Small Grains - Diseases

Small Grain Diseases

Parasitic Diseases

Fungus Diseases

Smut Diseases

The prevalence of smut diseases in wheat and other cereals triggered some of the earliest studies in plant pathology.

Common Bunt

Loose Smut

Dwarf Bunt

Karnal Bunt

Karnal bunt is a disease of wheat, durum, and triticale caused by the fungal pathogen Tilletia indica Mitra. Karnal bunt was first reported in India in 1931, and later in Pakistan, Mexico, the USA, Iran, and South Africa. The disease has been reported in Nepal and Brazil in isolated areas.

Rust Diseases

Three rust dieases have been identified on wheat grown in Arizona. However, none of the three diseases have caused significant losses in Arizona

Leaf Rust

Stripe Rust

Stem Rust

Seedling Diseases

Although Rhizoctonia solani and Pythium spp. have been ocasionally responsible for seedling disease (pre- and post emergence damping-off) in small grains in Arizona, the diseases caused by these fungi are rare and unimportant.

Rhizoctonia solani

Pythium spp.

Virus Diseases

Barley Yellow Dwarf

Wheat Streak Mosaic

Bacterial Diseases

Bacterial Streak

The only bacterial disease of small grains in Arizona presently is bacterial streak caused by xanthomonas campertris pv.

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Nonparasitic Diseases

In Arizona the most common nonparasitic diseases are:

Frost and cold damage

Water and high temperature stress

Yellow Berry

Nitrogen and Phosphorus deficiencies

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Disease Publications

Feb 2018

Stripe Rust of Small Grains

Publication (PDF, 689KB)

Authors: Jiahuai Hu and Mike Ottman

Stripe rust was reported for the first time on barley in Arizona in 1993. The disease is caused by the basidiomycete fungus Puccinia striiformis. Stripe rust appears as yellow orange stripes between the veins of the leaf blades. The disease increases water use, shrivels the grain, and decreases yield.
May 2015

Cultural Practices for Karnal Bunt Control

Publication (PDF, 1.35MB)

Authors: Michael J. Ottman

Karnal bunt is a disease of wheat, durum, and triticale caused by the fungal pathogen Tilletia indica Mitra. Karnal bunt was first reported in India in 1931. This article discusses it's cycle, symptoms, and suggestions on how to control it.
Feb 2014

Diagnosing Nutrient Deficiencies Quick-Reference

Publication (PDF, 429KB)

Authors: Shawna Loper

Nutrient deficiencies can be identified in field through visual observations. However, additional analysis, either plant or soil testing is often necessary to confirm nutrient stress. The following is a quick-reference flow chart that can be used in field to identify potential nutrient deficiencies. Each nutrient has unique deficiency symptoms. Deficiencies will appear in many ways. It can be confused with other plant problems like pathogens or spray damage. But nutrient deficiencies can often be recognized because they tend to form symmetrical patterns, where both sides of leaf or plant parts show the same pattern.
Sep 1992

Diseases and Nutritional Disorders of Wheat, Barley, and Oats

Publication (PDF, 7.13MB)

Authors: Richard Hine, Mike Ottman, and Thomas Doerge

The cultivation of wheat, barley, and oats has been around for a long time. There have been many different types of diseases that can attack these crops. This article talks about the diseases that are important to Arizona growers and discusses their symptoms.

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Disease Presentation

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Fungus Diseases

Virus Diseases

Bacterial Diseases

ARIZONA PEST MANAGEMENT CENTER