A Perfect Storm for Crop Disease?

From Agri-News

After a wet 2010 in many areas of the province, this spring is providing more of the same. Tight crop rotations coupled with another wet spring are ideal conditions for plant diseases to rear their ugly heads.

“There was a lot of disease showing up last year and it provided plenty of inoculum to infect this year’s crop,” says Harry Brook, crop specialist with Alberta Agriculture and Rural Development. “You might say that conditions this year are setting up for the perfect storm of crop disease.

“One disease of particular concern in Southern Alberta is stripe rust in wheat. Normally, this disease does not overwinter in Alberta but is blown in from the southern United States. However, early appearance of stripe rust in winter wheat this spring has the potential for causing serious crop yield losses. This is indicating that the rust actually overwintered in southern Alberta. Continued humid conditions favour the development and spread of this disease. With such an early start, the potential for crop damage is greatly increased. It is likely these pockets of leaf rust in the south will spread to spring cereals and have plenty of time to affect crop yield.”

The disease is easy to identify as it forms pustules on the leaf upper surface. Walking through an infected field leaves footwear and pants covered in dust which is composed of billions of disease spores. These spores can travel hundreds of miles on the wind, rapidly spreading the disease.

There are fungicides that can effectively control this disease, but it is imperative that it is caught early. This underscores the importance of regularly scouting fields and identifying issues before they can grow into serious problems. Under the right conditions the disease develops rapidly and the yield losses can quickly increase.

“Plenty of moisture and warm temperatures foster the growth of other plant diseases,” continues Brook. “In cereals, other diseases that are showing themselves include common root rot, fusarium root rot, fusarium head blight, tan spot, and septoria leaf blotch, just to name a few. Short rotations or growing the same crop on the same land year-after-year are probably the worst way to manage crop diseases. Infected plant material from the previous year has plenty of opportunity to infect the current year’s crop and cause even more damage.”

Diseases in canola expected to be a problem this year are sclerotinia and blackleg. Wet conditions have already caused problems with seedling blights, even though the seed was treated. In pulses, some of the diseases to watch for include ascochyta, mycosphaerella blight, sclerotinia stem rot and mildew.

“Regardless of the disease, we have weather conditions that are nearly perfect for the development of yield-robbing diseases in field crops,” says Brook. “It is essential to regularly scout your fields, identify the problems, then treat them if they are at economically damaging levels or monitor the situation. Putting the crop in the ground is a lot like putting all your eggs in one basket. . . watch that basket!”

For information on fungicides call your DynAgra representative today!