Fireblight monitoring in Lithuania1

Lithuania has requested that its whole territory should be recognized by the EU as a protected zone for Erwinia amylovora . Fireblight monitoring was performed in 1998/2002 with the aim of detecting and identifying the bacterium, and of determining its distribution in the country. The study consisted of periodic surveys (at least twice a year) of nurseries, orchards, collective farms and host plants, growing individually or in small groups, as well as the surrounding zone within a radius of 250 m. Tests, under conditions of quality control, were applied to host plants with and without symptoms, using detection methods such as ELISA and immunofluorescence (with polyclonal antibodies), semi-selective plating and pathogenicity.     

Mycological Diagnostic Problems1

In diagnostics we are constantly confronted with the gaps that exist in our knowledge of the pathogenic fungal flora. This situation is illustrated by recent information concerning various economically important fungal diseases. Where such problems arise it is only through international cooperation in diagnostic mycology that they can be efficiently tackled and solved. It appears that with increasing frequency the exact identification and differentiation of fungi is only made possible through familiarity with their growth characteristics in culture. Fungus culture collections can here play an important role, since exact comparison and identification is made possible. Such pathogenic fungi should be made available for diagnostic purposes under the auspices of the Plant Protection Services, so that the risk of unwanted spreading of these pathogens can be avoided. The Plant Protection Services would in fact become more effective in their attempts to prevent and limit the distribution of harmful organisms.     

Droplet Formation and Deposition1

At the EPPO Conference in Belgrade on 1970 the author reported on work showing that small, uniform, and non-volatile droplets appeared to offer the prospect for greatly reduced dosages of pesticides by both providing a more effective deposit and by controlling drift. Three recent studies provide further evidence for this hypothesis, which questions the very principles on which our present spraying practices are based. However, the deposition of droplets by the external forces of wind and gravity imposes lower limits on the droplet sizes capable of being used. These are 30 μm for insecticides and fungicides (except in the case of flying insects) and 150 μm for herbicides, since the droplets require sufficient energy to impact themselves on the target. Electrostatic charging of droplets promises to free us from these size constraints by providing the droplet with a depositional force of its own, allowing it to impact on any surface. Electrostatics, however, is solely a force of deposition and thus must be balanced with the forces required for spray dispersion so that the droplets can penetrate the crop canopy and/or be transported to the target     

Wheat Diseases in Turkey1

Cereal crop production is one of the most important projects in the agricultural improvement programme for Turkey. Overall, wheat represents 61 % of the cereal crop. While wheat production was almost 4 million tons in 1950, this reached a limit of 10 million tons in 1970. A number of diseases continue to afflict the crop from time to time, causing heavy losses. The most important of these are: bunt ( Tilletia foetida and T. caries ), loose smut ( Ustilago nuda ), rusts ( Puccinia strilformis, P. graminis f. sp. tritici, P. recondita f. sp. tritici ), leaf blotch ( Septoria tritici ), root and foot rots ( Fusarium spp., Drechslera sorokiniana, Pseudocercosporella herpotrichoides, Alternarla alternate, Sclerotium spp. and Rhizoctonia spp.). The diseases appear all over the country. Average losses due to rusts in epidemics are estimated at about 30–35 % in the whole country. Annual losses from covered smut are about 15–20 %, and from loose smut from 0.1 % to almost 20 % depending on the weather conditions of the year, on variety and on locality. Root rots have gained importance in some places, especially in Thrace in the last few years. In addition to the above diseases, several others occur occasionally but are of minor importance: powdery mildew ( Erysiphe graminis f. sp. tritici ), dwarf smut ( Tilletia contraversa ), flag smut ( Urocystis tritici ), take-all ( Gaeumannomyces graminis ) and a wheat mosaic virus (recently observed in a province of Central Anatolia).     

New Techniques in Seed Treatments1

The paper deals with the treatment of seeds other than cereals and describes the technique of seed coating with the incorporation of the required pesticides. The formulation of the pesticides has to be modified for this technique. The advantages of seed coating are given and include the increased loading of chemicals onto seeds, thereby increasing the diseases and pests that can be controlled by the coating technique.     

