This ultimate guide on disease of wheat will help you to know symptoms, and management of wheat diseases. After reading this article you will be able to identify and control wheat crop disease. According to bdspublishing.com disease infestation in wheat crop causes 20% wheat production losses globally.
Disease of Wheat
Wheat crop can get affected from fungal, bacterial, as well as viral diseases. Hence, it become very important to know about them for successful farming. You can control these diseases inorganically as well as organically.
However, in serious infestation, many a times organic application doesn’t work properly. But, prevention is always better than cure. Try to adopt preventive measures and spray organic pesticides such as neemastra, panchgavya, waste decomposer, etc. periodically.
You can spray any of these at the required interval. This will not only help to prevent your crop from hazardous pest and diseases, but will also improve fertility of the soil. Moreover better farm practices and use of disease and pest resistant improved variety also ensures better crop health.
Wheat Fungus Disease
According to United States Department of Agriculture, wheat crop can get affected by many fungal diseases. These fungal diseases of wheat are:
|Fungal Disease||Causal Organism|
|Powdery Mildew||Erysiphe graminis|
|Downy Mildew||Sclerophthora macrospora|
|Leaf Rust (Brown Rust)||Puccinia recondita|
|Stem Rust (Black Rust)||Puccinia graminis|
|Stripe Rust (Yellow Rust)||Puccinia striiformis|
|Common and Dwarf Bunt (Stinking Bunt)||Tilletia foetida|
|Karnal Bunt (Partial Bunt)||Tilletia indica|
|Loose Smut||Ustilago tritici|
|Flag Smut||Urocytis agropyri|
|Septoria Tritici Blotch||Mycosphaerella graminicola|
|Septoria Nodorum Blotch||Leptosphaeria nodorum|
|Septoria Avenae Blotch||Leptosphaeria avenaria|
|Spot Blotch||Cochliobolus sativus|
|Fusarium Leaf Blotch||Colonectria nivalis|
|Rhizoctonia Root Rot||Rhizoctonia solani|
|Common Root Rot||Helminthosporium|
|Alternaria Leaf Blight||Alternaria triicina|
|Sclerotium wilt||Corticum rolfsii|
|Tan Spot||Pyrenosphora trichostoma|
The causal organism of powdery mildew disease in wheat is Erysiphe graminis. Host plants are barley, oats, rye, etc. This fungus has high degree of host specificity. This disease can cause serious crop loss if not treated properly.
Cool temperature of around 15 to 22 degrees Celsius and high humidity in the atmosphere can favour the growth of this disease.
You can easily notice greyish to white powdery growth mainly on the leaves. However, you can also notice the growth on leaf sheath, stem, and floral parts of the plant. Later on, if not controlled then these initial infection turns into black lesion. At this stage leaves starts drying.
You can spray wettable sulphur @ 0.2%. You can also try to control this disease by spraying Carbendazin @ 500 grams per hectare.
However, you can read this article to know more about controlling powdery mildew disease.
READ MORE: LEARN TO CONTROL POWDERY MILDEW DISEASE
The causal organism of downy mildew in wheat is Sclerophthora macrospora. Host plant is wheat. Water logged condition in the field can increase the risk of this disease infestation. Moreover, temperature range between 10 to 25 degrees Celsius can enhance the spread.
The infected plant starts tillering profusely. These hollow stems are yellowish to green in colour. They are short, erect, and irregular in shape. The leaves are thick and erect. Premature death of tiller occurs or they never head.
But, if the heads are formed then they can be branched.
Avoid waterlogging condition in the field.
Growing resistant variety helps in preventing chances of disease infestation.
In case of infestation spray copper fungicide to control this disease. You can spray this fungicide once after every 7 days. Keep spraying frequently to control the disease.
The causal organism of ergot disease of wheat is Claviceps purpurea. Host plants are all small grains cereal crops. Infestation of this disease can result in small size and depleted grain quality. Moreover, cool and humid climate favours the growth of this disease.
During flowering stage, the floret gets infected. The infected part produces a yellowish, sweet, and sticky exudate. This sticky and yellowish exudate is easily visible on glumes. The development of kernels that occurs on infected florets gets replaced by fungus bodies.
They are generally brown to purplish black fungal structures. The primary infection can occur from ascospores in fruiting bodies. These are formed by sclerotia or ergot bodies from the previous year’s crop.
Selecting disease resistant and high quality seeds can prevent your crop from this disease.
Keep removing weeds from the field time to time.
Practice crop rotation with non-host crop such as legumes, sorghum, corn, etc. The sclerotia survives only for one year in the soil.
Spraying any broad spectrum fungicide can also help. But, for controlling ergot disease, prevention is better than cure. As there is no specific control measures for this disease.
The causal organism of leaf rust or brown rust disease is Puccinia recondita. Host plants are wheat, Triticale, and other related grasses. Infestation of this disease can result in serious reduction in crop yield. Atmospheric temperature near to 20 degrees Celsius and free moisture can result in the rapid spread of this disease.
Primary infection can occur on the upper surface of leaves and leaf sheath. You can notice elliptical to circular pustules. They are generally smaller than the postules of stem rust. Moreover, these pustules have orange to brown urediospores. The alternate host is Thalictrum species.
