A dunnett-type procedure for multiple endpoints

This paper describes a method for comparisons of several treatments with a control, simultaneously for multiple endpoints. These endpoints are assumed to be normally distributed with different scales and variances. An approximate multivariate t-distribution is used to obtain quantiles for test decisions, multiplicity-adjusted p-values, and simultaneous confidence intervals. Simulation results show that this approach controls the family-wise error type I over both the comparisons and the endpoints in an admissible range. The approach will be applied to a randomized clinical trial comparing two new sets of extracorporeal circulations with a standard for three primary endpoints. A related R package is available. © 2011 Berkeley Electronic Press. All rights reserved

Composition and Predominance of Fusarium Species Causing Fusarium Head Blight in Winter Wheat Grain Depending on Cultivar Susceptibility and Meteorological Factors

Fusarium head blight (FHB) is one of the most important diseases of wheat, causing yield losses and mycotoxin contamination of harvested grain. A complex of different toxigenic Fusarium species is responsible for FHB and the composition and predominance of species within the FHB complex are determined by meteorological and agronomic factors. In this study, grain of three different susceptible winter wheat cultivars from seven locations in northern Germany were analysed within a five-year survey from 2013 to 2017 by quantifying DNA amounts of different species within the Fusarium community as well as deoxynivalenol (DON) and zearalenone (ZEA) concentrations. Several Fusarium species co-occur in wheat grain samples in all years and cultivars. F. graminearum was the most prevalent species, followed by F. culmorum, F. avenaceum and F. poae, while F. tricinctum and F. langsethiae played only a subordinate role in the FHB complex in terms of DNA amounts. In all cultivars, a comparable year-specific quantitative occurrence of the six detected species and mycotoxin concentrations were found, but with decreased DNA amounts and mycotoxin concentrations in the more tolerant cultivars, especially in years with higher disease pressure. In all years, similar percentages of DNA amounts of the six species to the total Fusarium DNA amount of all detected species were found between the three cultivars for each species, with F. graminearum being the most dominant species. Differences in DNA amounts and DON and ZEA concentrations between growing seasons depended mainly on moisture factors during flowering of wheat, while high precipitation and relative humidity were the crucial meteorological factors for infection of wheat grain by Fusarium. Highly positive correlations were found between the meteorological variables precipitation and relative humidity and DNA amounts of F. graminearum, DON and ZEA concentrations during flowering, whereas the corresponding correlations were much weaker several days before (heading) and after flowering (early and late milk stage)

Temporal Changes in Sensitivity of Zymoseptoria tritici Field Populations to Different Fungicidal Modes of Action

Septoria tritici blotch (STB; Zymoseptoria tritici), one of the most important foliar diseases in wheat, is mainly controlled by the intensive use of fungicides during crop growth. Unfortunately, Z. tritici field populations have developed various extents of resistance to different groups of fungicides. Due to the complete resistance to quinone outside inhibitors (QoIs), fungicidal control of STB relies mainly on demethylation inhibitors (DMIs) and succinate dehydrogenase inhibitors (SDHIs) as well as multi-site inhibitors. In this study, temporal changes in the sensitivity of Z. tritici to selected DMIs (tebuconazole, propiconazole, prothioconazole, prochloraz), SDHIs (boscalid, bixafen), and multi-site inhibitors (chlorothalonil, folpet) were determined in microtiter assays using Z. tritici field populations isolated in 1999, 2009, 2014, and 2020 in a high-disease-pressure and high-fungicide-input area in Northern Germany. For the four tested DMI fungicides, a significant shift towards decreasing sensitivity of Z. tritici field populations was observed between 1999 and 2009, whereby concentrations inhibiting fungal growth by 50% (EC50) increased differentially between the four DMIs. Since 2009, EC50 values of tebuconazole, propiconazole, and prochloraz remain stable, whereas for prothioconazole a slightly increased sensitivity shift was found. A shift in sensitivity of Z. tritici was also determined for both tested SDHI fungicides. In contrast to DMIs, EC50 values of boscalid and bixafen increased continuously between 1999 and 2020, but the increasing EC50 values were much smaller compared to those of the four tested DMIs. No changes in sensitivity of Z. tritici were observed for the multi-site inhibitors chlorothalonil and folpet over the last 21 years. The sensitivity adaptation of Z. tritici to both groups of single-site inhibitors (DMIs, SDHIs) mainly used for STB control represents a major challenge for future wheat cultivation

