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Plant breeding and official variety testing involve the challenge to design multienvironmental trials in several years and locations. Several variables influence the performance and, therefore, the possible selection gain of such trials. We provide a simulation-based approach using SAS to vary these variables and to allow a comparison of different scenarios for the design of series of trials regarding selection gain. Our approach builds on the FORTRAN software tool SELSYS. Three examples of its application are given. [ABSTRACT FROM AUTHOR]

Genotypic, environmental and genotype by environmental variability of 30 different crops was evaluated by estimating variance components from trial series in 16 years. Yield data from official German variety trials for cultivation and use (VCU) were analysed over the period from 1991 to 2006. The natural dominant part was pure environmental variation. Genotype, genotype by environment and plot error are smaller and of the same magnitude. Interaction of genotypes with locations is larger than with years. Compared with variance component estimates of crops from a study involving 16 crops from former West German VCU trials between 1975 and 1986 overall variability of yielding performance was lower in the recent study for all components except for location. Precision of variety comparisons over locations and years is higher in recent VCU trial systems when assuming equal dimensioning of testing resources. Lower values for genotype by environmental variances, especially for the genotype by year component lead to lower standard errors for variety comparisons. [ABSTRACT FROM AUTHOR]

• Covariates associated with mean and variance of wheat and rye yield were investiagted. • Mixed models served to identify mean and variance trends associated with covariates. • Mean yield affected by water availability in different stages of the generative phase. • Yield variance was found to increase with the calendar year for both crops. • Coefficient of variation decreased for wheat and increased for rye with time. There is considerable interest in assessing genetic gain from breeding efforts, as well as trends from non-genetic sources such as climate change. Long-term data from official variety trials provide an ideal opportunity to do so. Whereas past work on the subject was mainly focussed on trends in mean performance, little attention has been paid to yield stability. The purpose of the present paper therefore is to provide a framework for assessing trends in stability and to exemplify this using long-term data from German variety trials. Specifically, trends in the mean and variance of winter wheat and winter rye yields associated with genotypic, spatial, and climatic covariates were investigated based on a long-term series of multi-environment trials from 1983/1985 to 2016. Yield stability is assessed based on the variance of yield. For climatic covariates, trends were investigated using growth stage-specific covariates which were obtained by dividing the total growth period into five or ten growth stages within which covariates were aggregated. The analysis was done by linear mixed models and forward selection served to identify trends in mean and variance. Specifically, trends in the mean were selected based on a coefficient of determination, R 2 , while variance trends associated with a covariate were selected based on the change in variance attributable to the covariate. For spatial covariates, mean yield increased with the field capacity in up to one meter soil depth in case of rye. For both crops, mean yield was negatively affected by a deficit in available water during the development of vegetative parts while water deficit towards the end of the growth period was positively associated with mean yield. Trends were also selected accounting for interactions of climatic covariates and genotypic groups (wheat: quality type; rye: breeding type), revealing that R 2 generally increased when interactions were taken into account. The responses to covariates were similar for the different groups, meaning the increase in R 2 is mainly attributable to the main effects of the genotypic groups. Variance trends associated with the calendar year were identified for both crops, revealing yield variance slightly increased with time. Based on the selected model, a coefficient of variation was obtained for each year to assess relative yield stability, showing a decrease for wheat and an increase for rye. [ABSTRACT FROM AUTHOR]

Key Message: VCU trials can provide unbiased estimates of post-breeding trends given that all data is used. Dropping data of genotypes tested for up to two years may result in biased post-breeding trend estimates. Increasing yield trends are seen on-farm in Germany. The increase is based on genetic trend in registered genotypes and changes in agronomic practices and climate. To estimate both genetic and non-genetic trends, historical wheat data from variety trials evaluating a varieties' value for cultivation und use (VCU) were analyzed. VCU datasets include information on varieties as well as on genotypes that were submitted by breeders and tested in trials but could not make it to registration. Therefore, the population of registered varieties (post-registration population) is a subset of the population of genotypes tested in VCU trials (post-breeding population). To assess post-registration genetic trend, historical VCU trial datasets are often reduced, e.g. to registered varieties only. This kind of drop-out mechanism is statistically informative which affects variance component estimates and which can affect trend estimates. To investigate the effect of this informative drop-out on trend estimates, a simulation study was conducted mimicking the structure of German winter wheat VCU trials. Zero post-breeding trends were simulated. Results showed unbiased estimates of post-breeding trends when using all data. When restricting data to genotypes tested for at least three years, a positive genetic trend of 0.11 dt ha -1  year -1 and a negative non-genetic trend (- 0.11 dt ha -1  year -1 ) were observed. Bias increased with increasing genotype-by-year variance and disappeared with random selection. We simulated single-trait selection, whereas decisions in VCU trials consider multiple traits, so selection intensity per trait is considerably lower. Hence, our results provide an upper bound for the bias expected in practice., (© 2023. The Author(s).)

