A year of extremes and wild fluctuations in moisture and temperature appear to have produced a very good soybean crop in much of the province, say experts.
Why it matters: A mismatch of plant development timing and swings in growing conditions — dry conditions at the start of the season followed by prolonged periods of high temperatures and rain — appear to have produced above-average soybean crops across the province. Producers were concerned the dry, late spring would result in lower yields.
Late spring and early summer brought very dry conditions in many areas, to the point where there “just wasn’t enough moisture to get seeds to emerge,” says Horst Bohner, soybean specialist with the Ontario Ministry of Agriculture, Food and Rural Affairs.
These parched conditions meant most soybeans did not flower until the relieving rains of mid-July.
This otherwise troubling state of affairs, however, appears to have worked in producers’ favour. This, says Bohner, is thanks particularly to the extended periods of hot weather along with rain that also featured prominently throughout July and August. Dry conditions early in the season generally lead to more root development and less disease pressure. If these conditions are followed with good moisture in August, yields are often above average.
Indeed, many areas throughout Ontario could see soybean harvests around 50 bushels per acre.
“There’s good seed size too. That’s very important because it can make up 20 per cent of yield,” says Bohner. “One way or another growers are generally looking at a good-size crop.”
While significant moisture can cause issues with white mould in soybeans, Bohner says the number of days over 28 C — the temperature threshold at which white mould cannot develop — also worked to counteract this risk, so white mould is not as large of an issue as it could have been.
Bohner adds growers who do have clear white mould issues should consider responding with more mould-tolerant varieties if planting soybeans in subsequent years. Fungicides and other controls are also options during various parts of the growing season.
“Some growers do still have significant mould issues. It’s a question of how much a problem it is for most though. A small amount of white mould in a field can actually be the sign of a high-yielding crop. You can have 20 per cent infection, not 20 per cent dead plants but an infection, and it won’t reduce yield,” he says.
Sudden Death Syndrome (SDS) has not been overly common, though cases do exist. According to Bohner, the conditions were not conducive to SDS in most places and instances can often be tied to the presence of soybean cyst nematode. Consequently, cases of SDS are not generally seen north or east of the London area. Even then, widespread damage is rare.
“We are seeing more in the southwest this year than average but the amount of yield loss associated with SDS is highly dependent on the amount of disease in a field,” he says. “It looks ugly because it’s so visual, but it’s pretty rare to have a whole field wiped out.”
When it comes to insects, Bohner also says the rain and heat of July and August stymied the proliferation of aphids and spider mites — two insects that can cause a tremendous amount of damage in hot, dry years.
Despite low spider mite numbers province-wide, however, higher populations have been a problem in some areas. According to Paul Sullivan, agronomist and owner of P.T. Sullivan Agro Inc. based in the Ottawa area, spider mites in parts of eastern Ontario were problematic enough to warrant spraying, particularly in “a few tough areas where it was dry.
“There’s a lot of regional variation. Things are better in the upper (Ottawa) valley,” he says.
Like Bohner, though, Sullivan reiterates that disease pressures in eastern Ontario have been generally low. With harvest season fast approaching — Sullivan estimates that more than 50 per cent of soybeans in his area are starting to turn — he says most farmers can likely expect above average crops.