Barley:Diagnostics

BARLEY PESTS AND NUTRITIONAL DISORDERS

AFRICAN CEREAL STREAK

‘‘‘African Cereal Streak:’‘‘ This disease is characterized by faint, broken, yellow streaks in the leaf that begin near the base of the blade. Eventually the entire blade may become streaked causing the leaves to become totally yellow. (Viral Disease)

ANTHRACNOSE (COLLETOTRICHUM GRAMINICOLA)

‘‘‘Anthracnose (Colletotrichum graminicola) ‘‘‘ This disease is characterized by the development of lesions that are elliptic in shape and first appear to be water-soaked, but later become bleached and dry . These lesions are usually confined to the lower half of stems and the plant may experience poor vigor, head blight, lodging, and shriveled grain. There are no control measures available at this time. (Fungal Disease)

ASCOCHYTA LEAF SPOT (ASCOCHYTA HORDEI)

‘‘‘Ascochyta Leaf Spot (Ascochyta hordei) ‘‘‘ This disease is characterized by only a few irregularly shapes lesions that develop on the lower leaves of a plant. The lesions are brown but the centers fade to a white or pale yellow with a few narrow brown margins. Infected leaves eventually wither and die. Because this disease is rarely a problem, there are no control measures associated with it at this time. (Fungal Disease)

ASTER YELLOWS

‘‘‘Aster Yellows:’‘‘ This disease is characterized by yellow blotches on the leaves of infected plants. As the disease progresses, these areas may develop a deeper yellow color and the leaves may roll inward. There are no control measures available at this time for the disease. (Bacterial and Mycoplasmal Disease)

AUSTRALIAN WHEAT STRIATE

‘‘‘Australian Wheat Striate:’‘‘ Plants that are infected with this disease are dwarfed and their leaves show fine, broken, yellow to gray streaks or stripes. There are no control measures available. (Viral Disease)

BACTERIAL LEAF BLIGHT (PSEUDOMONAS SYRINGAE)

‘‘‘Bacterial Leaf Blight (Pseudomonas syringae) ‘‘‘ This disease is characterized by small, water-soaked lesions that affect the uppermost leaves of the plant. These lesions group together to form larger lesions which may cover then entire leaf. The kernels that become infected show tan to dark brown dry spots with distinct margins. Unfortunately there is no information available that includes effective control measures for the disease. (Bacterial and Mycoplasmal Disease)

BACTERIAL LEAF STREAK AND BLACK CHAFF (XANTHOMONAS CAMPESTRIS PV TRANSLUCENS)

‘‘‘Bacterial Leaf Streak and Black Chaff (Xanthomonas campestris pv translucens) ‘‘‘ This disease is characterized by small, water-soaked lesions that develop into linear streaks on young green leaves. One helpful diagnostic feature of this disease, under wet conditions, an exudate appears on the leaf surface. The best form of control is to use pathogen-free seed produced under dry conditions and rotating the crop to destroy infested plant debris. (Bacterial and Mycoplasmal Disease)

BACTERIAL STRIPE BLIGHT (PSEUDOMONAS SYRINGAE PV STRIAFACIENS)

‘‘‘Bacterial Stripe Blight (Pseudomonas syringae pv striafaciens) ‘‘‘ This disease is characterized by small, water-soaked lesions on the leaves that may group together into stripes of blotches extending the length of the leaf blade. The best form of control is to use resistant cultivars and destroy plant residue of previously infected fields. (Bacterial and Mycoplasmal Disease)

BARLEY MOSAIC (BMV)

‘‘‘Barley Mosaic (BMV) ‘‘‘ Plants that are affected with this disease are stunted and their leaves become yellow. Late in the growing season, typical mosaic symptoms may develop on the leaves. Some barley cultivars show a high degree of resistance and should be used. (Viral Disease)

BARLEY STRIPE (PYRENOPHORA GRAMINEA)

