Beets:Key
KEY TO BEET PESTS AND NUTRITIONAL DISORDERS
Contents
- 1 Seed
- 2 Seedling
- 3 Root
- 3.1 BLACK
- 3.2 BROWN
- 3.2.1 Bacterial vascular necrosis and rot
- 3.2.2 Black root
- 3.2.3 Botrytis storage rot
- 3.2.4 Clover cyst nematode
- 3.2.5 Fusarium yellows
- 3.2.6 Phoma root rot
- 3.2.7 Phytophthora root rot
- 3.2.8 Rhizopus root rot
- 3.2.9 Scab
- 3.2.10 Southern Sclerotium root rot
- 3.2.11 Sugar beet cyst nematode
- 3.2.12 Verticillium wilt
- 3.2.13 Violet root rot
- 3.3 GRAY
- 3.4 GREEN
- 3.5 PINK
- 3.6 RED
- 3.7 TAN
- 3.8 VIOLET
- 3.9 WHITE
- 3.10 YELLOW
- 3.11 No Distinct Discoloration
- 3.11.1 Beet leaf curl
- 3.11.2 Beet necrotic yellow vein
- 3.11.3 Beet savoy
- 3.11.4 Crown gall
- 3.11.5 False root-knot nematodes
- 3.11.6 Fluchloralin; Nitralin; Pendimethalin; Trifluralin; 2,4-D
- 3.11.7 Freezing
- 3.11.8 Lightning damage
- 3.11.9 Rodents
- 3.11.10 Root-knot nematodes
- 3.11.11 Soil compaction
- 3.11.12 Stem and bulb nematode
- 3.11.13 Stubby-root nematodes
- 3.11.14 Sugar beet root maggot
- 3.11.15 Symphylan
- 3.11.16 White grubs
- 3.11.17 Wind damage
- 3.11.18 Wireworms
- 3.11.19 Yellow wilt
- 4 Crown
- 5 Stem
- 6 Leaf
- 6.1 BLACK
- 6.2 BRONZE
- 6.3 BROWN
- 6.4 DARK
- 6.5 GRAY
- 6.6 GREEN
- 6.7 PURPLE
- 6.8 RED
- 6.9 SILVER
- 6.10 TAN
- 6.11 WHITE
- 6.12 YELLOW
- 6.12.1 Beet necrotic yellow vein
- 6.12.2 Rhizoctonia root and crown rot
- 6.12.3 Charcoal rot
- 6.12.4 Freezing
- 6.12.5 Fusarium yellows
- 6.12.6 Sugar beet root aphid
- 6.12.7 Yellow wilt
- 6.12.8 Alternaria leaf spot
- 6.12.9 Bacterial leaf spot
- 6.12.10 Beet mosaic
- 6.12.11 Beet western yellows
- 6.12.12 Beet yellow net
- 6.12.13 Beet yellow stunt
- 6.12.14 Beet yellow vein
- 6.12.15 Beet yellows
- 6.12.16 Cucumber mosaic
- 6.12.17 Dalapon; Glyphosate; Desmedipham; Phenmedipham; Atrazine; Heazinone; Simazine; Chlorsulfuron; Pyrazon
- 6.12.18 Dodder
- 6.12.19 Genetic abnormalities
- 6.12.20 Lettuce infectious yellows
- 6.12.21 Nitrogen deficiency; Sulfur deficiency; Molybdenum deficiency
- 6.12.22 Zinc deficiency; Manganese deficiency; Iron deficiency; Chlorine deficiency; Copper deficiency
- 6.13 No Distinct Discoloration
- 6.13.1 Beet tumor or crown wart
- 6.13.2 Beet leaf curl
- 6.13.3 Beet savoy
- 6.13.4 Violet root rot
- 6.13.5 Alfalfa looper
- 6.13.6 Beet curly top
- 6.13.7 Beet latent rosette
- 6.13.8 Beet leafhopper
- 6.13.9 Beet petiole borer
- 6.13.10 Blister beetles
- 6.13.11 Calcium deficiency; Boron deficiency
- 6.13.12 Carrion beetles
- 6.13.13 Dicamba; 2,4-D; MCPA; Diethatyl ethyl; Ethofumesate; Picloram; Cycloate; Diallate; EPTC; Pebulate
- 6.13.14 Drought
- 6.13.15 False chinch bug
- 6.13.16 Flea beetles
- 6.13.17 Foliage-feeding aphids
- 6.13.18 Garden webworm
- 6.13.19 Grasshoppers
- 6.13.20 Hail damage
- 6.13.21 Lightning damage
- 6.13.22 Lygus bugs
- 6.13.23 Potassium deficiency; Magnesium deficiency
- 6.13.24 Salt-marsh caterpillar
- 6.13.25 Spider mites
- 6.13.26 Spinach leaf miner
Seed
Seed disorders are limited to disorders while in the ground and not to potential disorders inherent in the seed.
