20 research outputs found
Evaluation of Different Integrate Turf Management Programs to Reduce Microdochium Patch
To reduce the dependency of fungicides in treating turf grass diseases we investigated the use of biostimulants and colour pigments and their capacity to prevent the proliferation of microdochium and anthracnose on annual meadow grass (Poa annua). The study was conducted in two sites (Landvik, Norway and Bingley, United Kingdom) for two years (May 2020 – May 2022). The biostimulant Hicure could reduce the fungicidal use from three to two without loss of efficiency in treating the fungal diseases. The biostimulant also preserved the visual quality of the turf grasses when reducing the fungicidal treatment from three to two. The colour pigment Ryder in all treatments was effective at increasing the colour intensity of the turf grasses compared to the control. Additionally, the biostimulant treatments could treat anthracnose better than the fungicidal only treatment. The biostimulant Hicure and the colour pigment Ryder have potential for further research and development to reduce the use of fungicides while simultaneously preserving the pristine quality of turf grasses in golf greens.Evaluation of Different Integrate Turf Management Programs to Reduce Microdochium PatchpublishedVersio
Spatial Bi-hourly Variation of Alternaria Spore Concentration in Worcester, UK
Alternaria species are ubiquitous fungi affecting food security and human health. They are pathogenic on many economically important crops and allergenic to many sensitive people worldwide. Studies from Worcester, UK have shown high a concentration of Alternaria spores, most likely caused by agricultural activities. However, it is unknown whether Alternaria spore concentrations vary geographically throughout Worcestershire. An investigation on the spatial variation in bi-hourly concentration of Alternaria spores in Worcestershire during 2016 and 2017 was conducted. Spores were sampled using two Hirst-type Burkard spore traps at the University of Worcester. One on the rooftop of a building at St John’s Campus and another at Lakeside Campus approximately 7 km away. St John’s Campus is located in the centre of Worcester (52.1970, -2.2421), while Lakeside Campus is located in an agricultural environment (52.2537, -2.2535) with regularly cut grass in the near surroundings. Slides were counted using bi-hourly traverse at x 400 magnification. The total number of spores per slide were converted to the daily mean of spores m¯³ of air. There was a highly positive correlation in the concentration of Alternaria spores between the two sites in both 2016 and 2017. St John’s had the highest peak of spore concentration (213 m¯³) in 2016 and Lakeside had the peak concentration in 2017 (184 m¯³). Concentrations above 100 m¯³ of air were observed more frequently at Lakeside. The study revealed that Alternaria spore concentrations were higher at Lakeside than at St John’s. This could be attributed to spores released from either crops or agricultural activities (e.g. haying or harvesting) or from decomposed grass since the surrounding area is routinely managed. Further work in 2018 will include spore correlations with weather variables from a pair of weather stations located at each site, enabling studies caused by variations in weather and climate. Spatial variation in bi-hourly spore concentrations is useful information to atopic subjects, health experts and crop pathologists.
Keywords: Harvesting. Allergy. Fungal Spores
Aerobiology Meets Ecology: Development of Low-Cost Passive Gravitational Samplers
Access to proper and reliable research equipment is crucial in all natural science disciplines. This is especially true in biological research since experiments and observations require equipment that will show the same thing consistently. One method often utilized is called sampling, and it means collecting something by using a strict protocol. Our research is focused around sampling pollen and other biological particles from the air around us. If we want to sample particles in the air from locations where there is no electricity, the type of devices we can use limits us. This has led us to develop a sampler that does not require any electrical power; this technique is often referred to as passive sampling. We have created samplers with the design Sigma-2. It works by using a double wall and apertures with strategic placement to deflect the wind, and particles it carries, which then fall into a collection container within the sampler. In this poster we detail the construction, use and analysis using this passive sampler along with methods used to conduct quality control, to ensure that the results we acquire are reliable, replicable and comparable to other samplers
Spatial Flowering Patterns in Dactylis glomerata Populations
Background:
Dactylis glomerata is thought to be one of the major contributors to the annual grass pollen load in temperate regions due to wide distribution, high abundance and high pollen production. Detailed information about its flowering dynamics may therefore help in assessing the severity of the grass pollen season. Grass flora estimates of the flowering period are not enough to determine when the species is capable or most likely to release pollen. Observing multiple grass populations over time would enhance the detail and understanding of the flowering dynamics and reveal the variation in flowering events within a region.
Methods:
Eight populations were chosen in Worcestershire, UK in 2018, with minimum 150 individual tillers each to secure full variation within each population. Flowering progression was determined from the BBCH scale adapted from cereal monitoring. The phenology was focused on the percentage of extruded anthers, with equal intervals of 25, 50, 75 and 100%. Senescence was considered reached with the detachment of the last anther to avoid ambiguity in terms of pollen emission. The two main populations were observed every second day while the six secondary populations were observed ten times during the season.
