发展化学除草重视综合治理

我国农田杂草有２５０多种，全国农田受草害面积４３００多万ｈｍ２，平均受草害减产１３．４％，每年减产粮食１７５０万ｔ，皮棉２５．５万ｔ和大豆５０万ｔ。传统农业生产采用机械作业及人力等除草。随着农村经济的发展，化学除草面积迅速扩大，全国农田化学除草面积从１９７５年的１７０万ｈｍ２增加到１９９５年的４１３３万ｈｍ２。但是，长期化学除草也带来了除草剂土壤残留对后茬作物药害、农田杂草种群更替和产生抗药性等新问题。必须重视农田杂草综合治理，通过采用各种有效的农业技术措施，为农作物保持良好的生态条件，结合化学除草才是最有效的防除杂草方法     

我国农田杂草治理技术的发展

我国稻、麦、玉米、大豆及棉花等主要农作物农田杂草有580种,属于危害重而又难于防除的有17种,受杂草危害较重的农田有3 580万hm²,年平均受草害减产12.3％～16.5％(加权平均)。自1980年以来,全国化学除草面积以年增200万hm²的速度扩大,农田化学除草面积从20世纪70年代早期不到100万hm²扩大到近年来6 000万hm²。本文概述了我国农田主要作物杂草的发生危害、化学除草剂应用现状及其综合防治进展,并提出今后杂草防除的设想与建议。     

The more we do,the less we gain? Balancing effort and efficacy in managing the Solidago gigantea invasion

Developing invasive plant management strategies is an important task in modern ecology, conservation biology and land management. Solidago gigantea is considered a problematic invader in Europe and Asia, where it forms dominant stands that can decrease species diversity. There is, therefore, an urgent need for effective management to reduce S. gigantea infestations and their negative impacts. We examined the efficacy of multiple approaches to S. gigantea management in Hungary. In our study, we evaluated the effect of several long-term management techniques such as grazing, mowing and periodic flooding on the invader's density as well as native community diversity. In addition, we investigated the short- and long-term effects of mowing combined with other treatment options, to estimate the influence of increased management intensity. Our results indicate that all tested management techniques had negative impacts on S. gigantea density. Short-term mowing did not appear to improve species diversity in the resident community; however, all long-term options improved species diversity. Moreover, combining treatments with mowing varied in its effectiveness; mowing once increased the efficacy of flooding, but decreased the efficacy of grazing, while mowing twice decreased efficacy of flooding. We suspect this is due to the increased intensity of disturbance, which does not allow for the natural recovery of communities, and after management ceases, invasion is able to re-occur. Our results indicate that for effective management, we need to combine management options which act via different mechanisms, leading to cumulative positive effects on the resident community when applied at moderate levels.     

稔平半岛外来杂草入侵现状及防控措施

通过野外调查与查阅文献资料,首次对惠州稔平半岛的外来杂草种类、分布和危害现状做了调查研究,并分析了外来杂草的来源和入侵途径,针对稔平半岛外来杂草入侵现状提出防除和管理建议。     

江苏茶园秋季杂草群落及外来入侵杂草的数量生态学分析

为明确除草剂使用、翻耕、树龄、坡度和郁闭度等杂草管理措施及环境因子对江苏茶园秋季杂草群落和外来入侵杂草物种组成、群落结构的影响,于2013年10月分别对江苏茶叶主产区仪征、金坛和宜兴3地共90个样地进行了杂草调查。通过主成分分析和典范对应分析,90块样地可以依据优势杂草种类和杂草丰富度被分成3个类群。类群Ⅰ为荩草、野老鹳草、酢浆草、狗尾草、蓬蘽、麦冬杂草群落,该类群翻耕和化学除草频次少,树龄较大,郁闭度高,田间多年生杂草多,杂草种类多,田间杂草密度低;类群Ⅱ为马唐、小旱稗、小飞蓬、野老鹳草、狗尾草杂草群落,该类群以化学除草为主,田间一年生禾本科恶性杂草和抗除草剂杂草多,杂草优势种突出;类群Ⅲ为马唐、小旱稗、牛筋草、野老鹳草、酢浆草、虮子草杂草群落,该类群茶园管理较为精细,田间优势杂草种类少,杂草密度低。对外来入侵杂草与环境因子关系的数量分析发现,化学除草剂的使用和翻耕频率显著影响外来入侵杂草在江苏茶园的发生和分布。研究表明,不同管理措施,如化学除草剂和翻耕频率,对杂草群落的形成起决定性作用。     

The role of road disturbance in the dispersal and spread of Ageratina adenophora along the Dian–Myanmar International Road

This study was conducted to examine the roles of both environmental variables and road factors in explaining the spatial patterns of the exotic plant, Ageratina adenophora (Crofton weed), within the roadside habitats along the Dian–Myanmar International Road. The results indicate this plant was comparatively abundant along the middle part of this International Road and significantly less common along the northern section. The highest presence of A. adenophora was found at the site of new roads. This plant invaded more easily into spoil ground where road soil or construction waste was piled up. This road was confirmed as a corridor of A. adenophora invasion and should be considered as an important target of local and regional efforts to prevent and control cross-border and interior invasions of this exotic plant.     