No Distinct Discoloration
Salt injury
Unemerged or dead plants; accumulation of salt on the soil surface
Wireworms
Reduced stands; stunted, wilted, or dying plants; germinating seeds destroyed; taproots of small plants cut off, or roots of older beets scarred; damage caused by slender, tough, smooth, wirelike worms, from white or yellow to dark brown and 3-38 mm long
Seedling
ORANGE
Seedling rust
Yellowish orange pustules, only on cotyledons or very young first true leaves of seedlings
TAN
Freezing
Leaves or cotyledons of plants appear water-soaked and die after occurrence of low temperatures; roots appear healthy; in plants with large taproots, thawed tissue becoming yellow to light tan; with a sharp demarcation between frozen and healthy tissue
YELLOW
Freezing
Leaves or cotyledons of plants appear water-soaked and die after occurrence of low temperatures; roots appear healthy; in plants with large taproots, thawed tissue becoming yellow to light tan; with a sharp demarcation between frozen and healthy tissue
Seedling rust
Yellowish orange pustules, only on cotyledons or very young first true leaves of seedlings
No Distinct Discoloration
Aphanomyces cochlioides
Damping-off at high temperatures; nonseptate mycelium; long, narrow, filamentous sporangia with encysted spores at their tips; zoospores present in water culture
Flea beetles
Small shot holes in or complete consumption of cotyledons or first true leaves; damage caused by tiny, jumping beetles, up to 5 mm long, and brown, striped, or shiny black
Phoma betae
Damping-off at low temperatures; septate mycelium; pycnidia produced in water culture after seven days; holdfasts produced on the bottom of a plastic petri dish in water agar
Pythium aphanidermatum
Damping-off at high temperatures; nonseptate mycelium; lobed or inflated sporangia; submerged in water culture; zoospores may be present
Pythium ultimum
Damping-off at low or high temperatures; terminal, spherical sporangia on nonseptate mycelium; submerged in water culture
Rhizoctonia solani
Damping-off at high temperatures; regularly septate mycelium; floats in water culture; right angles formed at the juncture of side branches of mycelium with cross-walls just above the juncture
Salt injury
Unemerged or dead plants; accumulation of salt on the soil surface
Wireworms
Reduced stands; stunted, wilted, or dying plants; germinating seeds destroyed; taproots of small plants cut off, or roots of older beets scarred; damage caused by slender, tough, smooth, wirelike worms, from white or yellow to dark brown and 3-38 mm long
Crusting
Usually only emerging plants affected; plants emerging through cracks in the soil; soil plates raised by emerging plants
Root
BLACK
Bacterial vascular necrosis and rot
Dark black streaks in petioles; foaming at the centers of crowns; brownish soft rot of roots; in root tissue, black vascular bundles, with adjacent tissue turning pink if exposed to air; wilting of plants as the disease progresses
Black root
Hot-season rot; brown to black lesions on taproots; frequently, excessive formation of lateral rootlets; fibrous or tasseled appearance of severely rooted roots
Botrytis storage rot
Rotted tissue is black; dark brown to black sclerotia, 2-3 mm in diameter; gray spores present in masses
Charcoal rot
Charcoal black sclerotia in pockets on crowns or taproots; mustard yellow early rot; wilting of foliage after extensive root rot
Phoma root rot
Cool-season rot; rotted tissue dark brown to black with prominent black lines; pycnidia may be present on older tissue
Phoma storage rot
Rotted tissue is black; white mycelium in pockets in rotted tissue; black pycnidia present, exuding colorless spores
Phytophthora root rot
Hot-season rot; rotted tissue brown with black margin; tips of severely rotted roots brown and frayed; usually associated with excess of water
Pythium root rot
Hot-season rot; rotted tissue black; usually associated with excess of water
Rhizoctonia root and crown rot
Light tan to black sclerotia on root surfaces; chlorotic, wilted, and rosetted foliage; petioles turning black and brittle near the crown; circular dry rot cankers on crowns
Verticillium wilt
Black, very small, round or irregularly shaped sclerotia; vascular bundles of root tissue brown and threadlike; wilting of foliage at high temperature
BROWN
Bacterial vascular necrosis and rot
