Hans-Peter Piepho

University of Hohenheim · Institute of Crop Science

In Europe, before acceptance to a country's national list, crop variety candidates must undergo testing for value for cultivation and use (VCU) in multi‐environment trials. Once a variety is accepted to the national list of a country, it can be marketed in that county. Moreover, it may be marketed in other European countries as well, even if it has...

Check varieties are used in plant breeding and variety testing for a number of reasons. One important use of checks is to provide connectivity between years, which facilitates comparison among genotypes of interest that are tested in different years. When long‐term data are available, such comparisons allow an assessment of realized genetic gain (R...

Field experiments in crop variety testing are conducted in multiple environments. When the targeted growing area can be stratified into sub-regions (zones), a design problem arises regarding the number of trials to be performed in each sub-region. We propose an analytical solution and a computational approach for optimal allocation of trials to sub...

The dominance model of heterosis explains the superiority of F1-hybrids via the complementation of unfavorable by beneficial alleles in many genes. Consistent with this model, genes active in only one parent and the hybrid display single-parent expression (SPE) complementation. Here we demonstrated, that SPE can explain up to 29% of heterotic varia...

The BonnMu resource is a transposon tagged mutant collection designed for functional genomics studies in maize. To expand this resource, we crossed an active Mutator ( Mu ) stock with dent (B73, Co125) and flint (DK105, EP1, and F7) germplasm, resulting in the generation of 8064 mutagenized BonnMu F 2 ‐families. Sequencing of these Mu ‐tagged famil...

Understanding climate and vegetation trends and variations is essential for conservation planning and ecosystem management. These elements are shaped by regional manifestations of global climate change, impacting biodiversity conservation and dynamics. In the southern hemisphere, global climate change is partially reflected through trends in the he...

Recent evidence suggests a stabilizing effect of crop diversity on agricultural production. However, different methods are used for assessing these effects and there is little systematic quantitative evidence on diversification benefits. The aim of this study was to assess the relationship between volatility of combined crop yields (denoted as stan...

Progeny trials in tree breeding are often laid out using blocked experimental designs, in which families are randomly assigned to plots and several trees are planted per plot. Such designs are optimized for the assessment of family effects. However, tree breeders are primarily interested in assessing breeding values of individual trees. This paper...

As warm season droughts increase in frequency due to climate change, causing severe yield losses especially among cereal crops, European agriculture is in dire need of adaptation. While agroforestry is widely regarded as a key adaptation measure, little is known on how yield performance is influenced by changing water availability. Therefore, we as...

In 1925, the American entomologist Walter Sidney Abbott proposed an equation for assessing efficacy, and it is still widely used today for analysing controlled experiments in crop protection and phytomedicine. Typically, this equation is applied to each experimental unit and the efficacy estimates thus obtained are then used in analysis of variance...

Finlay–Wilkinson regression is a popular method for modeling genotype–environment interaction in plant breeding and crop variety testing. When environment is a random factor, this model may be cast as a factor‐analytic variance–covariance structure, implying a regression on random latent environmental variables. This paper reviews such models with...

Key messages We investigate a method of extracting and fitting synthetic environmental covariates and pedigree information in multilocation trial data analysis to predict genotype performances in untested locations. Abstract Plant breeding trials are usually conducted across multiple testing locations to predict genotype performances in the target...

Biodiversity of large wild mammals is declining at alarming rates worldwide. It is therefore imperative to develop effective population conservation and recovery strategies. Population dynamics models can provide insights into processes driving declines of particular populations of a species and their relative importance. But there are insufficient...

Progeny trials in tree breeding are often laid out using blocked experimental designs, in which families are randomly assigned to plots and several trees are planted per plot. Such designs are optimized for the assessment of family effects. However, tree breeders are primarily interested in assessing breeding values of individual trees. This paper...

The standard approach to variance component estimation in linear mixed models for alpha designs is the residual maximum likelihood (REML) method. One drawback of the REML method in the context of incomplete block designs is that the block variance may be estimated as zero, which can compromise the recovery of inter-block information and hence reduc...

Methods of network meta‐analysis (NMA) can be classified as arm‐based and contrast‐based approaches. There are several arm‐based approaches, and some of these have been criticized because they recover inter‐study information and hence do not obey the principle of concurrent control. Here, we point out that recovery of inter‐study information in arm...

Simplified cereal-based crop rotations are widely grown due to economic reasons, leading to the cultivation of wheat after wheat and associated yield losses. In this study, a crop rotation trial was conducted in Northern Germany on a Stagnic Luvisol from 2006 to 2018 with winter wheat after the four most widely used preceding crops in the region (s...

In a comprehensive study in the Mara Ecosystem, we conducted two rounds of household surveys in July 2019 and July 2020, encompassing interviews with 338 household heads. This was supplemented with interviews of 18 additional households with an exclusive focus on the Mara-Loita Migration in December 2019. The study spanned four zones: the Mara Rese...