Will Triazoles Still Be of Importance in Disease Control of Zymoseptoria tritici in the Future?

Septoria tritici blotch (STB), caused by Zymoseptoria tritici, is one of the most important foliar wheat diseases worldwide. Current control strategies of STB rely mainly on fungicides, whereby triazoles (demethylation inhibitors; DMIs) have been the backbone in the control of Z. tritici in the last decades. However, in recent years a gradual loss of sensitivity of Z. tritici to several active ingredients of the triazole group has been reported in several European wheat-growing areas. Nevertheless, a new triazole fungicide, namely, mefentrifluconazole, has recently become available in disease management of STB, which belongs to a completely new triazole subclass, the so-called isopropanol triazoles. In this study, the trend in sensitivity development of Z. tritici towards older triazoles (tebuconazole, prothioconazole, and propiconazole) and the new isopropanol triazole mefentrifluconazole was determined in microtiter assays using Z. tritici field populations isolated in 1999, 2009, 2014, and 2020 in a high-disease-pressure and high-fungicide-input area in northern Germany in order to investigate whether the loss of sensitivity of Z. tritici to older triazoles also applies to mefentrifluconazole. For the three triazole fungicides tebuconazole, prothioconazole and propiconazole, a significant shift towards decreasing sensitivity of Z. tritici field populations was observed from 1999 to 2020, whereas the efficacy of mefentrifluconazole in reducing the in vitro fungal growth by 50% (EC50) remained unchanged over the investigated period, demonstrating a stable sensitivity of Z. tritici towards mefentrifluconazole. Although older triazoles are suffering from a loss of sensitivity of Z. tritici field populations due to the selection and spread of less triazole sensitive strains within the Z. tritici population, the efficacy of the new triazole mefentrifluconazole with its unique isopropanol unit was not affected by these changes within the Z. tritici population. Thus, the introduction of such new molecular units could also represent an important contribution for older groups of active ingredients, which previously suffered from a loss of sensitivity

Root and shoot growth of spring wheat (Triticum aestivum L.) are differently affected by increasing subsoil biopore density when grown under different subsoil moisture

A column experiment with five different pore densities (0, 1, 2, 3, and 4 pores column−1) and two varying moisture regimes (comparatively dry and comparatively moist regime) in the subsoil part of the columns was established. In each pore, Lumbricus terrestris was introduced for 28 days before sowing wheat plants. After 40 days of plant growth, watering was stopped to induce progressive topsoil drying. Parameters describing the shoot hydration, mineral uptake, and aboveground biomass were quantified. Root biomass and root length densities (RLD) were measured separately for six soil layers. Under dry subsoil conditions, plants grown under increasing biopore density showed an increase of the RLD and an improved shoot hydration but the aboveground biomass was unaffected. Since RLD but not root biomass was enhanced, it is assumed that roots were able to explore a larger volume of soil with the same amount of root biomass. Thereby, subsoil water likely was used more efficiently leading to an improved hydration. Under moist subsoil conditions, plants grown with increasing biopore density revealed enhanced shoot biomasses and nutrient uptake while the belowground biomass was unaffected. The improved nutrient uptake can be ascribed to, first, the higher subsoil water availability favoring mass flow driven nutrient uptake, and second, to direct and indirect effects of earthworms on the availability of soil nutrients. It is concluded that high biopore abundancies have the potential to improve not only the belowground but also the aboveground biomass. This, however, largely depends on subsoil moisture.Bundesministerium für Bildung, Wissenschaft, Forschung und Technologie http://dx.doi.org/10.13039/501100010571Humboldt-Universität zu Berlin (1034)Peer Reviewe

Can Decision Support Systems Help Improve the Sustainable Use of Fungicides in Wheat?