Dark black streaks in petioles; foaming at the centers of crowns; brownish soft rot of roots; in root tissue, black vascular bundles, with adjacent tissue turning pink if exposed to air; wilting of plants as the disease progresses
Black root
Hot-season rot; brown to black lesions on taproots; frequently, excessive formation of lateral rootlets; fibrous or tasseled appearance of severely rooted roots
Botrytis storage rot
Rotted tissue is black; dark brown to black sclerotia, 2-3 mm in diameter; gray spores present in masses
Clover cyst nematode
Roots contain cysts; females turn yellow before becoming reddish brown cysts; found thus far only in the Netherlands and Sweden
Fusarium yellows
Vascular bundles of root tissue gray-brown; no sclerotia; yellowing of foliage of all ages
Phoma root rot
Cool-season rot; rotted tissue dark brown to black with prominent black lines; pycnidia may be present on older tissue
Phytophthora root rot
Hot-season rot; rotted tissue brown with black margin; tips of severely rotted roots brown and frayed; usually associated with excess of water
Rhizopus root rot
Cool- or hot-season rot; gray-brown lesions in injuries on crowns or taproots; infected roots become black and spongy; initially white mycelium, later turning black, on root surface; vinegary odor of internal fluid
Scab
Normal leaves with a brownish, roughened appearance on portions of roots or entire roots
Southern Sclerotium root rot
White to dark brown, round sclerotia on crowns and roots, accompanied by a mass of white mycelium; rotted tissue highly water-soaked
Sugar beet cyst nematode
Roots contain cysts; females do not turn yellow before becoming reddish brown cysts; found worldwide
Verticillium wilt
Black, very small, round or irregularly shaped sclerotia; vascular bundles of root tissue brown and threadlike; wilting of foliage at high temperature
Violet root rot
Violet to violet-brown, rounded sclerotia on roots, covered with a velvety mass of mycelium; wilting of foliage after extensive root rot
GRAY
Botrytis storage rot
Rotted tissue is black; dark brown to black sclerotia, 2-3 mm in diameter; gray spores present in masses
Fusarium yellows
Vascular bundles of root tissue gray-brown; no sclerotia; yellowing of foliage of all ages
Rhizopus root rot
Cool- or hot-season rot; gray-brown lesions in injuries on crowns or taproots; infected roots become black and spongy; initially white mycelium, later turning black, on root surface; vinegary odor of internal fluid
GREEN
Penicillium storage rot
Rotted tissue is brown; columnar tufts with green spores on the root surface
PINK
Bacterial vascular necrosis and rot
Soft rot; dark vascular bundles surrounded by pink tissue when cut
Bacterial vascular necrosis and rot
Dark black streaks in petioles; foaming at the centers of crowns; brownish soft rot of roots; in root tissue, black vascular bundles, with adjacent tissue turning pink if exposed to air; wilting of plants as the disease progresses
RED
Clover cyst nematode
Roots contain cysts; females turn yellow before becoming reddish brown cysts; found thus far only in the Netherlands and Sweden
Sugar beet cyst nematode
Roots contain cysts; females do not turn yellow before becoming reddish brown cysts; found worldwide
TAN
Rhizoctonia root and crown rot
Light tan to black sclerotia on root surfaces; chlorotic, wilted, and rosetted foliage; petioles turning black and brittle near the crown; circular dry rot cankers on crowns
VIOLET
Violet root rot
Violet to violet-brown, rounded sclerotia on roots, covered with a velvety mass of mycelium; wilting of foliage after extensive root rot
WHITE
Phoma storage rot
Rotted tissue is black; white mycelium in pockets in rotted tissue; black pycnidia present, exuding colorless spores
Southern Sclerotium root rot
White to dark brown, round sclerotia on crowns and roots, accompanied by a mass of white mycelium; rotted tissue highly water-soaked
YELLOW
Clover cyst nematode
Roots contain cysts; females turn yellow before becoming reddish brown cysts; found thus far only in the Netherlands and Sweden
Sugar beet cyst nematode
Roots contain cysts; females do not turn yellow before becoming reddish brown cysts; found worldwide
No Distinct Discoloration
Beet leaf curl
Leaf margins curled upward; veinclearing in youngest leaves; leaves curled upward, crinkled, and dwarfed; tops and roots markedly stunted
Beet necrotic yellow vein
