15％硝磺草酮防除草坪（早熟禾）杂草效果及其安全性

为了明确15％硝磺草酮悬浮剂防除草坪（早熟禾）杂草效果及对早熟禾的安全性,进行茎叶喷雾处理法防除草坪（早熟禾）田间药效试验。结果表明,硝磺草酮对反枝苋除草活性最高,其次为牛筋草和马唐,对马齿苋活性相对较低,总体防效好;不同草龄的杂草对药剂敏感程度有较大差异,草龄较小者则防效好。在供试剂量范围内对草坪作物早熟禾安全。     

河北省玉米田杂草组成及群落特征

采用倒置“W”取样法对河北省玉米田杂草进行了调查,以明确田间杂草的种类组成及群落结构.结果表明,河北省玉米田杂草有136种（含变种）,隶属于34科、97属,其中优势杂草有马唐、反枝苋、稗、马齿苋、藜、狗尾草、铁苋菜、刺儿菜、田旋花等9种,区域性优势杂草有10种,常见杂草有21种,一般杂草有96种.发生优势度较大的杂草为马唐、反枝苋、稗、马齿苋、藜、狗尾草等,是构成各地区田间杂草群落的优势种.张家口地区主要形成反枝苋＋狗尾草＋灰绿藜＋藜为主的杂草群落,承德地区为马唐＋稗＋反枝苋＋藜,唐山-秦皇岛地区为马唐＋马齿苋＋鸭跖草＋稗＋反枝苋,石家庄地区为马唐＋牛筋草＋铁苋菜＋马齿苋.张家口和承德地区玉米田杂草群落的物种丰富度、多样性及均匀度较其它地区高,而优势度较低.从群落相似性来看,石家庄与唐山-秦皇岛地区群落结构最为相似.地理环境、气候条件及控草措施的不同,可能是导致玉米田杂草发生及群落组成产生差异的原因.     

硝草酮在玉米田的除草效果及安全性研究

2005年在北京市小汤山进行了田间试验,对硝草酮做茎叶处理的除草效果及对玉米的安全性进行了研究。结果表明:供试试验田反枝苋、苍耳、苘麻、苦蘵、龙葵、稗草、马唐对硝草酮敏感。铁苋菜、马齿苋对该药中度敏感。牛筋草、狗尾草、葎草、野西瓜苗、扁蓄、打碗花、刺儿菜、半夏对该药不敏感。该药对阔叶杂草防效好于对禾本科杂草的效果。供试剂量范围内,随施药量增加对敏感杂草防效提高。杂草3～4叶期施用10%硝草酮水悬浮剂70g/667m2的处理对稗草和马唐鲜重防效接近90%,对反枝苋、苍耳、苘麻鲜重防效在90%以上;100g/667m2及140g/667m2的处理对稗草和马唐鲜重防效为90%～95%,对反枝苋、苍耳、苘麻鲜重防效在95%～100%。杂草叶龄越小,硝草酮对其防效越高。禾本科杂草3～4叶期前用药防效理想,阔叶杂草反枝苋、苘麻等10叶期施药也能达到较好防效。10%硝草酮水悬浮剂施药剂量应为70～100g/667m2商品量。硝草酮100～140g/667m2的处理个别玉米植株叶片表现白化,叶片白化的植株占全小区植株数的3%～20%,但随作物生长药害症状消失。硝草酮水悬浮剂40～70g/667m2在玉米3～8叶期用药,对玉米中单44产量无影响。该剂量在玉米3～4叶期用药,对8个供试玉米品种生长及产量无影响。     

山东省泰安市甘薯田杂草调查

山东省泰安市甘薯田杂草隶属12科35种,以禾本科杂草与阔叶杂草混生为主,常见一年生禾本科杂草以牛筋草、马唐、狗尾草为主,阔叶杂草以反枝苋、马齿苋、铁苋菜、饭包草为主,莎草科杂草以碎米莎草、异型莎草及香附子为主。甘薯扦插后生长前期主要以阔叶杂草反枝苋、藜、马齿苋、苘麻、碎米莎草占优势,甘薯生长后期(6～7月),以一年生禾本科杂草牛筋草、马唐、稗草及狗尾草为主。甘薯田杂草的防除重点是扦插后至封垄前,此阶段及时有效的除草对甘薯的优质高产至关重要。     

