HORT 2201 PLANT SCIENCE FINAL EXAM – ABAC SPRING QUESTIONS
AND ANSWERS | HORT 2201 FINAL STUDY GUIDE 2026/2027
Disease - ANS ✔✔A harmful physiological process caused by a continuous irritation of a plant by a
primary casual agent.
A disease results in ___________. - ANS ✔✔altered cellular activity
A disease is expressed in ______________. - ANS ✔✔characteristic responses called symptoms
Two factors resulting in irritation which causes breakdowns or injuries to plant tissues - ANS
✔✔pathogens and environmental factors
Diseases reduce ___________. - ANS ✔✔yields, quality of yield, and value of crop and profit to the
farmers
What five ways do diseases affect plants? - ANS ✔✔damage to leaves, stems, roots, fruits, and wilts
The factors of the disease triangle/disease pyramid are: - ANS ✔✔host, pathogen, environment, time
(humans, insects)
What type of plant is more resistant to diseases? - ANS ✔✔a healthy plant
The ________ of a crop affects diseases. - ANS ✔✔age
Examples of knowing about your host include.... - ANS ✔✔knowing how a healthy plant looks and
performs, knowing optimal water and nutritional requirements, knowing optimal plant spacing/growth
habit, knowing how fast it should grow and reach maturity, and knowing periods when host is
susceptible
How does temperature affect diseases? - ANS ✔✔cool weather is favorable for seedling diseases
warm weather is favorable for leaf and fruit diseases
Humidity is favorable for __________. - ANS ✔✔fungal infection and growth
What are two ways to spread pathogens moisture-wise? - ANS ✔✔rain & irrigation
Because there is too much rain.... - ANS ✔✔the disease may be worse than expected
Because there is too little rain... - ANS ✔✔the disease may be less severe than predicted
Early season cool and wet - ANS ✔✔more CBR, less Aspergillus crown rot
Early season warm - ANS ✔✔more spotted wilt and nematodes
, Impact of water on pathogens - ANS ✔✔spore germination
fungal growth
splash dispersal of pathogens
fungal sporulation
Impact of storms on pathogens - ANS ✔✔long range dispersal of spores
Impact of temperature on pathogens - ANS ✔✔cooler temps slow growth of plant, allows pathogen to
infect
some diseases (southern corn rust, white mold) favor warm temperatures
Some favor cooler temperatures (CBR, soybean rust, NCLB)
___________ crops are more "at risk" - ANS ✔✔long-season
___________ crops may "escape" - ANS ✔✔short-season
Fungi - ANS ✔✔most diverse and most common (8,000)
Bacteria - ANS ✔✔second to fungi in diversity and abundance (300)
Viruses - ANS ✔✔depend on vectors to infect and spread (300)
Nematodes - ANS ✔✔microscopic roundworms, most are non-parasitic (2500)
Parasitism - ANS ✔✔when one organism obtains nutrients from another wehre the parasite gains and
the host does not
Pathogen - ANS ✔✔this is a disease causing agent; the pathogen parasite actually is detrimental to th e
host as in the disease definition
What are examples of how to know your enemy? - ANS ✔✔Know what types of diseases affect the crops
you want to grow, be able to identify the diseases that may affect your crop (symptoms and signs),
understand the ecology of the diseases you deal with (life cycle, favorable environment), try to find weak
links or vulnerable areas in the pathogen life cycle to manipulate
Symptom - ANS ✔✔this is the reaction of the plant to the pathogen or casual agent
wilting, stunting, chlorosis, necrosis, lesion, canker, galling, etc - ANS ✔✔Symptom
Sign - ANS ✔✔the observance of the actual organism causing the disease
hyphae, fruiting structures, bacterial ooze, bacterial streaming, sporulation, cyst, etc - ANS ✔✔signs
How are pathogens and diseases spread? - ANS ✔✔fungal spores can be carried by the wind, spores and
bacteria carried in moving water, spores and bacteria spread by rain splash on diseased plants; spores,
nematodes, bacteria, sclerotia moved in soil and crop debris
AND ANSWERS | HORT 2201 FINAL STUDY GUIDE 2026/2027
Disease - ANS ✔✔A harmful physiological process caused by a continuous irritation of a plant by a
primary casual agent.