Mildly yellowed leaves; leaf blades upright, sometimes flabby and wilted; severe root stunting and proliferation of lateral rootlets; proliferation of leaves, resulting in formation of extensive crown tissue; occasional veinbanding on leaves
Beet savoy
Leaf margins curled downward; vein thickening and growth retardation of leaves, giving their lower surface a netted appearance; leaves dwarfed and curled downward at the edges; roots with phloem necrosis and discoloration
Crown gall
Normal leaves with a large gall or galls on roots
False root-knot nematodes
Roots with galls
Fluchloralin; Nitralin; Pendimethalin; Trifluralin; 2,4-D
Roots affected; twisting, excessive formation of root hairs
Freezing
Leaves or cotyledons of plants appear water-soaked and die after occurrence of low temperatures; roots appear healthy; in plants with large taproots, thawed tissue becoming yellow to light tan; with a sharp demarcation between frozen and healthy tissue
Lightning damage
Dead plants in a circular pattern, with the number of living plants increasing with distance from the center; root appear free of disease
Rodents
Crowns and roots eaten; usually, small cavities left, with tooth marks; burrows or mounds of soil may be present only the bottoms of taproots may be eaten, so that plants wilt
Root-knot nematodes
Roots with galls
Soil compaction
Wilting may occur; roots growing parallel to the soil surface above a compacted layer; sprangling of roots may occur
Stem and bulb nematode
Roots without cysts or galls; plants with swollen epicotyls and hypocotyls
Stubby-root nematodes
Roots without cysts or galls; roots stubbed off
Sugar beet root maggot
Reduced stands; stunted, wilted, or dying plants, white maggots, 6 mm long, without legs, eyes, or distinct head, present around roots; root riddled with burrows and surface scars
Symphylan
Plants stunted or dying; small roots eaten; active, fragile, small centipedes present, 6 mm long, whitish in coloration, with six to 12 or more pairs of legs
White grubs
Taproots of small plants cut off; bug holes cut in sides of larger roots; damage caused by soft, robust, U-shaped grubs, up to 38 mm long, with shiny brown heads, six legs, dark abdomens, and dirty white to grayish coloration
Wind damage
Plants flat on the soil surface; root girdling at the soil line; silvery foliage on older plants
Wireworms
Reduced stands; stunted, wilted, or dying plants; germinating seeds destroyed; taproots of small plants cut off, or roots of older beets scarred; damage caused by slender, tough, smooth, wirelike worms, from white or yellow to dark brown and 3-38 mm long
Yellow wilt
Yellowing of leaves, with tips turned down, followed by dwarfing of straplike new leaves; proliferation of rootlets may occur; wilting of plants when root tips die; reported only in South America
Crown
BLACK
Bacterial vascular necrosis and rot
Dark black streaks in petioles; foaming at the centers of crowns; brownish soft rot of roots; in root tissue, black vascular bundles, with adjacent tissue turning pink if exposed to air; wilting of plants as the disease progresses
Charcoal rot
Charcoal black sclerotia in pockets on crowns or taproots; mustard yellow early rot; wilting of foliage after extensive root rot
Rhizoctonia root and crown rot
Light tan to black sclerotia on root surfaces; chlorotic, wilted, and rosetted foliage; petioles turning black and brittle near the crown; circular dry rot cankers on crowns
BROWN
Rhizopus root rot
Cool- or hot-season rot; gray-brown lesions in injuries on crowns or taproots; infected roots become black and spongy; initially white mycelium, later turning black, on root surface; vinegary odor of internal fluid
Southern Sclerotium root rot
White to dark brown, round sclerotia on crowns and roots, accompanied by a mass of white mycelium; rotted tissue highly water-soaked
Beet tumor or crown wart
Greenish brown, rough galls, usually less than 1 cm in diameter, on older leaf blades and petioles; red to greenish brown galls, 8-10 cm in diameter, attached by a narrow base, may also occur on crowns but not on taproots; brown spores may fill tumors
GRAY
Rhizopus root rot
Cool- or hot-season rot; gray-brown lesions in injuries on crowns or taproots; infected roots become black and spongy; initially white mycelium, later turning black, on root surface; vinegary odor of internal fluid
RED
Beet tumor or crown wart