Wheat is one of the most economically important field crops worldwide. Foliar diseases are a major threat to wheat productivity and are primarily managed by implementing less susceptible cultivars and using fungicides. With the “Farm to Fork” strategy under consideration by the European Union to reduce pesticide usage by 50% by 2030, this elucidates the importance of utilizing decision support systems (DSS) to optimize fungicide applications. Therefore, three DSSs of different origins, namely the IPM-Wheat Model Schleswig-Holstein (scientific), the ISIP system (federal), and the xarvio© FIELD MANAGER (commercial), were analysed under maritime climate conditions at three locations in a high input area of wheat cultivation in northern Germany from 2019 to 2021. Fungicide efficacy was evaluated for yield as well as for the management of prevalent pathogens (Septoria tritici blotch, glume blotch, tan spot, powdery mildew, stripe rust, and leaf rust) on two different commercially available cultivars (highly and moderately susceptible). Compared to a stage-oriented standard system, no significant decrease in yield was observed in both cultivars, despite up to a 50% reduction in fungicide use through the use of DSSs. This was attributed to an optimized timing of fungicide applications, which resulted in slightly lower but still tolerable disease suppression efficacy compared to the stage-oriented system. In conclusion, minor disease severities are often overestimated, and DSSs can help improve the sustainability of fungicide use in wheat and pesticides in general

Silencing of the sulfur rich alpha-gliadin storage protein family in wheat grains (Triticum aestivum L.) causes no unintended side-effects on other metabolites

Zoerb C, Becker D, Hasler M, et al. Silencing of the sulfur rich alpha-gliadin storage protein family in wheat grains (Triticum aestivum L.) causes no unintended side-effects on other metabolites. Frontiers in Plant Science. 2013;4:369.Wheat is an important source of proteins and metabolites for human and animal nutrition. To assess the nutritional quality of wheat products, various protein and diverse metabolites have to be evaluated. The grain storage protein family of the alpha-gliadins are suggested to be the primary initiator of the inflammatory response to gluten in Celiac disease patients. With the technique of RNAi, the alpha-gliadin storage protein fraction in wheat grains was recently knocked down. From a patient's perspective, this is a desired approach, however, this study aims to evaluate whether such a down-regulation of these problematic alpha-gliadins also has unintended side-effects on other plant metabolites. Such uncontrolled and unknown arbitrary effects on any metabolite in plants designated for food production would surely represent an avoidable risk for the consumer. In general, alpha-gliadins are rich in sulfur, making their synthesis and content depended of the sulfur supply. For this reason, the influence of the application of increasing sulfur amounts on the metabolome of alpha-gliadin-deficient wheat was additionally investigated because it might be possible that e.g., considerable high/low amounts of S might increase or even induce such unintended effects that are not observable under moderate S nutrition. By silencing the alpha-gliadin genes, a recently developed wheat line that lacks the set of 75 corresponding alpha-gliadin proteins has become available. The plants were subsequently tested for RNAi-induced effects on metabolites that were not directly attributable to the specific effects of the RNAi-approach on the alpha-gliadin proteins. For this, GC-MS-based metabolite profiles were recorded. A comparison of wild type with gliadin-deficient plants cultivated in pot experiments revealed no differences in all 109 analyzed metabolites, regardless of the S-nutritional status. No unintended effects attributable to the RNAi-based specific genetic deletion of a storage protein fraction were observed

An efficient method to produce segregating populations in quinoa ( Chenopodium quinoa )