四川省玉米田杂草化学防除技术研究

翻耕地玉米进行土壤封闭处理,33%二甲戊灵EC、999 g/L乙草胺EC对马唐等禾本科杂草防效优良。38%莠去津SC对马唐防效差,对其他杂草防效优良。40%甲草.莠SC对禾本科杂草和阔叶杂草防效优良;苗期除草,80%烟嘧磺隆WP对铁苋菜防效差,对其他杂草防效优良。38%莠去津SC对除马唐以外的禾本科杂草和阔叶杂草防效优良。25%烟嘧磺隆.莠去津SC对禾本科杂草和阔叶杂草防效优良。42.5%氯氟比氧乙酸.2甲4氯EC对辣子草、凹头苋、荠菜防效优良。玉米植株较大(7叶期以上)时,用灭生性除草剂41%草甘膦AS具有传导作用,持效性好。20%百草枯AS除草具触杀性,速效性好。     

51%烟嘧·莠去津WP防除玉米田杂草的效果和安全性研究

51%烟嘧.莠去津作为玉米田苗期茎叶处理剂,在玉米4~6叶期施用,用量为1 500~1 875 g/hm2,可以有效防除马唐、稗草、马齿苋、反枝苋等一年生禾本科杂草和阔叶杂草,同时兼除多年生杂草香附子,一次用药基本控制玉米全生育期草害,对玉米安全,除草增产效果显著。     

丙炔氟草胺除草活性及对棉花的安全性

丙炔氟草胺是一种以原卟啉原氧化酶为作用标靶的N-苯基肽酰亚胺类除草剂。为探究其在棉花田的应用前景,通过温室盆栽法对丙炔氟草胺的杀草谱、除草活性及其对棉花的安全性进行了测定。结果表明:丙炔氟草胺对棉田常见阔叶杂草有较好防效,处理剂量为有效成分15 g/hm2时,对马齿苋Portulaca oleracea、反枝苋Amaranthus retroflexus、藜Chenopodium album、小藜Chenopodium serotinum和鳢肠Eclipta prostrata的鲜重防效均高于90%,对野油菜Rorippa indica、苣荬菜Sonchus arvensis、小飞蓬Conyza canadensis、龙葵Solanum nigrum、马唐Digitaria sanguinalis和牛筋草Eleusine indica等的鲜重防效高于80%;丙炔氟草胺对棉田4种常见阔叶杂草马齿苋、反枝苋、龙葵和藜的除草活性均显著高于二甲戊灵;丙炔氟草胺在鲁棉研28号与马齿苋、反枝苋、龙葵和藜之间的选择性指数依次为79.1、38.1、32.1和112.6,均显著高于二甲戊灵的12.0、9.9、5.8和9.2;鲁棉研37号、鑫秋4号与杂草间的选择性指数,与鲁棉研28号的相近。试验结果表明,丙炔氟草胺可作为棉田苗前防除阔叶杂草的候选药剂之一。     

杂草种类、叶龄及药后降水时间对烟嘧磺隆药效的影响

温室盆栽条件下研究了反枝苋Amaranthus retroflexus、马唐Digitaria sanguinalis、稗草Echinochloa crus-galli、牛筋草Eleusine indica和苘麻Abutilon theophrasti 5种杂草对烟嘧磺隆的敏感性。结果表明:反枝苋和稗草对该药剂最敏感,而苘麻对烟嘧磺隆的耐药性最高。药液中添加2.5 mL/L的有机硅助剂Silwet L-77提高了对除马唐以外的所有草种的防除效果,表明在作用于马唐时Silwet L-77与烟嘧磺隆之间存在拮抗作用。杂草叶龄对烟嘧磺隆的药效有明显的影响,3~5叶期施药,防效高达89.9%以上,而7叶期的防效只有75%。药后1.5 h和3.0 h降水3 mm降低了烟嘧磺隆的防效,但药后6.0 h降雨对药效无显著影响。烟嘧磺隆与Silwet L-77混用,可提高药剂对反枝苋的抗雨水冲刷能力,但对马唐的效果没有提高。     