Greenish brown, rough galls, usually less than 1 cm in diameter, on older leaf blades and petioles; red to greenish brown galls, 8-10 cm in diameter, attached by a narrow base, may also occur on crowns but not on taproots; brown spores may fill tumors
WHITE
Southern Sclerotium root rot
White to dark brown, round sclerotia on crowns and roots, accompanied by a mass of white mycelium; rotted tissue highly water-soaked
No Distinct Discoloration
Beet necrotic yellow vein
Mildly yellowed leaves; leaf blades upright, sometimes flabby and wilted; severe root stunting and proliferation of lateral rootlets; proliferation of leaves, resulting in formation of extensive crown tissue; occasional veinbanding on leaves
Rodents
Crowns and roots eaten; usually, small cavities left, with tooth marks; burrows or mounds of soil may be present only the bottoms of taproots may be eaten, so that plants wilt
Bacterial pocket
Normal leaves with large pustules or pockets on crowns
Cutworms
Plants wilted near thinning time and partially or completely cut off at the crown; damage caused by smooth, hairless, fat, soft-bodied, greasy-looking worms, 38-51 mm long, found near freshly cut plants, just under the soil surface
Sugar beet crown borer
Silken tubes, 5-15 cm long, radiating just under the soil surface from the crowns of wilted or cut-off plants; dirty white larvae, 13-19 mm long, with a distinct greenish tinge, present inside the tubes
Stem
No Distinct Discoloration
Cutworms
Plants wilted near thinning time and partially or completely cut off at the crown; damage caused by smooth, hairless, fat, soft-bodied, greasy-looking worms, 38-51 mm long, found near freshly cut plants, just under the soil surface
Lightning damage
Dead plants in a circular pattern, with the number of living plants increasing with distance from the center; root appear free of disease
Leaf
BLACK
Alternaria leaf spot
Dark brown to almost black spots, 2-10 mm in diameter, circular to irregularly shaped, with centers turning gray with age; dark fungal growth on spots during cool, humid periods; spots frequently occurring in yellowed areas of infected or deficient leaves
Bacterial leaf spot
Small to large, circular to angular, black spots and streaks on leaf blades, veins, and petioles; spots often bordered by brown tissue, which may be surrounded by a halo of yellow tissue
Cercospora leaf spot
Individual spots 3-5 mm in diameter mostly on older leaves, with tan to brown centers (or grayish fungal growth, under warm, humid conditions) and dark brown or purple borders; small black dots may be scattered in tan centers
Ramularia leaf spot
Spots on older leaves 4-7 mm or more in diameter, somewhat angular, with tan to medium brown centers (grayish white fungal growth may be present) and dark brown to almost black or purplish red borders; generally occurring under cool, damp conditions
Rhizoctonia foliar blight
Blackened marginal areas of smaller heart leaves, giving the appearance of having been burned; small leaves misshapen and irregular in appearance, often reduced to stubs
BRONZE
Powdery mildew
Whitish, dusty or powdery fungal growth on middle-aged and older leaves; leaves not distorted but may be reddish bronze under fungal growth
BROWN
Penicillium storage rot
Rotted tissue is brown; columnar tufts with green spores on the root surface
Alternaria leaf spot
Dark brown to almost black spots, 2-10 mm in diameter, circular to irregularly shaped, with centers turning gray with age; dark fungal growth on spots during cool, humid periods; spots frequently occurring in yellowed areas of infected or deficient leaves
Bacterial leaf spot
Definite black, circular or angular spots of all sizes on leaf blades or petioles; spots often surrounded by brown tissue and a halo of yellow tissue
Beet rust
Reddish brown pustules on mature leaves, petioles, or seedstalks
Cercospora leaf spot
Individual spots 3-5 mm in diameter mostly on older leaves, with tan to brown centers (or grayish fungal growth, under warm, humid conditions) and dark brown or purple borders; small black dots may be scattered in tan centers
Diquat; Paraquat; Endothall
Foliage affected; necrosis; browning
Phoma leaf spot
Spots up to 1-2 mm or more in diameter, round to oval, with light to dark brown centers and dark concentric rings near the perimeter, but usually without distinct borders; dark rings may contain small, black fruiting bodies on the fungus
Ramularia leaf spot
