Hans-Peter Piepho

University of Hohenheim · Institute of Crop Science

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...

Background Enhancing productivity and profitability and reducing climatic risk is the major challenge 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 systems...

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 precision of different spatial techniques in estimating genotypic effects using sorghum [Sorghum bicolor (L.) Moench] breeding data from Ethiopia, and to investigate alternative design strateg...

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...

Beneficial interactions with microorganisms are pivotal for plant adaptation and fitness. Yet, the adaptive trajectories and genetic mechanisms underlying plant-microbiome interactions remain elusive. Here, we surveyed the root and rhizosphere microbiome of 129 accessions of Zea mays, sourced from diverse habitats and grown under control and differ...

Finlay-Wilkinson regression is a popular method for analysing genotype-environment interaction in series of plant breeding and variety trials. The method involves a regression on the environmental mean, computed as the average of all genotype means. The environmental mean indexes the productivity of an environment, which is driven by a wide array o...

Two-phase experiments are widely used in many areas of science (e.g., agriculture, industrial engineering, food processing, etc.). For example, consider a two-phase experiment in plant breeding. Often, the first phase of this experiment is run in a field involving several blocks. The samples obtained from the first phase are then analyzed in severa...

Stem rust (SR) and leaf rust (LR) are currently the two most important rust diseases of cultivated rye in Central Europe and resistant cultivars promise to prevent yield losses caused by those pathogens. To secure long-lasting resistance, ideally pyramided monogenic resistances and race-nonspecific resistances are applied. To find respective genes,...

Background Different regression approaches may be useful to predict dynamics of copper (Cu), an essential element for plants and microorganisms that becomes toxic at increased contents, in soils. Aim Our objective was to explore the usefulness of mixed‐effects modeling and rule‐based models for a description and prediction of Cu contents in aqua r...

Production of wheat (Triticum aestivum L.) is affected by changing weather conditions, which are difficult to predict especially under climate change. Therefore, facultative varieties can be beneficial, because of their high adaptability in sowing time. Information on yield and yield components of facultative wheat in temperate climate, however, is...

Breeding of multi-resistant varieties to reduce yield loss due to disease damage and lodging, and reduction of input intensity are of high importance for a more sustainable cereal production. The aim of this study was to evaluate (i) yield reduction caused by diseases and lodging and (ii) impact of input intensity and soil fertility in cereal varie...

Crop breeders increasingly need to mitigate the effects of climate change. Ideally, their selection strategies are based on an understanding of crop responses to environmental covariates such as temperature. In this study, the height of 352 varieties (European and Swiss) was repeatedly measured in multiple years. P-splines were used as phenology mo...

Traditional (silage) maize production often has negative side-effects related to unprotected soil surface. There are several possibilities to enhance system sustainability through reducing soil disturbance. However, implementation may be hindered due to reduced nitrogen availability and increased weed infestation, especially in organic agriculture....

Previous studies on the relationships between locomotor activity and feather pecking in chickens did not show consistent results. In these studies means of locomotor acticity were used as criteria. This study shows that differences between lines selected for high and low severe feather pecking are expressed in the diurnal rhythm rather than in dail...

High mortality poses a serious threat to sustainable conservation of the African elephant (Loxodonta africana). Using detected carcass data collected by the Kenya Wildlife Service (KWS) during 1992-2017, we analyze temporal and spatial variation in elephant mortality in Kenya. We investigate the major mortality causes and means used to kill elephan...

Crop breeding has boosted global agricultural productivity over recent decades, but little is known about its contribution to climate change mitigation. Here we assess greenhouse gas emissions per unit land (GHGL) and greenhouse gas emissions per unit harvest product, i.e. carbon footprint (CFP) of winter wheat (Triticum aestivum) and winter rye (S...

Determination of sample size (the number of replications) is a key step in the design of an observational study or randomized experiment. Statistical procedures for this purpose are readily available. Their treatment in textbooks is often somewhat marginal, however, and frequently the focus is on just one particular method of inference (significanc...

Experiments with two factors are commonly analyzed using two-way analysis of variance, where testing significance of interaction is straightforward. However, using bilinear models, interaction can be analyzed further. The additive main effects and multiplicative interaction (AMMI) model uses singular value decomposition for partitioning interaction...

Key message: We propose a simulation approach to compute response to genomic selection on a multi-environment framework to provide breeders the number of entries that need to be selected from the population to have a defined probability of selecting the truly best entry from the population and the probability of obtaining the truly best entries wh...

Key message We assess the genetic gain and genetic correlation in maize yield using German and Polish official variety trials. The random coefficient models were fitted to assess the genetic correlation. Abstract Official variety testing is performed in many countries by statutory agencies in order to identify the best candidates and make decision...

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

Cover cropping is mainly used to prevent soil erosion, but the impacts of individual cover crops on the subsequent soybean (Glycine max (L.) Merr.) are hardly known. Therefore, two annual field trials with 15 cover crop species and bare fallow as control were conducted in semi‐arid East Austria in 2016 and 2017. Cover crops were sown in July in 3 ×...

