Last year, there were very few disease issues in the eastern Montana/western North Dakota region, according to Andrew Friskop, the new NDSU Extension plant pathologist.

“Tan spot was the most common disease in cereal fields, and there were some reports of ergot,” Friskop said.

The early use of fungicides can help protect cereals from leaf diseases like tan spot before heavy precipitation hits, he added.

Ergot is a historical fungal disease of wheat and grasses recorded as far back as the middle ages, Friskop said. Cool, wet weather can be a instigator for ergot.

“In the Salem witchcraft trials, some of the people on trial had eaten bread with ergot,” he said. “Today, in livestock, ergot can cause gangrene on the tissues of ears and tails and they can slough off.”

Some of the grains and grasses that can be infected with ergot include: rye, wheat, bromegrass and barley.

To manage ergot, Friskop suggests using crop rotations; ergot-free seed; mow and control grassy weeds; tillage where appropriate and use a gravity table to remove dense seed.

“A copper deficiency in plants can be one cause of ergot so check for copper deficiency,” Friskop said.

Gearing up for spring 2014, the wet conditions that have persisted this winter may mean a wetter spring, which could bring in cereal diseases. For instance, precipitation plus humidity plus temperature can spell a high chance for getting tan spot on wheat, he said.

“Root rots and wheat streak mosaic virus (WSMV) are other diseases to watch out for this year,” Friskop said.

He added there were several causes for root rot. Root rots that often develop in this region include common root rot, fusarium root rot and crown root rot, with yield losses being as high as 40 percent.

“Severity varies from year to year and can be affected by timing of planting and moisture level in the soil at planting,” he said.

“Signs such as a bare spot in a field, white heads or premature ripening of the plants could be root rot.”

To check if it is a root rot, look at the base of the stem and see if there is a lesion. Common root rot will have a dark, black lesion, he said, adding the common root rot fungus is widespread in this region’s soils.

In dry soils that get low annual rainfall such as in eastern Montana/western North Dakota, fusarium root rot can be a problem, especially on hillsides, according to Friskop.

“Fusarium root rots have a red lesion on the root at the soil line,” he said. “If you rub the lesion with your finger and it doesn’t come off, it is root rot.”

Root rot management includes using a good crop rotation; use seed treatment fungicides where indicated; and use less susceptible varieties, Friskop said.

A number of broad-spectrum registered seed treatment fungicides can help fight against the common root rot fungus in wheat and barley.

WSMV may also become an issue in 2014 especially in winter wheat, Friskop said. Corn acres have increased, and if it was planted late, it could still be green later in the year.

“North Dakota planted nearly four million acres of corn, but while signs are that corn is increasing, crop prices could mean some will cut back on corn this year,” he said.

The WSMV disease is carried from plant to plant by wheat curl mites, and symptoms include yellow streaking of leaves, stunting of the plant, and reduced yields. The mite needs a green bridge for survival, and it frequently overwinters on winter wheat or perennial grassy weeds.

“It appears first on the edges of fields or in patches next to volunteers. Multiple grass species are a host,” he said.

Seeing yellow in the field could be an indication of WSMV.

“This is a management disease. Break the green bridge before planting, and you won’t have WSMV,” Friskop said.

Source - http://www.farmandranchguide.com/