Spots on older leaves 4-7 mm or more in diameter, somewhat angular, with tan to medium brown centers (grayish white fungal growth may be present) and dark brown to almost black or purplish red borders; generally occurring under cool, damp conditions
DARK
Phoma leaf spot
Spots up to 1-2 mm or more in diameter, round to oval, with light to dark brown centers and dark concentric rings near the perimeter, but usually without distinct borders; dark rings may contain small, black fruiting bodies on the fungus
GRAY
Alternaria leaf spot
Dark brown to almost black spots, 2-10 mm in diameter, circular to irregularly shaped, with centers turning gray with age; dark fungal growth on spots during cool, humid periods; spots frequently occurring in yellowed areas of infected or deficient leaves
Cercospora leaf spot
Individual spots 3-5 mm in diameter mostly on older leaves, with tan to brown centers (or grayish fungal growth, under warm, humid conditions) and dark brown or purple borders; small black dots may be scattered in tan centers
Downy mildew
Grayish, downy fungal growth on heart leaves, usually on the lower surface; leaves sometimes tinged with purple, curled downward, and distorted
Ramularia leaf spot
Spots on older leaves 4-7 mm or more in diameter, somewhat angular, with tan to medium brown centers (grayish white fungal growth may be present) and dark brown to almost black or purplish red borders; generally occurring under cool, damp conditions
GREEN
Sugar beet root aphid
Small, light green or yellow-green plants; roots containing moldlike substance covering yellow-white, wingless aphids, up to 3 mm long, and fewer darker-winged aphids
Armyworms
Foliage eaten by thick-bodied caterpillars, 38 mm long, that crawl over the ground in masses and consume all green plants in their path
Beet mosaic
Leaves mottled in irregular patterns of shades of green; mottling consisting of chlorotic spots or rings with green centers
Beet webworm
Leaves skeletonized or ragged and webbed by active olive green worms, 13-38 mm long, with light and dark longitudinal stripes running the length of the body; when disturbed, worms hang from a silk thread or retreat into silken tunnels
Genetic abnormalities
Yellow streaks or spots on leaves or lack of green color in sectors of leaves
Phosphorus deficiency
Stunted greening
Zinc deficiency; Manganese deficiency; Iron deficiency; Chlorine deficiency; Copper deficiency
Yellowing with green veining
PURPLE
Cercospora leaf spot
Individual spots 3-5 mm in diameter mostly on older leaves, with tan to brown centers (or grayish fungal growth, under warm, humid conditions) and dark brown or purple borders; small black dots may be scattered in tan centers
Downy mildew
Grayish, downy fungal growth on heart leaves, usually on the lower surface; leaves sometimes tinged with purple, curled downward, and distorted
Ramularia leaf spot
Spots on older leaves 4-7 mm or more in diameter, somewhat angular, with tan to medium brown centers (grayish white fungal growth may be present) and dark brown to almost black or purplish red borders; generally occurring under cool, damp conditions
RED
Beet rust
Reddish brown pustules on mature leaves, petioles, or seedstalks
Powdery mildew
Whitish, dusty or powdery fungal growth on middle-aged and older leaves; leaves not distorted but may be reddish bronze under fungal growth
Ramularia leaf spot
Spots on older leaves 4-7 mm or more in diameter, somewhat angular, with tan to medium brown centers (grayish white fungal growth may be present) and dark brown to almost black or purplish red borders; generally occurring under cool, damp conditions
SILVER
Wind damage
Plants flat on the soil surface; root girdling at the soil line; silvery foliage on older plants
TAN
Freezing
Leaves or cotyledons of plants appear water-soaked and die after occurrence of low temperatures; roots appear healthy; in plants with large taproots, thawed tissue becoming yellow to light tan; with a sharp demarcation between frozen and healthy tissue
Cercospora leaf spot
Individual spots 3-5 mm in diameter mostly on older leaves, with tan to brown centers (or grayish fungal growth, under warm, humid conditions) and dark brown or purple borders; small black dots may be scattered in tan centers
Dodder
Fine, vinelike, yellow to light tan plants with very small leaves and no chlorophyll growing on the surface of beet plants; in later growth stages, the parasite appears somewhat like a coil of fine wire
