1999年全国农作物重大病虫发生趋势预报

根据“１９９９年全国农作物重大病虫发生趋势预测会商会”讨论结果及目前掌握的情况分析,预计：１９９９年全国主要农作物病虫仍将较重发生,其中小麦病虫中等偏重发生,接近１９９８年;棉铃虫等棉花害虫为偏重发生,轻于重发生的前几年;水稻病虫发生可能轻于１９９８...     

佛手瓜贮藏期病害鉴定

本文描述佛手瓜贮藏期病果的症状和病原形态，对其贮藏期发生的病害进行鉴定，结果表明：佛下瓜贮藏病害有8种，以佛手瓜灰霉病、软腐病、腐烂病发病率最高。     

Forecasting the Spread of Migrant Insect Pests1

When there is reasonable evidence that an insect pest is a migrant, the forecasting of outbreaks and the planning of control measures need an information service that can describe the continually changing distribution of the pest. As records are gathered the likely changes in a particular region and season become clear and forecasting by analogues is possible. More precise forecasts can be made when the mechanism of migration is understood, such as downwind movement. Effective forecasting of migrant pests needs continuity in the assessment of redistribution of all major populations of the species over a wide area - preferably the whole distribution area. Experience with forecasting infestations of certain tropical migrants, locusts and armyworms, suggests methods of organising and interpreting information from survey networks, so that the effects of migration can be taken into account when preparing warnings. Pour les insectes migrateurs, il est important d'établir un service d'information appeléà prévoir la distribution constamment changeante du ravageur, les gradations, et partant, les mesures de lutte. L'accumulation des données pour les regions et saisons differentes permet d'etablir des prévisions plus precises, en utilisant des modeles. Une meilleure comprehénsion du mécanisme de migration, découlant par exemple de I'étude de I'influence du vent, permettra également d'affner les prévisions. Pour émettre des prévisions cables, il faut assurer la continuityé des observations sur tous les deplacements majeurs des populations de L'espece, en tenant compte de grandes etendues embrassant si possible L'ensemble de L'aire de dissémination. Les expériences acquises par l'étude de certains migrateurs tropicaux (criquets et noctuelles) servent a mieux definir les méthodes dorganisation et d'interprétation des données accumulees par les reseaux de surveillance. Elles permettent d'émettre des avertissements qui tiennent compte des phénomenes de migration.     

Forecasting Infections of the Leaf Curl Disease on Peaches Caused by Taphrina deformans

An Israeli model forecasting leaf curl disease on peaches caused by Taphrina deformans was validated in the Emilia-Romagna region of northern Italy, during a three-year period (1996–1998), in 13 cases (year × location × cultivar). When the peach trees are susceptible to infection, the model uses mathematical functions to calculate the risk of infection on the basis of weather conditions (daily rainfall greater than 10mm, and maximum air temperature greater than 5°C), and it forecasts periods of possible symptom appearance based on the length of incubation. Peach trees became susceptible to infection between the end of January and mid March, when the first leaf buds attained phenological stage C, i.e. appearance of leaf apex. The trees remained susceptible for at least 9 weeks: the last infection occurred in mid-May.Since most of the leaf curl onsets observed in the orchards fell within the range of model forecasts, the model proved to be accurate in signalling both the first seasonal infection and repeated infections during the primary inoculum season. Few errors occurred, caused either by conditions of rainfall and temperature lower than the thresholds fixed in the model, or by discrepancies between forecast and actual length of incubation. Infection occurred also at 3.1–3.5°C, and with 9.6mm rainfall. Thus, thresholds should not be accepted too rigorously, and perhaps temperature should not be considered as a limiting factor for infection under the conditions of the present work. The length of incubation showed high variability: it was 23 days long on average, with a 95% confidence interval ranging from 20 to 27 days, and extreme values of 9 and 33 days.     

Forecasting the Incidence of Aphids Using Weather Data1

Aphids have been trapped continuously at several heights at Aberystwyth (United Kingdom) since 1969. Relationships have been found between prior meteorological parameters (normally recorded at Agricultural Meteorological Stations) and numbers of aphids flying during both summer and autumn peaks, and with the first occurrence in the trap each year. Numbers of cereal aphids caught in the autumn are associated with previous winter and spring temperatures and particularly with summer rainfall. Cereal aphid numbers are also associated with the yields of their summer grass hosts which in turn are related to summer rainfall, thus providing a causal relationship. The value and accuracy of using meteorological parameters to forecast the incidence of aphids of agricultural importance is discussed.     

