Recent rain was welcome, but disease will crop up if it lingers
The recent wave of June rains has been a bonanza for Washington’s wheat growers.
Now farmers are ready for some sun and heat to combat what has become a pesky and expensive problem: disease.
In recent years, lingering cool, wet spring weather has often brought a fungus called stripe rust. This tiny menace flourishes in Eastern Washington, sending its spores from field to field on the wind.
The disease attacks an important leaf on the wheat plant critical for photosynthesis and for helping the plant produce full, plump kernels for a good harvest.
During the last two years the disease ran rampant across wheat country, said Stephen Guy, an agronomist with Washington State University’s extension office in Pullman.
This year stripe rust is much less prevalent, said Xianming Chen, a WSU research plant pathologist who also works for the U.S. Department of Agriculture.
In 2010 agricultural chemical companies ran short of the fungicides needed to cover the vast acres of infected wheat.
Last year there was plenty of fungicide, but it became difficult to hire busy crop-dusters at just the right time.
Spraying fungicides can cost between $5 and $20 an acre, Guy said.
Over the past couple of years the problems led farmers to spend millions of dollars to spray fields. The fungicides break down and stop fighting the stripe rust after several weeks, which can require farmers to spray fields several times over the course of a crop year.
The spraying preserved what turned out to be an above-average wheat harvest at a time when grain prices remained high enough to offset the cost of added chemical applications along with higher fuel and fertilizer costs.
This year, Chen’s research on stripe rust will be updated regularly and shared with farmers in hopes that they don’t unnecessarily apply fungicides based on last year’s experience.
Some wheat varieties are more resistant to stripe rust, including the popular winter wheat variety called Madsen.
Guy said, however, that stripe rust can affect both winter and spring crops.
“It’s something that can affect any wheat in any field under the right conditions,” he said.