莜麦田间杂草调查及化学除草试验

通过几年的调研、试验,认为山西省五寨地区莜麦田间杂草主要有狗尾草、稗草、碱草、茅草、禾草、芒草、雀麦草等一年生禾本科杂草,灰菜、苋菜、胡舌芽等一年生黎科杂草,还有菊科杂草甜苣、苦苣和苍耳、田旋花、酸地柳等,这些杂草对莜麦的生长发育或产量形成影响甚大,使用传统的锄头灭草,增产的效果最好,使用2,4-D丁酯实施化学除草也有较好的效果。     

冀东滨海稻区化学除草技术

根据推广实践,总结了冀东滨海稻区稻田化学除草的技术方法,如主要用五氟磺草胺和氰氟草酯除治水稻秧田杂草;主要用丁草胺加苄嘧磺隆或吡嘧磺隆、丁草胺加西草净除治本田杂草;单用三苯基乙酸锡或西草净除治水绵;用灭生性除草剂草甘膦和百草枯于水稻插秧前除治田埂杂草,用选择性除草剂二氯喹啉酸、灭草松.二甲四氯于水稻插秧后除治田埂杂草等。     

磺酰脲类除草剂对抗性油菜田间杂草的防除效果及安全性评价

草害是影响油菜产量和品质的重要因素之一，种植抗除草剂品种，配合化学除草是解决油菜田杂草防治最经济有效的方法。为筛选适合抗除草剂油菜新品种搭配使用的除草剂，本研究以非转基因抗磺酰脲类除草剂油菜新种质M342为材料，比较了苯磺隆等11种磺酰脲类除草剂的防除效果和安全性。结果显示，11种磺酰脲类除草剂对油菜田杂草的鲜重防效均在70%以上，均能显著降低杂草对氮、磷、钾和水分的消耗。啶嘧磺隆对M342有严重药害，喷施后植株腐烂并逐渐坏死。苄嘧磺隆和氟唑磺隆也对M342的产量有显著影响，分别比人工除草对照减产6.22%和16.59%。其余8种磺酰脲类除草剂对M342的产量均无显著影响，可应用于抗磺酰脲类除草剂油菜新品种田间杂草的防除。     

如何避免水稻苗床除草剂药害

分析了水稻大、中棚旱育秧苗床药害逐年突出的原因,提出了为避免除草剂药害应注意的若干事项,即不要在施用过咪唑乙烟酸、氯嘧磺隆、异噁草松或莠去津等长残效除草剂的地块取表土育苗;不要施用乙草胺(或含有乙草胺的药剂),某些情况下也不宜施用丁.扑或丁草胺进行苗床封闭除草;水稻幼苗期不要施用二甲四氯、2.4-D丁酯,或过早、过量施用二氯喹啉酸;应推广使用千金、敌稗或灭草松等茎叶喷雾防除苗床杂草。     

豫西油葵田除草剂应用技术研究

[目的]筛选针对油葵田不同处理时期且对油葵安全、高效的除草剂。[方法]分别选择播后苗前和茎叶时期2个阶段进行,选择不同除草剂进行比较试验。[结果]播后苗前处理在茎叶处理除草剂中33%二甲戊乐灵除草效果较好,最后鲜重总防效达94.88%,且对油葵安全;苗后茎叶处理除草剂中10.8%精喹禾灵、8.8%精克草能除草剂仅对油葵田禾本科杂草有较好的防效,除草效果达100%,且持效性较好,但对阔叶杂草基本无除草效果。[结论]播后苗前可运用33%二甲戊乐灵进行除草,苗后茎叶处理可选用10.8%精喹禾灵、8.8%精克草能进行杂草防除     

新型麦田除草剂的筛选及残留对后茬作物药害分析

大田药效试验表明,扑草净与燕麦枯混用对麦田阔叶杂草和野燕麦防效显著;阔叶净(巨星)、甲磺隆、2,4-D丁酯与扑草净混用对阔叶杂草防效也较好.室内盆栽玉米、大豆进行残留分析表明,甲磺隆对后茬作物玉米、大豆有明显抑制作用.     

几种除草剂在豆科作物田除草效果及安全性测定

为探讨几种化学除草剂对大豆田主要杂草的除草效果及对其他豆科作物安全性,选用除草剂异恶草酮、咪草烟、恶草酮和氯嘧磺隆在4种豆科作物间作田进行播后苗前土壤处理.结果表明:4种除草剂的总杂草株防效和鲜重防效分别为84.2%和84.4%以上,均与对照达到极显著水平,除草效果优良.4种除草剂对藜、马齿苋、反枝苋的株防效最高可达到100%.异恶草酮对反枝苋株防效为45.2%.氯嘧磺隆对稗草的株防效仅为11.7%,但对多年生问剂防效达89.8%,其他3种除草剂对稗草防效均较高,对问剂防效较低.从对豆科作物安全性看,4种除草剂都可以用于大豆田除草,与实际应用情况相符;异恶草酮禁用于绿豆、黄芪和黑豆;恶草酮禁用于黄芪和黑豆;氯嘧磺隆禁用于黄芪;只有咪草烟对4种豆科作物安全.     

