Political efforts are made in the European Union (EU) to reduce pesticide use and to increase the implementation of integrated pest management (IPM). Within the EU project ENDURE, research priorities on pesticide reduction are defined. Using maize, one of the most important crops in Europe, as a case study, we identified the most serious weeds, arthropod pests, and fungal diseases as well as classes and amounts of pesticides applied. Data for 11 European maize growing regions were collected from databases, publications and expert estimates. Silage maize dominates in northern Europe and grain production in central and southern Europe. Crop rotations range from continuous growing of maize over several years to well-planned rotation systems. Weeds, arthropod pests and fungal diseases cause economic losses in most regions, even though differences exist between northern countries and central and southern Europe. Several weed and arthropod species cause increasing problems, illustrating that the goal of reducing chemical pesticide applications is challenging. Pesticides could potentially be reduced by the choice of varieties including genetically modified hybrids, cultural control including crop rotation, biological control, optimized application techniques for chemicals, and the development of more specific treatments. However, restrictions in the availability of alternative pest control measures, farm organization, and the training and knowledge of farmers need to be overcome before the adoption of environmentally friendly pest control strategies can reduce chemical pesticides in an economically competitive way. The complex of several problems that need to be tackled simultaneously and the link between different control measures demonstrates the need for IPM approaches, where pest control is seen in the context of the cropping system and on a regional scale. Multicriteria J. Appl. Entomol.

: Wilted grass and whole-crop maize silages taken from farm silos in northern Germany were analysed for fermentation pattern, mould counts and composition of mycoÑora as well as for roquefortine C. In general, increasing DM contents of visibly unmoulded silages resulted in decreasing amounts of volatile fatty acids and a greater portion of samples with a high number of mould propagules. The average mould count of these silages was found to be 1É4 ] 104 cfu g~1, whereas visibly moulded samples contained about 1 ] 108 cfu g~1. Penicillium roqueforti was the predominating fungal species in silages occasionally accompanied by species of the genera Aspergillus, Mucor, Monascus and/or Geotrichum. Penicillium roqueforti was detected in 89% of the visibly moulded and in 85% of the visibly unmoulded samples. Of 24 visibly moulded silages tested, 21 samples contained roquefortine C, a mycotoxin known to be produced by P roqueforti. The highest level of roquefortine C found was 36 mg kg~1 DM. Even 6 of 24 visibly unmoulded samples analysed for this mycotoxin were contaminated with roquefortine C but only in trace amounts. Roquefortine C is considered as a model compound for the biosynthesis of toxic fungal metabolites produced by P roqueforti in silages. The P roqueforti-count can be employed as a criterion to predict the contamination of silages with mycotoxins produced by this fungal species.1998 SCI. ( J Sci Food Agric 76, 565È572 (1998)

Infections of maize with phytopathogenic and toxinogenic Fusarium spp. may occur throughout the cultivation period. This can cause different types of diseases in vegetative and generative organs of the plant. Along with these infections, mycotoxins are often produced and accumulated in affected tissues, which could pose a significant risk on human and animal health when entering the food and feed chain. Most important fungal species infecting European maize belong to the Fusarium sections Discolour and Liseola, the first being more prevalent in cooler and humid climate regions than the second predominating in warmer and dryer areas. Coexistence of several Fusarium spp. pathogens in growing maize under field conditions is the usual case and may lead to multi-contamination with mycotoxins like trichothecenes, zearalenone and fumonisins. The pathways how the fungi gain access to the target organs of the plant are extensively described in relation to specific symptoms of typical rot diseases regarding ears, kernels, rudimentary ears, roots, stem, leaves, seed and seedlings. Both Gibberella and Fusarium ear rots are of major importance in affecting the toxinogenic quality of grain or ear-based products as well as forage maize used for human or animal nutrition. Although rudimentary ears may contain high amounts of Fusarium toxins, the contribution to the contamination of forage maize is minor due to their small proportion on the whole plant dry matter yield. The impact of foliar diseases on forage maize contamination is regarded to be low, as Fusarium infections are restricted to some parts on the leaf sheaths and husks. Mycotoxins produced in rotted basal part of the stem may contribute to forage maize contamination, but usually remain in the stubbles after harvest. As the probability of a more severe disease progression is increasing with a prolonged cultivation period, maize should be harvested at the appropriate maturity stage to keep Fusarium toxin contamination as low as possible. Ongoing surveillance and research is needed to recognise changes in the spectrum of dominating Fusarium pathogens involved in mycotoxin contamination of maize to ensure safety in the food and feed chain.