Plant Protection Forecasting Service in the Federal Republic of Germany1

In the Federal Republic of Germany, plant protection is a matter for the several Federal Lander. Each of the regional plant protection offices has built up a warning system of its own, although there are no essential differences between them. The warnings are based on field investigations which are mostly carried out by technicians. However, it is not possible to inspect all fields, orchards, etc., as the areas of crops are too vast. Warnings follow a general pattern: information on the situation, followed by conclusions on further development; recommendations for control measures; and, most importantly, indications of possible undesired or even dangerous side-effects and how to avoid them. The warnings are published and also distributed by telephone and radio. Warnings on sugar beet in the Nordrhein area are distributed by the sugar factories to each of the farmers concerned. The forecasting service can certainly be improved by scientific progress. On the other hand, practical improvement is indispensable. The main problem is how to get more information from the field. There is little hope that the personnel situation will change fundamentally, but every effort must be made, in view of the importance of the forecasting service. En République féderale d'allemagne, les Lander sont chargés de la protection des végétaux. Les bureaux régionaux ont développe leurs proprés systemes de prevision, mais ceux-ci sont neanmoins très semblables. Les avertissements sont basés sur des observations de plein champ qui sont réalisées pour la plupart par des techniciens. I1 n'est pas possible d'inspecter tous les champs, vergers, etc., en raison des enormes surfaces en jeu. Les avertissements reposent sur un système normalisé comprenant I'information sur la situation présente, suivie d'une évaluation de I'evolution ulterieure, dune recommandation sur les methodes de lutte, d'une indication sur les effets secondaires indesirables ou dangereux, ainsi que des moyens de les eviter. Les avertissements sont expedies sous forme de bulletins, ou communiques par telephone ou par radio. Dans la région de Nordrhein, les avertissements concernant la betterave sont distribues aux exploitants par les sucreries. Le système de prevision peut certainement btre ameliore, surtout sur le plan pratique en beneficiant des progres scientifiques qui sont realises. I1 est essentiel de mutiplier les observations de plein champ, mais il est improbable que les services responsables puissent disposer du personnel necessaire. Cependant, face à I'importance de la prévision, il faut tirer le meilleur parti des moyens disponibles.     

Principles in Pest Management: Forecasting the Occurrence of Animal Pests1

Typically, for insects in temperate climates, the number of generations and the rate of multiplication is low in comparison with micro-organisms. Therefore, it is possible to determine population densities about a year in advance if the present population density and the expected rate of multiplication is known. Forecasting becomes generally more inaccurate as the period forecast increases. Therefore, long-term forecasts are unsuitable for the immediate application of insecticides. However, it is possible to give an initial rough estimate, then an approximate statement about the infested area and, finally, more specific data on the size and extent of the infestation. This principle was fairly successfully applied in 1971 for certain agricultural pests. Prognoses were developed preferably from empirical data. En zone temperee les insectes ont moins de generations par an et se developpent plus lentement que les micro-organismes. I1 est donc possible de prevoir les densites de populations une annee a L'avance, lorsque sont connus la densite de populations presentes au depart et leur taux de multiplication. Les previsions deviennent moins precises au fur et a mesure que la periode de prevision s'etend. Les previsions a long terme ne conviennent donc pas pour definir le moment precis d'une intervention insecticide. I1 est cependant possible de faire une premiere evaluation, suivie d'une appreciation pour la region infestee, et, enfin, de fournir des donnees plus precises sur le niveau et L'etendue de I'infestation. Ces principes ont ete appliques avec succes en 1971 pour certains ravageurs des cultures, en faisant appel aux donnees empiriques.     

An Approach to Forecasting the Incidence of Potato and Cereal Aphids in Scotland1

