ILLINOIS SEED TREATMENT EXAM SCRIPT 2025/2026
QUESTIONS WITH ANSWERS GRADED A+
✔✔systemic pesticides - ✔✔help control seedborne pathogens both on the surface and
internally
✔✔alternatives to seed treatment - ✔✔1. crop rotation 2. good fertility management 3.
heat treatment 4. planting date 5. soil applied or post-emergence sprays 6. controlling
volunteer crop plants
✔✔fungi - ✔✔small organisms that are mostly saprophytic (live on dead plant or animal
material) but a few are pathogenic (live on live plants or animals)
✔✔Bacteria - ✔✔are single-celled organism that reproduce by division
✔✔viruses - ✔✔consist of either dna or rna with a protein coat
✔✔common bunt of wheat (external) - ✔✔*seeds dark and fish smelling (stinking bunt)
*bunted heads stay green longer * persitsts on seed and in soil *infects coleoptile before
evergence
✔✔loose smut of wheat (internal) - ✔✔*fungus lies dormant in the embryo until
germination *infected heads form head early and produce spores instead of seed
*neighboring plants are infected during flowering
✔✔pythium and phytophthora (seedling root diseases) - ✔✔*fungal-like organisms and
are considered water molds (spores swim in water) *they can infect and kill all season
as long as soil is wet *they sause soft rot of seed *phytophtora tolerant and resistant
varieties available: 70 races identified in Illinois -tolerance not effective until 10 to 14
days after emergence
✔✔fusarium seedling blight and root rots (seedling root diseases) - ✔✔*can
infect/damage early or late *symptoms are nondescript, but generally off color to dark
black to completely rotted (sometimes pinkish tinge) *infected seeds can result in
seedling blight
✔✔rhizoctonia (seedling root diseases) - ✔✔*usually a problem when crop is stressed-
soil compaction, dry emergence conditions, herbicide injury. *likes cool, then hot and
dry weather
✔✔Stewart's bacterial wilt (foliar diseases) - ✔✔*carried by flea beetles: which are more
common after mild winters (<27 degrees in dec. jan. and feb =no infection; >33
degrees=lots of insects/disease) sweet corn vulnerable *field corn generally has good
resistance. *symptoms -long yellowish streaks, parallel to the veins -wilting, may
resemble nutritional problems or drought stress. -seedling crown may have chocolate-
, brown soft rotted cavity at base of plant *control -systemic insecticide seed treatment
may reduce this disease. -grow resistant varieties
✔✔barley yellow dwarf virus (viral diseases) - ✔✔*an obligate parasite *vectored by
aphids *found along field border or in patches *seedling infection: -winter kill, stunted
growth, reduced tillers, and yellow leaves * post-seedling infection-yellow, red, or purple
leaf coloration. *fall infection is more important than spring infection *systemic seed
treatment insecticides may help reduce barley yellow dwarf virus
✔✔seedcorn beetles (soilborne insects) - ✔✔*apporoximately 1/4" long, light brown to
yellowish brown, with a broad black stripe on each wing cover. attacks sorghum and
corn during prolong cool wet weather. adults over-rated as a problem; larvae considered
benificial
✔✔slender seedcorn beetle (soilborne insects) - ✔✔Shiny, dark red in color. has a
constriction. attacks sorghum and corn during prolong cool wet weather. adults over-
rated as a problem; larvae considered benificial
✔✔seedcorn maggot (soilborne insects) - ✔✔*attacks corn, soybean, sorghum and
other crops * damage occurs as the larvae burrow into seed and destroy germ * larvae
are 1/4 " long, legless, pale yellow to white maggot that tapers somewhat like a carrow.
*adult is a brown fly which lays its eggs in moist soil rich in organic matte (manure
applied fields) *several generations per year
✔✔wireworms (soilborne insects) - ✔✔* larvae are shiny. they are pale yellow when
small and reddish brown when are larger * corn, sorghum, soybeans, and vegetable
seeds and or the base seedlings-often a problem on crops after small grain, sod, or
pasture. *use soil insecticides for heavy infestations
✔✔chinch bug (foliar insect) - ✔✔*attacks corn, sorghum and small grains *adults
overwinter in grass and move to small grains in spring *nymphs move to field edges
next to corn or sorghum *nymphs feed on lower leaves and plant base-entire plant may
wilt and turn white *systemic insecticide seed treatment can help control this insect
✔✔corn flea beetles (foliar insect) - ✔✔*attack sweet corn and vegatables *adult beetle
is black and 1/16 to 1/8' long *overwinters in grassy areas *adults cause scratch areas
on leaves (both sides) parallel to veins -leaves look whitish or silvery *during feeding
they may transmit stewart's wilt disease
✔✔Hessian flies (foliar insect) - ✔✔* attack wheat *they cause damage in spring and fall
* damaged plants are dark green, stunted, and easily lodge. *second generation adults
emerge from wheat stubble in late summer/early fall and lay eggs on winter wheat
leaves (new crop or volunteer) *larvae feed between leaf sheath and stem and pupate
by mid fall. * overwinter as flaxseed like puparia, and emerge as adults in spring. * use
QUESTIONS WITH ANSWERS GRADED A+
✔✔systemic pesticides - ✔✔help control seedborne pathogens both on the surface and
internally
✔✔alternatives to seed treatment - ✔✔1. crop rotation 2. good fertility management 3.
