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54 Cards in this Set
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Fungus:
Powdery Mildew |
Symptom: white powdery hyphae and spores on surface of leaves and flowers
Conditions: humidity, low air circulation
Control: fungicide (jojoba, neem), reduce humidity, destroy fallen leaves |
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Fungus:
Botrytis rot |
Symptom: dehydration rot on grape clusters
Conditions: drought followed by high humidity
Control: air circulation |
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Fungus:
Brown patch |
Symptom: circular, brown patches; fungus grows near crown, cutting off nutrient flow
Conditions: humidity, 85F+ Temp, affect cool season grasses, high nitrogen
Control: fungicide spray when nights are 70F+, 14 days |
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Fungus:
Dollar spot |
Symptom: small, circular, white patches (close together make larger patches)
Conditions: warm daytime temps, cool/clear nights; low soil moisture and humidity on surface (dew or fog)
Control: fungicide |
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Fungus: Summer patch |
Symptom: root disease creates frog-eye brown patches affecting cool season grasses
Conditions: fungus affects roots and crowns in late spring; hot, direct sun or other stress factors in summer exacerbates problem
Control: lower pH; 5-10 (raise) mower height; balance fertilization |
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Daconil |
Fungicide: contols 14 turfgrass diseases and 50 ornamental diseases |
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Fungus:
Pink snow mold |
Symptoms: round tan/gray/red patches 6-8", w/ pink tinge on margins during wet/cool weather
Conditions: cool temps and high moisture
Control: control nitrogen fertilizing; |
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Fungus:
Pythium blight |
Symptoms: cottony growth grows particularly on rye and bent grasses
Conditions: high, 86-95F temps, high humidity, poorly drained soil,
Control: improve drainage; do not overwater |
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Fungus:
Anthracnose disease |
Symptoms: sunken, ulcer-like lesions on stems, leaves, fruit or flowers (browning around leaf veins on sycamore; around margins on maple)
Conditions: cool temps; prolonged moisture
Control: clean up plant debris; fungicide |
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Fungus:
Dothistroma needle blight |
Symptoms: deep green bands turn yellow/tan; needle drop, typically of older needles on lower branches; Austrian pine particular
Conditions: ?
Control: fungicide (copper); Bordeaux |
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Bordeaux mixture |
a mixture of copper(II) sulfate (CuSO4) and slaked lime (Ca(OH)2) used as a fungicide to control downy mildew, powdery mildew, blights, etc |
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Fungus:
Sphaeropsis tip blight |
Symptoms: young growth attacked, scales of young cones, excessive resin produced; dead needles at tips of branches held (Austrian and Scots pines)
Conditions:
Control: maintain health of tree (deep watering, fertilizing, etc); remove blighted shoots; fungicides (Bordeaux, Mancozeb) |
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Mancozeb |
fungicide control for blights |
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Fungus:
Brown spot |
Symptoms: neddles develop yellow/tan, resin-soaked spots; needle drop (Scots and Ponderosa pine; Austrian pine resistant)
Conditions:
Control: fungicide (Bordeaux, Mancozeb) |
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Fungus:
Phomopsis tip blight of juniper |
Symptoms: damage to new growth, foliar blighting, tip die back, small gray lesions girdle tips
Conditions: high humidity
Control: plant spacing for air circulation; water early hours; prune dead tips; avoid over fertilizing; fungicides (Mancozeb, Bordeaux) |
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Fungus:
Chestnut blight |
Symptoms: grows through vascular cambium, girdling and killing
Conditions: invades wounds of cracks in the bark
Control: None (keep tree healthy/isolated) |
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Fungus:
Blotch |
Symptoms: diseased areas of leaf are irregular in shape and size (light green to yellow to brown) develop overnight Jun-Aug
Conditions: unknown (assoc. w/ dithiocarbamate fungicides
Control: ? |
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Fungus:
Canker |
Symptoms: localized wound or necrotic lesion
Conditions:
Control: cut affected limbs (no chemical agents effective); prevention: fertilization, drainage, watering, selection |
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Fungus:
Apple Scab |
Symptoms: localized lesions (raised, cracked scab-like) on fruit, leaves, etc.
Conditions: high humidity/rainfall in spring (incubate/accelerate germination/infection
Control: Fungicide benomyl (Benalte), chllorothalonil (Daconil, Bravo. Thalonil, Echo), coppers (Bordeaux, Kocide), etc |
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Fungus:
Cedar-apple rust (ala Hawthorn and Cedar Quince rust) |
Symptoms: overwinter on junipers as galls, "telia" form in April producing spores which infect apple (or other Rosaceae) trees forming orange spots on leaves and "aecia" on underside, which spread back to junipers
Conditions: ?
