seeds could not emergence at all when the burial depth of the seeds was over 1.5cm.3. P. hysterophorus developed easily to be a dominant population in its invaded area, and had inhibitory effect on the growth of local plants by its allelopathy, which affected the biodiversity of invaded area. In the environment which P. hysterophorus had planted, the Indices of Species Richness, Dominance and Evenness were only 1.91-2.31, 0.54-0.63 and 0.56-0.62, respectively.4. P. hysterophorus had allelopathic potential which may serve as an important invasion mechanism of the weed. The allelopathy of the aqueous extract from P. hysterophorus on Raphanus sativus L., Cucurrds sativus L., Digitaria sanguinalis （L.） Scop, and Bidens pilosa L.were determined by measuring the seed germination and seedling growth of the plants. The results indicated that the aqueous extract showed someway stimulating effects on seedling growth of R sativus and C. sativus at a concentration of 0.01 g·mL^-1. But at a concentration of 0.05 g·mL^-1, the aqueous extract got inhibitory effect on the seedling growth of R sativus and C. sativus. The aqueous extract significantly inhibited the seed germination and seedling growth of D. sanguinalis and B. pilosa at four concentration (0.01、0.05、0.15 and 0.50 g·mL^-1) . The exudates from the root of P. hysterophorus had inhibitory effect on the seed germination and seedling growth of D. sanguinalis and B. pilosa.5. Six kinds of herbicides were screened on the toxicity against P. hysterophorus through pre-emergence application and foliage application. The results showed that bensulfuron, atrazine and ametryn had a good control effect on P. hysterophorus with pre-emergence application, and metaxon, ametryn and atrazine showed well-controlled activity on this weed with foliage application in early post-emergence period.6. Field test results showed that the pre-emergence and early post-emergence were the most suitable periods for control on P. hysterophorus. The best control effect on the weed was attained by appling bensulfuron at a dose of 30-40 g·ai/ha, or （acetochlor+atrazine） at a dose of 500-600 g·ai/ha +21 g·ai/ha, or （acetochlor+atrazine） at a dose of 405 g·ai/ha +150-450 g·ai/ha at pre-emergence period. Besides, the best control effect on P. hysterophorus was attained by spraying metaxon at a dose of 840-1260 g·ai/ha, or ametryn at a dose of 1200-1920 g·ai/ha, or （acetochlor+atrazine） at a dose of 405 g·ai/ha +150-450 g·ai/ha on the weed at 3-4 leaves stage.更多还原