With increasing specialisation in agriculture, stockless cropping gains importance, also in organic agriculture. Although stockless farms have no direct need for fodder, the cropping of clover-grass is essential in organic agriculture due to the input of nitrogen via symbiotic fixation. Additionally, clover-grass has a positive impact, a.o. on soil...

Agricultural experiments are often laid out as blocked designs such as the randomized complete block designs (RCBD) or split‐plot designs (SPD). Statistical analysis should follow the principle “analyze as randomized.” However, block effects are often not modeled or are typically dropped from the model when non‐significant. Additionally, if linear...

Although pesticides are seen as one of the main drivers of insect decline, there are still only few studies that assess their effects on non-target species under field conditions. Here we investigated the effects of the neonicotinoid insecticide Mospilan(R)SG (active ingredient acetamiprid) on plant bugs (Heteroptera: Miridae), a dominant group of...

Cover cropping plays an important role in Integrated Weed Management (IWM). Weed suppression of cover crops occurs by competition, physical barrier on the soil and allelopathy. Under favourable growing conditions, cover crops can provide similar weed suppression in the autumn‐to‐spring period as repeated stubble tillage and non‐selective herbicides...

Beneficial interactions with microorganisms are pivotal for crop performance and resilience. However, it remains unclear how heritable the microbiome is with respect to the host plant genotype and to what extent host genetic mechanisms can modulate plant–microbiota interactions in the face of environmental stresses. Here we surveyed 3,168 root and...

The phospholipid fatty acid (PLFA) composition of soils was analysed at three poplar-based silvo-arable systems and at one willow-based silvo-grassland alley agroforestry system in Central Germany. The objective was to analyse tree row effects on the PLFA composition of main fungal and main bacterial groups. The fungal groups were BAM (Basidiomycot...

Understanding climate and vegetation trends and variations is essential for conservation planning and ecosystem management. These elements are shaped by regional manifestations of global climate change, impacting biodiversity conservation and dynamics. In the southern hemisphere, global climate change is partially reflected through trends in the he...

Heat and drought are major abiotic stressors threatening cereal yields, but little is known regarding the spatio-temporal development of their yield-effects. In this study, we assess genotype (G) × environment (E) × management (M) specific weather-yield relations utilizing spatially explicit weather indices (WIs) and variety trial yield data of win...

Key message Grain yield and NUE increased over time while nitrogen yield did not drop significantly despite reduced nitrogen input. Selection for grain and nitrogen yield is equivalent to selection for NUE. Abstract Breeding and registration of improved varieties with high yield, processing quality, disease resistance and nitrogen use efficiency (...

Background The accurate prediction of genomic breeding values is central to genomic selection in both plant and animal breeding studies. Genomic prediction involves the use of thousands of molecular markers spanning the entire genome and therefore requires methods able to efficiently handle high dimensional data. Not surprisingly, machine learning...

Finding economic optimum fertilizer rate with good accuracy is essential for optimal crop yield, efficient resource utilization, and environmental well-being. However, the prevailing incomplete understanding of input-output relationships leads to imprecise crop yield response functions, such as those for winter wheat, and potentially biased fertili...

The increasing demand for cultivated lands driven by human population growth, escalating consumption and activities, combined with the vast area of uncultivated land, highlight the pressing need to better understand the biodiversity conservation implications of land use change in Sub-Saharan Africa. Land use change alters natural wildlife habitats...

Crop growth and phenology are driven by seasonal changes in environmental variables, with temperature as one important factor. However, knowledge about genotype-specific temperature response and its influence on phenology is limited. Such information is elementary to improve crop models and adapt selection strategies. We measured the height develop...

Plant breeding trials are usually conducted across multiple testing locations to predict genotype performances in the targeted population of environments. The predictive accuracy can be increased by the use of adequate statistical models. We compared models with and without synthetic covariates (SC) and pedigree information under the identity, the...

Checking for possible inconsistency between direct and indirect evidence is an important task in network meta‐analysis. Recently, an evidence‐splitting (ES) model has been proposed, that allows separating direct and indirect evidence in a network and hence assessing inconsistency. A salient feature of this model is that the variance for heterogenei...

BACKGROUND Enhancing productivity and profitability and reducing climatic risk are the major challenges for sustaining rice production. Extreme weather can have significant and varied effects on crops, influencing agricultural productivity, crop yields and food security. RESULTS In this study, a comparative evaluation of two crop management system...

Simulations demonstrated that estimates of realized genetic gain from linear mixed models using regional trials are biased to some degree. Thus, we recommend multiple selected models to obtain a range of reasonable estimates. Genetic improvements of discrete characteristics are obvious and easy to demonstrate, while quantitative traits require reli...

Introduction Yield and its stability are both vital characteristics to evaluate the viability of cropping systems. However, the current frames of field research hardly allow an accurate evaluation of short-term effect stability. Therefore, over nine German environments (three years and three locations), first crop, maize, total harvested dry biomas...

Large mammals, such as hippopotamuses (Hippopotamus amphibius), can significantly alter the landscape, vegetation composition, and structure in savannas through their grazing habits and ecosystem engineering effects, especially around rivers. However, livestock grazing can strongly change these effects, as seen in the Kenyan Maasai Mara Ecosystem....