Key Message: A novel approach based on the loaf volume-grain protein content relation is suggested to consider the static protein use efficiency and stability as efficient quality-related descriptors for wheat varieties. The most important trait for baking quality of winter wheat is loaf volume (V). It is mostly determined by grain protein content (GPC) and quality. New varieties with a high potential of grain protein use efficiency (ProtUE) are very important for reducing the surplus use of nitrogen fertilizer in areas where nitrogen leaching is large. This is also an important goal of agricultural policies in the European Union. Additionally, ProtUE needs to be very stable across environments in the face of progressing climate change with more volatile growing conditions. We evaluated a new approach to assess ProtUE and stability based on the V-GPC relationship instead of using only single traits. The study comprised 11,775 baking tests from 355 varieties grown 1988-2019 in 668 different environments in Germany. V was predicted by quadratic and linear regression functions for quality groups, indicating a reduction of ProtUE from 1988 to 2019. We introduced a dynamic and a static approach to assess ProtUE and stability as potential criteria in variety registration. We found a considerably lower heritability of the dynamic ProtUE (h 2  = 43%) compared to the static ProtUE (h 2  = 92%) and a lower dynamic stability (h 2  = 32%) than for the static stability (h 2  = 51%). None of these measures is in conflict with the selection for high V. In particular, V and static ProtUE are strongly genetically associated (r = 0.81), indicating an advantage of the static over the dynamic approach., (© 2022. The Author(s).)

Key Message: Evaluation of breeding progress for spring barley varieties in Germany showed that both grain yield and malting quality were considerably improved during the last 33 years, and that genetic effects of protein concentration and malting traits were not associated. Based on historical data, this study aimed to investigate yield potential and malting quality of 187 varieties tested and released in German registration trials to evaluate the value for cultivation and use (VCU) during 1983-2015, and to quantify the environmental variability and the association among traits. We used mixed linear models with multiple linear regression terms to dissect genetic and non-genetic trend components. Grain yield increased by 43% (23.4 dt ha -1 ) in VCU trials and 35% (14.0 dt ha -1 ) on-farm relative to 1983. All yield components contributed significantly. Malting quality was also considerably improved by 2.3% for extract content up to 25.1% for friability, relative to 1983, nearly completely due to new varieties. Total variability of individual traits was very different between traits (2.4-24.4% relative to 1983). The relative influence of genotypes on total variation was low for grain yield and its components, whereas it was considerably larger for other traits. We found remarkable differences between phenotypic and genetic correlation coefficients for grain yield and protein concentration with malting traits. The observed positive phenotypic relation between grain yield and malting quality can be attributed to a shift of selection and environmental effects, but genetic correlations showed a negative association. Genetic effects of protein concentration and malting quality were not correlated indicating that both were not genetically linked. Considerable yield progress and improvement of malting quality were achieved despite of their weak to moderate negative genetic dependence.

Key Message: Grain yield of hybrid varieties and population varieties in official German variety trials increased by 23.3 and 18.1%, respectively, over the last 26 years. On-farm gain in grain yield (18.9%) was comparable to that of population varieties in variety trials, yet at a level considerably lower than in variety trials. Rye quality is subject to large year-to-year fluctuation. Increase in grain yield and decline of protein concentration did not negatively influence quality traits. Performance progress of grain and quality traits of 78 winter rye varieties tested in official German trials to assess the value for cultivation and use (VCU) were evaluated during 1989 and 2014. We dissected progress into a genetic and a non-genetic component for hybrid and population varieties by applying mixed models, including regression components to model trends. VCU trial results were compared with grain yield and quality data from a national harvest survey (on-farm data). Yield gain for hybrid varieties was 23.3% (18.9 dt ha -1 ) and for population varieties 18.1% (13.0 dt ha -1 ) relative to 1989. On-farm yield progress of 18.9% (8.7 dt ha -1 ) was considerably lagging behind VCU trials, and mean yield levels were substantially lower than in field trials. Most of the yield progress was generated by genetic improvement. For hybrid varieties, ear density was the determining yield component, whereas for population varieties, it was thousand grain mass. Results for VCU trials showed no statistically significant gains or losses in rye quality traits. For on-farm data, we found a positive but non-significant gain in falling number and amylogram viscosity and temperature. Variation of grain and quality traits was strongly influenced by environments, whereas genotypic variation was less than 19% of total variation. Grain yield was strongly negatively associated with protein concentration, yet was weakly to moderately positively associated with quality traits. In general, our results from VCU trials and on-farm data indicated that increasing grain yield and decreasing protein concentration did not negatively affect rye quality traits.