International Cooperation in Plant Protection1

Preventing the introduction of dangerous organisms into new countries and regions requires an international approach. The article reviews the most dangerous organisms for different continents, and describes in particular the procedures developed in Europe for assessing quarantine risks, through international cooperation within the European and Mediterranean Plant Protection Organization. The activities of EPPO are reviewed, and also those of the ISHS Plant Protection Commission, especially in relation to fruit-tree viruses. The implementation of international cooperation within the European Community, and specifically in Denmark, is described.     

High Performance Self-Propelled Sprayers1

Self-propelled sprayers, which are the result of recent technological advances in farm machinery for crop protection, combine the advantages of ground equipment and airborne spraying appliances: a work rate of 100 ha per day can be achieved under comfortable working conditions, their ease of handling makes it possible to work at short notice and at almost any time of the year. Labour costs are reduced, and effective treatment can be guaranteed. This is the main economic justification of the use of these machines which, in view of their relatively high purchase cost, are suitable for farms of at least 300-400 ha.     

Presence of Phytophthora fragariae var. fragariae in Norway

The strawberry red core disease caused by Phytophthora fragariae var. fragariae has until recently not been reported from Norway. During 1995 and 1996, samples from 323 Norwegian strawberry fields were tested in a root-tip bait test for possible detection of red core. Symptoms of the disease developed in test plants cultivated in growth medium containing root tips from 21 fields at eight locations in four different counties. Disease symptoms included wilting of plants, root rot, red steles in the roots, and oogonia and oospores identical in size and appearance to those of P.f. fragariae developing along the root steles. In V8 juice agar, the mycelium was slow-growing, thick, fluffy and aerial. Sporangia were large, mainly inversely pyriform, and without papillae. Optimum temperature for mycelial growth was 21°C, and the fungus ceased to grow at 25°C. In infested fields, the most severe attacks were found in low, often poorly drained areas. The means by which red core may have been introduced and spread in the country are discussed, together with preventive action to avoid further dissemination.     

Possibilities of Microwaves in Soil Disinfestation1

In the search for alternative methods for soil disinfestation, various soil types (sand-loam, loam, clay-loam) with mycelium of Rhizoctonia solani, Fusartum oxysporum f. sp. lycopersici and Trichoderma longibrachiatum and seeds of Lepidium sativum , all present at various depths, were treated with microwaves (2540 MHz, 600 W). High lethality was found to be dependent on the duration of irradiation. The granulometric composition of the soil had a relatively strong effect on killing rate. The reaction to soil moisture content was remarkable, but quite reproducible: two maxima in killing rate could be established, one with extremely dry soil and the other with a relative soil moisture content of 60%. The effect of irradiation on CO₂ production and N-mineralization in the soil was also investigated.     

Cost/Benefit Analysis as Used in the United Kingdom for Eradication Campaigns against Alien Pests and Diseases1

The reasons for using, and the methods used for cost benefit analysis of eradication campaigns against alien pests and diseases in the UK are discussed. Details of the costanalysis for a current campaign against white rust of chrysanthemums ( Puccinia horiana ) are given.     

Survey for Phytophthora fragariae var. fragariae in Finland

A survey for the possible occurrence of red-core disease ( Phytophthora fragariae var. fragariae ) was carried out on 250 strawberry production sites in Finland. The fields were inspected visually. A total of 1080 samples of strawberry roots were taken in spring and autumn 1995 and examined visually, microscopically and by isolation in the laboratory. Root-tip bait-plant tests were performed in the glasshouse to look for the latent presence of the fungus. No red-core disease was detected in any of the inspected fields or in the examined samples.     

Analyzing Cost Effectiveness of EPIPRE1

EPIPRE is an integrated pest and disease management system for wheat, fully computerized, based on on-line calculations of costs and benefits of pesticide treatments; it is field-specific and utilizes disease and pest monitoring in the field. The development of the project took five years (1977/1981). Cost effectiveness has been estimated in retrospect and in prospect using 1980 as a base year, covering the period 1977 through 1985. Future costs were disccrunted at a 10 % rate. The Net Present Worth of the project was estimated at nearly eight million Dutch guilders. The nonmeasurable effects of the project seem to be even more important than the measurable effect.     

