Temporal and spatial dynamics of Fusarium spp. and mycotoxins in Swedish cereals during 16 years

We analysed the dynamics of Fusarium spp. and mycotoxin contamination in Swedish cereals during 2004-2018. More than 1400 cereal samples from field trials were included, collected in a monitoring programme run by the Swedish Board of Agriculture. Five Fusarium mycotoxins were quantified with LC-MS/MS and fungal DNA from four species was quantified using quantitative real-time PCR. Correlation analyses revealed that deoxynivalenol (DON) and zearalenone (ZEN) were mainly associated with Fusarium graminearum, but stronger correlations with F. culmorum was seen some years. Nivalenol (NIV) was associated with F. poae and the HT-2 and T-2 toxins with F. langsethiae. Clear differences in mycotoxin contamination between different cereal crops and geographical regions were identified. The highest levels of DON and ZEN were found in spring wheat in Western Sweden. For NIV, HT-2 and T-2 toxins, the levels were highest in spring oats and spring barley. Regional differences were not detected for NIV, while HT-2 and T-2 toxins were associated with the northernmost region. We found that delayed harvest was strongly associated with increased levels of DON and ZEN in several crops. However, harvest date did not influence the levels of NIV or HT-2 and T-2 toxins. Our results suggest similar distribution patterns of DON and ZEN, in contrast to NIV and HT-2 and T-2 toxins, probably mirroring the differences in the ecology of the toxin-producing Fusarium species. Timely harvest is important to reduce the risk of DON and ZEN contamination, especially for fields with other risk factors

Individual tree detection and estimation of stem attributes with mobile laser scanning along boreal forest roads

The collection of field-reference data is a key task in remote sensing-based forest inventories. However, traditional methods of collection demand extensive personnel resources. Thus, field-reference data collection would benefit from more automated methods. In this study, we proposed a method for individual tree detection (ITD) and stem attribute estimation based on a car-mounted mobile laser scanner (MLS) operating along forest roads. We assessed its performance in six ranges with increasing mean distance from the roadside. We used a Riegl VUX1LR sensor operating with high repetition rate, thus providing detailed cross sections of the stems. The algorithm we propose was designed for this sensor configuration, identifying the cross sections (or arcs) in the point cloud and aggregating those into single trees. Furthermore, we estimated diameter at breast height (DBH), stem profiles, and stem volume for each detected tree. The accuracy of ITD, DBH, and stem volume estimates varied with the trees' distance from the road. In general, the proximity to the sensor of branches 0-10 m from the road caused commission errors in ITD and over estimation of stem attributes in this zone. At 50-60 m from roadside, stems were often occluded by branches, causing omissions and underestimation of stem attributes in this area. ITD's precision and sensitivity varied from 82.8% to 100% and 62.7% to 96.7%, respectively. The RMSE of DBH estimates ranged from 1.81 cm (6.38%) to 4.84 cm (16.9%). Stem volume estimates had RMSEs ranging from 0.0800 m(3) (10.1%) to 0.190 m(3) (25.7%), depending on the distance to the sensor. The average proportion of detected reference volume was highly affected by the performance of ITD in the different zones. This proportion was highest from 0 to 10 m (113%), a zone that concentrated most ITD commission errors, and lowest from 50 to 60 m (66.6%), mostly due to the omission errors in this area. In the other zones, the RMSE ranged from 87.5% to 98.5%. These accuracies are in line with those obtained by other state-of-the-art MLS and terrestrial laser scanner (TLS) methods. The car-mounted MLS system used has the potential to collect data efficiently in large-scale inventories, being able to scan approximately 80 ha of forests per day depending on the survey setup. This data collection method could be used to increase the amount of field-reference data available in remote sensing based forest inventories, improve models for area-based estimations, and support precision forestry development

Effekter av olika växtföljder på rotröta hos klöver

We studied effects of crop rotations with different amounts of grass/clover ley, especially the effect of fodder rape on the development of clover root rot in red clover. Clover plants, one to three and a half years old, with the root-system were collected from a long-term crop rotation experiment in spring and late autumn. Disease severity index (DSI) of clover root rot and the abundance of the clover root rot causal organism Fusarium avenaceum was evaluated. The results showed that development of clover root rot clearly depends on the age of clover plants regardless of the cropping system. Even though there was a higher abundance of F. avenaceum in one year old clover from crop rotations with more ley, this effect did not persist with increasing age of clover. We did not find any robust correlation between the level of DSI and the abundance of F. avenaceum in clover root. In conclusion, the crops and crop rotations used in this long term-experiment were not effective as control of clover root rot and did not increase the longevity of clover in the leys. This project has been financed by The Royal Swedish Academy of Agriculture and Forestry

Concentration- and time-dependent effects of isothiocyanates produced from Brassicaceae shoot tissues on the pea root rot pathogen Aphanomyces euteiches