‘‘‘Barley Stripe (Pyrenophora graminea) ‘‘‘ This disease is characterized by yellow stripes that develop on the leaf sheaths and basal portions of new leaf blades. As the disease progresses, these stripes gradually extend the full length of the leaf and soon become dry and will eventually die. Plants infected with barley stripe will also experience stunted growth. The best forms of control would be to use resistant cultivars and pathogen-free seed. (Fungal Disease)

BARLEY STRIPE MOSAIC (BSMV)

‘‘‘Barley Stripe Mosaic (BSMV) ‘‘‘ This disease is characterized by plants that are stunted in growth, have poorly developed heads and kernels, and some florets express sterility. Yellow to white spots and streaks develop which may progress to a brownish, dry and dead stripe in the shape of a V. The best form of control has been to use resistant cultivars. (Viral Disease)

BARLEY YELLOW DWARF (BYDV)

‘‘‘Barley Yellow Dwarf (BYDV) ‘‘‘ This disease is characterized by plants that are stunted in growth and leaves that begin to lose their color. The green tissues of older leaves begin to discolor unevenly along the leaf margins, at the tips, or within the leaf blade in blotches. The tissues next to the midrib seem to remain green longer than the rest of the leaf. The best control is use of resistant or tolerant cultivars. (Viral Disease)

BARLEY YELLOW MOSAIC (BYMV)

‘‘‘Barley Yellow Mosaic (BYMV) ‘‘‘ This disease is characterized by plants with stunted growth and leaves with yellow spots. As the disease matures, the entire leaf will turn yellow beginning at the leaf tip. The best form of control is the use of resistant cultivars. (Viral Disease)

BARLEY YELLOW STRIPE

‘‘‘Barley Yellow Stripe:’‘‘ This disease is characterized by fine continuous stripes on leaves often followed by yellowing and death of the plant. (Viral Disease)

BASAL GLUME ROT (PSEUDOMONAS ATROFACIENS)

‘‘‘Basal Glume Rot (Pseudomonas atrofaciens) ‘‘‘ This disease is characterized by a brown discolored area near the base of the glumes covering the kernels. Infected kernels show a faint, brown to black discoloration on the basal end. There are no control measures available at this time. (Bacterial and Mycoplasmal Disease)

BLACK POINT OR KERNAL BLIGHT

‘‘‘Black Point or Kernel Blight:’‘‘ This disease is characterized by dark brown to black kernels with low levels of germination. The only control measure available is the apply fungicides to the infected seeds. (Fungal Disease)

BORING INJURY

‘‘‘Boring Injury:’‘‘ This disease is characterized by the invasion of insect pests with include the Hessian fly, wheat stem sawfly, gout fly and wheat bulb fly. (Insect Injury)

BORON

‘‘‘Boron:’‘‘ Boron deficiency symptoms have not been reported in barley, but excess amounts can cause a toxic reaction resulting in small brown spots on the leaves. (Nutrient Disorder)

BROME MOSAIC (BMV)

‘‘‘Brome Mosaic (BMV) ‘‘‘ This disease is characterized by yellow or white spots and streaks all over the leaves. As the disease progresses, these spots develop from a pale yellow to a bright yellow mosaic pattern on the leaves. Plants suffering from this disease may also appear somewhat dwarfed and produce shriveled heads. No control measures are available at this time. (Viral Disease)

CALCIUM

‘‘‘Calcium:’‘‘ Plants suffering from calcium deficiency will grow abnormal shoots and roots, especially noticeable at the growing point. Symptoms are first observed on the youngest leaves where the leaf tips become yellow and die. (Nutrient Disorder)

CEPHALOSPORIUM STRIPE (CEPHALOSPORIUM GRAMINEUM)

