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In July 2000, a bacterial wilt was found on China aster (Callistephus chinensis Nees) on Hokkaido, Japan. Bacteriological characteristics of the isolated bacteria were identical to Erwinia chrysanthemi. This is the first report on bacterial wilt of China aster caused by E. chrysanthemi. Received 4 June 2001/ Accepted in revised form 6 September 2001  相似文献   

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Strawflower (Helichrysum bracteatum) with symptoms resembling those associated to phytoplasma infection were observed in several areas in the Czech Republic during the period 1994–2001. Plants with leaf bronzing, reddening and necrosis, proliferation of secondary shoots, flower abnormalities and dwarfing died in advanced stages of the disease. The disease incidence ranged from 2% to 70% and caused significant loss to the flower and seed production. Transmission electron microscopy showed phytoplasmas in sieve cells of affected plants, but not in healthy ones. Association of phytoplasmas with the disease was confirmed by polymerase chain reaction using phytoplasma universal ribosomal primers R16F2n/R16R2. An amplification product of the expected size (1.2 kb) was observed in all samples of the symptomatic strawflowers. The restriction profiles obtained following separate digestion with three endonucleases (AluI, HhaI, MseI) showed that phytoplasmas infecting strawflowers from different localities in the Czech Republic were uniform and undistinguishable from aster yellows (subgroup 16SrI-B). Sequence analysis of 1771 bp of the ribosomal operon amplified with primers P1/U3, R16F2n/R2 and 16R758/P7 indicated that the closest related phytoplasmas were those associated with 'Rehmannia glutinosa var. purpurea', both originating from Bohemia. This is the first report on the occurrence of a phytoplasma-associated disease of strawflower in the Czech Republic.  相似文献   

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Spores of the biocontrol agentTalaromyces flavus were recovered from coating material of chinese aster and tomato seeds in which they were incorporated 17 years before. The seeds had been stored at room temperature. About 20% of the ascospores had retained their heat resistance and survived treatment in aqueous suspension at 60°C for 30 min. None of the chinese aster seeds and 90% of the tomato seeds germinated after the storage period. Presence ofT. flavus during storage had not affected germinability of the seeds.  相似文献   

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Insecticide resistance management (IRM) is a component of integrated pest management (IPM) that has the goal of forestalling resistance development to all insecticides. Since the advent of the organochlorine insecticides in the 1940s, an average of about one class of insecticide has been lost every 10 years because of resistance. Effective insecticides are necessary for optimum IPM and are too important and too expensive a resource to be lost so rapidly. By adhering to the principles of IPM and utilizing other IPM components such as biological and cultural control, IRM has the potential of conserving the susceptibility of pests to insecticides. Although initial attempts of IRM appear to be successful, it is imperative that research to undergird IRM be greatly accelerated.  相似文献   

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There is interest in more diverse weed management tactics because of evolved herbicide resistance in important weeds in many US and Canadian crop systems. While herbicide resistance in weeds is not new, the issue has become critical because of the adoption of simple, convenient and inexpensive crop systems based on genetically engineered glyphosate‐tolerant crop cultivars. Importantly, genetic engineering has not been a factor in rice and wheat, two globally important food crops. There are many tactics that help to mitigate herbicide resistance in weeds and should be widely adopted. Evolved herbicide resistance in key weeds has influenced a limited number of growers to include a more diverse suite of tactics to supplement existing herbicidal tactics. Most growers still emphasize herbicides, often to the exclusion of alternative tactics. Application of integrated pest management for weeds is better characterized as integrated weed management, and more typically integrated herbicide management. However, adoption of diverse weed management tactics is limited. Modifying herbicide use will not solve herbicide resistance in weeds, and the relief provided by different herbicide use practices is generally short‐lived at best. More diversity of tactics for weed management must be incorporated in crop systems. © 2014 Society of Chemical Industry  相似文献   

