OTPS (Alabama) A SERIES OF QUESTIONS AND
CORRECT ANSWERS WITH VERIFIED SOLUTIONS.
Disease - ANSWER: Abnormal function caused by a continuously irritating agent and
expressed by noticeable symptoms
Requirements for disease - ANSWER: (1) disease agent; (2) susceptible plant; (3) favorite
environment
Symptom - ANSWER: The visible effect produced in or on a plant by the presence of
pathogen or disease agent
Sign - ANSWER: An indication of a disease from direct visibility of the pathogen
Examples of Disease Symptoms - ANSWER: Spots, blights, cankers, diebacks, stunting,
chlorosis, galls, root-knot, wilt.
Disease Agents - ANSWER: (1)Living and (2) Non-living
Living Disease Agent - ANSWER: : Fungi, Bacteria, Viruses, Viroids, Mycoplasmas,
Nematodes, Parasitic Higher Plants, Protozoa
Non-living Disease Agent - ANSWER: Environmental factors, Nutrition, Pollution, etc.
Fungi: small organisms (Kingdom Mycetae) - ANSWER: 8000 species cause plant disease
ii. Cause over 80% of plant disease iii. Consist of microscopic filaments called hyphae iv.
Reproduce by spores v. Identified by spores and reproductive structures vi. Survive as
parasites and saprophytes vii. Spread by wind/rain/insects
Bacteria: primitive microscopic organisms (Kingdom - Prokaryotes) - ANSWER: i. 200
species cause plant disease ii. Microscopic, one-celled organisms iii. Reproduce by binary
fission iv. Survive as parasites/ saprophytes v. Infect plant wounds/ natural openings vi.
Spread by wind/ insects
, Viruses: submicroscopic structures - ANSWER: i. 500 + cause plant disease ii.
Submicroscopic organisms iii. Obligate parasites iv. Nucleic acid and protein coat v.
Replicate within the host cell vi. Infect plants through wounds vii. Spread by
insect/seed/animals
Nematodes: small round worms (Kingdom - Animal) - ANSWER: i. Round worms - plant
parasites are microscopic ii. Need live host to survive iii. Use stylet to feed on plant cells iv.
Most plant nematodes feed on roots v. 4 Juvenile stages and adult form and over-winter egg
stage vi. Generation time 30 days (1-5 generations/yr.) vii. Spread by soil transport
Disease Control Principles - ANSWER: i. Exclusion ii. Eradication iii. Protection iv.
Resistance
Disease Control Practices/Methods - ANSWER: i. Cultural: modifications in planting, soil
fertilization, irrigation, soil preparation, etc. ii. Chemical: most are protective sprays; some
chemicals provide eradication iii. Genetic: plant resistant varieties or cultivars iv. Biological
Field Diagnosis Observe Plants carefully - ANSWER: 1. Check foliage for spots,
yellowing, mosaics, marginal burns, growth abnormalities, insect damage 2. Examine stems
and crowns for internal discoloration, external discoloration, fungal structures, bacterial ooze.
3. Examine roots for discoloration, swelling, stunting, absence of secondary roots
Field Diagnosis Considerations - ANSWER: recent weather, chemicals/fertilizers applied,
soil conditions, insect problems, animal damage disease, nematodes, patterns of the damage
Collecting/ Packages Mailing Samples Collecting - ANSWER: 1. If spots, collect affected
plant parts 2. If poor growth, collect whole plants 3. Include development stages of the
problem 4. Include damage but not dead plants 5. If large plants, collect 1-3 6. If small plants,
collect several - many 7. Collect and record and include information
Collecting/ Packages Mailing Samples Packaging - ANSWER: 1. Gently shake soil from
roots 2. Package plants in dry plastic 3. May need to wrap root ball separately 4. Packaging
loose soil separately 5. Package fruits/crucifiers in newspaper
CORRECT ANSWERS WITH VERIFIED SOLUTIONS.
Disease - ANSWER: Abnormal function caused by a continuously irritating agent and
expressed by noticeable symptoms
Requirements for disease - ANSWER: (1) disease agent; (2) susceptible plant; (3) favorite
environment
Symptom - ANSWER: The visible effect produced in or on a plant by the presence of
pathogen or disease agent
Sign - ANSWER: An indication of a disease from direct visibility of the pathogen
Examples of Disease Symptoms - ANSWER: Spots, blights, cankers, diebacks, stunting,
chlorosis, galls, root-knot, wilt.
Disease Agents - ANSWER: (1)Living and (2) Non-living
Living Disease Agent - ANSWER: : Fungi, Bacteria, Viruses, Viroids, Mycoplasmas,
Nematodes, Parasitic Higher Plants, Protozoa
Non-living Disease Agent - ANSWER: Environmental factors, Nutrition, Pollution, etc.
Fungi: small organisms (Kingdom Mycetae) - ANSWER: 8000 species cause plant disease
ii. Cause over 80% of plant disease iii. Consist of microscopic filaments called hyphae iv.
Reproduce by spores v. Identified by spores and reproductive structures vi. Survive as
parasites and saprophytes vii. Spread by wind/rain/insects
Bacteria: primitive microscopic organisms (Kingdom - Prokaryotes) - ANSWER: i. 200
species cause plant disease ii. Microscopic, one-celled organisms iii. Reproduce by binary
fission iv. Survive as parasites/ saprophytes v. Infect plant wounds/ natural openings vi.
Spread by wind/ insects
, Viruses: submicroscopic structures - ANSWER: i. 500 + cause plant disease ii.
Submicroscopic organisms iii. Obligate parasites iv. Nucleic acid and protein coat v.
Replicate within the host cell vi. Infect plants through wounds vii. Spread by
insect/seed/animals
Nematodes: small round worms (Kingdom - Animal) - ANSWER: i. Round worms - plant
parasites are microscopic ii. Need live host to survive iii. Use stylet to feed on plant cells iv.
Most plant nematodes feed on roots v. 4 Juvenile stages and adult form and over-winter egg
stage vi. Generation time 30 days (1-5 generations/yr.) vii. Spread by soil transport
Disease Control Principles - ANSWER: i. Exclusion ii. Eradication iii. Protection iv.
Resistance
Disease Control Practices/Methods - ANSWER: i. Cultural: modifications in planting, soil
fertilization, irrigation, soil preparation, etc. ii. Chemical: most are protective sprays; some
chemicals provide eradication iii. Genetic: plant resistant varieties or cultivars iv. Biological
Field Diagnosis Observe Plants carefully - ANSWER: 1. Check foliage for spots,
yellowing, mosaics, marginal burns, growth abnormalities, insect damage 2. Examine stems
and crowns for internal discoloration, external discoloration, fungal structures, bacterial ooze.
3. Examine roots for discoloration, swelling, stunting, absence of secondary roots
Field Diagnosis Considerations - ANSWER: recent weather, chemicals/fertilizers applied,
soil conditions, insect problems, animal damage disease, nematodes, patterns of the damage
Collecting/ Packages Mailing Samples Collecting - ANSWER: 1. If spots, collect affected
plant parts 2. If poor growth, collect whole plants 3. Include development stages of the
problem 4. Include damage but not dead plants 5. If large plants, collect 1-3 6. If small plants,
collect several - many 7. Collect and record and include information
Collecting/ Packages Mailing Samples Packaging - ANSWER: 1. Gently shake soil from
roots 2. Package plants in dry plastic 3. May need to wrap root ball separately 4. Packaging
loose soil separately 5. Package fruits/crucifiers in newspaper