Quinoa offers a promising alternative for staple food, considering its outstanding nutritional value and tolerance to abiotic stresses. To develop breeding programmes in quinoa, a reliable crossing method for increasing the genetic variation is required. In the following study, we aimed to develop segregating populations in quinoa. We tested the efficiency of three different crossing methods (hand emasculation, warm water emasculation and no emasculation). Moreover we developed a two-stage selection strategy based on morphological traits and molecular markers for the se- lection of hybrid plants. We reported hand emasculation to be the most efficient crossing method, followed by warm water emasculation and no emasculation. Our results demonstrated that crosses in quinoa can be successfully performed, despite its complicated flower structure and high self-pollination rate. Additionally, we de- veloped 30 segregating populations from crosses between accessions of different origins with varying phylogenetic relationship, which offers a promising perspective for quinoa breeding programmes in the future

Yield Progress in Forage Maize in NW Europe—Breeding Progress or Climate Change Effects?

Yield increases in forage maize (Zea mays L.) in NW Europe over time are well documented. The driving causes for these, however, remain unclear as there is little information available regarding the role of plant traits triggering this yield progress. Ten different hybrids from the same maturity group, which have typically been cultivated in Northwest Germany from 1970 to recent and are thus representing breeding progress over four decades, were selected for a 2-year field study in northern Germany. Traits that were investigated included leaf area index, leaf architecture, photosynthesis, radiation use efficiency, root mass, root length density, and turnover. Based on a mixed model analysis with these traits as co-variates, parameters related to leaf characteristics, in particular the number and length of leaves, the radiation use efficiency, and the leaf orientation, were identified as most influential on the yield progress (0.13 tons ha-1 year-1). In contrast to our hypothesis, root biomass only increased negligibly in newer hybrids compared to older ones, confirming the ‘functional equilibrium’ theory for high input production systems. Due to an abundance of nutrients and water in such high input systems, there is no incentive for breeders to select for carbon partitioning toward the rooting system. Breeding evidence to increase forage quality were also negligible, with no change in cob starch concentration, forage digestibility, nor NDF content and NDF digestibility. The observed increase in yield over the last four decades is due to a combination of increased temperature sums (~240 GDD within 40 years), and a higher radiation interception and radiation use efficiency. This higher radiation interception was driven by an increased leaf area index, with a higher number of leaves (16 instead of 14 leaves within 40 years) and longer leaves of newer compared to older hybrids. Future selection and adaptation of maize hybrids to changing environmental conditions are likely to be the key for high productivity and quality and for the economic viability of maize growing and expansion in Northern Europe

Methane Emission and Milk Production from Jersey Cows Grazing Perennial Ryegrass–White Clover and Multispecies Forage Mixtures

Methane is a major constituent of greenhouse gas (GHG) emissions from ruminants, and mitigation strategies are needed to alleviate this negative environmental impact while maintaining the environmental and other benefits of grazing systems. Forages containing plant-specialized metabolites (PSM), particularly condensed tannins, may help reduce enteric methane (CH4) emis- sions. However, information on in vivo CH4 emissions from cows grazing mixtures that contain bioactive herbs is scarce. Accordingly, this study compared a binary mixture of perennial ryegrass (Lolium perenne) and white clover (Trifolium repens) against a diverse mixture of six additional species, including tannin-rich species like birdsfoot trefoil (Lotus corniculatus) and salad burnet (Sanguisorba minor), in a full-grazing dairy system. Enteric CH4 emissions were measured using the SF6 tracer technique. Cows grazing diverse mixtures increased their energy-corrected milk (ECM) yield by 4% (p < 0.001) compared with binary mixtures. However, CH4 emissions per kg ECM were also 11% greater for the diverse mixtures (p < 0.05). The very high feed quality and milk yield from both mixtures explained the low CH4 emissions recorded relative to the milk output. The addition of forbs did not provide additional benefits at these intensities, as they were maintained in low yield shares throughout