2Plant Pathology orPhytopathology is thestudy of plantdiseases.
3Did you know that plants have diseases and getsick just like people andanimals do?
4Most people don’t realize that plants are affected byinfectious diseasescaused by livingorganisms (called PlantPathogens).
5Infectious plantpathogens include fungi,bacteria, nematodes,viruses, and parasiticplants.
6Plant Diseases are also caused by non-living orabiotic causes such asair pollution, nutrientdeficiencies and variousenvironmental factors.
7Are Plant Diseases Important? YOU BET THEY ARE!!!
8All of our food, much ofour clothing, buildingmaterials, and much ofthe beauty in nature isprovided by plants.
9Plant diseases are aconstant threat to theworld’s food and fibercrops, forests, andlandscape plants.
10Throughout history, plant diseases have beenresponsible for the death andsuffering of millions of peopleand countless animals.
11A few examples of devastating diseases are: 1. Potato Late Blight2. Ergot of Rye3. Black Stem Rust of Wheat4. Southern Corn Leaf Blight5. Dutch Elm Disease6. Bacterial Canker on Citrus7. Plum Pox Virus on Stone FruitAll of these are infectious diseases caused by plant pathogens.
12Let’s take a closer look at a few of these important plant diseases
13Late Blight of Potato Caused by the fungus Phytophthora infestans The fungus killed most of the potatoes grown in Ireland during the mid 1800’s.Potatoes were the main source of food for the Irish people.This plant disease resulted in the Irish Potato Famine of 18451 million people died1.5 million people left Ireland
15Ergot of Rye Caused by the fungus Claviceps purpurea The pathogen produces a structure called a sclerotium that grows in place of the rye kernel. This sclerotium contains poisons that are very harmful to man and animals.The sclerotium is harvested with the rye grain. The grain is ground into flour, made into bread and is eaten by people. Eating the contaminated bread results in a disease called Ergotism.ERGOTISM OFTEN RESULTS IN DEATH.
17Ergot of Rye Holy Fire or St. Anthony’s Fire The scelotia also contains hallucinogeniccompounds. People that eat ergot often see Fire.In the middle ages, people called the vision of fire induced by ErgotHoly Fire or St. Anthony’s FireErgotism can also cause abortions and gangrene.THIS PLANT DISEASE IS STILL KILLINGPEOPLE IN THE WORLD TODAY
18Black Stem Rust of Wheat Destroyed 300 millionbushels of wheat in the United States and CanadaDestroyed 135 millionbushels in Dakotas and MinnesotaSPORATIC EPIDEMICS STILL COST NORTHAMERICAN FARMERS BILLIONS OF DOLLARS
20Southern Corn Leaf Blight An epidemic caused a 15% loss of the U.S. corn crop. This resulted in a one billion dollar loss in the United States.This was enough corn that, if fed to cattle,it would make 30 BILLION HAMBURGERS
22Plum Pox Virus Plum Pox is caused by a virus and is a very serious disease that infects all stone fruit.- It is estimated that 100 million stonefruit trees are infected with the virus inEurope.- Infected trees become nonproductiveand must be removed. This results intremendous economic losses to stonefruit producers.
24Plum Pox VirusIn 1999, the virus was identified on peach trees in Pennsylvania. This is the first observation of the virus in North America.The virus was probably introduced into the U. S. in an infected tree or budwood. The disease is a major threat to stone fruit production throughout North America.At present, plant pathologists and regulatory agencies are trying to eradicate the virus.
25Plant diseases cause an estimated loss of 8 billiondollars per year in theUnited States alone.
27We rely upon Plant Pathologists to provide information about plant diseases and how to manage them.
28A Plant Pathologist is a professional who specializes in plant health much as a physician specializes in human health or a veterinarian in animal health.
29Controlling plant diseases and keeping plants healthy is the main objective of a plant pathologist.
30Controlling plant disease requires an understanding of the agents that cause disease as well as an understanding of how plants are affected by disease.
31Through college courses in botany, microbiology, horticulture, crop science, soil science, ecology, genetics, biochemistry, molecular biology, and physiology, students receive the necessary background for exciting careers in the interdisciplinary science of plant pathology.
32Plant pathologists are employed by colleges and universities, state and federal agencies, industrial firms, international institutes, and as private practitioners.
33Most Plant Pathologists are members of The AmericanPhytopathological Society(APS)
34APS is an international scientific organization devoted to the study of plant diseases and their control.
35The society has a membership of nearly 5000 plant pathologists and other scientists located in 80 countries worldwide.
36The common goal of APS and Plant Pathologists worldwide is to develop and promote knowledge about plant diseases and their control.
37We should all remember that we need HEALTHY PLANTS in order to have HEALTHY AND HAPPY PEOPLE.