A disease results in ___________. - ANS ✔✔altered cellular activity
A disease is expressed in ______________. - ANS ✔✔characteristic responses called symptoms
Two factors resulting in irritation which causes breakdowns or injuries to plant tissues - ANS
✔✔pathogens and environmental factors
Diseases reduce ___________. - ANS ✔✔yields, quality of yield, and value of crop and profit to the
farmers
What five ways do diseases affect plants? - ANS ✔✔damage to leaves, stems, roots, fruits, and wilts
The factors of the disease triangle/disease pyramid are: - ANS ✔✔host, pathogen, environment, time
(humans, insects)
What type of plant is more resistant to diseases? - ANS ✔✔a healthy plant
The ________ of a crop affects diseases. - ANS ✔✔age
Examples of knowing about your host include.... - ANS ✔✔knowing how a healthy plant looks and
performs, knowing optimal water and nutritional requirements, knowing optimal plant spacing/growth
habit, knowing how fast it should grow and reach maturity, and knowing periods when host is
susceptible
How does temperature affect diseases? - ANS ✔✔cool weather is favorable for seedling diseases
warm weather is favorable for leaf and fruit diseases
Humidity is favorable for __________. - ANS ✔✔fungal infection and growth
What are two ways to spread pathogens moisture-wise? - ANS ✔✔rain & irrigation
Because there is too much rain.... - ANS ✔✔the disease may be worse than expected
Because there is too little rain... - ANS ✔✔the disease may be less severe than predicted
Early season cool and wet - ANS ✔✔more CBR, less Aspergillus crown rot
Early season warm - ANS ✔✔more spotted wilt and nematodes
, Impact of water on pathogens - ANS ✔✔spore germination
fungal growth
splash dispersal of pathogens
fungal sporulation
Impact of storms on pathogens - ANS ✔✔long range dispersal of spores
Impact of temperature on pathogens - ANS ✔✔cooler temps slow growth of plant, allows pathogen to
infect
some diseases (southern corn rust, white mold) favor warm temperatures
Some favor cooler temperatures (CBR, soybean rust, NCLB)
___________ crops are more "at risk" - ANS ✔✔long-season
___________ crops may "escape" - ANS ✔✔short-season
Fungi - ANS ✔✔most diverse and most common (8,000)
Bacteria - ANS ✔✔second to fungi in diversity and abundance (300)
Viruses - ANS ✔✔depend on vectors to infect and spread (300)
Nematodes - ANS ✔✔microscopic roundworms, most are non-parasitic (2500)
Parasitism - ANS ✔✔when one organism obtains nutrients from another wehre the parasite gains and
the host does not
Pathogen - ANS ✔✔this is a disease causing agent; the pathogen parasite actually is detrimental to th e
host as in the disease definition
What are examples of how to know your enemy? - ANS ✔✔Know what types of diseases affect the crops
you want to grow, be able to identify the diseases that may affect your crop (symptoms and signs),
understand the ecology of the diseases you deal with (life cycle, favorable environment), try to find weak
links or vulnerable areas in the pathogen life cycle to manipulate
Symptom - ANS ✔✔this is the reaction of the plant to the pathogen or casual agent
wilting, stunting, chlorosis, necrosis, lesion, canker, galling, etc - ANS ✔✔Symptom
Sign - ANS ✔✔the observance of the actual organism causing the disease
hyphae, fruiting structures, bacterial ooze, bacterial streaming, sporulation, cyst, etc - ANS ✔✔signs
How are pathogens and diseases spread? - ANS ✔✔fungal spores can be carried by the wind, spores and
bacteria carried in moving water, spores and bacteria spread by rain splash on diseased plants; spores,
nematodes, bacteria, sclerotia moved in soil and crop debris