Control: fungicide in spring on apple |
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Fungus:
Dutch elm disease (DED) |
Symptoms: blockage of fungus causes discoloration of vascular tissue; wilting first in upper branches
Conditions: elm bark beetle vector; root grafting with nearby trees
Control: insecticide sanitation to reduce insects; fungicide |
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Fungus:
Early blight |
Symptoms: spots on tomato leaves, infection spreads upwards, leaf drop,
Conditions:
Control: clean up debris; fungicide (Mancozeb, cholorothalonil, maneb) |
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Fungus:
Fusarium wilt |
Symtoms: invades roots and affects oldest leaves and moves up; yellow to white to brown wilting of tomatoes
Conditions: cool soil; heat of summer; humdity
Control: 4-6 year crop rotation as it persists in soil |
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Fungus:
Verticillim wilt |
Symptoms: invades roots and affects oldest leaves and moves up; yellow to white to brown wilting of 200+ species (strawberry and raspberry highly susceptible)
Conditions: cool soil; heat of summer; humidity
Control: 4-6 year crop rotation as it persists in soil |
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Fungus:
Black spot (roses) |
Symptoms: localized lesion on upper leaf surface starting lower and moving up; (hybrid tea very susceptible)
Conditions: warm, moist weather
Control: good sunlight and air circulation to keep foliage dry; water from below; remove infected leaves; preventative fungicides |
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Fungus:
Mycosphaerella leaf spot (ash tree) |
Symptoms: small, brown spots; early leaf drop;
Conditions: wet summers
Control: preventative fungicides |
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Fungus:
Root rot mold ([Christmas] Fraser fir tree) |
Symptoms: deadening of leaves and limbs
Conditions: high moisture; poor drainage; standing water
Control: improve drainage |
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Fungus:
Clematis wilt |
Symptoms: leaf spot fungus grows to stem causing cankers, wilting; purple veins
Conditions: poor air and soil circulation?
Control: good sunlight (6+hours); rich, well-drained coil; clean debris |
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Fungus:
Apple powdery mildew |
Symptoms: distorted foliage; stunted twig growth; russetted/discolored/dwarfed fruit
Conditions: 90+% humidity; 50-77F temps
Control: good sun and air circulation; fungicide spray program |
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Fungus:
Powdery mildew of turf |
Symptoms: powdery dusting on blades' upper surface causing withering and dieback
Conditions: shady sites, high humidity, ~65F temps; poor air circulation; Aug-Sep
Control: fertilize to get grass to outgrow disease; prune trees and shrub to improve light |
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Fungus:
Grape black rot |
Symptoms: rot dramatically on berries which turn dark purple/black; berry shriveling (black rot mummies); brown rot on leaves with black lesions
Conditions: humidity?
Control: good air circulation; fungicides inhibit further infection |
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Fungus:
Brown rot of peach |
Symptoms: affect blossoms (brown spots, turn black and die) have fungal growth which later infect twigs (stem cankers) and fruit (light brown spots grow);
Conditions: two infection periods: blossoming (temps 77F) and before harvest
Control: Sanitation is critical, debris clean up and fungicide |
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Fungus: Ash rust |
Symptoms: leaves and petioles distort; bright orange powdery cups which infects cord grass; cycles back next year
Conditions: wet springs;
Control: watering, mulching, fertilizing to increase tree vigor; prune infected areas; remove cord grass |
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Fungus:
peach leaf curl and plum pocket |
Symptoms: leaves with thickened midrib with red/purple hue, die and fall; white spots on fruit enlarge, become seedless and enlargen
Conditions:
Control: new, uninfected leaves typically grow back, but spores in fruit keep cycle going each year; fungicide |
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Fungus:
Rhizosphaera needlecast on spruce tree |
Symptoms: infects older, leaves on lower limbs turning needles purple/brown; late fall/next spring they fall off; does not kill, but severely affect the form of the tree
Conditions: low limbs infected by fruiting bodies which spread with rainfall
Control: fungicide (Bordeaux, Daconil, etc) |
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Fungus:
Root diseases of juniper |
Symptoms: root rot
Conditions: presence of soil-born fungi with parasitic nematode, excessive watering and poor soil drainage
Control: plant in well-drained sites; fungicides/neamticides |
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Fungus:
Tip dieback of oak |
Symptoms: wilting ("flagging") of black, cracked twigs or small branches throughout canopy; leaves bend backwards and turn brown (pin and red oaks)
Conditions: ?
