Corn growers reap rewards with warm, frost-free spring

Although some reported Goss’s wilt, yields weren’t affected

READYMADE, Alta. — It was a good year for all types of corn in southern Alberta, including crop grown for silage, earlage and grain.

Corn heat units reached 2,500 in some regions, which was higher than the average of 2,200 to 2,400.

That, when combined with warmer nights and plenty of irrigation, led to high silage tonnage and grain yields in the 140 to 150 bushels per acre range.

Lloyd Van Eeden Petersman, a Dupont Pioneer representative from Taber, Alta., told an Oct. 28 corn production meeting that warm spring weather started the season and “we just kind of stayed ahead of the norm.”

It was a marked contrast to last year, when a killing frost occurred in mid-September, which limited the amount of grain harvested.

Irrigation pivots ran from early May, producing corn six to eight feet tall that touched the truss rods on the pivots.

Goss’s wilt, a bacterial disease, made another appearance, said Van Eeden Petersman. It didn’t limit yield in most cases, but its effects depend on growth stage.

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Goss’s wilt needs an entry point, which can be furnished by sand blasting, hail or broken stalks in violent storms.

It doesn’t do much damage if it enters plants later in their growth stage, but it can limit photosynthesis and thus yield if it is able to attack in early July.

The disease tends to be more of a problem in fields where corn has followed corn because spores can overwinter in crop residue.

Burying that residue provides some protection, as does baling, but that can transfer spores to another field.

Van Eeden Petersman also re-ported the appearance of holocus leaf spot in corn crops this year. It is a bacterial disease so it can’t be controlled with fungicides.

He said holocus leaf spot looks similar to foliar burn that might occur from herbicide or fertilizer and usually doesn’t limit yield.

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“It’s generally just a cosmetic thing,” he said.

European corn borer is common in this part of Alberta, though most varieties now have the B.t. trait, which provides protection. Once again, planting corn after corn exacerbates the problem.

This year also brought two-spotted spider mites to some cornfields.

“Perhaps we’ve had this before but haven’t really seen it,” he said.

The mites kill plants from the bottom up and can affect ear development.

Signs of two-spotted spider mites include a dusty appearance in plants at field edges and a cottony-looking material on the undersides of leaves. The mites are tiny and red, so producers might notice a dusty reddish material clinging to their jeans after field scouting.

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