Results:
A total of 2672 tillers were observed. The spatial investigation highlighted the uniformity of flowering progression between both main and secondary populations, with a mean seasonal difference of less than 1/10th of a phase. Both main populations started to flower on May 29th. The main populations reached peak flowering on June 14th while the average population reached full flowering on June 20th. Peak flowering is reached earlier than average full flowering in all populations due to the divergent growth progression of individual Dactylis tillers. The flowering ended on Aug 9th, 73 days later.
Conclusion:
This study highlights that Dactylis glomerata flowering is uniform over an entire region. There is little to no difference between populations in the timing of crucial flowering events such as start, peak and full flowering. It also notes the difference between peak and full flowering, which will be of importance in the aspect of pollen release
Effekter av gjødsling med nitrogen og aske i et rikt granbestand på Østlandet
I norsk skog på mineraljord er det stort sett nitrogen (N) som gir positivt utslag på trærnes vekst. Men også andre næringsstoffer kan i visse tilfeller øke veksten, blant annet i bestand på høy bonitet. Treaske inneholder både fosfor og kalium i tillegg til andre næringsstoffer, og har en kalkvirkning. Asken kan derfor være en bærekraftig gjødselressurs. I 2012 ble det anlagt et forsøk i Hobøl, Viken, hvor en rik granskog ble gjødslet med N (15 kg per daa), treaske (300 kg per daa) og en kombinasjon. Vi studerte effektene på trær, vegetasjon og jordsmonn. Humuskjemien ble undersøkt før behandling og to år etter, og jordvannkjemien under vekstsesongen i samme periode. Trærnes tilvekst ble undersøkt etter fem og ti år, og effekter på vegetasjonen etter to og ni. Ren N-gjødsling ga en viss effekt på trærnes tilvekst. Etter ti år var det ikke lenger økt årringvekst etter N-gjødsling. Derimot var effekten av å tilføre aske sammen med N god. Effekten av ren aske var liten i starten, men stigende gjennom perioden. Resultatene bekrefter at asketilførsel på fastmark kan gi positive tilveksteffekter på felt med god bonitet, men særlig i kombinasjon med N. To år etter gjødsling fant vi små effekter på mangfold av karplanter, men redusert mangfold av moser og lav. Antall og dekning av urter hadde økt i alle gjødslingsbehandlingene etter ni år, mens artsmangfold av bladmoser og levermoser var ytterligere redusert. Dekningen av blåbær og store moser som etasjemose og furumose økte i alle behandlinger, og antyder at andre faktorer enn gjødslingen også bidro. Det ble ikke funnet signifikante effekter av å tilføre aske eller aske + N på karbon- eller N-innholdet i humusen. Plantetilgjengelig konsentrasjon av flere andre stoffer som aluminium, kobolt, jern, nikkel, bly og sink gikk ned etter asketilførsel. Jordvannet viste kortvarige økninger av nitrat, ammonium og ulike grunnstoffer, samt lavere pH, etter tilførsel av N. Askegjødsling ga ikke effekter på jordvannkjemien.Effekter av gjødsling med nitrogen og aske i et rikt granbestand på ØstlandetpublishedVersio
Assessment of the Relationship Between the Grass Pollen Season and Flowering Phenology in Dactylis glomerata
Pollen season trends as markers of climate change impact:Betula, Quercus and Poaceae
The incidences of respiratory allergies are at an all-time high. Pollen aeroallergens can reflect changing climate, with recent studies in Europe showing some, but not all, pollen types are increasing in severity, season duration and experiencing an earlier onset. This study aimed to identify pollen trends in the UK over the last twenty-six years for a range of pollen sites, with a focus on the key pollen types of Poaceae (grass), Betula (birch) and Quercus (oak) and to examine the relationship of these trends with meteorological factors.
Betula pollen seasons show no significant trends for onset, first high day or duration but increasing pollen production in the Midlands region of the UK is being driven by warmer temperatures in the previous June and July. Quercus pollen seasons are starting earlier, due to increasing temperature and sunshine totals in April, but are not becoming more severe. The seasons are lasting longer, although no significant climate drivers for this were identified. The first high day of the Poaceae pollen season is occurring earlier in central UK regions due to an increasing trend for all temperature variables in the previous December, January, April, May and June. Severity and duration of the season show no significant trends and are spatially and temporally variable.