Control: largely unnecessary as infection is minor; remove dead twigs |
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Bacteria: ERWINIA
Fire blight (apple, crabapple, pears, Rosaceae family) |
Symptoms: infected leaves turn brown as if scorched;
Conditions: spring temps of 65+F; rain and pollinating insects;
Control: systemic antibiotics; program of several practices; prune; high nitrogen fertilizing |
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Bacteria: ERWINIA
Bacterial wilt |
Symptoms: leaf wilt then plant wilts, browns and dies (cucumber and musk melon susceptible); test by cutting near crown; squeeze to see milky sap/fine threads
Conditions: cucumber beetle vector
Control: remove and destroy plant debris; insecticides |
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Bacteria:
Bacterial spot of peach |
Symptoms: affects fruit, leaves (pale green/yellow angular spots near leaf tip which fall off) and twigs (overwinters as cankers); (not extensive)
Conditions: rain and winds spread the bacteria from erupted cankers in spring
Control: proper fertilizer; hot/dry conditions inhibit |
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Bacteria:
Pseudomonas blight |
Symptoms: (on ornamentals, lilac, flowering (Bradford) pear, etc) enter through natural and wound openings and translocate to new growth, blackening new tissue
Conditions: cool, wet springs
Control: prune diseased limbs on warm, sunny day copper fungicide |
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Bacteria:
Bacterial canker |
Symptoms: (tomatoes) lesions and cankers anywhere; yellow wilting leaves become brittle and drop; fruit spots with white border halo
Conditions: wet, humid hot 80+F; spread by water/irrigation; infect wounds; carried systemically through plant
Control: use disease-free seed and soil |
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Fugicide:
Pageant (R) |
ornamental industry's foremost fungicide: effective on all four classes of fungicide |
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Fungus, Bateria, Virus effect:
Apple russetting |
Symptoms: brown, corky, netlike condition on skin of fruit; cracking of fruit when severe
Conditions: environmental (heavy dew and cold temps during initial fruit development); chemical damage; excess nitrogen;
Control: ? |
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Fungus:
Seiridium canker of oriental arborvitae (also junipers and cypress) |
Symptoms: formation of distinct, sunken lesions on bark, these cankers restrict water and nutrients leading to branch dieback and tree death; bleeding and resin formations in canker
Conditions: drought, winter damage, environmental stresses
Control: sufficient wateringer (esp in winter); prune out cankered limbs |
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Other: (mycoplasma-like [between bacteria and virus])
Aster yellow |
Symptoms: green/yellow and twisted leaves (chlorosis, but has clear veins) and flowers; stunted, stiff, upright growth; blossoms deformed and sickly leaves
Conditions: spread by insect vector (aster leafhopper); cool, wet summers
Control: remove infected plants; insecticide |
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Fungus:
Corn smut |
Symptoms: immature galls grow where spores land, white and spongy w/ greenish membrane, grow brown with powdery spores
Conditions: hot, dry weather; damaged plants
Control: remove infected plants before galls rupture |
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Fungus:
Iris leaf spot |
Symptoms: small brown spots w/ water-soaked margins near leaf tip, enlarge w/ gray centers and may cause leaf death
Conditions: Rain in spring/growing season
Control: remove infected leaves; fungicide for severe conditions |
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Virus:
Rose mosaic virus |
Symptoms: ringspots, wavy lines, chlorotic vein banding, oak-leaf/mosaic/yellow net patterns symptoms show in late spring and endure all growing season; infection for life of plant
Conditions: transmission through vegetative propagation
Control: remove severely diseased plants |
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Virus:
Rose rosette virus |
Symptoms: rapid elongation of shoot; "witches' broom" cluster of small branches forms; excessive thorniness w/ red/purple pigmentation
Conditions: ? (transmitted possibly by eriophyid mite
Control: remove and destroy |
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Virus:
Tomato spotted wilt virus |
Symptoms: (tomato, pepper, other vegetables/ornamentals) inward cupping and off-color (bronzing) of leaves; tops appear yellow and wilting; white/yellow, half-inch rings on fruit
Conditions: ?
Control: remove and destroy; insecticides |
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Virus:
Cucumber mosaic virus |
Symptoms: (tomato, pepper, cucumber, melon, squash, spinach, celery, beet, petunia) distortion and mottling on older leaves (shoestring); stunted; reduced and mottled fruit
Conditions: infected aphids
Control: remove and destroy; insectidices |
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Physiological:
orange tomatoes |
Symptoms: orange or yellow pigmentation
Conditions: temps above 95F; dry, hot winds; night temps above 75F
Control: harvest a bit early and store in 75-85F to develop red color |
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Physiological:
Blossom end-rot of tomato |
Symptoms: small, water-soaked spot enlarges and darkens
Conditions: drought; lack of calcium
Control: plant in rich, well-drained, aerated soil; water as needed; mulching; fertilize (lower nitrogen; higher superphosphate) |