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建昌县是葫芦岛市的玉米生产大县,全县耕地面积5.93万hm2,常年玉米种植面积3.73万hm2左右,总产约25万t.2005~2008年实施国家粮食丰产科技项目,示范区玉米0.67万hm2,平均667 m2产量550kg.  相似文献   

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Phelipanche and Orobanche species (broomrapes) are root holoparasitic plants that cause severe damage to economically important crops. Phelipanche and Orobanche spp. are widespread in Mediterranean areas, in Asia and in Southern and Eastern Europe, attacking dicotyledonous crops and depending entirely on their hosts for all nutritional requirements. Phelipanche aegyptiaca , Phelipanche ramosa and Orobanche cernua are extremely troublesome weeds on tomatoes. These noxious parasites exert their greatest damage prior to their shoot emergence and flowering; therefore, the majority of field loss may occur before diagnosis of infection. This review summarises the four main control measures for the weedy root parasites Phelipanche and Orobanche in tomato, namely chemical and biological control, resistant varieties and sanitation. Some of these methods are commercially widely used by farmers in Israel (chemical control), some are in the final stages of development towards commercialisation (resistant varieties and sanitation), and some still require further development and improvement before commercial implementation (biological control). The review presents an up-to-date summary of the available knowledge on their use for broomrape management in processing tomatoes.  相似文献   

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植物病害管理与生物安全   总被引:2,自引:0,他引:2       下载免费PDF全文
植物病害管理是一个复杂的系统工程,病害管理过程中采取的一系列措施和方法会对生物安全产生积极或消极作用。本文论述了植物检疫、转基因抗病植物、转基因生防微生物、生物多样性、农业防治、化学防治等与生物安全的关系及在病害管理中应注意的问题,指出病害风险评估和转基因生物风险分析对生物安全具有重要意义。  相似文献   

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芝麻病虫害的综合防治除要在种子处理、土壤消毒、栽培措施上下功夫外,种植抗病品种,生物、化学药剂防治也是综防中的主要措施,详细介绍了化学防治各种芝麻病虫害的具体药剂、方法。  相似文献   

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Area-wide management is recommended for managing several mobile pests. With limited on-ground government assistance available, several Australian local industry groups drive such initiatives to minimise Queensland Fruit Fly impacts on production and market access. This qualitative study investigates how adaptive co-management thinking can assist industry-driven area-wide management. The concepts of social learning, communication, adaptive capacity, shared decision-making and shared authority can make valuable contributions to strengthening collaborative pest management. The tension between “top-down” market requirements and “bottom-up” adaptive co-management principles is best addressed if local industries focus primarily on minimising pest infestation and view market requirements as a bolt-on component.  相似文献   

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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.  相似文献   

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Weed biology serves practical weed management   总被引:2,自引:0,他引:2  
Weed science is an applied science that serves practical weed management. Traditionally, effective weed management has been dependent upon farmers gaining knowledge of the characteristics of the weeds they were managing. The advent of herbicides has not made this knowledge-based approach redundant and problems, including herbicide resistant weeds, have made weed biology studies necessary even in the herbicide era. Weed populations continue to evolve and weed problems persist, sustaining a requirement for effective management strategies. In this paper, we exhibit several approaches to linking weed biology studies to practical weed management. These approaches demonstrate both the value of and synergy between an in-depth knowledge of weed biology and weed management practices to provide practical solutions in the field.  相似文献   

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抗药性杂草与治理   总被引:7,自引:0,他引:7  
抗药性杂草对农田杂草治理和农业生产构成严重威胁,成为备受全球关注的严重问题。随着长期、大量使用相对有限的化学除草剂,全球抗药性杂草发展迅猛,目前已有217种杂草对化学除草剂产生了抗药性,我国抗药性杂草发展也十分迅猛。本文在介绍杂草抗药性基本概念、抗药性杂草发展过程、抗药性杂草现状的基础上,重点描述了抗药性杂草治理策略,以期为我国抗药性杂草研究和治理提供参考。  相似文献   

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