Crop Advisor’s Casebook Is This Soggy, Stunted Canola Be Nutrient Deficient?

Last year, crops in southern Alberta struggled under the wet conditions Mother Nature delivered. Farmers are experiencing those cold, damp conditions again this season, once more resulting in areas with excess surface moisture.

In mid-June of 2010 Jarod, who farms 1,500 acres of canola, wheat, barley and timothy under irrigation south of Nobleford, Alta., called me about his canola crop. Like other farmers in the province, his fields had been saturated with moisture for weeks.

Jarod wanted a second opinion on the diagnosis of his unhealthy canola stand. He said his plants were small and stunted, and their leaves were yellowing, cupping and some were turning purple. “I’ve been told my field may be suffering from nitrogen deficiency, and I should spray a foliar application of nitrogen — I’d like a second opinion before I put more money into this crop,” he said. It sounded to me as though his plants were nitrogen or sulphur deficient, but to be sure I headed out to Jarod’s farm that afternoon.

The soil in Jarod’s field was extremely wet, with moss growing on the surface. Although it had not rained for a few days, because of the excessive amount of precipitation that had already fallen on his field, the soil was not drying out.

There were a few possible causes of the damage to Jarod’s crop. The uncommonly wet, cool growing conditions could be causing stress to the plants, resulting in poor development. A nutrient imbalance or deficiency was also a possibility, especially as the plants were showing purple, yellowing and cupping leaves — classic symptoms of sulphur deficiency. I wondered what crop had been planted in this field before the canola, and what chemicals had been used on it. Could herbicide carryover be causing the damage?

Jarod told me the previous crop was timothy. Records indicated no chemicals had been applied that would negatively affect canola plant development, so herbicide carryover was not the problem.

Fertilizer application rates and blend were correct according to soil test results and recommendations performed prior to seeding the crop. Jarod’s plants should

have had enough nutrients for that time of year.

Again, I looked at the moss growing on the surface of the soil. Jarod’s field was very wet. He’d asked me for a second opinion and I was glad he did.

“Don’t take that wallet out just yet,” I said.

What is causing the poor development of Jarod’s canola plants, and why are the leaves cupping and turning yellow and purple? Send your diagnosis to Grainews,Box 9800, Winnipeg, Man., 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 aGrainews cap and a one-year subscription to the magazine. The best answer, along with

www.dowagro.ca

0811-16921-3

of Dow AgroSciences LLC.

the reasoning which solved the mystery, will appear in the next Crop Advisor’s Solution File.

ShaneShermanisalocationmanageratRichardson PioneerLtd.atNobleford,Alta.

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