摘要:

AbstractPlant quarantine is a part of crop protection strategies and has generally not received the scientific support it deserves neither has the usefulness of quarantine actions which are a matter of public policy been verified. Experience shows that introduction of exotic pathogenic organisms often fails in establishment because the complicated sets of biological conditions needed are not met; however, with increased frequency of introductions, the probability of meeting the right combination of circumstances increases. This is of fundamental importance in quarantine.Protecting a bio‐geographical area rather than individual countries against emigrant pests and diseases is a prerequisite for a successful quarantine. It is explained how this approach is currently implemented within the EPPO area on the grounds of scientific data.A major breakthrough in evaluating the potential hazards inherent in emigrant pests has been made in the United States through mathematical modelling. Many gaps in the biological knowledge remain and there is a clear need for collaborative action on a global scal

ISSN:0250-8052    

DOI:10.1111/j.1365-2338.1975.tb02465.x

出版商:Blackwell Publishing Ltd    

年代:1975

数据来源: WILEY

ISSN:0250-8052    

DOI:10.1111/j.1365-2338.1975.tb02466.x

出版商:Blackwell Publishing Ltd    

年代:1975

数据来源: WILEY

摘要:

AbstractVarious important factors in the evaluation of the acute and chronic toxicity of agricultural pesticides are discussed. Special attention is drawn to the residues in food and fodder of active ingredients, including their degradation and reaction products. A general evaluation of the effects of pesticides on roan, animals and the environment is only possible if their properties and behaviour in the different fields of application and under various conditions are known. This is illustrated by a few examples.Manufacturers (especially involved in residue analysis), chemists, toxicologists, biologists, advisors, farmers and operators dealing with pesticides are faced with many questions and problems which can only be solved through close cooperation. Public authorities and responsible organizations have to elaborate national and international guide‐lines, rules and regulations, which have to be constantly improved and adapted to the latest state of knowledge ‘for the sake of safety and efficacy.’The expression « health aspects » is often used as a synonym for « toxicological aspects ». In order to avoid misunderstandings, it is pointed out that toxicology is merely one important part of general health aspects; this is illustrated by some

ISSN:0250-8052    

DOI:10.1111/j.1365-2338.1975.tb02467.x

出版商:Blackwell Publishing Ltd    

年代:1975

数据来源: WILEY

摘要:

AbstractPotato cyst‐nematode pathotypes fall into 2 groups distinguished by morphological and biological differences, corresponding to the speciesHeterodera rostochiensisWollenweber, 1923 (the golden nematode) andH. pallidaStone, 1973. The species may most readily be distinguished by differences in length and knob shape of second stage juveniles' stylets, by differences in the cuticular pattern of the female or cyst perineum (the region between vulva and anus) and by the colour of the maturing female. Both species occur in the United Kingdom, continental Europe, South America and elsewhere, and include pathotypes able to develop on potato cultivars bearing genes for resistanc

ISSN:0250-8052    

DOI:10.1111/j.1365-2338.1975.tb02468.x

出版商:Blackwell Publishing Ltd    

年代:1975

数据来源: WILEY

摘要:

SommaireL'étude des répercussions des herbicides sur la biosphère a suscité un vif intérêt depuis que la sauvegarde de l'environnement est devenue une préoccupation prioritaire. La documentation qui s'y réfère est encore fragmentaire; elle concerne l'impact de ces produits sur la faune sauvage, les poissons et les abeilles, ainsi que sur le sol et l'eau en général. Il est fait état des recherches dans ces domaines et des conclusions que l'on peut en tirer. L'eau demeure un point vulnérable dans le cadre des applications de certains herbicides en raison des dangers de contamination par la dérive et des possibilités d'infiltration dans les zones de captage

ISSN:0250-8052    

DOI:10.1111/j.1365-2338.1975.tb02469.x

出版商:Blackwell Publishing Ltd    

年代:1975

数据来源: WILEY

摘要:

