Hans-Peter Piepho

Hans-Peter Piepho
University of Hohenheim · Institute of Crop Science

Dr. sc. agr.

About

792
Publications
190,255
Reads
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18,572
Citations
Introduction
My main interests are related to statistical procedures as needed in plant sciences, crop breeding and cultivar testing. These include genomic prediction, spatial methods for field trials, design of comparative experiments, models for genotype-environment interaction, and network meta-analysis. Moreover, I have various collaborations with researchers in different branches of the agricultural sciences. In most of my research, mixed model procedures form the methodological backbone.
Additional affiliations
October 2001 - present
University of Hohenheim
Position
  • Professor of Biostatistics
March 1993 - October 2001
Universität Kassel
Position
  • Professor
January 1991 - December 1992
Christian-Albrechts-Universität zu Kiel
Position
  • PhD Student
Education
January 1990 - December 1990
Technische Universität Berlin
Field of study
  • Seminar für Ländliche Entwicklung (SLE)
October 1983 - September 1989
Justus-Liebig-Universität Gießen
Field of study
  • Agricultural Sciences
October 1982 - September 1983
Justus-Liebig-Universität Gießen
Field of study
  • Chemistry

Publications

Publications (792)
Article
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...
Article
Full-text available
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...
Preprint
Full-text available
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...
Article
Full-text available
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....
Poster
Full-text available
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...
Article
Full-text available
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...
Article
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...
Article
Full-text available
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...
Article
Full-text available
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...
Preprint
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...
Preprint
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...
Preprint
Full-text available
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...
Article
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...
Article
Full-text available
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...
Article
Copper (Cu) is an essential element for plants and microorganisms and at larger concentrations a toxic pollutant. A number of controlling factors of Cu dynamics have been reported, but information on quantitative relationships is scarce. We aimed to (i) quantitatively describe and predict soil Cu concentrations (CuAR) in aqua regia considering site...
Article
Full-text available
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...
Article
Full-text available
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...
Article
Full-text available
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...
Article
Full-text available
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...
Article
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...
Article
Full-text available
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...
Article
The paper reviews approaches to employ environmental covariate information for predicting genotype performance in new environments.
Preprint
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...
Chapter
Full-text available
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...
Article
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...
Article
Full-text available
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...
Article
Full-text available
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...
Article
Full-text available
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...
Code
The SAS macro computes letter displays for all pairwise mean comparisons
Code
The file gives some example showing the usage of the %mult macro for SAS.
Conference Paper
Full-text available
In the face of a changing climate, yield stability is becoming increasingly important for farmers and breeders. Long-term field experiments (LTEs) generate data sets that allow the quantification of stability for different agronomic treatments. However, there are no commonly accepted guidelines for assessing yield stability in LTEs. The large diver...
Preprint
Full-text available
Many important traits in plants, animals, and microbes are polygenic and are therefore difficult to improve through traditional marker?assisted selection. Genomic prediction addresses this by enabling the inclusion of all genetic data in a mixed model framework. The main method for predicting breeding values is genomic best linear unbiased predicti...
Article
Full-text available
Sparse testing in genome-enabled prediction in plant breeding can be emulated throughout different line allocations where some lines are observed in all environments (overlap) and others are observed in only one environment (nonoverlap). We studied three general cases of the composition of the sparse testing allocation design for genome-enabled pre...
Article
Full-text available
The cover image is based on the Original Article High-throughput field phenotyping reveals genetic variation in photosynthetic traits in durum wheat under drought by Nícolas Zendonadi dos Santos et al., https://doi.org/10.1111/pce.14136.
Article
Full-text available
A lack of nutrients in the seed can be supplemented by seed coating and has the potential to improve germination and seedling growth. In this research, we studied the physiological effect of coating tomato seeds with plant nutrient formulations (PNF) on the dehydrogenase activity during germination and nutrient content of the seedlings. Two tomato...
Article
Full-text available
The search for approaches to a holistic sustainable agriculture requires the development of new cropping systems that provide additional ecosystem services beyond biomass supply for food, feed, material, and energy use. The reduction of chemical synthetic plant protection products is a key instrument to protect vulnerable natural resources such as...
Article
Full-text available
The development of genome-informed methods for identifying quantitative trait loci (QTL) and studying the genetic basis of quantitative variation in natural and experimental populations has been driven by advances in high-throughput genotyping. For many complex traits, the underlying genetic variation is caused by the segregation of one or more ‘la...
Article
Full-text available
Multiparental advanced generation inter-cross (MAGIC) populations are valuable crop resources with a wide array of research uses including genetic mapping of complex traits, management of genetic resources and breeding of new varieties. Multiple founders are crossed to create a rich mosaic of highly recombined founder genomes in the MAGIC recombina...
