Laurence (Larry) V. Madden was born in Ashland, Pennsylvania. He received his BS in 1975, his MS in 1977, and his PhD in 1980—all from The Pennsylvania State University. He joined the Department of Plant Pathology at The Ohio State University in 1980 and was appointed Distinguished Professor of Plant Protection in 2008.
Madden is well recognized around the world for his 40 years of seminal research contributions that have substantially increased our understanding of plant disease epidemics. He pioneered the use of many modeling approaches to analyze, compare, and understand the spatial and temporal components of plant disease epidemics. He has used the knowledge gained from these research advances to predict the risk of disease outbreaks and the rates of disease increase in agricultural fields and also to develop and test efficient disease management strategies using decision-analytical tools. In numerous ways, his work has defined the modern field of quantitative epidemiology around the world.
Of great significance is Madden's early work on the development and application of flexible differential equation-based nonlinear models for epidemics and the evaluation of proper statistical methods for estimating and comparing model parameters. In a key breakthrough, he and colleagues Mike Jeger and Frank van den Bosch developed a coupled differential equation model that directly links the population dynamics of insect vectors with the temporal progression of plant viral diseases. In a landmark contribution, the basic reproduction number (R0) for predicting invasion and persistence of plant viruses of different transmission types was derived. This work has served as the basis for numerous subsequent studies.
Madden's research from the 1980s to the present has shown the critical importance of the spatial component of epidemics, and his foundational work has led to numerous studies by investigators in many countries. He has demonstrated the dynamic and predictable change of disease clustering over time in crop fields, and he was the first to characterize this process using STARIMA and related models. Recently working with Xiangming Xu, Madden developed a new statistical index for large-scale clustering of organisms within the SADIE methodology popular in ecology. His ongoing research on spatial heterogeneity of disease incidence has altered how plant pathologists should assess small-scale patterns. He and Gareth Hughes developed the binary power law to characterize spatial heterogeneity of disease incidence and showed that diseased plants follow a beta-binomial distribution as a direct consequence of the empirical law. This power law relationship, confirmed by dozens of researchers in many countries, has led to development of revised methods of sampling for incidence; determining the effects of experimental treatments on incidence in the field; and predicting disease dynamics at multiple scales in a spatial hierarchy (e.g., leaves, plants, fields).
Madden conducted early ground-breaking research on the mechanisms of rain-splash dispersal of plant pathogens, giving us a new understanding of this obligatory mode of dissemination for many pathogens. He characterized the entrainment of spores into splash droplets, determined the physical relations between properties of impacting raindrops and resulting trajectories of splash droplets, and demonstrated the pronounced effect of surface topography (ground cover) and plant canopy structure on the biophysics of splash dispersal. A new generation of researchers is now building on his pioneering work.
Throughout his career, Madden has dramatically improved our understanding of the functional relationship between epidemics and yields in plant populations. This work has been extended to include epidemics and toxins in grain. Madden has developed a sound set of protocols for analyzing and modeling crop losses (or toxin contamination) in response to disease. He has also shown how to link temporal disease progress and spatial pattern models to models for yield and has recently shown how to incorporate heterogeneity of disease or yield at multiple scales into risk models.
Madden has always been able to combine basic research on the mathematical aspects of epidemics with more applied research to solve agricultural problems. He has developed several prediction systems for plant disease outbreaks based on linear and nonlinear models of disease in relation to environmental conditions, and he is now pioneering the use of machine-learning algorithms (such as boosted regression trees) and functional data analysis (FDA) to improve prediction systems. Together with his former post-docs Erick DeWolf and Pierce Paul (both now professors), Madden has been a leader in the creation and deployment of the national forecasting system for Fusarium head blight of wheat, which is used regularly in more than 30 U.S. states. Furthermore, he continues to utilize the most recent developments in statistics to solve biological problems. He has become an international authority on the use of meta-analysis, mixed models, and nonparametric analysis in agriculture, and he is making original contributions in the plant and statistical literature on meta-analysis for quantitative research synthesis.
Madden's research has been extremely productive. He has authored or co-authored more than 260 refereed articles and 20 book chapters, and he is an author of the two primary textbooks in epidemiology written during the past 30 years. He is in great demand as a lecturer and has been an invited speaker at numerous national and international meetings, and he has organized several symposia.
Madden has a long history of distinguished service. He was editor-in-chief of Phytopathology from 1991 to 1993 and president of The American Phytopathological Society (APS) from 1996 to 1997. During the past 15 years, he has frequently organized and taught statistics workshops at scientific conferences and other events. Madden's ability to present state-of-the-art and complex statistical concepts in a clear, organized fashion has made these workshops sold-out events for several years.
In recognition of his numerous accomplishments, Dr. Madden has received many honors—locally, nationally, and internationally. He is an elected Fellow of APS and of AAAS. In 2003, he received the APS Ruth Allen Award, and in 2005, he was honored with the E. C. Stakman Award for his lifetime contributions in advancing epidemiology and plant protection around the world. Then, most notably, he received the Jakob Eriksson Prize and Gold Medal in 2008 “in recognition of outstanding contributions to the understanding of plant disease epidemiology and for research in plant pathology of a distinct international value and merit."