‘‘‘Cephalosporium Stripe (Cephalosporium gramineum) ‘‘‘ This disease is characterized by showy, yellow, longitudinal stripes on leaves during jointing and heading. The stripes eventually dry up and die and are most prominent on younger green leaves. Normally, there will be only one or two stripes per leaf but they may also develop discolored veins. The best forms of control are to plant late in the autumn before the chance of frost and use clean seed and equipment. There are no resistant cultivars available at this time. (Fungal Disease)

CEREAL CYST NEMATODE (HETERODERA AVENAE)

‘‘‘Cereal Cyst Nematode (Heterodera avenae) ‘‘‘ This disease is characterized by seriously damaged root systems. Infected roots divide near the invasion point forming two roots creating a stunted, knotted root system that may develop immature white cysts. There are no aboveground recognizable symptoms. There are resistant cultivars available and should be used. (Nematode Disease)

CEREAL ROOT-KNOT NEMATODE (MELOIDOGYNE NAASI)

‘‘‘Cereal Root-Knot Nematode (Meloidogyne naasi) ‘‘‘ This disease is characterized by small galls developing near the root tips in the early stages of infection. The galls are frequently shaped like curves, horseshoes, or spirals. Plants will also have patchy stunted, yellow growth. There is no specific form of control, but rotating the plants with dicots may prove to be effected; however, some dicots may show susceptibility. (Nematode Disease)

CEREAL TILLERING

‘‘‘Cereal Tillering:’‘‘ This disease is characterized by plants that have a dark green color, poor yields and stunted growth. Leaves may also appear malformed with serrated margins. (Viral Disease)

CHEWING INJURY

‘‘‘Chewing Injury:’‘‘ The major insect pests that causes chewing injury is the grasshopper, cutworms, wireworm larvae of click-beetles, cereal leaf beetles, armyworms and barley flea beetles. (Insect Injury)

CHLORINE

‘‘‘Chlorine:’‘‘ Plants suffering from chlorine exhibit tip and marginal leaf yellowing with occasionally dead spots and blotches. Dry, dead leaf tissues begin as tan to red-brown spots and contrast sharply with surrounding green tissue. (Disorder Caused by Environmental Stress)

COMMON ROOT ROT AND SEEDLING BLIGHT (COCHLIOBOLUS SATIVUS AND FUSARIUM SPP)

‘‘‘Common Root Rot and Seedling Blight (Cochliobolus sativus and Fusarium spp.) ‘‘‘ This disease is characterized by small, oval, brown lesions on the roots, the lower leaf sheath, or the subcrown internode. Infected leaf tissue near the crown of the plant may become yellow with brown lesions developing near the base. The best form of control is to use clean seed and apply fungicides as a seed treatment. (Fungal Disease)

COPPER

‘‘‘Copper:’‘‘ Plants suffering from copper deficiency will experience marginal yellowing and the tips of the younger leaves may wither. Sometimes the youngest leaves fail to unroll and the foliage appears to wilt. Heads do not always develop but those that do are small and malformed and may also be yellow. (Nutrient Disorder)

COVERED SMUT (USTILAGO HORDEI)

‘‘‘Covered Smut (Ustilago hordei) ‘‘‘ This disease is characterized by heads that are delayed or never completely emerge. The best forms of control is to use resistant cultivars where available or treating the seeds with a protective fungicide. (Fungal Disease)

DOWNY MILDEW (SCLEROPHTHORA MACROSPORA)

‘‘‘Downy Mildew (Sclerophthora macrospora) ‘‘‘ This disease is characterized by plants that are stunted, yellowed, and excessively tillered, with thickened, leathery, or warty leaves. The heads and leaves are often twisted and deformed which may prevent the plant from reaching maturity. The best form of control is to improve the drainage system and rotate the crop with non-cereal crops. (Fungal Disease)

DWARF BUNT (TILLETIA CONTROVERSA)