安徽沿江棉区除草剂使用中的问题及对策

安徽沿江棉区以种植棉花、油菜、小麦为主，一般为两熟制。在当地广泛使用的除草剂类型主要有：（1）灭生性除草剂有10％草甘膦、62％草甘膦、40％草甘膦、百草枯等；（2）阔叶除草剂有苯磺隆、乙羧氟草醚、二甲四氯等；（3）禾本科除草剂有高效盖草能、精奎禾灵；（4）芽前除草剂有乙草胺、金都尔、床草净、野老等。灭生性除草因省工省时、除草效果好，备受农户青睐，在棉花生产中至少使用2次，即移栽棉花前使用一次，封行前再使用一次。     

连作大豆田苗前防除恶性杂草除草剂筛选

针对北方连作大豆田恶性杂草难防治这一生产实际问题,采用田间试验选择了5种除草剂进行复配组合筛选,试验结果显示,3个供试组合对大豆基本安全,对大豆田稗草、苍耳、问荆、鸭趾草和藜均有很好的防效,15 d株防效在70.2%~81.7%,30 d株防效在69.5%~78.7%,30 d鲜重防效在60.6%~71.3%,也有一定的增产效果,增产幅度为7.%~11.2%。总体看对恶性杂草防效、增产效果及投入产出比,效果顺序为处理1(48%异噁草松+96%金都尔80+80%阔草清)处理2(48%异噁草松+72%异丙草胺+80%阔草清)处理3(48%异噁草松+90%乙草胺140+80%阔草清)处理4当地农民常用的三元复配制剂(75%噻吩磺隆4.4+72%2,4-D丁酯44+99%乙草胺249),即供试的3个组合总体上要好于对照组合。     

菜王星防除油菜田杂草的效果

菜王星防除油菜田杂草的效果丁新天（浙江省缙云县病虫观测站）菜王星，又名菜无草、菜丰、金星；化学名称胺苯磺隆，是一种超高效油菜田除草剂。该除草剂药效期长，对单、双子叶杂草均有较高的防效。１９９３年冬季在本县的城东、东川、东方、壶镇，武义县的桐琴、上菱道...     

Comparison of various weed control programs for potatoes

All weed control programs resulted in satisfactory weed control. Costs of controlling weeds ranged from $10 to $93/ha. Cultivation alone was the cheapest method of controlling weeds. Controlling weeds by using herbicides alone with no cultivation resulted in the highest weed control costs but tended to give the best weed control at harvest. Herbicides saved one to two cultivations. EPTC (S-ethyl dipropylthiocarbamate) gave slightly better control of green foxtail [Setaria viridis (L.) Beauv.] and slightly poorer control of broadleaf weeds than trifluralin (α,α,α,-trifluoro-2,6-dinitro-N, N-dipropyl-p-toluidine). Cultivation helped control weeds but had no other apparent beneficial or adverse effect on potatoes. The correlation coefficient between total tuber yield and dry weight of weeds was ?0.97 at Grand Forks, North Dakota and ?0.85 at Casselton, North Dakota.     

茶园常用除草剂田间药效试验与残留动态

对比评价了草甘膦、草铵膦、复配剂型草甘膦-乙草胺及草甘膦-助剂对茶园主要恶性杂草的防治效果,并对试验小区土壤中各除草剂的残留水平进行了评估。试验结果表明,与草甘膦相比,草铵膦起效快,在施药第7天杂草覆盖度降低到9.15%,施药14βd后对野老鹳、续断菊、小飞蓬等杂草的防治效果在95%以上,草胺磷在茶园土壤中降解较快,30βd的消解率达到94%,残留水平较低（第58天残留量为0.01βmg·kg^-1）,可能是替代草甘膦除草剂的较优选择;乙草胺作为封闭型除草剂,能够抑制禾本科杂草出苗,且在土壤中消散较快（21βd后的消解率为97%）,可用于防治禾本科等杂草。     

不同水稻品种抑制杂草的差异性研究

 选择江苏主栽水稻品种5个,以及具有化感特性的PI312777和华抗草78为试验材料,通过田间小区试验对比各水稻品种与稗草、莎草科杂草和阔叶杂草的生态竞争关系。结果表明,扬稻6号和PI312777对杂草发生株数的抑制率达70%~80%,扬稻6号、徐稻4号和PI312777对杂草干质量抑制率超过80%,具有良好的抑制杂草萌发、生长和干物质积累的作用。 同时,供试水稻品种对稗草地下部的抑制效果显著优于对稗草地上部的抑制效果,对稗草整株干质量的抑制率与对稗草地上部干质量抑制率呈相同趋势。     

