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.

In growth room regimes arranged to simulate field conditions which coincide with natural infection of oilseed rape by Leptosphaeria maculans, leaf inoculation resulted in systemic infection. After colonizing intercellular spaces in the spongy mesophyll of the lamina, the fungus reached a vascular strand and spread down the petiole mainly in xylem vessels or between cells of the xylem parenchyma and cortex, eventually invading and killing cells of the stem cortex and causing the stem canker symptom. The intercellular systemic phase of growth, which was biotrophic and virtually sytnptomless, occurred under a wide range of temperatures.

The main source of Leptosphaeria maculans (Desm.) Ces. & de Not. infection on winter oilseed rape in Cambridgeshire was stubble debris from the previous season. Heavy leaf spot infection of seedlings near unploughed oilseed rape stubble resulted in complete crop loss. The fungus actively colonised stubble debris after harvest and perithecia were formed predominantly on tissues colonised during this period. Ascospores were detected throughout the year, mainly from October to April. The degree of leaf spot infection in the autumn was correlated with stem canker infection at the end of flowering and with severe stem lesions at harvest. The incidence of leaf spot infection was greater in the spring than in the autumn, particularly during the period of extension growth and early flowering. Stem canker infections were first seen in March and continued to develop up to and after harvest.

No abstract

No abstract

FHB is one of the most devastating fungal cereal diseases worldwide. As the pathogen overwinters on crop residues, application of antagonists on residues of the previous crop during harvest could be a promising approach to efficiently control FHB in cereals as an essential part of an integrated disease management.

To assess the in vitro activity of three phenolic acids (ferulic acid, p-hydroxybenzoic acid, vanillic acid) and two flavonols (quercetin, rutin) on mycelial growth and mycotoxin accumulation of Fusarium graminearum (FG), F. langsethiae (FL) and F. poae (FP), two different approaches were chosen. First, grains from oat varieties were inoculated with a suspension of three FL isolates to determine the influence of phenolic compounds on the accumulation of mycotoxins. The oat variety Zorro showed a tendency for lower accumulation of T-2/HT-2, diacetoxyscirpenol and neosolaniol. Second, a mycelium growth assay was conducted to follow FG, FL and FP growth on cereal based media supplemented with phenolic compounds. Increasing concentrations of ferulic acid substantially inhibited growth of FG and FL, while FP growth was reduced to 57%. In contrast, p-hydroxybenzoic acid, vanillic acid, quercetin, and rutin slightly stimulated mycelium growth. Results about mycotoxin production in cereal based media were less conclusive.

Fusarium head blight is one of the most important cereal diseases worldwide. Cereals differ in terms of the main occurring Fusarium species and the infection is influenced by various factors, such as weather and cropping measures. Little is known about Fusarium species in barley in Switzerland, hence harvest samples from growers were collected in 2013 and 2014, along with information on respective cropping factors. The incidence of different Fusarium species was obtained by using a seed health test and mycotoxins were quantified by LC-MS/MS. With these techniques, the most dominant species, F. graminearum, and the most prominent mycotoxin, deoxynivalenol (DON), were identified. Between the three main Swiss cropping systems, Organic, Extenso and Proof of ecological performance, we observed differences with the lowest incidence and toxin accumulation in organically cultivated barley. Hence, we hypothesise that this finding was based on an array of growing techniques within a given cropping system. We observed that barley samples from fields with maize as previous crop had a substantially higher F. graminearum incidence and elevated DON accumulation compared with other previous crops. Furthermore, the use of reduced tillage led to a higher disease incidence and toxin content compared with samples from ploughed fields. Further factors increasing Fusarium infection were high nitrogen fertilisation as well as the application of fungicides and growth regulators. Results from the current study can be used to develop optimised cropping systems that reduce the risks of mycotoxin contamination.