A review of the biology and control of selected weed species in the genus Oxalis: O. stricta L., O. latifolia H.B.K. and O. pes-caprae L.

This review considers the distribution, weed problems, biology and control of Oxalis stricta, O. latifolia and O. pes-caprae. The rhizomatous O. stricta is a persistent seed-producing weed which invades horticultural crops in North America. Chemical control is generally most effective in situations where soil-applied residual herbicides can be used; in turfgrass however, foliage-applied herbicides provide suppression only. O. latifolia is widely distributed in a range of annual and perennial crops growing in temperate and tropical locations. This pernicious perennial weed reproduces exclusively by asexual structures, underground bulbs, stolons and tubers. The complexities of the perennating system have rendered ineffective a wide range of herbicide families as a means of restricting the spread of O. latifolia. Similarly, cultural methods of control have not been successful. O. pes-caprae also grows and perennates from bulbs. This weed is essentially a problem in cereal crops in Southern Australia and Mediterranean fruit orchards. Cultural and chemical control difficulties and inadequacies are similar to those in O. latifolia. Future research strategies involving weed physiology, herbicide action and cultural control including biological control are discussed in relation to obtaining improved control methods for the selected Oxalis species.     

唑嘧磺草胺WG对大豆田阔叶杂草的防除效果及安全性

为了解80%唑嘧磺草胺WG土壤处理对大豆田阔叶杂草的除草活性及对大豆的安全性,参照GB/T17980.40—2000进行田间除草活性试验。结果表明,80%唑嘧磺草胺WG对大豆田地锦、鳢肠防效最好,对铁苋菜、小藜防效稍差,施后18 d的总草株防效为79.84%～98.72%,施后35 d总草株防效为81.93%～99.66%,施后35 d鲜重防效达80.76～99.77%,大豆增产幅度为7.91%～15.47%。80%唑嘧磺草胺WG作为土壤处理,在大豆田最佳使用剂量为56.25～75g/hm2,用水量600L/hm2,对大豆安全。     

上海外高桥口岸从进境羊毛中截获的杂草种类

上海外高桥口岸是原毛进境的重要口岸,外高桥检验检疫局在进境羊毛检验检疫中发现进境羊毛携带有大量杂草籽。本文对外高桥局2011年1～9月份进境羊毛中截获的杂草进行了统计与分析,共截获杂草10112批次,73种;其中检疫性杂草4种,435批次。并针对外来入侵杂草管理提出对策和建议。     

Critical period for weed control in direct seeded red pepper (Capsicum annum L.)

Direct seeded red pepper is a cash crop in Kahramanmara? province of Turkey as well as some other nearby provinces. Weeds are a major constraint in red pepper production. Field studies were conducted to determine critical period for weed control (CPWC) in direct seeded spice pepper in Kahramanmara?, in 2008 and 2009. The CPWC in red pepper based on a 2.5%, 5% and 10% acceptable yield loss (AYL) was calculated by fitting logistic and Gompertz equations to relative yield data. The CPWC in red pepper was determined from 0 to 1087 growing degree days (GDD) in 2008 and from 109 to 796 GDD in 2009 for 10% AYL after crop emergence in red pepper. For 2.5–5% AYL, the CPWC starts with germination and lasts until harvest. Direct seeded red pepper is very vulnerable to weed competition and weed control programs for direct seeded spice pepper in Turkey should include pre‐emergence and residual herbicides.     

江浙地区草坪杂草调查研究进展

近20年来,以上海、南京等为代表的江浙地区城市对高羊茅、马尼拉、狗牙根等草坪的杂草分布情况进行了调查,发现杂草种类最高达34科、112种,禾本科和菊科种类最多,香附子、狗牙根、马唐、狗尾草、牛筋草、空心莲子草、天胡荽等杂草分布最普遍。不同养护水平、草坪类型、季节、建植年限等方面的草坪杂草分布存在较大差异,有关草坪草种和环境因素对杂草分布影响的研究还需要加强。     

石楠拟盘多毛孢致病毒素除草作用的初步研究

石楠拟盘多毛孢(Pestalotiopsis photiniae)是草莓根腐病的优势致病菌,主要通过毒素引发病害。为明确该病菌毒素对常见几种杂草的影响,本试验利用离体叶片和种子根芽伸长法研究了该病菌粗毒素对几种杂草的致病作用。结果表明:该粗毒素对供试的13种杂草叶片均有不同程度的致病作用,致病强度与杂草种类及粗毒素浓度有关,其中车前、马齿苋、马唐、反枝苋和灰菜5种杂草受害最重,经较低浓度(0.036mg/mL)毒素处理后1d即开始出现褐色斑点,第3天病斑面积达到最大(50%以上);该粗毒素(0.036mg/mL)对车前等5种杂草种子萌发、幼根和幼芽伸长也均有显著的抑制作用,且随毒素浓度升高抑制作用增强,抑制率均在53%以上,但对小麦和大豆种子萌发及根芽伸长均无明显的抑制作用;粗毒素经紫外线照射后,对车前和蒲公英的除草活性在自然光照下比黑暗下明显增强。这些结果揭示石楠拟盘多毛孢粗毒素有一定的除草潜力。     

常德地区茄果类蔬菜田间杂草种类、分布及危害

对常德地区茄果类蔬菜田间杂草种类、分布及危害特点进行研究,结果表明,该地区现有茄果类蔬菜田间杂草16科38种,以禾本科、菊科、石竹科、蓼科、玄参科、莎草科、十字花科等为优势科,其中优势种有菵草（Beckmannia syzigachne）、马唐（Digitaria sanguinalis）、莎草(Cyperus rotundus)、卷耳（Cerastium arvense）、马齿苋（Portulaca oleracea）、水花生（Alternanthera philoxeroidea）、铁苋菜（Acalypha australis）、通泉草（Mazus japonicusxo）、丁香蓼（Ludwigia prostrata）、早熟禾(Poa annaua)等。并对盖有地膜和未盖地膜的茄果类蔬菜田间杂草种类、分布及危害特点进行了综合分析,为常德地区茄果类蔬菜田间杂草的综合防除提供了重要资料。     

淮北地区外来杂草的研究

经野外调查和相关资料的整理分析,初步确定淮北地区已知的外来杂草有60种,隶属于23科。分析研究了外来杂草的危害现状,并提出了一些可行的防治建议。     

云南省农科院热带亚热带经济作物研究所胡椒园杂草种类调查研究

通过对云南省农科院热带亚热带经济作物研究所科技园内胡椒园杂草种类调查,结果表明,该胡椒园内杂草有14科42种,外来入侵杂草有8科17种。从胡椒园杂草的田间均度、田间密度、田间频率和相对多度分析结果得出:该胡椒园主要杂草为马齿苋(Portulaca oleracea L.)、酢浆草(Oxalis corniculata L.)、白茅[Imperata cylindrica var.jnajor(Nees)C.E.Hubb]、胜红蓟(Ageratum conyzoides L)和反枝苋(Amaranthus retroflexus L.),其相对多度分别为35.51%、32.42%、31.62%、30.47%和27.18%。本研究对明确云南省农科院热经所科技园内胡椒园杂草种类、危害程度具有重要意义,同时为整个云南怒江干热河谷区胡椒园杂草危害情况调查以及外来入侵杂草的后续监测提供基础数据。