陕西烟田杂草初步调查

在室内查阅标本和文献资料的基础上,结合野外实地调查,对陕西烟田主产区的汉中、安康、商洛、宝鸡、咸阳和延安等的杂草进行了全面调查。结果表明:陕西烟田共有杂草35科72属88种,其中恶性杂草13种,次恶性杂草14种,一般杂草59种,偶见杂草2种。     

瓜列当对新疆甜瓜的危害及化学防治初探

调查瓜列当对新疆甜瓜的危害,探索瓜列当化学防控方法,为瓜列当防治措施制定及实施提供技术支撑。以新疆伽师县4个甜瓜主产乡镇为代表,调查瓜列当对甜瓜的危害程度及规律。结合新疆甜瓜栽培模式,进行2种除草剂各2种浓度对瓜列当的防治试验。调查的4个乡镇瓜列当都有不同程度的发生。甜瓜播种后50 d直到收获,都有瓜列当寄生危害。75%磺酰磺隆和甲基咪草烟都可用于对甜瓜列当的防治,磺酰磺隆效果优于甲基咪草烟。结合浇水冲施37.5 g a.i.·hm-275%磺酰磺隆,是最有效的新疆甜瓜瓜列当化学防治的施用方式和浓度。     

三种土壤封闭式除草剂在欧李园应用效果研究

以2a生欧李为试材,利用吉林省常用的土壤封闭式化学除草剂48％阿特拉津胶悬剂、43％甲草胺乳油、50％乙草胺乳油进行杂草防除试验.结果表明:地面喷施43％甲草胺乳油250 mL/667m2不仅对杂草的防除效果好,且对欧李园安全无害.地面喷施48％阿特拉津胶悬剂200 mL/667m2和50％乙草胺乳油150 mL/667m2也具有良好的杂草防除效果,但对欧李植株都存在着不同程度的药害,在欧李生产中不宜使用.     

Impact of Soil Tillage and Crop Rotation on Barley (Hordeum vulgare) and Weeds in a Semi-arid Environment

Experiments were conducted to evaluate the effect of mouldboard‐ or chisel‐ploughing and rotations on barley crops and associated weeds in a semi‐arid location. Two primary soil tillage operations and eight crop rotation‐tillage operation combinations were evaluated over two successive seasons. Drought conditions prevailed (<152 mm annual precipitation) and affected the measured parameters. Barley grown in mouldboard‐ploughed plots had higher biomass compared with chisel‐ploughed plots. Barley grain yield was greater in mouldboard‐ploughed plots in a fallow‐fallow‐barley rotation. Weed species densities varied between tillage systems and rotations. Density of Hordeum marinum, for example, was high in fallow‐barley‐fallow in chisel‐ploughed plots, and was high under more continuous fallow in mouldboard‐ploughed plots. Similar variations were also observed in weed fresh weights and in numbers of seed produced. The results describe the productivity of barley under extremely dry conditions, where an advantage for mouldboard ploughing was observed. The results also indicate the complexity of weed communities in their response towards different tillage‐rotation combinations.     

The use of manatees for the control of aquatic weeds in Guyana

The West Indian Manatee (Trichechus manatus) has been widely suggested as a means of biological control of aquatic weeds. Despite significant research little data is available from existing manatee installations.Manatees have been used in Guyana for weed control for over a century and are still being used today. Data was collected from a number of sites, both past and present, to establish the reliability of the manatee as a weed control agent and to formulate a series of guidelines on which to base future manatee developments.     

Weed problems and their management in rice fields of Malaysia: An overview

The available literature on weed problems and weed control in rice fields in Malaysia is reviewed and suggestions for future research are included. The problem of weed competition with rice is of great economic importance in the country because it causes a 10–35% reduction in grain yield. About US$4.10 million is spent annually on herbicides for rice alone, and this amounts to approximately 7% of the total expenditure on herbicides. The shift in methods of rice culture from transplanting to direct seeding has magnified the weed problem. The problem of weedy rice is particularly acute in the direct-seeding rice areas. Although a number of sulfonylurea herbicides (e.g. cinosulfuron, metsulfuron, bensulfuron and pyrazosulfuron) have been found to be suitable alternatives to the old herbicide 2,4-D, an integrated weed management program must be developed in order to reduce the problem of herbicide resistance in weeds. Weed control methods that are more friendly to the environment and affordable to farmers must be sought. Weed-competitive and allelopathic rice varieties must be produced. The problem of weeds in rice calls for systematic studies on biotechnological methods of control of weedy rice. Detailed studies on the biology and ecology of notorious rice weeds, particularly Oryza sativa L. (weedy rice), Echinochloa spp., Leptochloa chinensis (L.) Nees, Fimbristylis miliacea (L.) Vahl. and Limnocharis flava (L.) Buch. need to be done in order to formulate successful weed control measures.     

