sealPurdue News

December 1996

Spring fertilizing may reduce take-all disease in winter wheat

WEST LAFAYETTE, Ind. -- This year's delayed corn and soybean harvest may have caused some farmers to plant wheat after wheat, and that could mean trouble, according to Purdue University plant pathologists Greg Shaner and Don Huber.

Wheat after wheat can lead to root-rot problems, especially from the disease take-all. The fungus is native to soils nearly everywhere in the world, which is one reason why long crop rotations (one or more years out of wheat) fail to provide more than one year of control.

But the Purdue experts say there are a couple of management practices than can help reduce the chances of losing yield to take-all damage:

First, make sure the field has adequate nitrogen fertilizer in the spring. Nitrogen-deficiency stress increases damage from take-all. Timely, springtime top-dressing when the wheat breaks winter dormancy, with enough nitrogen to maintain a healthy green color in the foliage, will reduce damage.

Ammoniacal nitrogen and slow-release forms of nitrogen tend to suppress the disease, while nitrate forms of nitrogen may favor the disease. High soil pH also favors take-all, and it is not recommended to apply lime prior to wheat, unless the soil pH is below 5.2.

Though it's too late in this growing season to implement the following control method, it's important to note it for next year: Plant following the fly-free date to reduce the severity of take-all. Even when wheat following wheat is planted after the fly-free date, fields should be adequately fertilized in the spring.

The bottom line: As a general management practice, do whatever is possible to avoid planting wheat after wheat.

CONTACTS: Shaner (765) 494-4651; e-mail,
Huber, (765) 494-4652; e-mail,
Compiled by Chris Sigurdson, (765) 494-8415; e-mail,
Purdue News Service: (765) 494-2096; e-mail,

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