Currently, European farmers do not have access to sufficient numbers and diversity of crop species/varieties. This prevents them from designing cropping systems more resilient to abiotic and biotic stresses. Crop diversification is a key lever to reduce pest (pathogens, animal pests and weeds) pressures at all spatial levels from fields to landscapes. In this context, plant breeding should consist of: (1) increased efforts in the development of new or minor crop varieties to foster diversity in cropping systems, and (2) focus on more resilient varieties showing local adaptation. This new breeding paradigm, called here ‘breeding for integrated pest management (IPM)’, may boost IPM through the development of cultivars with tolerance or resistance to key pests, with the goal of reducing reliance on conventional pesticides. At the same time, this paradigm has legal and practical implications for future breeding programs, including those targeting sustainable agricultural systems. By putting these issues into the context, this article presents the key outcomes of a questionnaire survey and experts' views expressed during an EU workshop entitled ‘Breeding for IPM in sustainable agricultural systems’. © 2017 Society of Chemical Industry

There is limited understanding of the genetic variability in Phytophthora infestans in the major potato cultivation region of north-western Russia, where potato is grown primarily by small households with limited chemical treatment of late blight. In this study, the mating type, sensitivity to metalaxyl, and genotype and population genetic diversity (based on 12 simple sequence repeat (SSR) markers) of 238 isolates of P. infestans from the Pskov region during the years 2010–2013 were characterized. The aim was to examine the population structure, phenotypic and genotypic diversity, and the prevalent reproductive mode of P. infestans, as well as the influence of the location, time, and agricultural management practices on the pathogen population. The frequency of the A2 mating was stable over the four seasons and ranged from 33 to 48% of the sampled population. Both mating types occurred simultaneously in 90% of studied fields, suggesting the presence of sexual reproduction and oospore production in P. infestans in the Pskov region. Metalaxyl-sensitive isolates prevailed in all four years (72%), however, significantly fewer sensitive isolates were found in samples from large-scale conventional fields. A total of 50 alleles were detected in the 141 P. infestans isolates analyzed for genetic diversity. Amongst the 83 SSR multilocus genotypes (MLGs) detected, 65% were unique and the number of MLGs varied between locations from 3 to 20. These results, together with the high genotypic diversity observed in all the locations and the lack of significance of linkage disequilibrium, suggest that sexual recombination is likely responsible for the unique MLGs and the high genetic diversity found in the Pskov region population, resembling those of north-eastern European populations.

Efficacy of the fungicide tebuconazole was tested in 2 treatment regimes in 3 spring barley varieties over three years (2003–2005). The impact of the fungicide on the control of major barley pathogens Pyrenophora teres and Cochliobolus sativus, as well as kernel yield was studied in the course of field trials. The fungicide treatments had a strong impact on the control of infection of P. teres and increased kernel yield in variable disease infection conditions. For the more resistant genotype, fungicide application had relatively low returns because of the much higher level of biological resistance and small disease-related yield reductions. For the susceptible genotype, severe disease infection caused bigger yield reduction, not compensated by the use of fungicides. Use of fungicide demonstrated the highest economic return in the case of the moderately susceptible barley variety.;

Late blight ( Phytophthora infestans ) is a major disease in potato cultivation, managed primarily with synthetic fungicides. This reliance makes potatoes one of the crops with the highest fungicide load. To reduce chemical dependence and promote integrated pest management (IPM), alternative solutions are needed. This study explores biological control agents (BCAs) and plant resistance inducers (PRIs) as sustainable alternatives. We screened 17 BCAs and 3 PRIs in a detached leaf assay (DLA) and selected the most effective for further trials. The chosen BCAs—Polyversum ( Pythium oligandrum ), Nvs 2 ( Bacillus amyloliquefaciens ), TC 4 ( Trichoderma atroviride ), TC 6 ( T. harzianum )—and the PRI ChiProPlant (Chitosan hydrochloride) were tested in glasshouse and field trials across five European countries. In glasshouse trials, ChiProPlant and T. atroviride significantly controlled late blight. The applied doses did not affect the efficacy of most BCAs and PRI; however, application timing proved to be crucial in the glasshouse trials. Treatments applied 1 and 5 days before inoculation were most effective, while post-inoculation treatments were least effective. Field trials showed that weekly applications of ChiProPlant, Polyversum, and Bacillus amyloliquefaciens significantly reduced late blight infection. However, none matched the efficacy of synthetic fungicides. This study highlights the potential of BCAs and PRIs in late blight management but underscores the need for further research to optimize their integration into IPM strategies.

Tomato ( Solanum lycopersicum L.) is an economically important vegetable susceptible to various fungal diseases, including leaf spot caused by Alternaria spp. from the section Alternaria. In our study, a total of 72 tomato- associated Alternaria spp. strains from Latvia, Lithuania, Estonia, and Algeria were analysed by integrating morphological data, pathogenicity assay, multi-locus phylogeny, and haplotype assignment. Recovered Alternaria spp. strains were characterized by considerable variation in phenotypic diversity, non-pathogenicity to their host of origin and absence of the AAL-toxin biosynthesis gene (ALT1). Multi-locus phylogeny of the RNA polymerase II second largest subunit (rpb2), putative F-box-domain-containing protein ( ASA-10 ), and putative histone-like transcription factor ( ASA-19 ) confirmed the occurrence of both A. alternata and A. arborescens species complexes along with A. longipes and A. postmessia on symptomatic tomatoes. The discordant tree topology among single-gene phylogenies suggested the occurrence of potential recombination between phylogenetic lineages in the section Alternaria, resulting in putative alternata-arborescens and alternata-longipes hybrids. DNA polymorphism analysis of the rpb2, ASA-10, and ASA-19 loci revealed a high level of genetic diversity in the section Alternaria, and the number of single nucleotide polymorphisms (SNPs) and haplotypes varied among loci and lineages studied. A total of 16 and 6 multi-locus haplotypes were assigned in alternata and arborescens lineages, respectively. Global genetic diversity analysis of A. alternata and A. arborescens strains at the rpb2 locus confirmed that major haplotypes described from tomatoes were shared among other hosts of origin.

This study explores the population dynamics of Phytophthora infestans in Estonia from 2005 to 2022, focusing on genetic diversity and potential shifts in reproductive strategies. In total, 153 P. infestans isolates were collected throughout Estonia over ten growing seasons. Genotyping revealed considerable genetic diversity, with most isolates not corresponding to known multilocus genotypes (MLGs). Still, instances of invasive clonal lineages were observed, notably EU_41_A2. The data indicate the likelihood of random mating rather than clonal reproduction in all the analyzed years. The principal coordinate analysis (PCoA) results revealed no distinct clustering among the sampling years. Statistical analysis and the minimum spanning network (MSN) indicated low genetic differentiation between years with minimal fluctuations in allele frequencies. The continuous monitoring of P. infestans populations is essential for detecting any changes from the current evolutionary trajectory and implement effective disease management strategies, especially considering the recent emergence of EU_41_A2 in the Nordics and the potential impacts of climate change.