Infection with Neotyphodium endophyte was detected in 33 of 38 ecotype populations of Lolium perenne originating from old grassland at four widespread sites in Germany. The frequency of individual infected plants of the different populations ranged mostly from 1% to 30%; a few populations showed higher infection levels, up to 80%. The contribution of endophyte‐positive plants to the biomass of the original swards was estimated to range from 1% to 34%. Concentrations of the indole alkaloid lolitrem B detected in the endophyte‐positive German ecotypes were similar to those in the endophyte‐positive cultivars‘Ellett’and‘Grasslands Nui', originating in New Zealand, when all were cultivated under the climatic conditions of northern Germany. A seasonal variation in lolitrem B concentrations was observed from 1993 to 1996. The highest concentrations, 0·8–1·4 mg kg−1 dry matter of herbage, were recorded during the months of July and August. These concentrations were not considered to be sufficient to induce‘ryegrass staggers', a neurological disorder in grazing animals. It is concluded that further research is necessary to elucidate the implications of grass endophytes under the climatic conditions of Central Europe.

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amount of light energy absorbed by the green foliage, the efficiency of the foliage to use the energy captured Transgenic potatoes (Solanum tuberosum L.) overexpressing Arafor biomass production, and the partitioning of the crop bidopsis thaliana (L.) Heynh. phytochrome B (phyB) have been reported to exhibit a substantially modified plant architecture, increased biomass to the harvested plant part. Because potato has photosynthetic performance, reduced photoinhibition, delayed leaf one of the highest harvest indices of major crops and senescence, and increased tuber yield. A greenhouse and a growth there may be little potential for significant shifts in total chamber experiment were conducted at Braunschweig, Germany, to biomass accumulation, genotypes with superior net phoelucidate the crop physiological basis for the yield differences between Abbreviations: CER, carbon exchange rate; CER max , light-saturated

amount of light energy absorbed by the green foliage, the efficiency of the foliage to use the energy captured Transgenic potatoes (Solanum tuberosum L.) overexpressing Arafor biomass production, and the partitioning of the crop bidopsis thaliana (L.) Heynh. phytochrome B (phyB) have been reported to exhibit a substantially modified plant architecture, increased biomass to the harvested plant part. Because potato has photosynthetic performance, reduced photoinhibition, delayed leaf one of the highest harvest indices of major crops and senescence, and increased tuber yield. A greenhouse and a growth there may be little potential for significant shifts in total chamber experiment were conducted at Braunschweig, Germany, to biomass accumulation, genotypes with superior net phoelucidate the crop physiological basis for the yield differences between tosynthesis will likely be needed for further yield immoderately phyB-overexpressing transgenic (Dara-5) and wild-type provement. Flynn et al. (1998), in a study of a historical potato plants. In the greenhouse experiment, Dara-5 leaves showed series of European potato cultivars, in spite of large a 23% greater leaf carbon exchange rate (CER) at light saturation,

With the focus on minimizingFusarium head blight and the deoxynivalenol (DON) contamination of wheat a three year crop rotation system starting with forage maize and followed by two years of winter wheat was combined with three soil tillage systems and selected plant varieties with varying susceptibility toFusarium infection.Higher DON concentrations were generally observed in wheat grain when the soil was mulched rather than ploughed, depending on the mass of maize residues remaining on the soil surface. Maize residues are the most important source ofFusarium inoculum. Infected maize residues had a main impact on the level of DON contamination in wheat grain particularly in the first year after maize cultivation. When the maize stubble was chopped before mulching, the decomposition of the residues was speeded up and the DON contamination of the wheat grain was lower. In the second year following the maize crop, the decomposition of the maize residues/Fusarium biomass was nearly complete and the infection risk was reduced considerably. An influence of the susceptibility of the maize variety against stem rot on the DON concentration of the succeeding winter wheat crop was not observed. The less susceptible wheat variety was suitable for controlling the higher infection risk deriving from the introduction of maize in wheat rotation and the use of mulching techniques.