Category : Bacterial
Bacterial blight (Bacterial leaf blight, Black chaff)
Xanthomonas translucens also known as Xanthomonas campestris
Bacterial blight on wheat glumes
Symptoms in barley field
Leaf lesions generally appear as short necrotic streaks unless they coalesce into larger necrotic areas
Bacterial blight symptoms in chaff row of barley
Bacterial blight symptom
Symptoms
Water soaked spots on foliage; shriveling dead leaves; glossy yellow or brown streaks; plant appears stunted, slow plant growth.
Cause
Bacteria
Comments
Management
Use only certified, disease-free seed; treat seeds with a fungicide prior to planting to prevent diseases which allow bacteria to enter easily; practice crop rotation to reduce disease build-up in soil.
Basal glume rot
Pseudomonas syringae
Wheat spike showing symptoms of basal glume rot (Pseudomonas syringae pv. atrofaciens)
Symptoms
Brown discoloration at base of the glume (bract covering the kernel); dark line where glume attaches to spike; water soaked spots on leaves; yellow and necrotic spots on leaves.
Cause
Bacterium
Comments
Management
Treat seeds with a fungicide prior to planting to prevent diseases which allow bacteria to enter easily; practice crop rotation to reduce disease build-up in soil; plow crop residue into soil.
Category : Viral
Barley stripe
Pyrenophora graminea
Barley stripe symptoms on barley leaves
Symptoms
Small yellow spots on seedling leaves; yellow to tan stripes along leaf blade before heading; red margins on stripes; death of diseased tissue; heads not emerging; plants stunted.
Cause
Fungus
Comments
Management
Use only certified seed.
Barley yellow dwarf
Barley yellow dwarf virus (BYDV)
Symptoms of Barley Yellow Dwarf Virus.
Wheat showing an upright posture with thickened, stiff leaves, caused by barley yellow dwarf virus (BYDV). The virus also causes yellowing of the leaves and stunting.
The bright yellow of wheat leaves infected with barley yellow dwarf virus contrasts sharply with the deep green of normal, healthy wheat.
Yellowing of leaves of wheat caused by barley yellow dwarf virus (BYDV).
Barley yellow dwarf virus (BYDV) symptom
Symptoms
Stunted growth of plants; yellow green blotches at leaf tip, leaf margin or leaf blade; leaves turning bright yellow, red or purple.
Cause
Virus
Comments
Management
Grow resistant or tolerant varieties; avoid planting crop very early or very late when aphid populations are high.
Category : Fungal
Common root rot
Bipolaris sorokiniana
Cochliobolus sativus
Fusarium culmorum
Fusarium graminearum
Common root rot symptom
Symptoms
Brown lesions on leaves nearest soil extending to stem; resembles drought; death of lower leaves; rotting roots.
Cause
Fungi
Comments
Management
No chemical treatments for this disease; plant crop in late fall to avoid warm soils which favor emergence of disease; do not fertilize crop excessively; use irrigation to reduce water stress.
Covered smut
Ustilago hordei
Covered smut symptoms on barley
Symptoms
Stunted growth; late emergence of heads; kernels replaced with grey fungal masses.
Cause
Fungus
Comments
Management
Use only certified smut-free seed; treat seeds with hot water prior to planting to kill fungi; treat seeds with contact fungicide; grow resistant varieties.
Downy mildew
Sclerophthora rayssiae
Wheat downy mildew symptom- distorted head
Distortion of wheat heads due downy mildew disease
Distorted wheat heads with crazy top symptoms.
Distortion of wheat heads caused by downy mildew (Sclerophthora macrospora)
Symptoms
Dwarfed and/or deformed plants; flag leaves yellow; leathery leaves; heads distorted; seed not formed.
Cause
Fungus
Comments
Management
Plant crop in well-draining soils; control weeds in field which can act as reservoirs for the disease; sow seed only from disease free plants.