Ramularia leaf spot
Spots on older leaves 4-7 mm or more in diameter, somewhat angular, with tan to medium brown centers (grayish white fungal growth may be present) and dark brown to almost black or purplish red borders; generally occurring under cool, damp conditions
WHITE
Powdery mildew
Whitish, dusty or powdery fungal growth on middle-aged and older leaves; leaves not distorted but may be reddish bronze under fungal growth
Ramularia leaf spot
Spots on older leaves 4-7 mm or more in diameter, somewhat angular, with tan to medium brown centers (grayish white fungal growth may be present) and dark brown to almost black or purplish red borders; generally occurring under cool, damp conditions
YELLOW
Beet necrotic yellow vein
Mildly yellowed leaves; leaf blades upright, sometimes flabby and wilted; severe root stunting and proliferation of lateral rootlets; proliferation of leaves, resulting in formation of extensive crown tissue; occasional veinbanding on leaves
Rhizoctonia root and crown rot
Light tan to black sclerotia on root surfaces; chlorotic, wilted, and rosetted foliage; petioles turning black and brittle near the crown; circular dry rot cankers on crowns
Charcoal rot
Charcoal black sclerotia in pockets on crowns or taproots; mustard yellow early rot; wilting of foliage after extensive root rot
Freezing
Leaves or cotyledons of plants appear water-soaked and die after occurrence of low temperatures; roots appear healthy; in plants with large taproots, thawed tissue becoming yellow to light tan; with a sharp demarcation between frozen and healthy tissue
Fusarium yellows
Vascular bundles of root tissue gray-brown; no sclerotia; yellowing of foliage of all ages
Sugar beet root aphid
Small, light green or yellow-green plants; roots containing moldlike substance covering yellow-white, wingless aphids, up to 3 mm long, and fewer darker-winged aphids
Yellow wilt
Yellowing of leaves, with tips turned down, followed by dwarfing of straplike new leaves; proliferation of rootlets may occur; wilting of plants when root tips die; reported only in South America
Alternaria leaf spot
Dark brown to almost black spots, 2-10 mm in diameter, circular to irregularly shaped, with centers turning gray with age; dark fungal growth on spots during cool, humid periods; spots frequently occurring in yellowed areas of infected or deficient leaves
Bacterial leaf spot
Small to large, circular to angular, black spots and streaks on leaf blades, veins, and petioles; spots often bordered by brown tissue, which may be surrounded by a halo of yellow tissue
Beet mosaic
Leaves mottled in irregular patterns of shades of green; mottling consisting of chlorotic spots or rings with green centers
Beet western yellows
Interveinal yellowing, thickened leaves; little or no veinclearing or necrotic spotting in interveinal tissue; lesions caused by Alternaria on leaf edges
Beet yellow net
Bright yellow chlorosis of veins and veinlets, sometimes becoming interveinal and involving entire leaf blades; at later stages, symptoms may disappear, and plants appear normal
Beet yellow stunt
Interveinal yellowing, thickened leaves; severe twisting, cupping, and epinasty of leaves; shortened petioles; leaves becoming mottled and yellowed
Beet yellow vein
Dwarfing and yellowing of young leaves; yellowing of main veins, extending into adjacent tissue and producing conspicuous veinbanding; isolated, irregular yellow areas may develop in smaller infected veins; dwarfing, often on only one side of the plant
Beet yellows
Interveinal yellowing, thickened leaves; pale yellowing and vein etching on younger leaves, with necrotic flecking and necrotic areas in interveinal areas; leaves may have translucent pinpoint spots
Cucumber mosaic
Leaves mottled with bright yellow, puckered, and blistered
Dalapon; Glyphosate; Desmedipham; Phenmedipham; Atrazine; Heazinone; Simazine; Chlorsulfuron; Pyrazon
Foliage affected; chlorosis, yellowing
Dodder
Fine, vinelike, yellow to light tan plants with very small leaves and no chlorophyll growing on the surface of beet plants; in later growth stages, the parasite appears somewhat like a coil of fine wire
Genetic abnormalities
Yellow streaks or spots on leaves or lack of green color in sectors of leaves
Lettuce infectious yellows
Interveinal yellowing and very mild mottle
Nitrogen deficiency; Sulfur deficiency; Molybdenum deficiency
Uniform yellowing
