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Agricultural Crop Disease Management -
Category 1C - Iowa Commercial Pesticide
Applicator Manual - Vocabulary
Plant Disease - Answer✔Any abnormal plant growth.
Symptoms - Answer✔Visible effects of a plant disease on a host plant.
Pathogen - Answer✔The parasitic organism that causes a disease.
Plant Disease Triangle - Answer✔1 - Susceptible Host Plant
2 - Pathogen
3 - Favorable Environment
Host - Answer✔Plant being invaded by pathogen and serving as food source.
Favorable Environment - Answer✔Environmental factors that allow the pathogen to invade the
host plant.
Environment - Answer✔The surroundings and/ or conditions that the plants exist in.
Vector - Answer✔A virus transmitted by an insect.
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Stylet - Answer✔A needlelike structure found on plant-parasitic nematodes.
Disease Cycle - Answer✔The chain of events involved in disease development.
Inoculum - Answer✔Any material capable of producing infection and causing disease.
Dissemination of Inoculum - Answer✔The spread or dispersal of a pathogen.
Incubation Period - Answer✔The period between infection and the first appearance of
symptoms.
Economic Injury Level - Answer✔The density of a pest population when the cost of
management equals the amount of crop lost by the pest.
Economic Threshold - Answer✔The density of a pest population that justifies a management
measure to keep an increasing population from reaching the economic injury level.
Immune - Answer✔The pathogen cannot cause disease even under favorable conditions.
Tolerant - Answer✔Even with a pathogen present, the plant can produce a good yield.
Susceptible - Answer✔With a pathogen present, the plant(s) will be greatly damaged or killed
by the pathogen.
Fungicides - Answer✔Chemical or physical agents that kill or inhibit the growth of fungi.
Chemical Name - Answer✔The name of an active ingredient in a fungicide.
Common Name - Answer✔The non-technical term for the active ingredient or chemical name.
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Agricultural Crop Disease Management -
Category 1C - Iowa Commercial Pesticide
Applicator Manual - Vocabulary
Plant Disease - Answer✔Any abnormal plant growth.
Symptoms - Answer✔Visible effects of a plant disease on a host plant.
Pathogen - Answer✔The parasitic organism that causes a disease.
Plant Disease Triangle - Answer✔1 - Susceptible Host Plant
2 - Pathogen
3 - Favorable Environment
Host - Answer✔Plant being invaded by pathogen and serving as food source.
Favorable Environment - Answer✔Environmental factors that allow the pathogen to invade the
host plant.
Environment - Answer✔The surroundings and/ or conditions that the plants exist in.
Vector - Answer✔A virus transmitted by an insect.
1|Page
, ©FYNDLAY 2025 ALL RIGHTS RESERVED 11:49 AM A+
Stylet - Answer✔A needlelike structure found on plant-parasitic nematodes.
Disease Cycle - Answer✔The chain of events involved in disease development.
Inoculum - Answer✔Any material capable of producing infection and causing disease.
Dissemination of Inoculum - Answer✔The spread or dispersal of a pathogen.
Incubation Period - Answer✔The period between infection and the first appearance of
symptoms.
Economic Injury Level - Answer✔The density of a pest population when the cost of
management equals the amount of crop lost by the pest.
Economic Threshold - Answer✔The density of a pest population that justifies a management
measure to keep an increasing population from reaching the economic injury level.
Immune - Answer✔The pathogen cannot cause disease even under favorable conditions.
Tolerant - Answer✔Even with a pathogen present, the plant can produce a good yield.
Susceptible - Answer✔With a pathogen present, the plant(s) will be greatly damaged or killed
by the pathogen.
Fungicides - Answer✔Chemical or physical agents that kill or inhibit the growth of fungi.
Chemical Name - Answer✔The name of an active ingredient in a fungicide.
Common Name - Answer✔The non-technical term for the active ingredient or chemical name.
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