Increasing yield trends are seen on-farm in Germany. The increase is based on genetic trend and changes in agronomic practices and climate. To estimate both genetic and non-genetic trends, historical VCU datasets can be analyzed. Such analyses are based on genotypes submitted by breeders and hence represent the post-breeding population of genotypes...

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 methods are...

Network meta‐analysis is a popular method to synthesize the information obtained in a systematic review of studies (e.g. randomized clinical trials) involving subsets of multiple treatments of interest. The dominant method of analysis employs within‐study information on treatment contrasts and integrates this over a network of studies. One advantag...

Temperature is a main driver of plant growth and development. New phenotyping tools enable quantifying the temperature response of hundreds of genotypes. Yet, for field-derived data, temperature response modeling bears flaws and pitfalls concerning the interpretation of derived parameters. In this study, climate data from five growing seasons with...

Copper (Cu) is an essential element for plants and microorganisms and at larger concentrations a toxic pollutant. A number of factors controlling Cu dynamics have been reported, but information on quantitative relationships is scarce. We aimed to (i) quantitatively describe and predict soil Cu concentrations (Cu AR ) in aqua regia considering site‐...

The dominance model of heterosis explains the superior performance of F1 hybrids via the complementation of deleterious alleles by beneficial alleles in many genes. Genes active in one parent but inactive in the second lead to single-parent expression (SPE) complementation in maize (Zea mays L.) hybrids. In this study, SPE complementation resulted...

Many important traits in plants, animals, and microbes are polygenic and challenging to improve through traditional marker-assisted selection. Genomic prediction addresses this by incorporating all genetic data in a mixed model framework. The primary method for predicting breeding values is genomic best linear unbiased prediction (GBLUP), which use...

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. Abstract The most important trait for baking quality of winter wheat is loaf volume (V). It is mostly determined by grain protein...

Statistical models that capture the phenotypic plasticity of a genotype across environments are crucial in plant breeding programs to potentially identify parents, generate ofspring, and obtain highly productive genotypes for target environments. In this study, our aim is to leverage concepts of Bayesian models and probability methods of stability...

Thyroid hormones and the factors influencing them are rarely studied in tortoises. This study therefore aimed to calculate reference intervals (RI) for thyroid hormones and iodine concentrations by species, sexes, and seasons in four species of adult Mediterranean tortoises (Testudo spp.), and to evaluate possible correlations between plasma thyroi...

Large agricultural field trials may display irregular spatial trends that cannot be fully captured by a purely randomization‐based analysis. For this reason, paralleling the development of analysis‐of‐variance procedures for randomized field trials, there is a long history of spatial modeling for field trials, starting with the early work of Papada...

The paper reviews approaches to employ environmental covariate information for predicting genotype performance in new environments.

The goal of any plant breeding program is to maximize genetic gain for traits of interest. In classical quantitative genetics, the genetic gain can be obtained from what is known as “Breeder’s equation”. In the past, only phenotypic data was used to compute the genetic gain. The advent of genomic prediction has opened the door to the utilization of...

The goal of any plant breeding program is to maximize genetic gain for traits of interest. In classical quantitative genetics, the genetic gain can be obtained from what is known as Breeders equation. In the past, only phenotypic data was used to compute the genetic gain. The advent of genomic prediction has opened the door to the utilization of de...

Having a reliable yield map is an important key to unlock the value of precision agriculture. This work demonstrates an application of unsupervised machine learning for harvester yield monitoring recovery in the presence of noise for constructing a reliable yield map. The objective of this research is to propose a fully automated statistical and ma...

Cover cropping provides versatile benefits for sustainable agriculture, but many cover crops are potential host plants for pathogens such as Sclerotinia sclerotiorum (Lib.) de Bary. Therefore, 14 cover crops were investigated for their interaction with sclerotia, topsoil moisture and temperature in two consecutive field trials in East Austria. In J...

Depolymerization of high-molecular weight organic nitrogen (N) represents the major bottleneck of soil N cycling and yet is poorly understood compared to the subsequent inorganic N processes. Given the importance of organic N cycling and the rise of global change, we investigated the responses of soil protein depolymerization and microbial amino ac...

Decision-making in breeding increasingly depends on the ability to capture and predict crop responses to changing environmental factors. Advances in crop modeling as well as high-throughput field phenotyping (HTFP) hold promise to provide such insights. Processing HTFP data is an interdisciplinary task that requires broad knowledge on experimental...

Key message Considerable breeding progress in cereal and disease resistances, but not in stem stability was found. Ageing effects decreased yield and increased disease susceptibility indicating that new varieties are constantly needed. Abstract Plant breeding and improved crop management generated considerable progress in cereal performance over t...

The SAS macro computes letter displays for all pairwise mean comparisons

The file gives some example showing the usage of the %mult macro for SAS.

Organic certification, especially for smallholders, often uses group certification procedures. An internal control system (ICS) visits all farmers, and then the external certification body (CB) inspects a sample to assess the ICS' performance. Harmonised methods for measuring the ICS' reliability are missing so far. Here, we define criteria of "ICS...