Zinc deficiency; Manganese deficiency; Iron deficiency; Chlorine deficiency; Copper deficiency
Yellowing with green veining
No Distinct Discoloration
Beet tumor or crown wart
Greenish brown, rough galls, usually less than 1 cm in diameter, on older leaf blades and petioles; red to greenish brown galls, 8-10 cm in diameter, attached by a narrow base, may also occur on crowns but not on taproots; brown spores may fill tumors
Beet leaf curl
Leaf margins curled upward; veinclearing in youngest leaves; leaves curled upward, crinkled, and dwarfed; tops and roots markedly stunted
Beet savoy
Leaf margins curled downward; vein thickening and growth retardation of leaves, giving their lower surface a netted appearance; leaves dwarfed and curled downward at the edges; roots with phloem necrosis and discoloration
Violet root rot
Violet to violet-brown, rounded sclerotia on roots, covered with a velvety mass of mycelium; wilting of foliage after extensive root rot
Alfalfa looper
Plants bordering alfalfa fields are eaten by light green, dark olive green, or pale greenish brown larvae, up to 38 mm long, tapering toward the head, and moving in a looping manner
Beet curly top
Leaves crinkled, dwarfed, and rolled upward; veins roughened on the lower side of leaves; swelling of veins and spinelike outgrowths on them; necrotic phloem tissue of leaves, with phloem contents visible on the leaf surface
Beet latent rosette
Leaves twisted, with tips turned down; later, formation of leaf rosette
Beet leafhopper
Curling of leaves, caused by a virus transmitted by small, slender, wedge-shaped, active, jumping and flying insects, 3 mm long
Beet petiole borer
Small pits and punctures on leaf petioles; damage caused by shiny, dark brown weevils, 3 mm long; legless larvae, white with a brown head capsule, burrowing into the tissue and producing tunnels
Blister beetles
Leaves eaten by ash gray, black, spotted or striped, slender beetles, from 13 to over 25 mm long and 6 mm wide, with conspicuous heads, necks, long legs, and antennae
Calcium deficiency; Boron deficiency
Growing-point damage
Carrion beetles
Foliage eaten by oval beetles, 13 mm long; dull black adults, contrasting with shiny black immature beetles; wedge-shaped young beetles also eat foliage
Dicamba; 2,4-D; MCPA; Diethatyl ethyl; Ethofumesate; Picloram; Cycloate; Diallate; EPTC; Pebulate
Foliage affected; epinasty, malformations
Drought
Plants appear healthy; wilting of leaves; death of older leaves; dry soil
False chinch bug
Large numbers of grayish brown, narrow-bodied insects, 3 mm long, with transparent wings lying flat on their backs, sometimes clustered on plants
Flea beetles
Small shot holes in or complete consumption of cotyledons or first true leaves; damage caused by tiny, jumping beetles, up to 5 mm long, and brown, striped, or shiny black
Foliage-feeding aphids
On the underside of leaves, soft-bodied, slow-moving, pale yellow-green to black, winged or wingless insects, often feeding in colonies
Garden webworm
Leaves skeletonized or ragged and webbed by pale greenish yellow to dark yellow larvae with numerous black dots; slightly hairy larvae, a little smaller than the beet webworm
Grasshoppers
Foliage eaten in late summer or early fall by large, slender, jumping or flying insects, 3-5 cm long, usually moving into beet fields after other crops are harvested
Hail damage
Holes in leaves or torn or shredded leaves; dead or dying plant material surrounding plants
Lightning damage
Dead plants in a circular pattern, with the number of living plants increasing with distance from the center; root appear free of disease
Lygus bugs
Leaves sometimes wilted by shy, angular, flattish sucking bugs, 6 mm long, pale green, reddish, or dark brown but always difficult to see on green plants
Potassium deficiency; Magnesium deficiency
Leaf scorch
Salt-marsh caterpillar
Plants damaged late in the season by large caterpillars, up to 5 cm long, covered by long, reddish brown or black hairs and distinctly marked with yellow spots on their sides
Spider mites
Considerable fine webbing on the underside of leaves, leaf necrosis, or speckled appearance of leaves; damage caused by tiny eight-legged spiders, from yellow to green and red with darker-pigmented spots
Spinach leaf miner
Blisterlike or blasted spots and irregular tunnels between the leaf surfaces; damage caused by maggots, 13 mm long, eating the interior of leaves