Effects of mechanical and chemical methods on weed control,weed seed rain and crop yield in maize,sunflower and soyabean

Eight field experiments with maize (Zea mays L.), sunflower (Helianthus annuus L.) and soyabean (Glycine max (L.) Merr.) were carried out in central Italy in order to evaluate the effects of mechanical and chemical methods (spring-tine harrowing, hoeing, hoeing-ridging, split-hoeing, finger-weeding, herbicides in the row + inter-row hoeing, herbicides broadcast) on weed control, weed seed rain and crop yield. The choice of chemical and mechanical treatments in maize and soyabean compared to sunflower, required to be managed more carefully in order to maximize the weed control reducing yield losses. A global rating of weed control methods, based on their weed control efficacy, was obtained as useful means to assist farmers and technicians to choose the more appropriate weed control method. The combination of herbicides intra-row and hoeing inter-row gave best efficacy (on average 99% of weed control), with a 50% reduction in the chemical load in the environment. Hoeing-ridging gave good results, both inter- and intra-row (on average 93% of weed control); this method was also effective in reducing competitive ability and seed production of uncontrolled weeds. Split-hoeing or finger-weeding showed some limitations giving satisfactory results only when combined. Harrowing gave lowest weed control, although when combined to other mechanical methods, can help achieve a better efficacy.     

Chemical weed control in direct-seeded irrigated rice in the Lake Chad Basin,Nigeria

Two field experiments were conducted at Ngala in the Lake Chad Basin during the 1981 and 1982 wet seasons to investigate chemical weed control in direct-seeded, irrigated rice (Oryza sativa L.). Pre-plant-incorporated, pre- and post-emergence herbicides and their mixtures were tested in replicated, completely randomized block trials. Rice variety IR 28 was drilled each season at 125 kg/ha and fertilized with N (150 kg/ha) and P₂O₅ (40 kg/ha). In both seasons, the post-emergence herbicides propanil + oxadiazon at 3·0 + 1·0 kg a.i./ha, propanil+fluorodifen at 1·4 + 1·8 kg a.i./ha, propanil + bentazone at 3·6 + 1·5 kg a.i./ha and propanil at 3·6 kg a.i./ha as well as thiobencarb applied pre-emergence at 5·0 kg a.i./ha controlled the weeds effectively and gave similar grain yields to that from hand-weeding twice, and significantly higher grain yield than the unweeded control treatments. Grain yields similar to those from the ‘two hand-weeding control’ were achieved also by use of the herbicide dymrone at 3·0 kg a.i./ha, either soil-incorporated pre-sowing or sprayed before weed emergence. The herbicides gave satisfactory control of the weeds, which were predominantly the broad-leaved weed Luffa echinata Roxb., together with the grasses Sorghum aethiopicum (Hack.) Rupr. ex Stapf., Echinochloa colona (L.) Link, Eleusine indica (L) Gaertn, Digitaria sanguinalis (L.) Scop., Oryza longistaminata (Chev. & Roehr.), and sedges Cyperus rotundus L. and Cyperus esculentus L. The studies indicate that effective weed control by these herbicides and herbicide mixtures are dependable alternatives to hand weeding for direct-seeded, irrigated rice cultivation in the Chad Basin area.     

Weed emergence as affected by maize (Zea mays L.)-cover crop rotations in contrasting arable soils of Zimbabwe under conservation agriculture

Weed control in smallholder farming systems of sub-Saharan Africa is labour intensive or costly. Many researchers have therefore advocated for the use of cover crops in weed management as an affordable alternative for smallholders. Cover crops may be grown in rotations to suppress weeds and reduce the reliance on herbicides. The use of cover crops creates microenvironments that are either conducive or inhibitive to the emergence of certain weed species. A study, initiated in 2008 in contrasting soils at four different locations of Zimbabwe, investigated the effect of maize (Zea mays L.)-cover crop rotations on the emergence of weeds that showed dominance in those soils. Weed assessments were however, carried out from 2011 to 2014. The weed species Galinsoga parviflora Cav., Commelina benghalensis L., and Richardia scabra L. showed dominance in all four locations with weed densities as high as 500 plants m⁻² being recorded for R. scabra L. in a sandy soil. Maize-cover crop rotations resulted in higher densities of Bidens pilosa compared with maize monocropping (control treatment) due to its high nitrogen (N) requirement to produce more seeds. On the other hand, the integration of cover crops such as pigeon pea [Cajanus cajan (L.) Millsp.] that had poor shading qualities, due to large gaps or spaces and slower initial growth, had limited effects on competitive weeds such as Cyperus esculentus L. which tend to dominate exhausted soils. The density of C. esculentus was 38% greater in maize–pigeon pea rotations compared with the control treatment. Variability between seasons and sites affected emergence of all weeds in the present study, which masked long-term trends. The results suggest that there is need to identify the germination and emergence requirements of specific weeds and select cover crops best suitable for their control. The study provides useful information for farmers and advisors on the best cover crops for control of certain problematic weeds in different soil types of Zimbabwe.     