‘‘‘Dwarf Bunt (Tilletia controversa) ‘‘‘ This disease is characterized by severely stunted tiller with compact heads. These heads become infected and form s bunt ball that, when broken open, have a fishy odor to them. Most winter barley cultivars are resistant to dwarf bunt. Because this disease is of minor importance, there are no control measure at this time. (Fungal Disease)

EASTERN WHEAT STRIATE

‘‘‘Eastern Wheat Striate:’‘‘ This disease is characterized by fine yellow stripes that develop on leaf blades and may also develop on the leaf sheath. These plants usually experience stunted growth. (Viral Disease)

ENANISMO

‘‘‘Enanismo:’‘‘ If this disease infects seedlings, they are usually killed or experience severe stunting. If the infection appears on a more mature plant, yellow leaf blotches with dark green stripes are visible. Galls may also appear on the leaves of older infected plants. (Viral Disease)

ERGOT (CLAVICEPS PURPUREA)

‘‘‘Ergot (Claviceps purpurea)’‘‘ This disease is characterized by purple-black, hornlike tissue hardening that replace one or more seeds in the head. This tissue protrudes from the glumes as the barley matures and can be up to four times larger than normal seed. The best form of control is to plant clean seed and develop good practices of crop rotation, deep soil tillage, and clean cultivation. (Fungal Disease)

EYESPOT OR STRAWBREAKER (PSEUDOCERCOSPORELLA HERPOTRICHOIDES)

‘‘‘Eyespot or Strawbreaker (Pseudocercosporella herpotrichoides) ‘‘‘ This disease is characterized by lesions that begin firm, but become sunken and brittle. Eyespot symptoms are most obvious on plants that have headed although lesions may appear on the surface of leaf sheath. There are no symptoms that appear on the roots. There are no known control measures for the disease although applying benomyl on winter barley may provide temporary control. (Fungal Disease)

GLUME BLOTCH (SEPTORIA NODORUM)

‘‘‘Glume Blotch (Septoria nodorum) ‘‘‘ This disease is characterized by brown or grayish spots on the leaf blade and leaf sheath in the spring. As the disease progresses, oval or lens-shaped, red-brown spots with yellow tissue develop along the veins. There are no control measures available at this time. However, it is believed that the control measures for wheat glume would also apply for barley glume blotch. (Fungal Disease)

HAIL DAMAGE

‘‘‘Hail Damage:’‘‘ Plants that have suffered from hail damage experience damaged tissues well above the ground instead of just at the base of the plant. These damaged areas become dry and bleached and tissued do not mature properly. Some plants may have white heads and stem lesions. (Disorder Caused by Environmental Stress)

HALO SPOT (SELENOPHOMA DONACIS)

‘‘‘Halo Spot (Selenophoma donacis) ‘‘‘ This disease is characterized by halo spots that appear on the leaves and sometimes the culms. These halo spots may appear to be elliptical, rectangular, or squarish lesions. New lesions have purple-brown margins (halos) that fade with age. The best form of control is to use resistant cultivars where they are available and to apply fungicides. (Fungal Disease)

HORDEUM MOSAIC (HMV)

‘‘‘Hordeum Mosaic (HMV) ‘‘‘ This disease is characterized by scattered, yellow spots and streaks may develop near the base of young leaves. There are no control measures available at this time. (Viral Disease)

HYDROGEN FLUORIDE

‘‘‘Hydrogen Fluoride:’‘‘ Plants that are suffering from hydrogen fluoride have dead tissue at the leaf margins and tips because the gas is easily absorbed. (Disorder Caused by Environmental Stress)

IRON

‘‘‘Iron:’‘‘ Plants that are suffering from iron deficiency appear yellow in younger plant parts and the leaves may show continuous stripes between the veins or appear totally bleached. (Nutrient Disorder)

LEAF RUST (PUCCINIA HORDEI)

‘‘‘Leaf Rust (Puccinia hordei) ‘‘‘ This disease is characterized by small, round, light orange-brown spores that develop on leaf sheaths and leaf blades. The best form of control is to apply foliar fungicides although there are efforts being made to develop resistant cultivars. (Fungal Disease)