Many potato and cereal infesting aphids in Scotland are either completely cr partially anholocyclic. This makes forecasting their first appearance and abundance on crops difficult, when compared with holocyclic species such as Aphis fabae Scopoli. This paper describes an analysis of the early movement of nine aphid species, commonly found on potatoes and cereals in Scotland, in relation to winter and early spring climate. Data on their early movement have been extracted from the catches in three of the sjx.12–2.rn suction traps now operating in Scotland in cooperation with the Rothamsted Insect Survey. The particular importance of early spring temperature has been established. The extension of this work to develop a predictive forecast of summer activity of anholocyclic aphid species is discussed. En Ecosse, une forte proportion de pucerons des pommes de terre et des céréales est entièrement ou partiellement anholocyclique. Ceci complique la prévision sur le moment de leur première apparition et sur leur abondance par rapport aux espéces holocycliques telles qu'Aphis, fabae. Cette étude concerne les déplacements précoces de neuf espéces de pucerons retrouveés fréquemment sur les pommes de terre et les céSreales. Les données sur les deplacements ont été obtenues à partir de trois des six piegès à succion de I2,2 m installes en Ecosse en cooperation avec le « Rothamsted Insect Survey », Il est apparu que la température printanière revêt une importance particuliere. Les recherches se poursuivent dam le but d'établir des prévisions sur le développement estival des espèces anholocycliyues de pucerons.     

Monitoring and Forecasting Methods for Codling Moth Management in the United States and Canada1

With the renewed emphasis on integrated control in fruit growing, new monitoring and forecasting methods had to be developed to achieve efficient and economical but less disruptive codling moth control. Attractant traps for monitoring adults have long been in use; pheromone traps are a recent addition. They allow for easy monitoring of moth populations but interpreting the significance of catches remains difficult. Pheromone trap catches have been correlated with the seasonal phenology and with estimates of fruit injury. In the United States and Canada critical catch levels below which no treatments are advised have been determined. In addition, new forecasting methods are being developed which include simple physiological-time tables, phenological models and « strategic » population models. Computer-based information delivery systems allow access to these models from the field. It is too early to assess the total impact of these new monitoring and forecasting programs on control practices. Aux Etats-Unis, les systemes de lutte integree suscitent un inter& croissant. Dans les vergers, toute approche dans ce sens requiert un affinement des methodes de recensement des populations de carpocapse des pommes et des poires, de mbme qu'une amelioration des previsions. Depuis longtemps, plusieurs types de pieges attractifs ont ete utilises, mais les pieges a pheromones sont d'introduction recente. Ceux-ci permettent de reveler d'une facon remarquable I'activite des populations, alors que I'interpretation de la signification economique des captures demeure difficile. Aux Etats-Unis et au Canada, il a ete possible d'etablir une relation entre les captures realisees a I'aide de pheromones et les degsts observes sur fruits. Ceci a permis d'etablir des seuils critiques au-dessous desquels il n'est pas: recommande de recourir a une mesure de protection. Parallelement au developpement de tables de survie, de modeles phenologiques et stratkgiques, il a ete etabli un systeme d'information par ordinateurs. I1 est encore trop tat pour evaluer la valeur de ces nouveaux éléments.     

新疆主要污灌区养分资源特征的研究

通过对新疆七个主要污灌地区养分含量的研究表明污灌区钾含量丰富,氮素含量不足,磷缺乏。库尔勒地区污灌时间最长,养分含量丰富;昌吉地区养分含量属中等水平,其它地区都有不同程度的养分缺乏状况。与新疆土壤普查资料对比,污灌后,土壤的C/N比差异不大9.86—13.85;供磷强度有所改善,均>1%;但供氮及供钾能力并没有显著改善,部分地区的供肥强度极低。相关性研究分析表明,土壤中大部分养分含量与有机质含量呈现极显著或显著相关,只有全钾与之无相关性;其它养分之间也存在相关性,但是部分养分之间的相关性是由于有机质含量干扰所致。     

黑河流域灌溉绿洲农业生态结构探讨

本文用生态学的原理、系统论的方法,以黑河流域大农业生态结构的历史和现状为素材,对农业生态的系统中优化结构发挥高效功能的问题进行了研究。并针对当前农业结构提出四个层次的调整:第一层次,调整大农业生态结构,协调农林牧副渔各业之间比例关系;第二层次,农林牧各业内部结构的调整;第三层次,充分利用空间,发展立体农业;第四层次,生物和环境因子间的相互适应和相互协调的发展。调整后的生态结构应使农业资源得到充分、合理的利用,达到营养结构和网络结构的平衡,收到最高的经济效益、生态效益和社会效益,并使三个效益最佳结合。     

稻田中性昆虫多样性及其生态功能分析

以广东省四会市大沙镇水稻害虫综合防治稻作区为试验基地 ,用吸虫器法采样 ,对稻田节肢动物群落中的中性昆虫、捕食性天敌、寄生性天敌与害虫进行了系统调查。在整个稻田节肢动物群落中 ,稻田中性昆虫物种丰富度的比例 ,在早稻和晚稻分别为 1 6 .98%和 6 .82 % ;而其数量比例为 :早稻 73.6 1 %、晚稻 37.94 %。稻田中捕食性天敌亚群落的发生与重建比水稻害虫亚群落发展快 ,前者在水稻生长发育前期主要依赖于稻田中的中性昆虫重建其亚群落     

