Abstract The global sustainability agenda is increasing the demand for reduction in inputs into agricultural production while maintaining profitable yield of quality products. Plant diseases are a major constraint both and product quality, but often tools their control ineffective or lacking. Biological using antagonistic microorganisms has long been subject research resulting wide range products that now available marketed specific territories around world. These preparations niche with...

We used the PCR to study presence of two plant pathogens in archived wheat samples from a long-term experiment started 1843. The data were construct unique 160-yr time-series abundance Phaeosphaeria nodorum and Mycosphaerella graminicola , important wheat. During period since 1970, relative DNA these has reflected importance diseases they cause U.K. disease surveys. Unexpectedly, changes ratio over very strongly correlated with atmospheric pollution, as measured by SO 2 emissions. This...

This paper reviews the evidence relating to question: does risk of fungicide resistance increase or decrease with dose? The development progresses through three key phases. During ‘emergence phase’ resistant strain has arise mutation and invasion. subsequent ‘selection phase’, is present in pathogen population fraction carrying increases due selection pressure caused by fungicide. final phase ‘adjustment’, dose choice may need be changed maintain effective control over a where developed...

Geographic distributions of pathogens are the outcome dynamic processes involving host availability, susceptibility and abundance, suitability climate conditions, historical contingency including evolutionary change. Distributions have changed fast changing in response to many factors, climatic The time arable agriculture is intrinsically fast, but perennial crops especially forests unlikely adapt easily. Predictions variables needed predict changes pathogen range still rather uncertain,...

Measures blocking hybridization would prevent or reduce biotic environmental change caused by gene flow from genetically modified (GM) crops to wild relatives. The efficacy of any such measure depends on hybrid numbers within the legislative region over life-span GM cultivar. We present a national assessment between rapeseed ( Brassica napus ) and B. rapa combination sources, including population surveys, remote sensing, pollen dispersal profiles, herbarium data, local Floras, other...

Epidemics of disease caused by Septoria tritici were studied in detail 11 crops winter wheat cv. Longbow over 4 years. Serious damage to the uppermost two leaf layers was splash‐borne infection from lower crop early life leaves, followed one or rarely cycles multiplication within a layer. Infection conditions limited damage, even dry year; timing and, lesser extent, amount initial inoculum movement an upper layer greater importance. Timing determined when rain splash occurred relation...

The pattern and extent of primary infection by Septoria tritici were compared over a period 3 years in winter wheat grown at sites with differing histories from seed stocks obtained different countries, the open, under airtight cover sterilized soil. Only altered number lesions found, substantially reducing it. Lesions evenly distributed. found throughout autumn occasionally spring on seedlings exposed trays to open air for periods 1 week, then given good conditions occur. This was true even...

Key weather factors determining the occurrence and severity of powdery mildew yellow rust epidemics on winter wheat were identified. Empirical models formulated to qualitatively predict a damaging epidemic (>5% severity) quantitatively disease given occurred. The data used was from field experiments at 12 locations in UK covering period 1994 2002 with matching stations within 5 km range. Wind December February most influential factor for mildew. Disease best identified by model...

Evolution of resistance to drugs and pesticides poses a serious threat human health agricultural production. CYP51 encodes the target site azole fungicides, widely used clinically in agriculture. Azole can evolve due point mutations or overexpression CYP51, previous studies have shown that fungicide-resistant alleles arisen by de novo mutation. Paralogs CYP51A CYP51B are found filamentous ascomycetes, but has been lost from multiple lineages. Here, we show barley pathogen Rhynchosporium...

Succinate dehydrogenase inhibitor (SDHI) fungicides are important in the management of Zymoseptoria tritici wheat. New active ingredients from this group have been introduced recently and widely used. Because act at a single enzyme site, resistance development Z. is classified as medium-to-high risk.Isolates Irish experimental plots 2015 were tested against SDHI penthiopyrad during routine monitoring. The median population was approximately 2 times less sensitive than baseline population....

Visual estimates of wheat disease severity were compared with actual severities determined using image analysis tracings diseased leaves. Septoria tritici , leaf senescence and Erysiphe graminis studied. Observer widely scattered about the (i.e. they imprecise), differed substantially from even after averaging inacctirate), varied considerably over short time‐scales. Relative bias decreased increasing severity. In a comparison three seed treatments to control powdery mildew on winter barley,...

Effects of the B chromosome polymorphism grasshopper Eyprepocnemis plorans were analyzed in two natural populations. Postmating sexual selection, female fertility, and survival studied. The lacks drive has no detectable effects on fitness. A neutral cannot invade a population establish polymorphism, but confidence limits our estimates exclude possibility that is maintained by balance between weak selection against individuals with three B's. However, other lines evidence favor following...

Relationships between weather, agronomic factors and wheat disease abundance were examined to determine possible causes of variability on century time scales. In archived samples grain leaves obtained from the Rothamsted Broadbalk experiment archive (1844-2003), amounts wheat, Phaeosphaeria nodorum Mycosphaerella graminicola DNA determined by quantitative polymerase chain reaction (PCR). pathogens environmental multiple regression. Wheat decayed at approx. 1% yr(-1) in stored grain. No M....

After inoculation of winter wheat cv. Longbow at a single time, lesions M. graminicola were produced over long interval starting 15–35 days after inoculation, dependent on temperature. There was no evidence that infection gave rise to more than one lesion. the initial period 100% relative humidity (r.h.), keeping leaves wet for c. 10 h per day did not shorten latent seedlings. Experiments in controlled‐environment chambers demonstrated minimum approximately 17°C Variation individual also...

Botrytis species are generally considered to be aggressive, necrotrophic plant pathogens. By contrast this general perception, however, could frequently isolated from the interior of multiple tissues in apparently healthy hosts many species. Infection frequencies reached 50% samples or more, but were commonly less, and cryptic infections rare absent some Prevalence varied substantially year tissue tissue, host routinely had high prevalence. The same genotype was found occur throughout a...

Summary The incidence and severity of light leaf spot epidemics caused by the ascomycete fungus P yrenopeziza brassicae on UK oilseed rape crops are increasing. disease is currently controlled a combination host resistance, cultural practices fungicide applications. We report decreases in sensitivity modern . isolates to azole (imidazole triazole) class fungicides. By cloning sequencing CYP51 ( PbCYP51 ) gene, encoding target sterol 14α‐demethylase, we identified two non‐synonymous mutations...