The management of climate-resilient grassland systems is important for stable livestock fodder production. In the face of climate change, maintaining productivity while minimizing yield variance of grassland systems is increasingly challenging. To achieve climate-resilient and stable productivity of grasslands, a better understanding of the climati...

In plant breeding field experiments, proper statistical design and analysis improve precision of genotype comparisons. The focus of this study was to compare the precision of different spatial techniques in estimating genotypic effects using sorghum [Sorghum bicolor (L.) Moench] breeding data from Ethiopia and to investigate alternative design stra...

Often, comparative experiments involve a single treatment factor and two blocking factors, for example, augmented row-column, two-phase, and incomplete row-column experiments. These experiments are widely used in agriculture. Finding good designs for these experiments is a major challenge when the number of treatments is large and the blocking stru...

Crop yields are increasingly affected by climate change-induced weather extremes in Germany. However, there is still little knowledge of the specific crop-climate relations and respective heat and drought stress-induced yield losses. Therefore, we configure weather indices (WIs) that differ in the timing and intensity of heat and drought stress in...

Finlay–Wilkinson regression is a popular method for analysing genotype–environment interaction in series of plant breeding and variety trials. It involves a regression on the environmental mean, indexing the productivity of an environment, which is driven by a wide array of environmental factors. Increasingly, it is becoming feasible to characteriz...

Agroforestry is a land-use system that combines arable and/or livestock management with tree cultivation, which has been shown to provide a wide range of socio-economic and ecological benefits. It is considered a promising strategy for enhancing resilience of agricultural systems that must remain productive despite increasing environmental and soci...

Large-effect loci-those statistically significant loci discovered by genome-wide association studies or linkage mapping-associated with key traits segregate amidst a background of minor, often undetectable, genetic effects in wild and domesticated plants and animals. Accurately attributing mean differences and variance explained to the correct comp...

The purpose of plant breeding is the genetic improvement of plant characteristics. For discrete characteristics such as flower color, the genetic improvements are obvious and easy to demonstrate; however, for characteristics that are measured on continuous scales, the genetic contributions are incremental and less obvious. Incremental changes to su...

The coefficient of determination (R2 ) is a common measure of goodness of fit for linear models. Various proposals have been made for extension of this measure to generalized linear and mixed models. When the model has random effects or correlated residual effects, the observed responses are correlated. This paper proposes a new coefficient of dete...

Unlabelled: The management of climate-resilient grassland systems is important for stable livestock fodder production. In the face of climate change, maintaining productivity while minimizing yield variance of grassland systems is increasingly challenging. To achieve climate-resilient and stable productivity of grasslands, a better understanding o...

Beneficial interactions with microorganisms are pivotal for crop performance and resilience. However, it remains unclear how heritable the microbiome is with respect to the host plant genotype and to what extent host genetic mechanisms can modulate plant-microbe interactions in the face of environmental stress. Here, we surveyed 3,168 root and rhiz...

Abstract Excessive nitrogen (N) input is one of the major threats for species‐rich grasslands. The ongoing deterioration of habitat quality highlights the necessity to further investigate underlying N turnover processes. Our objectives were (1) to quantify gross and net rates of mineral N production (mineralization and nitrification) and consumptio...

The increasing demand for cultivated lands driven by human population growth, escalating consumption and activities, combined with the vast area of uncultivated land, highlights the pressing need to better understand the biodiversity conservation implications of land use change in Sub-Saharan Africa. Land use change alters natural wildlife habitats...

There are often negative side-effects associated with the traditional (silage) maize cropping system related to the unprotected soil surface. Reducing soil disturbance could enhance system sustainability. Yet, increased weed pressure and decreased nitrogen availability, particularly in organic agriculture, may limit the implementation of alternativ...

Structure-sensory relationships are essential for understanding food perception. Food microstructure impacts how a food is comminuted and processed by the human masticatory system. This study investigated the impact of anisotropic structures, explicitly the structure of meat fibers, on the dynamic process of mastication. For a general understanding...

Various aspects of activity, such as spontaneous activity, explorative activity, activity in open-field tests, and hyperactivity syndrome have been explored as causal factors of feather pecking in laying hens, with no clear results. In all previous studies, mean values of activity over different time intervals were used as criteria. Incidental obse...

The design of climate-resilient cereal cropping systems is important for global food security and stable cereal production over time. However, in the face of climate change and the associated increases in abiotic stresses, maintaining productivity while minimizing temporal yield variability of cereal cropping systems will become increasingly challe...

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. Abstract Increasing yield trends are seen on-farm in Germany. The increase is based on genetic trend in registered genotypes and changes...

To assess the efficiency of genetic improvement programs, it is essential to assess the genetic trend in long-term data. The present study estimates the genetic trends for grain yield of rice varieties released between 1970 and 2020 by the Bangladesh Rice Research Institute. The yield of the varieties was assessed from 2001–2002 to 2020–2021 in mul...