You can practice mixed cropping system of farming.
Applying excess doze of nitrogen can increase the risk of leaf rust disease infestation.
Moreover, you can start cultivating wheat crop with disease resistant variety. Try to find out the best resistant variety fit for your region in local government or private agricultural institutions.
The causal organism of stem rust or black rust of wheat is Puccinia graminis. The host plants are wheat, barley, triticale, and other related grasses. Loss in grain weight and quality occurs due to stem rust disease infestation.
Moderate temperature and free humidity in the form of rain and dew can favour the growth of this disease. The initial infection or primary infections are light and occurs because of wind borne urediospores.
You can notice dark reddish brown pustules mainly on upper and lower surface of the leaves. However, you can also notice them on all aerial parts of the plant. These pustules remain separate and scattered. In case of heavy infestation these scattered pustules coalesce.
You can practice mixed cropping or crop rotation to prevent your crop from this disease.
Do not apply excess doze of fertilizer, especially nitrogen. Excess nitrogen application can increase the risk of disease infestation.
You can try sulphur dusting @ 35 to 40 Kilograms per hectare. Moreover you can also apply Mancozeb @ 2 grams per litre of water.
Grow disease resistant variety crop to ensure better results.
Wheat Bacterial Disease
According to United States Department of Agriculture your wheat crop can get infected with the bacterial diseases. Hence, knowing about these disease becomes very important to save your crop from them.
|Bacterial Disease||Causal Organism|
|Bacterial Black Chaff||Xanthomonas campestris|
|Bacterial Stripe||Xanthomonas campestris|
|Basal Glume Rot||Pseudomonas syringae|
|Bacterial Leaf Blight||Pseudomonas syringae|
|Bacterial Spike Blight||Corynebacterium tritici|
Bacterial Black Chaff & Bacterial Stripe
The causal organism of bacterial black chaff and bacterial stripe disease in wheat is Xanthomonas campestris. This bacteria survives on crop residues under the soil. It can tolerate warm as well as freezing temperature. However, free moisture can result in the spread of this disease.
There are various strains of this bacterium. And according to its strain symptoms varies. In case of bacterial black chaff, you can notice the initial symptoms on the glumes. But, in case of bacterial stripe you can notice the initial symptoms on leaves or leaf sheath.
You can easily notice narrow chlorotic lesions or stripes. They have water soaked appearance. Later on if the atmospheric moisture remains nearly similar then you can notice sticky yellowish exudates. They will eventually dry and will form crusty droplets.
In severe infection, spikes become sterile.
Use disease free or pathogen free seeds to prevent your crop from these disease.
Control weeds and pests in the field to save your crop.
You can also apply neemastra to prevent the spread of bacteria.
Avoid late sowing of seeds.
Basal Glume Rot & Bacterial Leaf Blight
The causal organism of basal glume rot and bacterial leaf blight in wheat crop is Pseudomonas syringae. The host plants are all small grains cereal crops. The bacteria can survive on crop residues and grass hosts. Wet and humid climate favours the growth of this disease.
You can notice small, dark green, water soaked lesions at the base of the glume. Later on these lesions turn dark brown to blackish in colour and spread on leaves and spikes. If you will hold the diseased glumes toward light then they will appear translucent. However, lesions may also appear on rachis and kernels.
You can use disease resistant crop variety to save your crop.
Practicing good farm sanitization and timely removal of host grass weeds can help to save your crop.
Till now there is no proper chemical control of this disease. Hence try to use organic alternatives such as neemastra, or aagneyastra.
Remove the infected plant immediately and burn them at a far distance from the field.
Bacterial Spike Blight
The causal organism of bacterial spike blight in wheat is Corynebacterium tritici. The host plants are wheat and some wild grasses. This is not so hazardous disease. The pathogens remains in the soil and spread with the help of Anguina tritici.
You can notice yellow exudate on the spikes during initial infection. Later on this exudate dries and turns into white in colour. Old leaves gets twisted and wrinkled.
Use certified and disease resistant seeds.
Avoid late sowing of seeds.
Treat the seeds with panchgavya before sowing or practice seed treatment with solarization technique.
Do not allow weed growth and follow field sanitization.
Wheat Viral Disease
According to United States Department of Agriculture wheat crop can get affected from viral disease too.
|Viral Disease||Causal Organism|
|Barley Yellow Dwarf||Barley Yellow Dwarf Virus (BYDV)|
Barley Yellow Dwarf
The causal organism of barley yellow dwarf disease in wheat is Barley Yellow Dwarf Virus (BYDV). The host plants are wheat, barley, triticale, oats and many grass species. Temperature range around 20 degrees Celsius favours the growth of this disease.
The symptoms of this disease can vary. The main factors according to which the symptoms varies are:
Age of plant,
Time of infection,
and strain of the virus.
General symptoms are yellowing or reddening of leaves. Reduced growth of roots and thickened stiff leaves. This virus can spread from the 20 different species of aphids.
You can spray insecticides to stop the spread of this disease. As this disease spreads through aphids. So try to control their population the field. You can check out the following article to learn on how to deal with aphids.
ALSO READ: HOW TO CONTROL APHIDS?