50%炔苯酰草胺WP防除移栽莴苣田杂草的效果及安全性

50%炔苯酰草胺WP 1 120~2 000 g/hm2对藜、反枝苋、稗、马唐等莴苣田主要一年生杂草具有好的防效,药后40 d鲜重防效达95%以上,对莴苣安全。     

550g／L硝磺·氰草津悬浮剂防除玉米田杂草的田间药效试验

采用田间小区试验方法,研究硝磺·氰草津对玉米田杂草的防除效果。结果表明,550g／L硝磺·氰草津悬浮剂825-1650ga．i．／hm^2能有效防除玉米田主要杂草,其中对玉米田中的反枝苋防效最理想,对牛筋草、铁苋菜防效较好,对马唐的防效稍差,且本试验剂量范围对玉米安全。     

Chemical control of Crotalaria goreensis and other weeds in Macroptilium atropurpureum

The effects of several selective herbicides, combinations of diuron with activated carbon, slashing and stale seed bed treatments were tested in five field experiments conducted at Walkamin, Queensland, Australia to determine the best methods of controlling weeds, particularly the legume Crotalaria goreensis Guill. & Perr., in crops of Macroptilium atropurpureum (DC.) Urb. cv. Siratro, grown for seed. Alachlor alone and combinations of trifluralin with either alachlor or propachlor were effective in preventing weeds causing a yield reduction in one experiment but not in a second. Trifluralin plus propachlor was more effective in controlling broad-leaved weeds while trifluralin plus alachlor was more effective in controlling grasses. Activated carbon effectively protected M. atropurpureum from diuron damage but the control of weeds, particularly grasses, was not effective. Stale seed bed treatments involving three sequential applications of diquat prior to planting the crop was the most effective method of controlling C. goreensis.     

Control of barnyardgrass and yellow foxtail by herbicides in relation to the sucrose content of the seedling leaves

The ability of triazine and urea herbicides to reduce the sucrose level of seedlings of barnyardgrass (Echinoehloa crusgalli (L.) (Beauv.) and yellow foxtail (Setaria Iutescens (L.) Beauv.) was compared with their effectiveness in controlling these weeds by pre-emergence application to maize. In 2 years out of 3 a significant positive correlation was obtained between the sucrose content of the third leaf and the number of these grasses on the field plots 2 months after planting. The regression of number of grasses on sucrose content for the combined treatments of 3 years was also significant indicating that, in general, control of grasses is improved as the inhibition of photosynthesis in the seedlings is increased.     

Effects of different cultivated or weed grasses, grown as pure stands or in combination with wheat, on take-all and its suppression in subsequent wheat crops

Grass species were grown in plots, as pure stands or mixed with wheat, after a sequence of wheat crops in which take-all ( Gaeumannomyces graminis var. tritici ) had developed. Annual brome grasses maintained take-all inoculum in the soil as well as wheat (grown as a continuous sequence), and much better than cultivated species with a perennial habit. Take-all developed more in wheat grown after Anisantha sterilis (barren brome) or Bromus secalinus (rye brome), with or without wheat, than in continuous grass-free wheat in the same year, where take-all decline was apparently occurring. It was equally or more severe, however, in wheat grown after Lolium perenne (rye-grass) or Festuca arundinacea (tall fescue), despite these species having left the least inoculum in the soil. It was most severe in plots where these two grasses had been grown as mixtures with wheat. It is postulated that the presence of these grasses inhibited the development of take-all-suppressive microbiota that had developed in the grass-free wheat crops. The effects of the grasses appeared to be temporary, as amounts of take-all in a second subsequent winter wheat test crop were similar after all treatments. These results have important implications for take-all risk in wheat and, perhaps, other cereal crops grown after grass weed-infested cereals or after set-aside or similar 1-year covers containing weeds or sown grasses, especially in combination with cereal volunteers. They also indicate that grasses might be used experimentally in wheat crop sequences for investigating the mechanisms of suppression of, and conduciveness to, take-all.     