AbstractA realistic appraisal of insect and mite control on apple suggests that the existing status of almost total reliance on chemicals is very precarious. During the past 10 to 15 years integrated systems of biological control of mites and chemical control of insects have been developed. The most common integrated system makes use of predacious phytoseiid mites resistant to insecticides used for the control of major pests.In the United States, there are currently 4 federally funded apple pest management projects (Washington, Pennsylvania, Michigan and New York). While there are differences among these in their scope and structure, they all aim at implementing new pest management systems on a commercial level and to train fruit pest managers.SummaryThe pest problems on apples in North America, which include insects, mites, fungal, virus and bacterial disease organisms, weeds and mammals, are very complex and difficult to solve. Chemical control of insects has been practised on this fruit since before 1900 with considerable success but there have been problems of acquired resistance and destruction of parasites and predators by certain insecticides and fungicides. As a result mites and a few insects have become greater problems than formerly. Currently organophosphates are being used as the basic control agents for most insects. Phytophagous and some predacious mite species are now resistant to these materials. Chemical control is needed in all commercial apple planting to prevent severe fruit damage.During the past 10 to 15 years successful integrated systems of biological control of mites and chemical control of insects have been developed in several widely scattered apple‐growing areas. Fruit growers are using these more or less depending upon the severity of mite problems and the availability of effective acaricides. The most common integrated system makes use of predacious phytoseiid mites which have developed resistance to insecticides essential to controlling major insect pests of apple. All pesticides known to be harmful to these mites are avoided during critical periods. In Pennsylvania an integrated system employing the chrysomelid beetle,Stethorus punctum, is used. In this case, the predator is preserved by using reduced dosages and limited spray coverage.Considerable progress has been made in recent years in reducing the quantity of insecticide used on apple. The basis for the reduction has been the use of very effective insecticides which essentially eliminate major pests from orchards. This level can be maintained by reduced schedules, i.e., applying treatments only when pests are present as indicated by monitoring and inspections. The development of sex pheromone traps has enabled excellent progress in this direction.Currently there are 4 federally funded pest management projects in important apple‐producing regions. The objectives are to implement new pest management systems on a commercial level and to train fruit pest manag

ISSN:0250-8052    

DOI:10.1111/j.1365-2338.1975.tb02470.x

出版商:Blackwell Publishing Ltd    

年代:1975

数据来源: WILEY

摘要:

AbstractResearch on maize storage in villages, conducted in Malawi (C. Africa) between 1968–1972 is described. Large differences in susceptibility to insects were found between the maize varieties which are currently grown. Local varieties were very resistant, improved varieties had a higher susceptibility while certain hybrids were very easily damaged by insects. Surveys showed that the annual loss was still small because most of the crop consists of local varieties.Lindane 0.5% dust applied at a dosage of 12 ppm on cobs with husks gave a good protection for about 10 months. This insecticide, however, cannot be used anymore because it may contaminate tobacco, the main export crop. Farmers therefore have to go over to the storage of shelled maize. Because of the occurrence of resistance to insecticides other techniques to prevent storage losses are necessary. Recommended is the breeding of high yielding varieties with a good husk cover and hard grains, the use of inert dusts and the development of small silos which can be fumigated.SummaryBetween 1968–1972, a study was made on losses of maize stored in villages in Malawi and different methods were tested to reduce these losses. Cylindrical cribs made from bamboos or twigs are used to store the maize on the cob with the husks. Moisture content of the maize at harvest in June‐July is around 14–15 %. During the subsequent dry season, it dries to about 11 % in November, after which the moisture content increases again to about 14 % in the rainy season.Infestation by pests such asSitophilus spp.andSitotroga cerealellastarts in the field. Populations build up slowly during the dry season but in the rainy season those ofSitophilusincrease rapidly while those ofSitotrogadecrease. The percentage of bored grains shows the same trend, a slow increase during the dry season, followed by a steep rise after the onset of the rains. There were, however, considerable differences in susceptibility to insects between the maize varieties grown in Malawi. Local varieties characterized by hard grains and a good husk cover were very resistant to insect damage. Grain damage at the end of a storage period of 9 months was, in local varieties, about 10%; improved varieties showed after the same period a grain damage of 15–30%, while for certain varieties like SR 52, which have very soft grains and a poor husk cover 70–90% of the grains were bored.Several techniques were tested to assess losses in the country which all, however, had their limitations and were in some way or another unsatisfactory. The most reliable method consisted of sampling 25 cobs from the top layer of the crib. These were shelled and thoroughly mixed and then a sub‐sample of about 700 g was taken which was immediately fumigated. In the laboratory the percentage of bored grains was determined in a sub‐sample of 1,000 grains. The overall loss of the 1971 crop caused by insects was very low (about 1%) because over 90% of the crop consisted of local varieties. A survey conducted in a small area showed that the combined loss due to rodents, termites and moulds was about 1–3%.Lindane 0.5 % dust was tested as a protectant of maize cobs. It was found to be most effective when applied on cobs with husks. Treated cobs without husks became infested byS. cerealella.Lindane dust was made available to the farmers but had to be withdrawn because of possible incidences on the tobacco trade. Farmers are now advised to shell their maize during the dry season and to mix it with malathion dust at 1 %. Resistance to insecticides will, however, create problems in the near future. It is recommended, therefore, to develop high yielding maize varieties which are more resistant to storage pests, to look into the possibilities of using inert dusts as pesticides and to develop cheap small silos which are insect proof and

