Common and Dwarf Bunt (Stinking Smut)

Tilletia caries, T. foetida, T. controversa

Symptoms: The main symptoms caused by these three species are fungal structures called "bunt balls," which resemble kernels but are completely filled with black teliospores. The bunt balls of common bunt, caused by T. caries and T. foetida, are about the same size and shape as the kernels they replace ; those of dwarf bunt, caused by T. controversa, are more nearly spherical When bunt balls are crushed, they give off a fetid or fishy odor. Infected spikes tend to be bluish green in color (or darker), and the glumes tend to spread apart slightly; the bunt balls often become visible after the soft dough stage . A slight reduction in plant height is typical of common bunt, while a pronounced reduction in height is typical of dwarf bunt.

Development: Spores lying dormant in the soil or on seed germinate and infect emerging seedings. Infection is favored by cool temperatures during germination. The disease develops systemically, with visible symptoms appearing after heading.

Hosts/Distribution: Wheat and (less commonly) triticale are affected by these diseases, as are several other related grasses. Common and dwarf bunts can occur worldwide. Both are limited to temperate climates; dwarf bunt occurs in areas having prolonged snow cover.

Importance: Considerable yield losses can occur when susceptible cultivars are grown or chemical seed treatments are not used.

Stripe Rust (Yellow Rust)

Puccinia striiformis

Symptoms: The pustules of stripe rust, which, contain yellow to orange-yellow urediospores, usually form narrow stripes on the leaves. Pustules also can be found on leaf sheaths, necks, and glumes

Development: Primary infections are caused by wind-borne urediospores that may have travelled long distances. The disease may develop rapidly when free moisture (rain or dew) occurs and temperatures range between 10-20C. At temperatures above 25C, the production of urediospores is reduced or ceases and black teliospores are often produced.

Host/Distribution: Stripe rust can attack wheat, barley, triticale, and many other related grasses. The disease is found in all highland and/or temperate areas where cereals are grown. No alternate host is known.

Importance: Severe infections can cause yield losses, mainly by reducing the number of kernels per spike, test weights, and kernel quality.

Leaf Rust (Brown Rust)

Puccinia recondita

Symptoms: The postules are circular or slightly elliptical, smaller than those of stem rust, usually do not coalesce, and contain masses of orange to orange-brown urediospores. Infection sites primarily are found on the upper surfaces of leaves and leaf sheaths (1), and occasionally on the neck and awns.

Development: Primary infections usually are light and develop from wind-borne urediospores that may have travelled long distances. The disease can develop rapidly when free moisture is available and temperatures are near 20C. Successive generations of urediospores can be produced every 10-14 days if conditions are favorable. As plants mature or when environmental conditions are not favorable, masses of black teliospores may become evident (2).

Hosts/Distribution: Leaf rust can affect wheat, triticale and many other related grasses. The disease is found wherever temperate cereals are grown. The alternate hosts are Thalictrum, Isopryum, Anemonella, and Anchusa spp.

Importance: Severe early infections can cause significant yield losses, mainly by reducing the number of kernels per spike, test weights, and kernel quality.

Wheat Diseases and Pests

Fungal Diseases
Leaf Rust (Brown Rust)
Stem Rust (Black Rust)
Stripe Rust (Yellow Rust)
Common and Dwarf Bunt (Stinking Smut)
Karnal Bunt (Partial Bunt)
Loose Smut
Flag Smut
Powdery Mildew
Septoria Tritici Blotch
Septoria Nodorum Blotch
Septoria Avenae Blotch
Spot Blotch (Helminthosporium Leaf Blotch)
Tan Spot (Yellow Leaf Spot or Blotch)
Alternaria Leaf Blight
Fusarium Leaf Blotch (Snow Mold)
Scab (Head Blight)
Ergot
Black Point
Downy Mildew
Take-All
Eyespot (Strawbreaker)
Sharp Eyespot and Rhizoctonia Root Rot
Common Root Rot, Foot Rot, and Crown Rot
Sclerotium Wilt (Southern Blight)
Black Molds (Sooty Molds)

Bacterial Diseases
Bacterial Black Chaff and Bacterial Stripe
Basal Glume Rot and Bacterial Leaf Blight
Bacterial Spike Blight (Yellow Ear Rot)

Viral Diseases
Barley Yellow Dwarf

Insect Pests
Aphids
Stink Bugs
Armyworms, Cutworms, and Stalk Borers
Cereal Leaf Beetle
Thrips
Hessian Fly
Wheat Stem Maggot
Sawfly
White Grubs
Wireworms
Slugs, Snails, Grasshoppers, and Crickets
Mites

Nematodes
Seed Gall Nematode (Wheat Nematode or Ear Cockle)
Cereal Cyst Nematode
Root Knot Nematode

Physiologic and Genetic Disorders
Physiological Leaf Spot
Melanism and Brown Necrosis (False Black Chaff)
Genetic Flecking
Hybrid Necrosis (Dwarf Clumping)

Mineral and Environmental Stresses
Nitrogen, Phosphorus, and Potassium Deficiencies
Minor Element Deficiencies
Aluminum Toxicity
Salt Stress
Moisture Stress
Heat Stress
Herbicide Damage
Frost Damage