Plant pathology has developed from antiquity, but scientific study began in the Early modern period and developed in the 19th century.^[1]

Early history

• 300–286 BC; Theophrastus, father of botany, wrote and studied diseases of trees, cereals and legumes^[2]

17th century

• 1665; Robert Hooke illustrates a plant-pathogenic fungal disease, rose rust^[1]
• 1675; Antony van Leeuwenhoek invents the compound microscope, in 1683 describes bacteria seen with the microscope^[2]

18th century

• 1729; Pier Antonio Micheli observes fungal spores, conducts germination experiments^[2]
• 1755; Mathieu Tillet reports on treatment of seeds^[2]

19th century

• 1802; Lime sulfur first used to control plant disease^[1]
• 1845–1849; Potato late blight epidemic in Ireland^[1]
• 1853; Heinrich Anton de Bary, father of modern mycology, establishes that fungi are the cause, not the result, of plant diseases,^[2] publishes "Untersuchungen uber die Brandpilze"
• 1858; Julius Kühn publishes "Die Krankheiten der Kultergewachse"^[1]
• 1865; M. Planchon discovers a new species of Phylloxera, which was named Phylloxera vastatrix.^[3]
• 1868–1882; Coffee rust epidemic in Sri Lanka^[1]
• 1871; Thomas Taylor publishes the first USDA papers on microscopic plant pathogens^[4]
• 1875; Mikhail Woronin identified the cause of clubroot as a "plasmodiophorous organism" and gave it the name Plasmodiophora brassicae^[1]
• 1876; Fusarium oxysporum f.sp. cubense, responsible for Panama disease, discovered in bananas in Australia^[5]
• 1878–1885; Downy mildew of grape epidemic in France^[1]
• 1879; Robert Koch establishes germ theory: diseases are caused by microorganisms^[2]
• 1882; Lehrbuch der Baumkrankheiten (Textbook of Diseases of Trees), by Robert Hartig, is published in Berlin, the first textbook of forest pathology.^[1]
• 1885; Bordeaux mixture introduced by Pierre-Marie-Alexis Millardet to control downy mildew on grape^[1]
• 1885; Experimental proof that bacteria can cause plant diseases: Erwinia amylovora and fire blight of apple^[1]
• 1886–1898; Recognition of plant viral diseases: Tobacco mosaic virus^[1]
• 1889; Introduction of hot water treatment of seed for disease control by J. L. Jensen^[1]

20th century

• 1902; First chair of plant pathology established, in Copenhagen^[1]
• 1904; Mendelian inheritance of cereal rust resistance demonstrated^[1]
• 1907; First academic department of plant pathology established at Cornell University^[1]
• 1908; American Phytopathological Society founded^[1]
• 1910; Panama disease reaches Western Hemisphere^[5]
• 1911; Scientific journal Phytopathology founded^[1]
• 1925; Panama disease reaches every banana-growing country in the Western Hemisphere^[5]
• 1951; European and Mediterranean Plant Protection Organization (EPPO) founded^[1]
• 1967; Recognition of plant pathogenic mycoplasma-like organisms^[1]
• 1971; T. O. Diener discovers viroids, organisms smaller than viruses^[6]