Plant pathology is the scientific study of diseases in plants caused by pathogens and environmental conditions. Organisms that cause infectious disease include fungi, oomycetes, bacteria, viruses, viroids, virus-like organisms, phytoplasmas, protozoa, nematodes and parasitic plants. Not included are ectoparasites like insects, mites, vertebrate, or other pests that affect plant health by eating plant tissues. Plant pathology also involves the study of pathogen identification, disease etiology, disease cycles, economic impact, plant disease epidemiology, plant disease resistance, how plant diseases affect humans and animals, pathosystem genetics, and management of plant diseases.
Blight refers to a specific symptom affecting plants in response to infection by a pathogenic organism.
Fire blight, also written fireblight, is a contagious disease affecting apples, pears, and some other members of the family Rosaceae. It is a serious concern to apple and pear producers. Under optimal conditions, it can destroy an entire orchard in a single growing season.
Stewart's wilt is a serious bacterial disease of corn caused by the bacterium Pantoea stewartii. This bacterium affects plants, particularly types of maize such as sweet, flint, dent, flour, and popcorn. The disease is also known as bacterial wilt or bacterial leaf blight and has shown to be quite problematic in sweet corn. The disease is endemic in the mid-Atlantic and Ohio River Valley regions and in the southern portion of the Corn Belt.
Rebecca J. Nelson, is an American biologist and a professor at Cornell University and a MacArthur Foundation Fellow.
Curtobacterium flaccumfaciens is a Gram-positive bacterium that causes disease on a variety of plants. Gram-positive bacterium characteristics include small irregular rods, lateral flagella, the ability to persist in aerobic environments, and cells containing catalase. In the interest of studying pathogenicity in plants, the species Curtobacterium flaccumfaciens is broken down further into pathovars, which help to better describe the pathogen.
Frances Meehan Latterell was an American plant pathologist whose research in the late 1940s opened a major new area of inquiry into the physiological basis of plant disease. She was the senior author on a classic 1947 paper showing that the toxin victorin, produced by the pathogenic fungus Helminthosporium victoriae, caused symptoms of Victoria blight of oats, a new disease first described by Latterell and her major professor in 1946. This discovery of a host-specific toxin, as victorin was later named, gave scores of subsequent researchers new model systems for studying plant disease.
Plant disease forecasting is a management system used to predict the occurrence or change in severity of plant diseases. At the field scale, these systems are used by growers to make economic decisions about disease treatments for control. Often the systems ask the grower a series of questions about the susceptibility of the host crop, and incorporate current and forecast weather conditions to make a recommendation. Typically a recommendation is made about whether disease treatment is necessary or not. Usually treatment is a pesticide application.
Ruth Florence Allen (1879–1963) was an American botanist and plant pathologist and the first woman to earn her Ph.D. in botany from the University of Wisconsin. Her doctorate research focused on the reproduction and cell biology of ferns, particularly the phenomenon of apogamy. Later in her career, Allen shifted her focus to plant pathology. Her major contribution to the field of mycology was furthering the understanding of rust fungi, a group of economically important plant pathogens. Allen completed many studies on Puccinia graminis, once considered a catastrophically damaging disease-causing agent in cereal crops before the discovery of current management measures.
Southern corn leaf blight (SCLB) is a fungal disease of maize caused by the plant pathogen Bipolaris maydis.
Edwin Earle Honey was an American plant pathologist and mycologist. In 1936, he formally described the fungus and plant pathogen Monilinia azaleae, which preys upon crops and other plants in the families Rosaceae and Ericaceae.
Alice Crane Haskins Swingle was an American government botanist. With her husband, botanist Deane Bret Swingle (1879–1944), she co-authored the 1928 book A Textbook of Systematic Botany.
Collar rot is a symptomatically described disease that is usually caused by any one of various fungal and oomycete plant pathogens. It is present where the pathogen causes a lesion localized at or about the collet between the stem and the root. The lesions develop around the stem eventually forming a "collar". Observationally, collar rot grades into "basal stem rot", and with some pathogens is the first phase of "basal stem rot" often followed by "root rot". Collar rot is most often observed in seedings grown in infected soil. The pathogens that cause collar rot may be species or genera specific. But generalist pathogens such as Athelia rolfsii are known to attack over 200 different species. While bacteria caused collar rot is not common, trees infected with Fire blight may develop collar rot. Non-parasitic collar rot may be caused by winter damage.
Thousands of plant diseases have been recorded throughout the world, many of these causing heavy crop losses. Early detection and accurate diagnosis is essential for the effective management of plant disease. Thus the first step in studying any disease is its timely detection of the diseased plant. Quick initial detection is largely based on the signs and symptoms of disease.
Robert S. Dickey was an American phytopathologist, professor emeritus of Plant Pathology at the Cornell University and the namesake of the bacterial genus Dickeya.
Jean Beagle Ristaino is an American scientist and William Neal Reynolds Distinguished Professor of Plant Pathology. She is best known for her work on the epidemiology and population genetics of Oomycete plant pathogens in the genus Phytophthora and her work on the population genomics of historic outbreaks of the Irish famine pathogen, Phytophthora infestans
Said Amin (Gabe) Ghabrial was an Egyptian-American plant pathologist, known for his work on mycoviruses – viruses of fungi – and particularly their effects on the virulence of plant-pathogenic fungi. He also researched bean pod mottle virus, an economically important soybean disease. He was professor of plant pathology at the University of Kentucky (1986–2014).
Jan Elnor Leach is an American plant pathologist. She is known for her research of the molecular biology of plant pathogens, particularly those affecting rice plants. She has been the co-editor of the Annual Review of Phytopathology since 2015 and is a fellow of the American Association for the Advancement of Science and a member of the National Academy of Sciences.
Amy Olymbia Charkowski is an American plant pathologist and Professor of Plant Pathology at Colorado State University. She was elected Fellow of the American Association for the Advancement of Science in 2020.