Isothiocyanates (ITCs) hydrolyzed from glocosinolates (GSLs) in Brassicaceae tissue are toxic to soil organisms. In this study, the effect of aliphatic and aromatic ITCs from hydrated dy Brassicaceae shoot tissues on the mycelium and oospores of the pea root rot pathogen Aphanomyces euteiches was investigated. The profile and concentrations of GSLs in two test Brassicaceae species, Sinapis alba and Brassica juncea, and the ITCs from the dominant hydrolyzed parent GSLs were monitored. The concentrations of dominant ITCs and pathogen exposure time were evaluated in in vitro experiments. The greatest effect on the pathogen was observed from aliphatic ITCs hydrolyzed from B. juncea tissue, and the effect depended on the ITS concentration and exopsure time. ITCs were more effectively hydrolyzed from B. juncea GSLs than from S. alba GSLs; i.e., the ITC/GSL ratio was higher in B. juncea than in S. albatissue, giving a different release pattern. The release of phenylethyl isothiocyanate, which was common to both species, followed a pattern similar to that of the dominant ITC in each crop speices. This suggests that trait other than GSL content, e.g., plant cell structure, may affect the release of ITCs ans should therefore influence the choice of speices used for biofumigation purposes

Pelargon- och begoniabakterios

Pelargonbakterios (Xanthomonas hortorum pv. pelargonii, syn. Xanthomonas pelargonii) och begoniabakterios (Xanthomonas axonopodis pv. begoniae, syn. Xanthomonas camperstris pv. be· goniae) är vanligt förekommande sjukdomar, som kan orsaka odlarna stora förluster. Bakterierna kan finnas i plantorna utan att plantorna uppvisar några symptom. Bakteriesjukdomarna är omöjliga att bekämpa när väl plantorna är angripna. Nya friska plantor i ett smittfritt växthus är bästa lösningen, men det är inte alltid lätt att uppnå

Agricultural factors affecting Fusarium communities in wheat kernels

Fusarium head blight (FHB) is a devastating disease of cereals caused by Fusarium fungi. The disease is of great economic importance especially owing to reduced grain quality due to contamination by a range of mycotoxins produced by Fusarium. Disease control and prediction is difficult because of the many Fusarium species associated with FHB. Different species may respond differently to control methods and can have both competitive and synergistic interactions. Therefore, it is important to understand how agricultural practices affect Fusarium at the community level.Lower levels of Fusariwn mycotoxin contamination of organically produced cereals compared with conventionally produced have been reported, but the causes of these differences are not well understood. The aim of our study was to investigate the effect of agricultural factors on Fusarium abundance and community composition in different cropping systems. Winter wheat kernels were collected from 18 organically and conventionally cultivated fields in Sweden, paired based on their geographical distance and the wheat cultivar grown. We characterised the Fusarium community in harvested wheat kernels using 454 sequencing of translation elongation factor 1-alpha amplicons. In addition, we quantified Fusariwn spp. using real-time PCR to reveal differences in biomass between fields.We identified 12 Fusariwn operational taxonomic units (OTUs) with a median of 4.5 OTUs per field. Fusarium graminearum was the most abundant species, while F. avenaceum had the highest occurrence. The abundance of Fusariwn spp. ranged two orders of magnitude between fields. Two pairs of Fusariurt species co-occurred between fields: F. poae with F. tricinctwn and F. culmorwn with F. sporofrichoides. We could not detect any difference in Fusariwn communities between the organic and conventional systems. However, agricultural intensity, measured as the number of pesticide applications and the amount of nitrogen fertiliser applied, had an impact on Fusariwn communities, specifically increasing the abundance of F. tricinctwn. There were geographical differences in the Fusarium community composition where F. graminearwn was more abundant in the western part of Sweden. The application of amplicon sequencing provided a comprehensive view of the Fusarium community in cereals. This gives us better opportunities to understand the ecology of Fusarium spp., which is important in order to limit FHB and mycotoxin contamination in cereals

Body mass index best predicts recovery of recombinant factor VIII in underweight to obese patients with severe haemophilia A

Background Factor VIII (FVIII) products are usually dosed according to body weight (BW). This may lead to under- or over-dosing in underweight or obese patients, respectively. Objective This article evaluates the pharmacokinetics (PK) of recombinant FVIII concentrate, particularly recovery, in relation to body mass index (BMI) and other body composition descriptors. Materials and Methods Thirty-five previously treated adults with severe haemophilia A from five BMI categories (underweight, normal, overweight, obese class I and II/III) were included. PK was evaluated after 50 IU per kilogram of BW single-dose recombinant FVIII (turoctocog alfa). The body composition variable was based on measurements of weight, height, bioimpedance analysis, and dual-energy X-ray absorptiometry. A dosing model was derived to achieve similar peak FVIII activity levels across BMI categories. Results A statistically significant positive association between BMI and C30min, IR30min, and AUC0–inf was observed; CL and Vss showed a significant negative association with BMI; t½ was independent of BMI and other parameters. The dosing model introduced a correction factor ‘M’ for each BMI category, based on linear regression analysis of C30min against BMI, which ranged from 0.55 for underweight to 0.39 for obese class II/III. This model achieved similar peak FVIII activity levels across BMI categories, estimating an average dose adjustment of þ243.3 IU (underweight) to –1,489.6 IU (obese class II/III) to achieve similar C30min. Conclusion BMI appears to be the best predictor of recombinant FVIII recovery; however, PK endpoints were also dependent on other body composition variables. The model demonstrated that dosing can be adjusted for individual BMI to achieve better FVIII predictability across BMI categoriesThis work was funded by Novo Nordisk A/S (Bagsværd, Denmark)