AGRI 41

• Scientific study of plant diseases, what causes them, how and why they occur, and how to manage them.

  Plant Pathology
• "phyto"


  plant
• pathos


  suffering
• logos


  study
• study of fungi and fungi-like oomycetes

  mycology
• study of typical bacteria, fastidious bacteria, mollicutes (e.g., Phytoplasma and Spiroplasma)

  Bacteriology
• study of nematodes


  nematology
• study of virus and viroids

  virology
• what plant disease caused famine in Europe (Great Irish Famine)?

  Potato Late Blight
• Potato Late Blight

  • water-soaked lesions on the leaves
  • rotting of leaves and stems
  • rotting of tubers
• In 1861, Heinrich Anton de Bary showed that the potato late blight was caused by a fungus called


  Phytophthora infestans
• Father of Mycology

  Heinrich Anton de Bary
• It is caused by eating rye bread contaminated with sclerotia of Claviceps purpurea

  Ergotism
• Sclerotia contains alkaloids with a strong hallucinogenic effect
• first course in Plant Pathology taught as Botany 4 under the Agronomy dept.


  1910
• C. Baker published “The Lower Fungi of the Philippines Island” – a review of Philippine plant diseases


  1914
• Department of Plant Pathology was born and course offered as Plant Pathology 1; Otto Reinking as first department head


  1917
• enactment of Republic Act 3027 – known as Plant Quarantine Act


  1922
• Gerardo Ocfemia first Filipino department head; “Dean of Filipino Plant Pathology”


  1933
• • Studies on etiology and control of leaf and seedling diseases
  • Development program in upgrading staff and physical facilities

  1950-1960
• Philippine Phytopathological Society was developed


  1963
• Surveillance and Early Warning Systems established by BPI


  1970
• Exconde and co-workers controlled corn downy mildew by seed treatment


  1978
• Davide developed biological control against nematodes


  1983
• The PCAARD is an attached agency under the Department of Agriculture (DA). It serves as the national coordinating body for all agricultural research and development activities.
• 3 Direct Losses due to Plant Diseases

  • Reduction in yield
  • Reduction in quality of produce
  • Deterioration of produce during storage, marketing, and transport
• Plant pathologists

  Plant doctors
• Plant pathology


  • Study of plant pathogens and diseases they cause in plants
  • Understanding the components of plant disease, and the mechanisms by which plant pathogens induce disease in plants
  • Development of methods in preventing, controlling and management of plant diseases to reduce the damage on plants
• Composition of plant pathology

  • Mycology - fungi & fungal-like oomycetes
  • Bacteriology - typical bacteria, fastidious bacteria, mollicutes (e.g. Phytoplasma and Spiroplasma)
  • Nematology - nematodes
  • Virology - virus and viroids

  
• Plant pathology as a science

  • Nature/properties
  • Causes
  • Factors affecting disease development
  • Ways to control or manage them
• Plant pathology as an art


  • Skills to develop methods, equipment, and materials for disease identification and diagnosis; control and management
• Late blight of potato caused famine
• Ergotism caused deaths of thousands of people
• Coffee rust have changed the way people behave and/or their customs
• Southern corn leaf spot, chestnut blight, and dogwood anthracnose epidemics caused damage resulting to crop loss amounting to millions of dollars
• Potato late blight

  • Water-soaked lesions on the leaves
  • Rotting of leaves & stems
  • Rotting of tubers
• In 1861, Heinrich Anton de Bary showed that potato late blight was caused by a fungus Phytophthora infestans
• Heinrich Anton de Bary


  • German doctor, and botanist
  • Father of Mycology who started the scientific study of plant diseases; proved that the spores caused the disease
• Ergot of Rye


  Sclerota-hard survival structures shaped like the spur of the rooster
• Ergotism


  • Caused by eating rye bread contaminated with sclerotia of Claviceps purpurea
  • Sclerotia contain alkaloids with a strong hallucinogenic effect
  • Symptoms in humans: tingling of extremities, high fever; hallucinations; mental derangement; abortion; and loss of hands, feet, and legs due to restricted blood flow and subsequent gangrene, and death