云南省纳板河流域国家级自然保护区不同生境对外来入侵草本植物分布的影响

为探明外来入侵草本植物在不同生境中分布差异及关键影响因素,于2015年对云南省纳板河流域国家级自然保护区内天然林、天然林林缘、橡胶林、橡胶林林缘和农田5种生境共164个1 m2样方的外来入侵草本植物种类和数量进行调查,对比不同生境中外来入侵草本植物物种多样性的差异,运用主成分分析法分析5种生境中主要外来入侵草本植物群落组成及其与环境因子的关系。结果表明,5种生境中共发现外来入侵草本植物32种,其中橡胶林林缘和农田中外来入侵草本植物种类最多,达20余种,天然林中外来入侵草本植物最少,仅为6种。单因素方差分析结果表明,不同生境中外来入侵草本植物多样性指数差异显著。多重比较检验结果表明,天然林中外来入侵草本植物的物种丰富度指数、香农-威纳指数、辛普森指数和皮洛均匀度指数分别为0.50、0.15、0.09和0.16,均显著低于其它生境;橡胶林中外来入侵草本植物除均匀度指数外,其余多样性指数均显著高于天然林且显著低于其余3种生境;农田中外来入侵草本植物物种丰富度指数为5.50,显著高于其它生境。主成分分析结果表明,不同生境中外来入侵草本植物群落物种组成不同;本地乔灌木物种数量和海拔是影响外来入侵草本植物在不同生境分布的关键因子。     

行间种植不同草种对幼龄苹果园土壤特性的影响

于苹果园建植第一年春季,果树行间分别种植不同草种,以清耕的土壤为对照,研究果园土壤温度、含水量、pH值、有机质及N、P、K的变化。结果表明,种草后,夏季高温时土壤温度降低、日变幅减小,含水量增加,生长季结束时,果园土壤pH下降,碱解N、全N、速效P、全P、有机质含量增加,而除种植红三叶的土壤速效K显著(P<0.05)升高外,其余处理全K、速效K均无显著变化;种草后对不同深度土壤肥力的影响不同,马蹄金对土壤N、P和狗牙根与高羊茅对有机质的影响在0~20 cm内表现一致,而种植多年生黑麦草、狗牙根、紫羊茅的0~10 cm土壤碱解N、全N、全P和种植红三叶、紫羊茅的0~10 cm土壤有机质升高幅度较10~20 cm大,多年生黑麦草、高羊茅、紫羊茅、红三叶、白三叶的速效P,红三叶和高羊茅的碱解N、全N,马蹄金、多年生黑麦草、白三叶的土壤有机质0~10 cm土壤升高幅度较10~20 cm小,白三叶10~20 cm土壤碱解N增加幅度较0~10 cm小,全N则反之;草种不同对土壤作用不一,马蹄金对土壤肥力改善作用最大,红三叶、白三叶次之,而狗牙根、高羊茅较差。说明种草后可改善土壤性状,而草种是影响果园种草效益的关键因素。     

高粱田除草剂种类及施药方法筛选试验初报

为了筛选高效的高粱除草剂和适合的施药方式, 我们进行了高粱田间杂草化学防除药剂及施药方法筛选试验, 通过除草效果、产量和收益分析, 初步认为:施药方法上土壤封闭明显优于茎叶处理。土壤封闭剂中, 42%丁·异·莠去津SC、42%异丙草·莠SC除草剂对阔叶杂草和禾本科杂草防除作用优良, 鲜重防效均超过90%, 高粱产量虽低于人工除草, 但差异不显著, 减产幅度在1%以下; 使用这类药剂高粱生产的利润高于人工除草。茎叶处理剂中, 25%辛酰溴苯腈EC等除草剂对高粱生长影响较小, 对藜、反枝苋等阔叶杂草防效高, 高粱产量低于人工除草, 但高粱生产的利润高于人工除草。建议在高粱生产中使用这些除草剂。     