Important changes are occurring in the UK pollen seasons that will impact on the health of respiratory allergy sufferers, with more severe Betula pollen seasons and longer Quercus pollen seasons. Most of the changes identified were caused by climate drivers of increasing temperature and sunshine total. However, Poaceae pollen seasons are neither becoming more severe nor longer. The reasons for this included a lack of change in some monthly meteorological variables, or land-use change, such as grassland being replaced by urban areas or woodland
Spatial and Temporal Variance of Bi-hourly Grass Pollen Concentrations in the Local Surroundings of Worcester, UK
B:
Grass pollen is the most important aeroallergen worldwide and the health outcome among sensitive individuals is closely related to exposure. It has been argued that grass pollen concentrations can be expected to vary substantially within the urban environment, partly due to source distribution and partly due to dispersion and deposition mechanisms. Most studies conducted on local spatial and temporal variance of pollen concentrations are from one season. Only a few studies include multiple seasons and the results are inconclusive. The patterns and factors responsible for local spatial and temporal pollen variance are still largely unknown. Bi-hourly pollen data provides finer temporal resolution than the standardized daily data otherwise used. Bi-hourly data collected from two sampling sites are used to investigate local spatial and temporal patterns of grass pollen concentrations in Worcester.
M:
Grass pollen was sampled from two locations in Worcester during the years 2016 and 2017 using a Burkard sampler. Daily and bi-hourly grass pollen concentrations were investigated for temporal and spatial variance using statistical methods by comparing years and locations. The investigation is being repeated for the year 2018.
R:
Preliminary results from 2016 and 2017 suggest that there is a high spatial correlation for the bi-hourly concentrations in 2016 but not in 2017. In 2016, all recorded peaks except one coincide with a corresponding peak. In 2017, the highest peak coincided with a corresponding peak but the rest of the data did not. Results from 2018 are currently unknown.
C:
Spatial and temporal variance in grass pollen concentrations fluctuates between years and locations. Peak concentrations tend to have the highest correlations compared to low concentrations. The results show that at least two years of data are needed to establish potential autocorrelation between nearby sites. Future work needs to include longer time-series, more locations and local grass source maps to understand key underlying factors of localized grass pollen concentrations
Air mass trajectories and land cover map reveal cereal crops as major local sources of Alternaria spores in Worcester and Leicester, UK.
Alternaria is a plant pathogen and human allergen. Agricultural areas are known sources of Alternaria spores. Transport of Alternaria spores may occur between such geographical regions. This study examined Alternaria spore abundance and potential pathways for atmospheric transport of the spores between the cities of Worcester and Leicester in the UK, both surrounded by agricultural land. Alternaria spores were sampled using Burkard volumetric samplers for the period 2016-2018 at Worcester and Leicester, located ~90 km apart. The Hybrid Single-Particle Lagrangian Integrated Trajectory (HYSPLIT) model and UK’s land cover map for crops were used to examine the relationship between air mass trajectories and potential source areas of Alternaria spores at the two locations during an episode (27 Jul-07 Aug 2017) of high spore concentrations. During the 3 years of observation, 61 and 151 days of clinical relevance were recorded at Worcester and Leicester, respectively. Spore concentrations at Leicester were considerably higher than in Worcester. Analysis of the crop map showed higher amounts of winter barley and oilseed rape near to Leicester than Worcester. HYSPLIT calculations showed that during the episode, the air masses arrived at both stations from Ireland and the Atlantic Ocean. Long distance transport probably had a small and equal contribution to the observations at both sites. The hypothesis is therefore that the substantially higher concentrations of Alternaria spores at Leicester are caused by specific local sources with high emission potential: potentially winter barley and oilseed rape. Local sources of winter barley and oilseed rape likely contributed to Alternaria spore concentrations of clinical significance in the urban areas of Leicester and Worcester. The strength of the local sources likely resulted in higher emissions of spores at Leicester than at Worcester. Long distance transport probably had a small but equal contribution to the total spore load at the two stations
Near-ground Effect of Height on Pollen Exposure
The effect of height on pollen concentration is not well documented and little is known about the near-ground
vertical profile of airborne pollen. This is important as most measuring stations are on roofs, but patient
exposure is at ground level. Our study used a big data approach to estimate the near-ground vertical profile
of pollen concentrations based on a global study of paired stations located at different heights. We
analyzed paired sampling stations located at different heights between 1.5 and 50m above ground level (AGL). This provided pollen data from 59 Hirst-type volumetric traps
from 25 different areas, mainly in Europe, but also covering North America and Australia, resulting in about
2,000,000 daily pollen concentrations analyzed. The daily ratio of the amounts of pollen from different heights
per location was used, and the values of the lower station were divided by the higher station. The lower station
of paired traps recorded more pollen than the higher trap. However, while the effect of height on pollen concentration
was clear, it was also limited (average ratio 1.3, range 0.7–2.2). The standard deviation of the pollen
ratio was highly variable when the lower station was located close to the ground level (below 10m AGL). We
show that pollen concentrations measured at >10m are representative for background near-ground levels