Key Message: Over the last 32 years, a large gain in grain yield (24 %) was achieved in official German variety trials, and despite considerable loss in protein concentration (-7.9 %), winter wheat baking quality was partially improved over the last 32 years. On-farm gain in grain yield (32 %) exceeded gain in trials, but at yield level about 25 dt ha -1 lower. Breeding progress was very successfully transferred into both progress in grain yield and on-farm baking quality. Long-term gains in grain yield and baking quality of 316 winter wheat varieties from German official trials were evaluated. We dissected progress into a genetic and a non-genetic part to quantify the contribution of genetic improvement. We further investigated the influence of genotype and environment on total variation by estimating variance components. We also estimated genetic and phenotypic correlation between quality traits. For trial data, we found a large gain in grain yield (24%), but a strong decline in protein concentration (-8.0%) and loaf volume (-8.5%) relative to 1983. Improvement of baking quality could be achieved for falling number (5.8%), sedimentation value (7.9%), hardness (13.4%), water absorption (1.2%) and milling yield (2.4%). Grain yield, falling number and protein concentration were highly influenced by environment, whereas for sedimentation value, hardness, water absorption and loaf volume genotypes accounted for more than 60% of total variation. Strong to very strong relations exist among protein concentration, sedimentation value, and loaf volume. On-farm yields were obtained from national statistics, and grain quality data from samples collected by national harvest survey. These on-farm data were compared with trial results. On-farm gain in grain yield was 31.6%, but at a mean level about 25 dt ha -1  lower. Improvement of on-farm quality exceeded trial results considerably. A shift to varieties with improved baking quality can be considered as the main reason for this remarkable improvement of on-farm baking quality., Competing Interests: The authors declare that they have no conflict of interest.

Key Message: Yield progress in major German crops is generated mostly due to genetic improvement over the last 30 years. Comparison of trial-station with on-farm yield reveals considerable gaps that are widening over time. Yield progress of newly released varieties for 12 crops from official German trials over the period 1983 until 2012 was analysed to assess their value for cultivation and use (VCU). We paid special attention to dissect progress into a genetic and a non-genetic (agronomic) trend in order to quantify the contribution made by new varieties and by agronomic factors. In this study, we apply mixed models including regression components for genetic and agronomic trends. Ageing effects, depending on the difference of the actual testing year and the first year of testing of a particular variety, were estimated from the difference of fungicide and non-fungicide-treated trial pairs. Significant yield losses were found in all cereal crops due to assumed ageing effects. We compared national on-farm with official VCU trial yields with particular focus on whether gaps are widening over time. Results indicated a significant widening over time. In order to facilitate comparisons of results across crops, we calculated percent rates based on 1983 yield levels obtained from regression estimates. Most of the yield progress was generated by genetic improvement, and was linear showing no levelling-off. Ageing and selection effects need to be taken into account, because they may lead to overestimation of genetic trends. This study showed that contribution of agronomic factors is of minor importance in overall yield progress.

Key Message: Long-term yield trends have genetic and non-genetic components which may be dissected by a linear mixed model with regression terms. Disease-resistance breakdown must be accounted for in the interpretation. Long-term yield trends of crop varieties may be studied to identify a genetic trend component due to breeding efforts and a non-genetic trend component due to advances in agronomic practices. Many such studies have been undertaken, and most of these inspect trends either by plotting means against years and/or by some kind of regression analysis based on such plots. Dissection of genetic and non-genetic trend components is a key challenge in such analyses. In the present paper, we consider mixed models with regression components for identifying different sources of trend. We pay particular attention to the effect of disease breakdown, which is shown to be confounded with long-term genetic and non-genetic trends, causing an over-estimation of genetic trends based on long-term yield trial data. The models are illustrated using German multi-environment trial data on yield, mildew and Septoria leaf blotch susceptibility for winter wheat and yield, mildew and net blotch susceptibility for spring barley.

A prospective controlled intervention cohort study in cancer pain patients (n=50 per group) admitted to radiation oncology wards (62 beds, 3 wards) was conducted in a 1621-bed university hospital. We investigated the effect of an intervention consisting of daily pain assessment using the numeric visual analog scale (NVAS) and pain therapy counseling to clinicians based on a computerized clinical decision support system (CDSS) to correct deviations from pain therapy guidelines. Effects on guideline adherence (primary outcome), pain relief (NVAS) at rest and during physical activity (both groups: cross-sectional assessment on day 5; intervention group: every day assessment), co-analgesic prescription, and acceptance rates of recommendations (secondary outcomes) were assessed. The number of patients with at least one deviation from guidelines at discharge was decreased by the intervention from 37 (74%) in controls to 7 (14%, p<0.001). In the intervention group, pain (NVAS) decreased during hospital stay at rest from 3.0 (Delta(0.5) (Q(75%)-Q(25%))=3.0) on admission to 1.5 (Delta(0.5)=1.0) at discharge (p<0.01) and during physical activity from 7.0 (Delta(0.5)=4.0) on admission to 2.5 (Delta(0.5)=3.8) at discharge (p<0.001). At discharge, the number of patients treated with co-analgesics increased from 23 (46%) in controls to 33 (66%) in the intervention group (p=0.04). From 279 recommendations issued in the intervention 85% were fully accepted by the physicians. Deviations from well-established guidelines are frequent in pain therapy. A multidisciplinary pain management increased adherence to pain management guidelines.