Grey Mould Damage and Control in Hungary1

Grey mould is one of the most important fungal diseases of grapevine, and for this reason the successful control of Botrytis cinerea determines the result of grape growing. As far as damage is concerned, the most important infection occurs at the end of flowering and just before ripening. The conidia of the fungus infect the berries through wounds, which may be caused by hail or storms, or by chewing insects, or also, most importantly, by physiological berry splitting. This occurs when a long dry period in summer is followed by a rainy autumn at ripening time. The prevention of wounds is one of the most important aspects of control. For the first half of the year, we propose using the traditional contact fungicides against grey mould. The use of benzimidazole-type systemic fungicides is proposed only for the last two treatments, because they have a low persistence and because in this way we avoid the development of resistance to these systemic fungicides.     

Maize Pests and their Importance in Turkey1

Maize and related crops suffer from a large number of insect pests in Turkey but all are not of the same importance in different parts of the country. This paper lists about 80 species, of which only a few ( Sesamia nonagrioides, Helicoverpa armigera, Ostrinia nubilalis , cutworms ( Agrotis spp.), Tanymecus dilaticollis, Gryllotalpa gryllotalpa ) are of primary importance. The pest status and distribution of each species is described.     

Plant Quarantine Facilities in The Netherlands1

In The Netherlands germplasm and plants collected in the wild for breeding and scientific purposes may only be imported with a special licence. For this material specific post-entry import requirements are prescribed. A glasshouse with special quarantine facilities has been built on the premises of the Plant Protection Service at Wageningen. In this paper the special facilities needed to carry out post-entry quarantine are described.     

Electrostatic Application with Rotary Atomisers1

The APE80 charged rotary atomiser, and its larger, JUMBO, counterpart, both developed at Rothamsted, are briefly described. Recent design modifications allow control of the trajectory and subsequent distribution of the spray. Some field results illustrate the increase in deposition obtained with charged sprays and the effect on spray penetration.     

Evaluation of Novel Pesticide Application Techniques1

Most new pesticides are assessed in the laboratory and field assuming commercial application in sprays diluted to around 2001/na or more. Relatively few products are registered for ULV/CDA (ultra-low volume/controlled droplet application) sprays. Methodology for comparative assessment of novel application techniques is considered.     

Economic Aspects of Pest Control1)

The activities of economists associated with the IBP project entitled « The Principles, Strategies, and Tactics of Pest Population Regulation and Control in Major Crop Ecosystems » and their interaction with entomologists in the design and implementation of integrated control strategies are described. Profit maximization criteria and a method of considering farmers behaviour with respect to risk are developed. The term «economic threshold » is further clarified; and a simpler concept, « the damage threshold », is introduced. Regional institutions such as pest management co-operatives and districts and the factors which affect their introduction and successful operation are considered.     

The Evaluation of Aerial Application Systems1

There is no single measurement technique suitable for the evaluation of all aerial application systems, since the type of measurement required, and the technique used to obtain it, are dependent on the application method. In this paper, techniques used by the authors to assess atomiser performance, droplet dispersion, deposition, and aircraft swath width are described. The applicability of each technique to various application methods is described.     

The Performance of Rotating Metal-Foam Atomisers1

Prototype rotating metal-foam atomisers, designed for aerial application, have been extensively tested both in the laboratory and under field conditions. Laboratory tests were carried out in a wind tunnel and field tests in a large-scale aerial operation. The metal-foam atomisers showed advantages in droplet-spectrum control and vibration levels over currently available equipment, and, when used to spray 150,000 ha of cotton, four units required no maintenance. Rotating metal foam atomisers can operate safely at the high rotational speeds used for medium volume spraying of droplets with a diameter less than 50 μm (as in tse-tse control).