heat treatment 4. planting date 5. soil applied or post-emergence sprays 6. controlling
volunteer crop plants
✔✔fungi - ✔✔small organisms that are mostly saprophytic (live on dead plant or animal
material) but a few are pathogenic (live on live plants or animals)
✔✔Bacteria - ✔✔are single-celled organism that reproduce by division
✔✔viruses - ✔✔consist of either dna or rna with a protein coat
✔✔common bunt of wheat (external) - ✔✔*seeds dark and fish smelling (stinking bunt)
*bunted heads stay green longer * persitsts on seed and in soil *infects coleoptile before
evergence
✔✔loose smut of wheat (internal) - ✔✔*fungus lies dormant in the embryo until
germination *infected heads form head early and produce spores instead of seed
*neighboring plants are infected during flowering
✔✔pythium and phytophthora (seedling root diseases) - ✔✔*fungal-like organisms and
are considered water molds (spores swim in water) *they can infect and kill all season
as long as soil is wet *they sause soft rot of seed *phytophtora tolerant and resistant
varieties available: 70 races identified in Illinois -tolerance not effective until 10 to 14
days after emergence
✔✔fusarium seedling blight and root rots (seedling root diseases) - ✔✔*can
infect/damage early or late *symptoms are nondescript, but generally off color to dark
black to completely rotted (sometimes pinkish tinge) *infected seeds can result in
seedling blight
✔✔rhizoctonia (seedling root diseases) - ✔✔*usually a problem when crop is stressed-
soil compaction, dry emergence conditions, herbicide injury. *likes cool, then hot and
dry weather
✔✔Stewart's bacterial wilt (foliar diseases) - ✔✔*carried by flea beetles: which are more
common after mild winters (<27 degrees in dec. jan. and feb =no infection; >33
degrees=lots of insects/disease) sweet corn vulnerable *field corn generally has good
resistance. *symptoms -long yellowish streaks, parallel to the veins -wilting, may
resemble nutritional problems or drought stress. -seedling crown may have chocolate-
, brown soft rotted cavity at base of plant *control -systemic insecticide seed treatment
may reduce this disease. -grow resistant varieties
✔✔barley yellow dwarf virus (viral diseases) - ✔✔*an obligate parasite *vectored by
aphids *found along field border or in patches *seedling infection: -winter kill, stunted
growth, reduced tillers, and yellow leaves * post-seedling infection-yellow, red, or purple
leaf coloration. *fall infection is more important than spring infection *systemic seed
treatment insecticides may help reduce barley yellow dwarf virus
✔✔seedcorn beetles (soilborne insects) - ✔✔*apporoximately 1/4" long, light brown to
yellowish brown, with a broad black stripe on each wing cover. attacks sorghum and
corn during prolong cool wet weather. adults over-rated as a problem; larvae considered
benificial
✔✔slender seedcorn beetle (soilborne insects) - ✔✔Shiny, dark red in color. has a
constriction. attacks sorghum and corn during prolong cool wet weather. adults over-
rated as a problem; larvae considered benificial
✔✔seedcorn maggot (soilborne insects) - ✔✔*attacks corn, soybean, sorghum and
other crops * damage occurs as the larvae burrow into seed and destroy germ * larvae
are 1/4 " long, legless, pale yellow to white maggot that tapers somewhat like a carrow.
*adult is a brown fly which lays its eggs in moist soil rich in organic matte (manure
applied fields) *several generations per year
✔✔wireworms (soilborne insects) - ✔✔* larvae are shiny. they are pale yellow when
small and reddish brown when are larger * corn, sorghum, soybeans, and vegetable
seeds and or the base seedlings-often a problem on crops after small grain, sod, or
pasture. *use soil insecticides for heavy infestations
✔✔chinch bug (foliar insect) - ✔✔*attacks corn, sorghum and small grains *adults
overwinter in grass and move to small grains in spring *nymphs move to field edges
next to corn or sorghum *nymphs feed on lower leaves and plant base-entire plant may
wilt and turn white *systemic insecticide seed treatment can help control this insect
✔✔corn flea beetles (foliar insect) - ✔✔*attack sweet corn and vegatables *adult beetle
is black and 1/16 to 1/8' long *overwinters in grassy areas *adults cause scratch areas
on leaves (both sides) parallel to veins -leaves look whitish or silvery *during feeding
they may transmit stewart's wilt disease
✔✔Hessian flies (foliar insect) - ✔✔* attack wheat *they cause damage in spring and fall
* damaged plants are dark green, stunted, and easily lodge. *second generation adults
emerge from wheat stubble in late summer/early fall and lay eggs on winter wheat
leaves (new crop or volunteer) *larvae feed between leaf sheath and stem and pupate
by mid fall. * overwinter as flaxseed like puparia, and emerge as adults in spring. * use
