Did My Neighbour’s Spray Damage My Wheat?

I was able to help keep the peace between neighbours last June when Dave, who farms 1,500 acres of wheat and canola in Silver Valley, Alta., contacted me about his stressed and dying wheat.

“My neighbour sprayed out my wheat,” he told me, “It looks like it’s dying!” Dave thought his field had been victim to pesticide drift when his neighbour sprayed his own field of canola with herbicide.

When I examined his field, I noted Dave’s wheat did look poor and stressed—the upper third of the leaves were pinched and yellow, and the leaves were twisted or pigtailed about two inches from the tip. Also, the crop seemed to have stopped growing.

On the lower leaves there appeared a slight surfactant burn and from this I could identify the leaf-staging at herbicide application; however, the upper leaves had been affected post-application.

When we checked the field, no drift pattern was evident across from the canola. Dave’s stressed wheat was consistent throughout the field with some of the lighter soils more heavily affected. I noted at that time soil conditions overall were extremely dry. Taking all of these factors together—the symptoms appearing after herbicide application, no evidence of a drift pattern, and consistent damage across the entire field—I did not think we were dealing with a drift issue after all. Dave’s neighbour was innocent.

It was time to look at other factors that could be damaging Dave’s wheat. For instance, could environmental issues, such as weather, wind or precipitation be playing a role in damaging the wheat or, perhaps, pests and disease?

The season had started off with very cool, dry conditions, with snow falling on the May long weekend. But such environmental factors were not likely the cause of such widespread damage to Dave’s field and yet not to other crops in the area. Also, upon closer examination of the plants themselves, the damage did not look like it was caused by pests or disease typically found in the area and at that time.

When we checked fertilizer application rates we found Dave had used a macronutrient fertilizer sufficient for his needs at a 85-25-10-5 blend. But I was convinced we were dealing with a soil issue and I thought further tests were necessary. To determine macronutrient and micronutrient levels, soil samples and tissue tests were taken. The problem certainly was the soil, or more importantly, what was not in the soil.

“I think I’ve solved your problem,” I said to Dave when the test results confirmed my suspicions.

What is causing Dave’s wheat to stop growing, also twisting the leaves and turning them yellow? Send your diagnosis to Crop Advisor’s Casebook, Box 9800, Winnipeg, Man., R3C 3K7; e-mail [email protected]; or fax 1-866-835- 8467 c/o Lyndsey Smith. 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 correct answer, along with the reasoning which solved the mystery, along with the reasoning which solved the mystery, will appear in the next Crop Advisor’s Solution File.

TracyJouanisasalesagronomistat RichardsonInternationalinDunvegan,Alta.

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