Sometimes the diagnosis of a problem in the field is complicated and lengthy, and sometimes — as in this case — it takes just a glance. Jason, who farms 5,000 acres of wheat, canola, oats and barley west of Swan River, Man., called me at the beginning of August last year. He said some of his wheat heads were turning white or salmon pink and weren’t filling properly. He wasn’t 100 per cent sure, but he thought the problem might have something to do with the wet conditions they’d experienced that season. “At first I thought root rot,” he said, “but the roots look pretty healthy to me. It could be this new variety.” Jason said he seeded a half section with a variety he hadn’t used before, one rated for higher yield than the other variety he seeded in his other fields. He asked me to come take a look.
When I arrived at the field in question, one side of the half section seemed to be worse than the other. Approximately 10 to 15 per cent of the wheat heads in that area showed some sign of infection — the heads were not filling properly, some of the wheat heads had a pinkish tinge to them and some were white. The less affected side showed some of the same symptoms but at half the frequency.
Jason explained half of the field was seeded on wheat and the other, more healthy-looking half, was seeded on canola stubble.
To be thorough, I got a rundown of the field’s history from Jason. Fertilizer application rates and seed treatment were the same for all of his wheat fields, and all fields were seeded within the same week. Jason applied fungicide at the flag leaf stage to control leaf diseases. The weather had been humid and warm during head emergence and flowering. But root rot was not Jason’s problem, the roots were healthy.
I didn’t really need the history of Jason’s field to diagnose this problem. Just one glance at the pinkish heads was all it took.
10 to 15 per cent of the field had heads that weren’t filling and some showed a pinkish tinge.
What is causing the heads of Jason’s wheat to turn pink? Send your diagnosis toGrainews,Box 9800, Winnipeg, MB, R3C 3K7; email [email protected] or fax 204-944-5416 c/o Crop Advisor’s Casebook. Best suggestions will be pooled and one winner will be drawn for a chance to win aGrainewscap and a one-year subscription to the magazine. The best answer, along with the reasoning which solved the mystery, will appear in the next Crop Advisor’s Solution File.