The Role of Forecasting in Crop Protection Decision Making: an Economic Viewpoint1

In making crop protection decisions, farmers have to answer two questions: what type of control measure(s) should I adopt? How should I apply this (these) measure (s), when, how frequently, etc.? The answer to these questions will depend upon: a) the dimensions of pest attack and the damage it causes, b) farmers' goals, c) the range of protection measures available to them which they can use, and d) the information available, in the form of monitored and forecast information. It is within this context that the role of forecasting is considered. An analysis is made of the possible impact that forecast infomation can have on farmer decision-making, particularly with regard to the accuracy of the forecast and the time at which it is available. This leads on to the problem of assessing the value of a forecast at a regional level, against which the costs of providing such information can be set. Finally, situations in which forecast information is likely to be of greatest value (and of least value) are identified, and implications are drawn concerning the institutional and other changes that could be taken to allow better use to be made of forecast information. Lorsque les agriculteurs decident de proteger leurs cultures, ils doivent repondre aux deux questions suivantes: quel est le mode d'intervention a choisir et comment, quand et a frequence faut-il intervenir. La reponse dependra notamment: de I'etendue de I'infestation et de L'importance des deglts; des buts que s'est assignes L'arboriculteur; de la gamme de methodes dont il dispose; des previsions qui lui sont fournies. La prevision est condideree dans ce cadre, puisqu'elle est susceptible d'infuler sur les decisions de L'agriculteur dans la mesure ou elle est etablie avec precision et au bon moment. I1 est donc utile d'evaluer L'inter6t economique d'une prevision regionale en faisant intervenir le cofit de celle-ci. Enfin, il est fait etat de situations dans lesquelles la prevision est profitable ou non. Suivant les cas, certaines modifications structurelles peuvent s'imposer afin de mieux tirer benefice des previsions.     

The Forecasting System for Plant Protection in the USSR: Its Theory,Methods and Organization1

In the USSR, the system of forecasting the occurrence of crop pests and diseases consists of long-term, yearly or seasonal forecasts, and a warning service. They allow for prophylactic plant protection to be adequately planned and organized both on a country-wide and a regional scale. Theoretically, all kinds of forecasts are based on a knowledge of the population dynamics of pests. The criteria used to develop forecasts are the state of certain climatic and energetic factors during previous seasons, which determine the morphophysiological features of populations and the way they will react to the environment in the future. On this basis, mathematical formulae can be developed and the management of pest population dynamics can be planned. The main biological information required for forecasting is collected by the State Plant Protection Service. Data on climatic conditions and the state of crops are supplied by the Hydrometeorological Service. Methods of data collection, treatment and interpretation are developed by research institutes according to the accepted model of pest population dynamics. En URSS, les previsions se font a long terme, a echeance d'une annee et sous forme d'avertissements saisonniers. La protection des plantes peut, de ce fait, etre planifiee a I'echelle nationale et regionale. En principe, toutes les previsions sont basees sur la connaissance de la dynamique des populations de ravageurs et maladies. Les criteres utilises pour la preparation de previsions comprennent le recours a une serie de facteurs climatiques et energetiques qui ont prevalu durant les saisons precedentes. Ceux-ci determinent les caracteristiques morphophysiologiques des populations et la faGon dont elles vont repondre aux conditions de I'environnement. Ceci permet de developper des formules mathematiques de prevision et de planifier le management des populations des depredateurs. La plus grande partie des donnees necessaires a ces previsions sont recueillies par le Service de la protection des vegetaux. Les donnees sur le climat et sur la phenologie des cultures parviennent au Service hydrometeorologique, alors que les methodes de lutte sont developpees par les instituts de recherches, sur la base de modeles de la dynamique des populations.     

Usefulness of Stress Indicators in Forecasting Population Trends in Microtus arvalis (Pallas)1

The appearance of a stress condition in Microtus arvalis (Pallas) populations was established on the basis of histochemical analyses and correlated with population dynamics. It was found that stress appears only during invasions, i.e. when crop damage has already occurred. Commonly, the population crash occurs 30 to 50 days after the appearance of stress. It is concluded that stress indices can neither be used for warnings nor for long-term forecasts of outbreaks.