It’s been a tough year for growers in the west — some crops are getting by rain to rain, and some are relying on soil moisture alone with the chance of rain being a hope. Drought can affect silage quality and yield, obviously, but how can smoke from wildfires affect the corn crop?
Sara Meidlinger, market development agronomist at PRIDE Seeds joins Kara Oosterhuis for this Corn School episode to discuss silage quality, pollination, smoke effects, and more.
There’s not a lot of research on the effects of smoke on a crop, due to variability year to year, but in general the smoke is blocking out solar radiation that would otherwise contribute to photosynthesis and carbohydrate production, says Meidlinger.
“Carbon dioxide, water, plus light, makes your carbohydrates, which the plant uses to grow, develop, produce seed,” says Meidlinger. “Having less solar radiation means less photosynthesis, so that might delay our harvest a little bit.”
Smoky, hazy conditions can be likened to shade, under which yield loss can happen. Trying to find the silver lining, Meidlinger says that after those incredibly hot days, the smoke is giving the crop a bit of a break.
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The last week of July and into early August is when a lot of the corn silage, especially in Alberta, is in the reproductive/tasseling stage; so with drought, Meidlinger says that timing of the crop when drought occurs is important, as well as the duration of drought.
“If we had drought symptoms early in the year, and then we had some rain and it’s looking ok, you might not see as much of a yield impact as you do when you still have some drought-stressed corn at your flowering and pollination timing,” she says.
Kernel set happens at 50 per cent pollination, and with silage, 50 per cent of the yield will come from ear development; so if there’s poor ear development, there will be poor yield. Further to that, if ear development isn’t great then starch content also probably won’t be good.
However, Meidlinger says that there’s been some research that shows there’s more soluble sugars in the whole plant, and when that plant gets to the bunker and the ensiling process, there can still be some lactic acid production which will still be a bit of energy.
Nitrates are something to watch when cutting the silage, and Meiglinger says a red flag is if it rains before cutting, and to wait three or four days to let nitrates settle back down. “A feed test is never a bad idea to look into,” she adds.
If parts of the Prairies don’t see a rain, the corn crop will often look a lot worse than it is, and Meidlinger says that for silage harvest, 60 to 65 per cent moisture is the target, but to double check moisture before cutting.