LEPTOSPHAERIA LEAF SPOT (LEPTOSPHAERIA HERPOTRICHOIDES)

‘‘‘Leptosphaeria Leaf Spot (Leptosphaeria herpotrichoides) ‘‘‘ This disease is characterized by leaf spots that are irregular, diffuse, and yellow to tan. There are no control measures available. (Fungal Disease)

MAGNESIUM

‘‘‘Magnesium:’‘‘ Plants suffering from magnesium deficiency may have pale green leaves and dead areas developing near the leaf margins. Plants with extreme deficiency can result in dwarfed plants. (Nutrient Disorder)

MANGANESE

‘‘‘Manganese:’‘‘ Plants suffering from manganese deficiency are yellow with brown spots and stripes on the tips of the leaves. (Nutrient Disorder)

MOLLUSKS

‘‘‘Mollusks:’‘‘ Mollusks or slugs eat barley plants causing serious damage to all aboveground plant parts. They usually attack in soils that are heavy and wet with a high organic matter. (Insect Injury)

NET BLOTCH (PYRENOPHORA TERES)

‘‘‘Net Blotch (Pyrenophora teres) ‘‘‘ This disease is characterized by small spots or streaks that may take on a brownish color and spread across the leaves creating a netlike pattern. The affected part of the leaf turns brown and the adjoining tissues become yellow. The most effective means of controlling net blotch is through use of resistant cultivars. (Fungal Disease)

NITROGEN

‘‘‘Nitrogen:’‘‘ Plants suffering from nitrogen deficiency have restricted root and shoot growth. They also produce fewer tills and develop small, thin shoots with pale green leaves. If nitrogen is applied too heavily, the plant may experience lush growth, lodging, and delayed maturity. (Nutrient Disorder)

NORTHERN CEREAL MOSAIC

‘‘‘Northern Cereal Mosaic:’‘‘ This disease is characterized by a yellow mosaic, stunting, and yellow leaf streaks. (Viral Disease)

OAT BLUE DWARF (OBDV)

‘‘‘Oat Blue Dwarf (OBDV) ‘‘‘ This disease is characterized by stunted plants that have shortened, stiffened leaves with enations along the veins in leaves and leaf sheaths. These plants also show excessive tillering. (Viral Disease)

OAT PSEUDOROSETTE (OSRV)

‘‘‘Oat Pseudorosette (OSRV) ‘‘‘ This disease is characterized by excessive tillering and are stunted. Although no highly resistant barley cultivars are known, yields are reduced less in some cultivars than in others. (Viral Disease)

OAT STERILE DWARF (OSDV)

‘‘‘Oat Sterile Dwarf (OSDV) ‘‘‘ This disease is characterized by plants showing some stunting and a darker green color producing a few juvenile tillers. The only known measure of control is to control grassy weeds and avoiding oat cover crops. (Viral Disease)

OZONE

‘‘‘Ozone:’‘‘ Plants suffering from ozone appear slightly yellow. In only a few cases will leaf burn be noticeable. (Disorder Caused by Environmental Stress)

PHOSPHORUS

‘‘‘Phosphorus:’‘‘ Plants suffering from phosphorus deficiency have bluish green leaves that eventually develop brown tips and die. Purple anthocyanin pigments may develop in the leaves, culms, and heads of severely deficient plants. (Nutrient Disorder)

PHYSIOLOGIC LEAF SPOTS

‘‘‘Physiologic Leaf Spots:’‘‘ The characteristic blotches appear as irregular clusters of small dry spots surrounding a central brown spot, sometimes giving the appearance of an eyespot lesion. (Environmental Stress)

PIERCING-SUCKING INJURY

‘‘‘Piercing-Sucking Injury:’‘‘ The most common pierce-sucking insects are aphids, chinch bugs, planthoppers, and leafhoppers. (Insect Injury)