Low Temperature–Short Duration Steaming of Soil Kills Soil-Borne Pathogens, Nematode Pests and Weeds

Agricultural soil samples containing survival structures of the fungal crop pathogens Verticillium dahliae, Sclerotinia sclerotiorum, Sclerotium cepivorum, Pythium ultimum, potato cyst nematodes Globodera rostochiensis and G. pallida and weeds Chenopodium album and Agropyron repens [Elymus repens] were treated in the laboratory with aerated steam at temperatures ranging from 40 to 80°C in a specially constructed apparatus. Steaming at 50 or 60°C for 3min, followed by an 8-min resting period in the steamed soil and immediate removal from the soil thereafter, resulted in 100% kill of all weeds, diseases and nematodes. When steamed at 45°C, there was a small but significant reduction in the survival of V. dahliae microsclerotia but no reduction in survival of S. cepivorum.     

Integrated Pest management in Forage Alfalfa

Alfalfa, Medicago sativa L., is among the most prized of forages, and is grown worldwide as a feed for all classes of livestock. It is one of man's oldest crops, and its cultivation probably predates recorded history. In addition to its versatility as a feed, alfalfa is well known for its ability to improve soil structure and, as a legume, is an effective source of biological nitrogen. As a perennial crop, alfalfa has a lifespan approaching 5 years, but in some areas of the world fields may remain productive for considerably longer. Such a long stand life affords ample time for the establishment and development of a diverse community structure by an abundance of organisms. In spite of system perturbations caused by frequent harvests and occasional pesticide applications, an alfalfa field provides a temporal stability which is uncommon among field crops. As a result of this stability, alfalfa supports an immense diversity of flora and fauna which, at times, exceeds that of riparian ecosystems. While most of alfalfa's inhabitants have little or no impact on it as a crop, a few are capable of causing extensive damage. Arthropods, plant pathogens, weeds, vertebrates, and plant parasitic nematodes can all cause significant yield and/or quality reductions and frequently contribute to shortening the productive life of the stand. This paper reviews the major strategies which have been developed to manage many of these alfalfa pests including: host plant resistance; cultural controls, such as harvest strategies, irrigation management, sanitation, planting schedules, and crop rotation; mechanical and physical controls; chemical control; and biological controls. Multiple pest interactions, e.g. insect-insect; insect-disease; insect-weed, and their management are discussed. Potential conflicts arising from the use of strategies which may reduce one pest but exacerbate others are also examined. A cross index of management strategies and their role in managing multiple pests is provided. Computer models, both ecological and economic, and their role in alfalfa pest management are discussed. Selected information sources on alfalfa and alfalfa IPM available over the Internet are listed. Alfalfa's role in the agricultural landscape, as it relates to pests, natural enemies, and pest management in other cropping systems as well as its role in crop rotation, is considered.     

湘西南地区马蹄金草坪中春季杂草的化学防除试验

湘西南地区马蹄金Dichondra repens草坪化学防除春季杂草表明:0.05 g/m2 2甲4氯钠 0.045mL/m2高效盖草能能有效防除半边莲Lobelia chinensis,0.15 mL/m2猪秧净能有效防除空心莲子草Alter-nanthera philoxeroides、天胡荽Hydrocotyle sibthorpioides、香附子Cyperus rotundus、佛甲草Sedum lineare等.0.05 g/m22甲4氯钠 0.045 mL/m2高效盖草能 0.15 mL/m2猪秧净能有效防除空心莲子草、天胡荽、香附子、佛甲草、野艾蒿Artemisia lavandulaefolia、直立婆婆纳Veronica arvensis、半边莲、车前草Plan-tago asiatica,0.05 g/m22甲4氟钠 0.045 mL/m2高效盖草能 0.15 mL/m2猪秧净 0.01 mL/m2高效盖草特对马蹄金有伤害.     

几种除草剂对冬麦田杂草的防除效果

通过田间药效试验,比较不同除草剂对当前南疆地区冬麦田播娘蒿、萹蓄、硬草等杂草的防除效果,为科学、安全、高效应用除草剂提供依据。结果表明,药后50 d,10％苯磺隆可湿性粉剂18．0 g a．i．／hm2＋5％唑啉草酯·炔草酯乳油37．5 g a．i．／hm2、75％苯磺隆水分散粒剂18．0 g a．i．／hm2＋10％乙羧氟草醚乳油12．0 g a．i．／hm2＋5％唑啉草酯·炔草酯乳油37．5 g a．i．／hm2、37％炔·苄·唑草酮可湿性粉剂166．5 g a．i．／hm2对播娘蒿的株防效、鲜质量防效均为100％,对萹蓄的鲜质量防效均在92％以上,对硬草的株防效、鲜质量防效均在88％以上,且对小麦生长安全。