OTPS (Alabama) Exam Questions
Complete Solutions New Update
(Verified A+ Pass)
Disease - Answers -✔✔ Abnormal function caused by a continuously irritating agent
and expressed by noticeable symptoms
Requirements for disease - Answers -✔✔ (1) disease agent; (2) susceptible plant; (3)
favorite environment
Symptom - Answers -✔✔ The visible effect produced in or on a plant by the presence
of pathogen or disease agent
Sign - Answers -✔✔ An indication of a disease from direct visibility of the pathogen
Examples of Disease Symptoms - Answers -✔✔ Spots, blights, cankers, diebacks,
stunting, chlorosis, galls, root-knot, wilt.
Disease Agents - Answers -✔✔ (1)Living and (2) Non-living
Living Disease Agent - Answers -✔✔ : Fungi, Bacteria, Viruses, Viroids, Mycoplasmas,
Nematodes, Parasitic Higher Plants, Protozoa
Non-living Disease Agent - Answers -✔✔ Environmental factors, Nutrition, Pollution,
etc.
Fungi: small organisms (Kingdom Mycetae) - Answers -✔✔ 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) - Answers -✔✔ 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 - Answers -✔✔ 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) - Answers -✔✔ 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 - Answers -✔✔ i. Exclusion ii. Eradication iii. Protection iv.
Resistance
Disease Control Practices/Methods - Answers -✔✔ 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 - Answers -✔✔ 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 - Answers -✔✔ recent weather, chemicals/fertilizers
applied, soil conditions, insect problems, animal damage disease, nematodes, patterns
of the damage
Collecting/ Packages Mailing Samples Collecting - Answers -✔✔ 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 - Answers -✔✔ 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
Collecting/ Packages Mailing Samples Mailings - Answers -✔✔ 1. Use a sturdy padded
envelope or box 2. Mail early in week 3. Address properly The Plant Diagnostic Lab 101
Extension Hall Auburn University, AL 36849-5624
Laboratory Diagnosis Activities of the Plant Diagnosis Lab - Answers -✔✔ 1. Plant
problem/disease-diagnosis 2. Soil nematode analysis 3. Insect Identification 4.
Weed/plant identification
Laboratory Diagnosis Routine Lab Procedures for Plant Sample Problems - Answers -
✔✔ 1. Visual exam 2. Microscopic exam 3. Soil pH 4. Soil soluble salts 5. Culture
isolations - selective media 6. ELSA 7. Nematode analysis 8. Ref. for soil or tissue tests
for minerals 9. Ref. to agronomists, horticulturists, entomologists