CONTROLLED INTERFERENCE WITH NATURAL POPULATIONS OF PLANTAGO LANCEOLATA, P. MAJOR AND P. MEDIA

Summary. An experiment was made to determine the effect of the removal of grasses on the behaviour of populations of Plantago lanceolata , P. media and P. major in three grassland habitats. Treatments included the addition of seed of all three species to the existing vegetation. The grasses were removed by treatment with 2,2-dichloropropionic acid (dalapon), a herbicide selective against the Gramineae. The chemical appears to be slightly toxic to the Plantago species at the dose used (12 Ib/ac a.e.). The removal of the grasses was followed by a marked increase in the plantain populations shown both in counts of the numbers of plants and seedlings and in increased seed output per unit area. Deliberate sowing of seed into the habitats in autumn resulted in increased numbers of seedlings in the following spring, particularly in those plots where the grasses had been removed. Species of Plantago not occurring naturally in the communities were frequently established by sowing seed, if the grasses had been removed, but not otherwise. The overall results of the experiment suggest that in two of the communities the grasses played an important role in determining the presence or absence of particular Plantagn species and also in controlling the size of the existing plantain populations. The experiment is discussed in the wider context of population control in plants.
Tentative de modification de populations naturelles de Plantago lanceolata, P. major et P. media.     

Effects of winter barley as a cover crop on the weed vegetation in a no-tillage soybean

The present study clarified the effects of winter barley as a cover crop on the weed vegetation, expressed as a multiplied dominance ratio (MDR), and emergence of summer annual weeds in a no-tillage soybean system. A 3 year field study with treatments consisting of six systems was conducted: no-tillage single cropping, no-tillage cropping following winter barley and tillage single cropping, respectively with and without herbicide application. The MDR of perennial weeds increased annually in the no-tillage fields in spring, but summer annual weeds were abundant in all fields, including the no-tillage fields in summer. Grasses, for example Digitaria ciliaris (Retz.) Koeler, were especially abundant in the no-tillage fields. The MDR of summer annual weeds, especially grasses in the barley and soybean fields, were much lower than for the no-tillage single soybean fields. Densities of D. ciliaris and Echinochloa crus-galli (L.) Beauv. var. crus-galli in the no-tillage single soybean fields were much greater than in the tilled fields, with few exceptions. In contrast, broad-leaved weeds emerged more in tilled fields than in the no-tillage fields. Winter barley suppressed emergence of summer annual weeds, especially during the first 3 years. The MDR for grasses in summer showed a good correlation with the frequency of emergence for grasses every year. These results showed that the increase in the volume of grasses in summer resulted mainly from an increase in the frequency of emergence, and that the suppression of grasses by winter barley resulted mainly from suppression of the emergence frequency. Soybean yields were higher in the barley and soybean fields for the first 2 years.     

Transmission of barley yellow dwarf virus by cereal aphids collected from different habitats on cereal farms

Cereal aphids were collected from cereal crops, from Poa annua within cereal fields, from Lolium perenne pastures and from wild grasses in hedge bottoms and around farm buildings. The frequency of barley yellow dwarf virus (BYDV) transmission was assessed by aphid transmission tests. There were differences in transmission rates between aphid species, between host species and between years. The transmission rates of Rhopalosiphum padi from the different host species were broadly similar whereas for Sitobion avenae, P. annua within cereal fields was significantly better than the other host species. Wild grasses other than P. annua were relatively poor sources of virus. A large percentage of aphids frequently transmitted more than one strain, suggesting that host plants are often infected with more than one BYDV strain.     

翦股颖上腥黑粉菌近似种多重分子检测

匍匐翦股颖(Agrostis stolonifera)和细弱翦股颖(A. tenuis)是优良的牧草和草坪草。寄生于翦股颖上的腥黑粉菌共有3种,即小麦网腥黑穗菌(Tilletia caries,TCT)、翦股颖腥黑穗菌(T. sphaerococca)和苍白腥黑粉菌（T. pallida）。在形态、自发荧光和萌发生理3方面比较研究的基础上,选取冬孢子形态非常相似的2种腥黑粉菌TCT和T. sphaerococca为研究对象,依据序列特点设计4套引物,成功建立了TCT和T. sphaerococca菌丝基因组DNA的特异双重PCR检测方法和冬孢子的特异套式双重PCR检测方法。