Ergot
Claviceps purpurea
Symptoms
Ergot (Claviceps purpurea) symptoms
Sclerotia bodies
Sclerotia obvious in infected heads
Symptoms
Only head affected; flowers oozing sticky substance (honeydew); head appears dirty due to dust sticking to honeydew; diseased kernels turn to black mass of fungal mycelia.
Cause
Fungus
Comments
Management
Till crop residue deep into soil to prevent spores being released into the air; control weeds, especially grasses, in field which act as a secondary host for disease.
Eyespot (foot rot)
Pseodocercosporella herpotrichoides
Sample wheat plants showing symptoms of foot rot (Pseudocercosporella herpotrichoides).
Symptoms
Eye shaped lesions on basal leaf sheaths and stem; stems shriveled and/or collapsing; plants chlorotic; heads white and undersized.
Cause
Fungus
Comments
Management
Rotate barley with leguminous plants; sow spring barley which is more tolerant of spring frosts.
Fusarium head blight (FHB or scab)
Fusarium graminearum
Fusarium head blight on barley caused by “point” inoculation
Barley showing symtoms of Fusarium head blight (FHB), with sections of necrosis on the head. Barley normally has more points of initial infection than wheat, i.e., infection starts in multiple places on the head.
Barley spike showing symptoms of Fusarium head blight (FHB): chlorosis, necrosis, and the appearance of black perithecia, fruiting bodies containing spore sacs.
Kernel infected with head blight
Necrosis caused by Fusarium head blight (FHB) on six-row barley.
Scab or head blight infected spike
Symptoms
Initial symptoms show bleaching of some of the florets in the spike. Under favorable conditions, premature blight or bleaching of whole spike may occur. As the disease progress head turns tan to brown discoloration. Also, we can see pink or orange color mold appears at the base of the florets. The kernels become shriveled, white, and chalky.
Cause
Fungus
Comments
Management
Grow available resistant varieties. If the disease is severe, spray suitable fungicide.
Loose smut
Ustilago nuda
Ustilago tritici
Loose smut infected spikes
Loose smut infected barley spikes
Loose smut symptoms on barley (right) and wheat (left)
Loose smut symptoms
Loose smut (Ustilago avenae) symptoms
Difference between healthy and loose smut infected barley spike
Loose smut symptoms on barley
Symptoms
Early emergence of heads; dark green or black masses in place of kernels.
Cause
Fungus
Comments
Management
Use only certified smut-free seed; treat seeds with hot water prior to planting to kill fungi; treat seeds with systemic fungicide (fungi inside seed) fungicide; grow resistant varieties.
Net blotch
Pyrenophora teres
Close up of a Barley leaf up with Net Blotch.
Net blotch on barley
Symptoms
Dark green water soaked spots; narrow brown blotches with netted appearance, surrounding tissue yellow; stripes running the length of leaf.
Cause
Fungus
Comments
Management
Rotate barley with resistant crops; grow resistant varieties; remove and crop residue from soil surface; destroy volunteer barley plants.
Powder mildew
Blumeria graminis
Close up of Barley leaf with Powdery mildew.
Powdery mildew on leaf with cleistothecia present.
Symptoms on lower leaf surface
White cottony patches
Cleistothecia, of various maturities, developing in dense mycelial mat
Powdery mildew symptoms on lower and upper surface of barley leaves
Cottony mycelia on leaf.
White cottony patches become dull gray- brown color due to development of fruiting bodies (cleistothecia)
Patches of white cottony growth on lower leaf surface.
Symptoms
Initially the lower leaf surface shows white, cottony patches of fungal growth. The upper surface of these patches exhibit chlorotic spots. As the disease progress, this white cottony patches become dull gray- brown color due to development of fruiting bodies (cleistothecia). The infected plants show slow growth.
Cause
Fungus
Comments
Management
Grow available resistant varieties. Follow crop rotation. Keep the field free from weeds and other unwanted plants. Remove and destroy the infected crop residue.