APPLICATORS LICENSE 1C COMPREHENSIVE EXAM
1. Plant Disease: Any abnormal condition that damages a plant and alters its appearance
2. Plant Disease Triangle: Susceptible host plant, a pathogen, and a favorable environment
3. Symptoms: Visible effects of plant disease
4. Temperature and Moisture (Air and Soil): The most important environmental factors
5. Relative humidity, Soil pH, soil texture, light, nutrient status, compaction, tillage
practices, planting depth, seed bed preparation, and residue management: May affect disease
development
6. Major groups of plant pathogens: Fungi, bacteria, viruses, nematodes, non- infectious disorders
7. Fungi: Largest group, lack chlorophyll, obtain food from decaying organic matter/living tissue, has hyphae (fuzzy stuff) to absorb moisture
and nutrients, reproduce with spores that can survive in soil and decaying plant material for a long time, some produce sclerotia to store nutrients to help
them survive, leaf spots, blights, root rots, seedling blights,
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, wilts, stalk rots
8. Bacteria: .
Extremely small microorganisms, reproduce by simple division, split into two approximately equal halves that turn into
fully developed bacterium, can reproduce very quickly, clump together in colonies, obtain food from living and dead tissue, in the absence of a host
they decline quickly, leaf spots, water soaking of tissue, soft rots of tissues
9. Viruses: Infectious, disease producing particles, noncomplete living systems, complex chemical molecules, genetic material surrounded by
a protein coat, induce host cells to form more viruses, transmitted my insects machines and people when they take infected sap with them to a healthy
plant, mosaic patterns on leaves, deformation of plant tissues, stunting, reduced yield
10. Nematodes: Round slender worms, feed on decaying organic material, so small that they are relatively unseen, have a needlelike
structure called a stylet to push into plant cells to breakdown contents and withdraw liquified
contents, many different types, can cause knots or galls on roots, black flecking on roots, short fat/stubby roots, eggs stage, four juvenile stages,
and an adult, average life-cycle is 20-60 days, overwinter in egg stage, plants can appear to be moisture or fertilizer deficient when they should be
adequate, stunting, yellowing, loss of vigor, general decline, and eventual death
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10
1. Plant Disease: Any abnormal condition that damages a plant and alters its appearance
2. Plant Disease Triangle: Susceptible host plant, a pathogen, and a favorable environment
3. Symptoms: Visible effects of plant disease
4. Temperature and Moisture (Air and Soil): The most important environmental factors
5. Relative humidity, Soil pH, soil texture, light, nutrient status, compaction, tillage
practices, planting depth, seed bed preparation, and residue management: May affect disease
development
6. Major groups of plant pathogens: Fungi, bacteria, viruses, nematodes, non- infectious disorders
7. Fungi: Largest group, lack chlorophyll, obtain food from decaying organic matter/living tissue, has hyphae (fuzzy stuff) to absorb moisture
and nutrients, reproduce with spores that can survive in soil and decaying plant material for a long time, some produce sclerotia to store nutrients to help
them survive, leaf spots, blights, root rots, seedling blights,
1/
10
, wilts, stalk rots
8. Bacteria: .
Extremely small microorganisms, reproduce by simple division, split into two approximately equal halves that turn into
fully developed bacterium, can reproduce very quickly, clump together in colonies, obtain food from living and dead tissue, in the absence of a host
they decline quickly, leaf spots, water soaking of tissue, soft rots of tissues
9. Viruses: Infectious, disease producing particles, noncomplete living systems, complex chemical molecules, genetic material surrounded by
a protein coat, induce host cells to form more viruses, transmitted my insects machines and people when they take infected sap with them to a healthy
plant, mosaic patterns on leaves, deformation of plant tissues, stunting, reduced yield
10. Nematodes: Round slender worms, feed on decaying organic material, so small that they are relatively unseen, have a needlelike
structure called a stylet to push into plant cells to breakdown contents and withdraw liquified
contents, many different types, can cause knots or galls on roots, black flecking on roots, short fat/stubby roots, eggs stage, four juvenile stages,
and an adult, average life-cycle is 20-60 days, overwinter in egg stage, plants can appear to be moisture or fertilizer deficient when they should be
adequate, stunting, yellowing, loss of vigor, general decline, and eventual death
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10