Control of grassy weeds in annual canarygrass

There are currently no herbicides registered in Argentina for the selective control of grassy weeds in annual canarygrass (Phalaris canariensis L.). The principal grassy weeds are darnel ryegrass (Lolium temulentum L.) and wild oats (Avena fatua L.), which cause grain yield and quality losses. The potential of diclofop-methyl and clordinafop-propargyl for their control was assessed through greenhouse and field trials, in which crop phytotoxicity and weed control efficacy were evaluated. It was found that (i) field application of clordinafop-propargyl resulted in severe crop damage, except for low doses that did not affect the species to be controlled; (ii) although field application of diclofop-methyl resulted in a certain degree of phytotoxicity on wild oats, these effects were insufficient for efficacious control; and (iii) field and greenhouse application of diclofop-methyl between 200 and 500 g a.i. ha⁻¹ revealed differences between crop sensitivity and that of darnel ryegrass. In this range, crop phytotoxicity in the greenhouse was less than 20% compared to more than 60% in the weed, and in the field only slight crop phytotoxicity symptoms were observed. As in the greenhouse, field application resulted in significant phytotoxic effects upon darnel ryegrass, high efficacy levels, a low survival rate amongst treated plants and a notable reduction in seed production by surviving plants. Only the highest dose (500 g a.i. ha⁻¹) in one of the field trials resulted in a significant reduction in crop grain yield. Hence diclofop-methyl application appears to offer a promising means for controlling darnel ryegrass.     

12种除草剂对冬小麦田阔叶杂草的防除效果

为了筛选出对麦田阔叶杂草防效较高的药剂,选择12种目前生产中常用的除草剂进行大田试验。结果表明,施药后15d,对播娘蒿、荠菜、猪殃殃三种杂草总体株数防效最好的是对杂草致死速度快的唑草酮,40%唑草酮水分散粒剂30g(a.i.)·hm-2(指每公顷有效成分用量为30g,其余类推)处理的株数防效达91.78%;施药后30d对三种杂草总体株数防效最好的是55%苯·唑·2甲钠可湿性粉剂412.5g(a.i.)·hm-2处理,株数防效为96.53%,鲜重防效为98.79%;总体株数防效和鲜重防效仅次于55%苯·唑·2甲钠可湿性粉剂处理的分别是58g·L-1双氟·唑嘧胺悬浮剂11.8g(a.i.)·hm-2处理(株数防效为93.59%)、37%炔·苄·唑草酮可湿性粉剂222g(a.i.)·hm-2处理(鲜重防效为98.76%);总体鲜重防效最低的是30%二氯吡啶酸水剂202.5g(a.i.)·hm-2处理(鲜重防效仅为35.29%)。三种杂草对同种药剂的敏感性存在差异。12种除草剂对小麦的安全性有一定差异,唑草酮及其混剂处理后小麦产生的触杀型药害斑及啶磺草胺处理的小麦叶片黄化均可恢复,对小麦的产量无不良影响,其他处理均对小麦安全。     

Weed control efficacy and winter wheat safety of a novel herbicide HW02

HW02, a pyruvate dehydrogenase inhibitor, is a newly developed herbicide for broadleaf weed control in wheat, maize and turf in China. Greenhouse and field experiments were conducted to evaluate its efficacy against weeds and safety to winter wheat. In the greenhouse experiment, this herbicide had higher activities than 2,4-D against Descurainia sophia (L.) Schur., Amaranthus retroflexus L., Capsella bursa-pastoris (L.) Medic., and Malachium aquaticum (L.) Fries.. When it was applied at late tillering stage of winter wheat in spring, the herbicide provided weed biomass reduction of 98%–100% at the rates 225–525 g a.i. ha⁻¹ and was safe to the crop at the rate of up to 900 g a.i. ha⁻¹. These results showed HW02 could be an alternative herbicide for resistant weed management because its mode of action is different from herbicides presently used.     

瑞泽金水灵防治稻田杂草试验研究

瑞泽金水灵55%干悬浮剂80g/667m2(毒砂、肥)均匀撒施于插秧缓苗后,稗草2叶期前施药,可有效地防除稻田中的稗草、扁秆藨草、慈菇、雨久花、鸭舌草、异型莎草、碎米莎草等禾本科、阔叶及种子繁殖的莎草科杂草。防效达90%左右,是目前较理想的水稻田一次性除草剂。