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Wheat is a staple food crop all over the world. Wheat ranks second in India in terms of food grain production. In this article, we will discuss about the important diseases of wheat. Disease in wheat causes loss in production.

1. Black or stem rust 

Causal Organism: Puccinia graminis

It is also called cereal rust, black rust, red rust or red dust.

Symptoms: Symptoms are produced on almost all aerial parts of the wheat plant but are most common on stem, leaf sheaths and upper and lower leaf surfaces. Spores are readily released when touched. The color of the pustule changes from rust color to black as teliospore production progresses.

2. Brown or leaf rust

Causal Organism: Puccinia triticina

Symptoms: The most common site for symptoms is on leaf blades, however, sheaths,  glumes and awns may occasionally become infected and exhibit symptoms. Infection sites primarily are found on the upper surfaces of leaves and leaf sheaths and occasionally on the neck and awns. Heavy infection which extends to the flag leaf results in a shorter period of grain fill and small kernels.

3. Yellow or stripe rust

Causal Organism: Puccinia striiformis

Symptoms: Mainly occur on leaves than the leaf sheaths and stem. Bright yellow pustules (Uredia) appear on leaves at early stage of crop and pustules are arranged in linear rows as stripes.

Management:

• Grow resistant varieties: PBW 343, PBW 550, PBW 17

4. Loose smut

Causal Organism: Ustilago nuda tritici

Symptoms: At this time, infected heads emerge earlier than normal heads. The entire inflorescence is commonly affected and appears as a mass of olive-black spores, initially covered by a thin gray membrane.

Management:

• Treatment of seed with fungicide.

5. Flag smut

Causal Organism: Urocystis tritici

Symptoms: The symptoms can be seen on stem, clum and leaves from late seedling stage to maturity. The seedling infection leads to twisting and drooping of leaves followed by withering.

Management:

• Treat the seeds with carboxin at 2g /kg.
• Grow resistant varieties like Pusa 44 and WG 377.

6. Hill bunt or Stinking smut

Causal Organism: Tilletia caries / T.foetida

Symptoms: The fungus attacks seedling of 8-10 days old and become systemic and grows along the tip of shoot. At the time of flowering hyphae concentrate in the inflorescence and spikelet and transforming the ovary into smut sorus of dark green color with masses of chlamydospores.

Management:

• Treat the seeds with carboxin or carbendazim at 2g/kg.
• Grow resistant varieties like Kalyan Sona, S227, PV18, HD2021, HD4513 and HD4519.

7. Karnal bunt

Causal Organism: Neovassia indica

Symptoms: Symptoms of Karnal bunt are often difficult to distinguish in the field due to the fact that incidence of infected kernels on a given head is low. There may be some spreading of the glumes due to sorus production but it is not as extensive as that observed with common bunt. Symptoms are most readily detected on seed after harvest.

8. Foot rot

Causal Organism: Pythium graminicolum and P. arrhenomanes

Symptoms
The disease mainly occurs in seedlings and roots and rootlets become brown in color. Seedlings become pale green and have stunted growth. Fungus produces sporangia and zoospores and oospores.

Management:

• Follow crop rotation.
• Treat the seeds with Carboxin or Carbendazim at 2g/kg.

9. Powdery mildew

Causal Organism: Erysiphe graminis var. tritici

Symptoms: Greyish white powdery growth appears on the leaf, sheath, stem and floral parts. Powdery growth later become black lesion and cause drying of leaves and other parts.

10. Leaf blight

Causal Organism: Alternaria triticina / Bipolaris sorokiniana