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Plant Pathology
Question | Answer |
---|---|
Plant Pathology | The study of organisms that cause dieses and the resulting dieses that occours. |
Plant Disease | The affect or symptoms of a plant when it has been attacked by a pathogen. -Infers with plant functions -Toxins -Enzymes/Growth Regulators |
Pathogen | The actual organism that causes dieses. |
Ergot of small grains | -Caused by Calviceps Purpurea -High ammounts of LSD -Salem Witch trials/Holy Fire |
Late Blight of Potato | -Irish Potato Famin -Caused by Phytophthora Infestanas -Dependance on a single crop |
Southern Corn Leaf Blight | -Caused by Cochibolus Heterostropus -Use of CMS gene eliminated detasiling of corn -15% loss in 1970/Total Loss 1971 |
Cytoplasmic Male Sterility | What does CMS stand for |
Chestnut Blight | -Caused by Cryphonectria Parasitica -Introduced by wooden baskets from china in 1904 -No control availible today |
Dutch Elm Diease | -Caused by Ophiostoma Ulmi -Carried by Elm Bark Beetles -Kills tree in a few weeks to a year |
Diease Causing Organisms (pathogens) | -Fungi -Bacteria -Virusis -Nematodes -Algae -Protazoa -Parasitic seed plants |
1.Parisites- needs host 2.Biotrophs- needs live tissue that it kills 3.Necrotrophes- kills tissue first, lives on dead tissue | What are the 3 Classifications of Pathogens |
Environmental factors for pathogens | -temp -moisture -light -nutrients -pH |
5 Steps of the Disease Cycle | 1. Inoculation 2. penetration 3. infection 4. invasion 5. reproduction 6. dissemination |
Commom symptoms of infection | -Death of tissue -Under devoloped/overdeveloped tissue -Wilting -Cankers -Scorching |
Abiotic Plant Dieses | -pH -Nutrient excess/dificiency -flood/drought -light -salts |
Injury causing "Diease Like" symptoms | -Animal/Insect feeding -mowing -pruning -lightning -chemical |
What is a Fungi | -Eukarotic organism -NO clorophyl -HAVE cell walls -Reproduce by spores |
Classification of Fungi | -Basidiomycota -Ascomycota -Zygomycota -Duteromycota |
Structures of Fungi | Hypha- tubular, thread like structure,makes up body of fungus |
Hypha | -elongates by apical growth -secreates toxins and enzymes -penetrates cell wall -where spores are produced |
Dueteromycota | -Asexually produce conida on condiophores -cannot produce sexually |
Zygomycota | -Sporagnia asexually produced from hyphe on sporagnaiophores -sexually reproduce to form zygospores |
Ascomycota | -Sexually produce ascospores -asexually produce conida |
Basidiomycota | -sexually produce basidiospores on a basidia inside a Basidiocarp (mushroom) -Sexually produce Basidiospores without Basidiocarp (teliospores) -Asexually produce (ONLY BY MYCELIUM) |
Mushroom like fungi rusts | Basidiomycetes |
Dieases caused by Basidiomycetes | -tree root rot -smuts -rusts -southern blight/wilt |
Armillara Mellea (basidiomycete) | -attacks weak trees -lives in soil -black "shoe strings" -golden mushrooms at base of tree -controled by removing stumps and wood scraps |
Ustilago Maydis (basidiomycete) | -corn smut -edible fungi -only lives on living tissue |
Rusts (basidiomycete) | -Most damaging in the world -Very host specific -spores are sweet so attracts insects -lifecycle is very complex -5 different spore types |
Types of Rusts (basidiomycetes) | 1. Puccinia Hemerocallidis (daylilly) 2. Puccinia (corn, sorghum, veggies, wheat, cotton, flowers) 3. Cronartium (trees) 4. Hemileia (coffee) 5. Gymnosporangium (cedar-apple) 6. Phakopsora (soybean) |
Controll methods for Rusts (basidiomycetes) | -Nitrogen -Fungisides |
Soybean Rust (Phakopsora Pachyrhizi) | -in US since 2004 -fewer pods/unfilled pods -early planting/wet conditions favor diease -yield loss up to 80% -fungisides are effective if applied at exact right time |
Wheat Rusts (Puccinia Tritici) | -common in KY -Wet warm conditions favor disease -avoid dense stands -resistant varities avalible -fungisides have little affect unless in early stages |
Ceder-Apple Rust (Gymnosporangium Juniper-Virginianae) | -orange colored telial on ceder in april -teliospores can be deadly to apple trees -resistant cultivars of apple avalible -can be controled by fungisides |
Rhizoctonia Solani (basidiomycete) | -Necrotroph -No spors, live in soil -loves moist soil, high humidity, nitrogen -Very wide host range |
Effects of Rhizoctonia Solani (basidiomycetes) | -damping of seedlings -brown patch of turf -target spot on tobacco -azalea web blight |
Target Spot Tobacco (Rhizoctonia Solani/basidiomycete) | -very bad in greenhouse float beds -often mistaken for blue mold -loves high humidity -clipping and fungisides are affective |
Sclerotium Rolfsii (basidiomycete) | -southern blight/southern wilts -wide host range -lives in soil -thrives in HOT temps -white mycelial mats visible on soil -no spores, but does produce sclerotia |
Effects of Sclerotium Rolfsii (basidiomycete) | -damping of seedlings -stem crankers -root rots -fruit rots -rots stem at base -nitrogen, fungisides, and rotation are effective control methods |
Ascomycetes | What Classification are known as "True Fungi" |
Diseases caused by Ascomycetes | 1. Powdery mildews 2. Take-all of wheat 3. Nectria (cankers of trees) 4. Apple Scab 5. Gibberella stalk and ear rot corn 6. Southern Corn Leaf Blight 7. Ergot (wheat/small grain) 8. Dutch Elm Disease 9. Chestnut Blight |
Duteromycetes | -Fungi Imperfecti -Asexual reproduction ONLY |
Diseases Caused by Duteromycetes | 1. Aspergillus (ear rots corn) 2. Penicillium (ear rots corn) 3. Fasarium (ear rots corn, vascular wilts) 4. Verticillium (vascular wilts) 5. Collitricillium (Anthraconosis) 6. Marssonia (Black Spot Rose) 7. Cercospora (Leaf Spots) 8. Botrytis (Gre |
Ear and Kernal rots and molds (Duteromycetes) | -Destroy 30% grain each year -Enter through wounds, rain splash -becomes latent after harvest -controlled if moisture is 15% or less |
Post Harvest Fruit Rots (Duteromycetes) | -Apergillus Toxins (Green Molds) -Penicillium Toxins (Blue Molds) -Botrytis Toxins (Grey Molds) -Sclerotinia Toxins (White Cottoney Rots) -Fusarium Toxins (Pink and Yellow Molds) -Alternaria |
Diseases that live IN the soil | -Gaemannomyces -Nectria -Fusarium -Rhizocotonia -Armillaria -Sclerotium -Gibberella |
Diseases that only affect TERRESTRIAL plant parts (not in soil) | -Powdery Mildew -Rusts -Septoria -Cercospora -Alternaria -Ustilago -Botrytis |