Solarization for the control of Pueraria montana (kudzu)

The effects of translucent polyethylene sheeting as a thermal covering to eradicate Pueraria montana (kudzu) were investigated at Clemson, South Carolina on a clay loam. In 2005, the highest reduction of live root crowns was observed where P. montana was covered for the entire growing season (May–October) with a reduction of 42% of live root crowns compared with the control plots. Where P. montana was covered for alternate weeks throughout the growing season live root crowns were reduced by 35%. Covering P. montana for one week and then uncovering for four weeks repeatedly through the season killed 24% of root crowns. In 2006, the second year of treatment to the same plots, the three solarization treatments had similar efficacy of about 97%. The use of polyethylene sheeting appears not to be cost‐effective for general control of large P. montana infestations, but may be useful for small patches.     

Ophraella communa,the ragweed leaf beetle,has successfully landed in Europe: fortunate coincidence or threat?

We report the occurrence of the North American ragweed leaf beetle Ophraella communa in Europe. During our surveys to monitor populations of the invasive alien plant Ambrosia artemisiifolia in Europe, we found the beetle south of the Alps, in more than 130 sites in southern Switzerland (Ticino) and northern Italy (Lombardia, Piemonte and Emilia‐Romagna). At sites where O. communa was present, up to 100% of the plants were attacked with damage levels high enough to completely defoliate and prevent flowering and seed set of most ragweed plants. That in its first year of discovery, O. communa was already found over a large area of c. 20 000 km² and in all habitat types occupied by A. artemisiifolia reflects its great dispersal potential and wide habitat suitability. This oligophagous beetle is a successful biological control agent against A. artemisiifolia in China, but despite extensive host specificity tests, the risk of attack and the level of damage of sunflower under field conditions remain unclear. The recently launched COST Action on ‘Sustainable management of Ambrosia artemisiifolia in Europe (SMARTER)’ offers an ideal framework to respond quickly to the recent establishment of O. communa in Europe and to collect data that can help determine whether this event should be considered a troublesome introduction or whether it is likely to become the first case of a successful biological control of an invasive weed in continental Europe.     

外来假马鞭草的特征特性及控制

假马鞭草为马鞭草科假马鞭属多年生草本植物,原产中南美洲,19世纪末出现在中国香港,现在我国福建、广东、广西、云南南部、香港、海南和台湾有分布.文章在调查研究及查阅大量文献的基础上,归纳了外来杂草假马鞭草的形态特征、起源、入侵途径、在我国的分布、经济和生态影响、预防控制和管理措施等.     

草地植物入侵的预防和控制

外来植物入侵属于生物入侵的范畴,对生态、环境和生物多样性具有破坏性影响。植物入侵的途径很多,但有意引进是最主要途径。本文阐述了国外一些地方由于植物入侵所造成的损失和教训。重点介绍了我国植物入侵的形势及主要有害外来植物种类、来源、入侵途径、分布范围及危害程度,并根据国际、国内目前应对植物入侵的作法和未来趋势,提出了预防和控制植物入侵的办法和措施。认为预防和控制植物入侵是草地保护的一项重要任务。     

Long-term management of Striga hermonthica: strategy evaluation with a spatio-temporal population model

The parasitic weed Striga hermonthica poses a serious threat to cereal production in sub-Saharan Africa. Striga hermonthica seedbanks are long-lived; therefore, long-term effects of control strategies on the seedbank only emerge after several years. We developed a spatially explicit, stochastic model to study the effectiveness of control strategies in preventing invasion of S. hermonthica into previously uninfested fields and in reducing established infestations. Spatial expansion of S. hermonthica and decrease in millet yield in a field was slower, on average, when stochasticity of attachment of seedlings to the host was included and compared to the deterministic model. The spatial patterns of emerged S. hermonthica plants 4–7 years after point inoculation (e.g. seeds in a dung patch) in the spatial-stochastic model resembled the distribution typically observed in farmers' fields. Sensitivity analysis showed that only three out of eight life cycle parameters were of minor importance for seedbank dynamics and millet yield. Weeding and intercropping millet with sesame or cowpea reduced the seedbank in the long term, but rotations of millet with trap crops did not. High seedbank replenishment during years of millet monoculture was not sufficiently offset by seedbank depletion in years of trap crop cultivation. Insight from simulations can be employed in a participatory learning context with farmers to have an impact on S. hermonthica control in practice.