POTASSIUM

‘‘‘Potassium:’‘‘ Plants suffering from potassium deficiency have bluish green leaves that appear slightly yellow. The leaves also are marked with purple-brown spots and then become scorched on the tips and margins. An excessive number of tillers may develop, but only a few will produce heads. (Nutrient Disorder)

POWDERY MILDEW (ERYSIPHE GRAMINIS)

‘‘‘Powdery Mildew (Erysiphe graminis) ‘‘‘ This disease is characterized by a white spot on a leaf surface caused by the fungal mycelium. The tissue on the opposite side of an infected leaf turns pale green to yellow. The best form of control is the use of resistant cultivars. Applying fungicides provide an alternative form of control. (Fungal Disease)

PYTHIUM (BROWNING) ROOT ROT (PYTHIUM SPP)

‘‘‘Root Rot (Pythium spp.) ‘‘‘ This disease is characterized by light green to yellow infected tissues with soft and tan to light brown roots. Brown lesions may be present on larger roots. The best forms of control are to apply the proper amounts of phosphorus fertilizer at seeding time and increase drainage. (Fungal Disease)

RICE BLACK-STREAKED DWARF (RBSDV)

‘‘‘Rice Black-Streaked Dwarf (RBSDV) ‘‘‘ This disease is characterized by severe plant stunting and twisted leaves with waxy veinal swellings on their under surface and on culms. The best form of control is to use resistant cultivars and avoid planting near rice. (Viral Disease)

RICE STRIPE (RSV)

‘‘‘Rice Stripe (RSV) ‘‘‘ This disease is characterized by plants that have stunted growth and leaves that have yellowish green to yellowish white stripes running parallel to the midrib. The bet form of control is to use resistant cultivars.

ROOT-GALL NEMATODE (SUBANGUINA RADICICOLA)

‘‘‘Root-Gall Nematode J(Subanguina radicicola) ‘‘‘ This disease is characterized by twisted or spiral shaped roots which become branched. The tips of outer leaves on seedlings become yellow. The best form of control is to rotate barley with legume and root crops. (Nematode Disease)

ROOT-LESION NEMATODES (PRATYLENCHUS SPP)

‘‘‘Root-Lesion Nematodes (Pratylenchus spp.) ‘‘‘ This disease is characterized by oblong dry lesions that are visible the roots. Aboveground symptoms include stunted growth and often some yellowing of the plant. The only known control is to apply soil fumigants that reduce nematode populations. (Nematode Disease)

RUSSIAN WINTER WHEAT MOSAIC (WWMV)

‘‘‘Russian Winter Wheat Mosaic (WWMV) ‘‘‘ This disease is characterized by yellow spots and streaks running parallel with the leaf veins which develop into mosaic and streak-mosaic patterns on leaves. Plant may also experience mild stunted growth. (Viral Disease)

RUSTS (PUCCINIA SPP)

‘‘‘Rusts (Puccinia spp.) ‘‘‘ This disease is characterized by reddish brown to brown spots or yellow pustules that erupt through the epidermis of the aboveground portions of the plant. Depending on the severity of the infection the disease may vary from a few small flecks of spots to pustules that may cover almost the entire plant. The best forms of control are the use of resistant cultivars and applying protective fungicides. (Fungal Disease)

SCAB OR HEAD BLIGHT (FUSARIUM GRAMINEARUM)

‘‘‘Scab or Head Blight (Fusarium graminearum) ‘‘‘ This disease is characterized by a small, water-soaked, somewhat brownish spot at the base or middle of the glume on the rachis. The glumes turn a salmon-pink to reddish color and take on a fluffy, dustlike appearance. The kernels are usually shrunken and grayish brown, especially toward the base of infected spikelets. There are no resistant cultivars available but the best form of control is to rotate the crop with at least a one-year break in cereal and grass cultivation. (Fungal Disease)

