It was in early July that I got a call from Bob, who farms 7,000 acres of canola, durum wheat and peas near Lampman, Sask.
“My durum wheat heads are drying up and not filling properly,” Bob said, sounding concerned. “Honestly, I have no idea what could be causing these symptoms.” He explained that the worrying trend was occurring randomly across his fields. Also, the tillers were not fully emerging from the shoots.
When I arrived at Bob’s operation, I discovered that what he’d described over the phone was true — the symptoms were spread sporadically throughout the fields — in low-lying areas as well as at higher elevations.
I weighed all possible contributing factors in my mind one by one. It had been dry and hot for weeks, with sporadic rain, and some fields had received more moisture than others. However, I immediately ruled out lack of moisture as the direct cause of Bob’s problem, as the plants in the fields that had received adequate moisture still showed the symptoms.
I asked Bob if the seed was certified and whether it had been treated or not. I also asked for details on Bob’s fertility regime. But his answers didn’t add up to the issues we were observing in the fields — different varieties of seed, certified or not, exhibited the same symptoms. We ruled out untreated seed as a contributing factor, as there was little to no visual difference between the treated and untreated crops. With respect to fertility, Bob had supplied above-adequate nutrients to the crop, and as the previous year had been wet, the fields had lain fallow in 2011.
Next, we considered whether compaction along the headlands had contributed to the problem as the spring had been so wet. But we ruled out this possibility as the symptoms were spread throughout the field. Could it be root rot that was causing these conditions in Bob’s crop?
Then something occurred to me, triggered by the sporadic nature of the deaths in the durum wheat heads. But I needed to be absolutely sure.
“I’ll need to collect some samples and send them for analysis,” I told Bob. “I think I know what might be causing the problem with your wheat—but it’s not what you’d expect.”
What do you think is the problem with Bob’s wheat? Send your diagnosis to Grainews, 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 a Grainews cap 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. †