Article
A common task in the analysis of multi‐environmental trials (MET) by linear mixed models (LMM) is the estimation of variance components (VCs). Most often, MET data are imbalanced, e.g., due to selection. The imbalance mechanism can be missing completely at random (MCAR), missing at random (MAR), or missing not at random (MNAR). If the missing‐data...
Article
Despite increasing pressure on land, many hill tribe communities in Northern Thailand practice traditional swidden agriculture with long fallow periods that allow the soil to recover from cropping. To determine the most appropriate time for a new cropping cycle, farmers, in a collective decision making process, often use presence or numbers of tree...
Article
Full-text available
Long-term field experiments (LTEs) play an important role in studying the effects of different management strategies on the soil ecosystem. However, LTEs are very diverse regarding location, duration, experimental design or research question. Therefore, in October 2020, experts on LTEs from five different European countries met in a virtual worksho...
Preprint
Temperature is a main driver of plant growth and development. New phenotyping tools enable quantifying the temperature response of hundreds of genotypes. Yet, particularly for field-derived data, the process of temperature response modelling bears potential flaws and pitfalls with regard to the interpretation of derived parameters. In this study, c...
Article
Full-text available
Pesticide residues are much lower in organic than in conventional food. The article summarizes the available residue data from the EU and the U.S. organic market. Differences between samples from several sources suggest that organic products are declared conventional, when they have residues—but the origin of the residues is not always investigated...
Article
Full-text available
Agroforestry systems (AFS) can provide positive ecosystem services while at the same time stabilizing yields under increasingly common drought conditions. The effect of distance to trees in alley cropping AFS on yield-related crop parameters has predominantly been studied using point data from transects. Unmanned aerial vehicles (UAVs) offer a nove...
Article
Full-text available
The purpose of order‐of‐addition (OofA) experiments is to identify the best order in a sequence of m components in a system. Such experiments may be analyzed by various regression models, the most popular ones being based on pairwise ordering (PWO) factors or on component‐position (CP) factors. This paper reviews these models and extensions and pro...
Article
Full-text available
Chlorophyll fluorescence (ChlF) is a powerful non-invasive technique for probing photosynthesis. Although proposed as a method for drought tolerance screening, ChlF has not yet been fully adopted in physiological breeding, mainly due to limitations in high-throughput field phenotyping capabilities. The Light-Induced Fluorescence Transient (LIFT) se...
Preprint
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 modelling for field trials, starting with the early work of Papad...
Preprint
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...
Article
Crop nutrient deficiencies are determined based on leaf nutrient composition, and rarely on food composition. Consequently, it remains unclear whether leaf nutrients are useable to form conclusions on quality of produced foods. This study aimed to investigate the relationships between plant macro- (Mg, P, S, K, Ca) and micronutrient (Fe, Zn, Mn, Cu...
Article
Full-text available
Key message Hyperspectral data is a promising complement to genomic data to predict biomass under scenarios of low genetic relatedness. Sufficient environmental connectivity between data used for model training and validation is required. Abstract The demand for sustainable sources of biomass is increasing worldwide. The early prediction of biomas...
Article
Full-text available
Key message Breeding progress of resistance to fungal wheat diseases and impact of disease severity on yield reduction in long-term variety trials under natural infection were estimated by mixed linear regression models. Abstract This study aimed at quantifying breeding progress achieved in resistance breeding towards varieties with higher yield a...
Article
Full-text available
Key message We propose the utilisation of environmental covariates in random coefficient models to predict the genotype performances in new locations. Abstract Multi-environment trials (MET) are conducted to assess the performance of a set of genotypes in a target population of environments. From a grower’s perspective, MET results must provide hi...
Article
Full-text available
Improved management and breeding increased maize (Zea mays L.) yields over the last century, but nutritional efficiency was usually not the focus. This study investigates whether old and recently released flint and dent maize seedlings vary in the phosphorus (P) acquisition and utilization. P use efficiency (PUE) and related traits were measured an...
Preprint
Full-text available
Multiparental advanced generation inter-cross (MAGIC) populations are valuable crop resources with a wide array of research uses including genetic mapping of complex traits, management of genetic resources and breeding of new varieties. Multiple founders are crossed to create a rich mosaic of highly recombined founder genomes in the MAGIC recombina...
Preprint
Full-text available
Statistical models that capture the phenotypic plasticity of a genotype across environments are crucial in plant breeding programs to potentially identify parents, generate offspring, and obtain highly productive genotypes for distinct environments. In this study, our aim is to leverage concepts of Bayesian models and probability methods of stabili...
Article
Random walks, intrinsic autoregression, state‐space models, smoothing splines etc. have been widely used in various areas of statistics. However, practitioners wanting to fit these models using existing packages for random‐effects models are often faced with the difficulty that their covariance matrices are not uniquely determined. Unfortunately, d...
Article
Full-text available
The rearing of piglets is a demanding phase of pig production partly because of the changing temperature requirements of the piglets during rearing. Piglets need high temperatures in the resting area, especially at the beginning, while the optimal temperature is lower toward the end of rearing. To meet the changing temperature demands of the piglet...
Article
Full-text available
In designed experiments, different sources of variability and an adequate scale of measurement need to be considered, but not all approaches in common usage are equally valid. In order to elucidate the importance of sources of variability and choice of scale, we conducted an experiment where the effects of biochar and slurry applications on soil pr...