SCALD (RHYNCHOSPORIUM SECALIS)

‘‘‘Scald (Rhynchosporium secalis) ‘‘‘ This disease is characterized by lesions that form on leaves, leaf sheaths, glumes, floral bracts, and awns. The infection first appears as lesions that may vary in color from dark or pale gray to bluish gray. As the disease progresses, the lesions take on a water-soaked appearance. The best form of control is to use resistant cultivars and destroy and previous evidence of disease. (Fungal Disease)

SEMILOOSE SMUT (USTILAGO NIGRA)

‘‘‘Semiloose Smut (Ustilago nigra) ‘‘‘ This disease is characterized in many of the same ways as true loose smut, but the notable difference is made by germinating the fungus. Smutted heads will germinate slightly earlier than healthy heads. The best forms of control is to use resistant cultivars or a protective fungicide such as carboxin. (Fungal Disease)

SEPTORIA LEAF BLOTCH (SEPTORIA AVENAE PV TRITICEA)

‘‘‘Septoria Leaf Blotch (Septoria avenae pv triticea) ‘‘‘ This disease is characterized by lesions that are grayish green and turn light tan. The lesions appear mainly on the leaves and the leaf sheaths. The margins of the lesions are not well defined because the yellowish brown areas of the lesions blend into the green leaf blades and sheaths. This disease is of minor importance and there are no control measures available at this time. (Fungal Disease)

SHARP EYESPOT (RHIZOCTONIA CEREALIS OR SOLANI)

‘‘‘Sharp Eyespot (Rhizoctonia cerealis or solani) ‘‘‘ This disease is characterized by small brown lesions that appear on seedlings. As the disease progresses, the center of the lesion will rot leaving a small hole surrounded by dark brown tissue. Sometimes the entire plant is affected which causes the whole plant to be distorted below the soil line leaving only a small aerial shoot. The best form of control is to apply fungicide seed treatments. (Fungal Disease)

SNOW MOLDS

‘‘‘Snow Molds:’‘‘ This disease is characterized by small, round dark or pinkish red masses of hardening plant tissue along with fungal growth on both living and dead plant parts. Leaves commonly die and quickly dry and disintegrate once snow is gone and temperatures rise. The best control is to avoid planting barley in areas of long persistent snow cover and rotating with spring-sown crops or legumes helps to lower infection levels. (Fungal Disease)

SPOT BLOTCH (COCHLIOBOLUS SATIVUS)

‘‘‘Spot Blotch (Cochliobolus sativus) ‘‘‘ This disease is characterized by the development of lesions that vary in size and are uniformly brown, often with yellow halos. The best form of control is to use resistant cultivars where they are available in connection with the use of pathogen-free or fungicide-treated seed. Foliar application of fungicides to control spot blotch may also inhibit infection. (Fungal Disease)

STEM RUST (PUCCINIA GRAMINIS)

‘‘‘Stem Rust (Puccinia graminis) ‘‘‘ This disease is characterized by red-brick pustules with ragged edges that develop into spores and break through the epidermis. The stems and leaf sheaths are most often attacked but the leaf blades, glumes and awns may also become infected. Resistant cultivars are the best form of control. (Fungal Disease)

STORAGE MOLDS (ASPERGILLUS SPP AND PENICILLIUM SPP)

‘‘‘Storage Molds (Aspergillus spp. And Penicillium spp.) ‘‘‘ Seeds that are infected with storage molds have a musty odor and low levels of germination. When mold infections are present, seed embryos can be killed and turn a dark color. Seeds that are exposed to too much heat may develop a fungus which can lead to seed decay. Seeds can be treated with fungicides that can slow down the production of storage mold, but the best form of control is to monitor storage temperature and seed moisture and keep them at levels too low for fungal growth. (Fungal Disease)