ISSN:0250-8052    

DOI:10.1111/j.1365-2338.1975.tb02471.x

出版商:Blackwell Publishing Ltd    

年代:1975

数据来源: WILEY

摘要:

En Autriche, la protection des plantes repose sur la loi de 1948, adaptée à la situation particuliére du pays qui est composé de 9 provinces. Les dispositions intéressent la production et le commerce; une attention particulière est vouée à l'application des pesticides qui sont assujettis à l'homologation et doivent répondre aux critères d'efficacité et de sécurité. Ainsi, ce système est conçu de manière à mettre à la disposition de l'agriculture et de la sylviculture des produits répondant aux exigences d'une lutte économique sans qu'il en résulte des effets indésirables pour l'homme, les écosystèmes et l'

ISSN:0250-8052    

DOI:10.1111/j.1365-2338.1975.tb02472.x

出版商:Blackwell Publishing Ltd    

年代:1975

数据来源: WILEY

摘要:

AbstractRelevant data on the possibilities of changing the stored grain environment, for the sake of better preservation of grain in storage, are reviewed. The grain bulk is regarded as an ecosystem, in which the impact of damaging organisms can be controlled by ambient conditions. The influence of humidity, temperature, composition of atmospheric gases, atmospheric pressure and light is discussed. Lowering humidity and grain temperatures are well known effective and practical ways for the prevention of storage damage. The modification of atmospheric gas compositions has been subjected to very extensive research, on which new methods for insect control could be based. Lowering the absolute pressure in storage containers has detrimental effects on storage insects; the practical implementation of this technique is discussed. Research on the effects of changing light conditions on stored grain insects is in its earliest stage, but shows promise. Studies on an integrated approach using several environmental elements for the containment of grain insects and microflora are proposed.

ISSN:0250-8052    

DOI:10.1111/j.1365-2338.1975.tb02473.x

出版商:Blackwell Publishing Ltd    

年代:1975

数据来源: WILEY

摘要:

SommaireEn France, le maïs est souvent produit en monoculture ou placé en tête d'un assolement réduit à la rotation maïs‐blé, avec quelques variantes. D'autre part, cette culture s'étend vers des zones climatiques plus marginales à la faveur des nouveaux hybrides. Ces conditions, auxquelles s'ajoute l'uniformité des variétés, sont favorables au développement des maladies.Deux types de problèmes sont examinés dans le cadre de cette évolution; ils se rattachent aux affections suivantes: 1) les maladies communes au maïs et aux céréales à paille, comprenant notammentFusarium roseum(Link) Sn. et H., et 2) les maladies spécifiques du maïs; elles se réfèrent àHelminthosporium turcicumPass.,H. maydisNisikado et Miyake, race T etKabatiella zeaeNarita et Hiratsuka.Les possibilités de lutte contre ces différentes maladies sont examinées ainsi que les mécanismes qui peuvent être rendus responsables de leur

ISSN:0250-8052    

DOI:10.1111/j.1365-2338.1975.tb02474.x

出版商:Blackwell Publishing Ltd    

年代:1975

数据来源: WILEY