STRIPE RUST (PUCCINIA STRIIFORMIS)

‘‘‘Stripe Rust (Puccinia striiformis) ‘‘‘ This disease is characterized by spores that are yellow and sometimes develop into a conspicuous stripe. They are particularly found on the leaves and heads of infected plants and appear earlier in the spring than other rust diseases. (Fungal Disease)

STUNT NEMATODE (MERLINIUS BREVIDENS)

‘‘‘Stunt Nematode (Merlinius brevidens) ‘‘‘ This disease is characterized by plants that are stunted and yellow and produce fewer tiller and smaller kernels than healthy plants. In winter barley, the stunting is first observed in the spring shortly after active growth begins but severe stunting will occur later in the season. There are no control measures available at this time. (Nematode Disease)

SULFUR

‘‘‘Sulfur:’‘‘ Plants suffering from sulfur deficiency experience stunted growth and delayed maturity. It may also cause younger leaves to be pale yellow. (Nutrient Disorder)

SULFUR DIOXIDE

‘‘‘Sulfur Dioxide:’‘‘ Plants suffering from exposure to sulfur dioxide develop dead spots and blotches on the leaf blades and take on a tan-white appearance. (Disorder Caused by Environmental Stress)

TAKE-ALL (GAEUMANNOMYCES GRAMINIS PV TRITICI)

‘‘‘Take-All (Gaeumannomyces graminis pv tritici) ‘‘‘ This disease is most obviously characterized by the development of white heads during the grain-filling stage. Plants that are infected are also stunted in growth, have fewer tillers and can easily be pulled from the soil. The roots break off, leaving the plant with short, stubby roots that are usually brittle and black. There are no resistant cultivars available but the form of control is to practice crop rotation and use nitrogen fertilizer in the form of ammonia, especially in areas where the soil pH is acidic. (Fungal Disease)

TRUE LOOSE SMUT (USTILAGO NUDA)

‘‘‘True Loose Smut (Ustilago nuda) ‘‘‘ This disease is characterized by blackened heads that usually emerge slightly earlier than healthy heads. The spikelets of these plants are entirely transformed into a dry, olive-black spore mass. The best forms of control include using resistant cultivars where available and applying fungicide treatments. (Fungal Disease)

WHEAT DWARF

‘‘‘Wheat Dwarf:’‘‘ This disease is characterized by plants that are dwarfed and develop fine, light green to yellow- brown spots and blotches all over the leaf surface. There are no control measures available at this time. (Viral Disease)

WHEAT SOILBORNE MOSAIC (WSBMV)

‘‘‘Wheat Soilborne Mosaic (WSBMV) ‘‘‘ This disease is characterized by mild green to yellow leaf mosaics and stunting of the plant. (Viral Disease)

WHEAT STREAK MOSAIC (WSMV)

‘‘‘Wheat Streak Mosaic (WSMV) ‘‘‘ This disease is characterized by stunted, spotty green-yellow streaked leaves. These streaks are parallel and discontinuous. There are no control measures available but it can be controlled by destroying any evidence that it had previously been a problem. (Viral Disease)

WHEAT YELLOW LEAF (WYLV)

‘‘‘Wheat Yellow Leaf (WYLV) ‘‘‘ This disease is characterized by leaf yellowing and blight and infected plants usually ripen or die prematurely. This disease may resemble the symptoms associated with barley yellow dwarf virus. (Viral Disease)

YELLOW LEAF SPOT (TAN SPOT) (PYRENOPHORA TRICHOSTOMA)

‘‘‘Yellow Leaf Spot (Tan Spot) (Pyrenophora trichostoma) :’‘‘ This disease is characterized by tan flecks that appear on both sides of the leaf beginning on the lower leaves of the plant. These tan flecks eventually become diamond shapes lesions with a yellow border and a dark brown spot in the center. This disease is not one of extreme importance and there are no control measures available at this time. (Fungal Disease)