A wet spring pushed Ontario soybean acres to a record high of 3.1 million acres seeded in 2024. This was up 7% from 2023. To date, with approximately half of yields reported the provincial yield is above average at 108%. This number will be updated in January when all acres have been reported. The Agricorp floating claim price was $13.1103/bu in 2024. Ontario is Canada’s largest producer of soybeans, growing 57% of the country’s soybeans. Soybeans are the third largest field crop in Canada in terms of farm cash receipts. The 5-year Ontario average is now approximately 50 bu/ac. A few Ontario fields yielded over 80 bu/ac and some trials yielded an astounding 100 bu/ac. However, growers also faced significant challenges including, excess rainfall, poor plant stands, slug feeding, white mould, and spider mites. This resulted in fields yielding below 30 bu/ac in some regions. Overall, the saying that “rain makes grain” held true in 2024 with higher yields than anticipated for many growers. Above average temperatures in September and October and a late frost also meant that double crop soybeans were more successful this year than other years. A killing frost (negative 2 degrees Celsius) was not reported in some southwestern Ontario locations until the end of November. For example, Sarnia and Hamilton reached negative 2 Celsius for the first time on November 29. This is a full month later than in 2023. A dry fall enabled a timely harvest with overall good seed quality, although protein levels were slightly lower this year.
Wet Spring
The biggest soybean production challenge in 2024 was an extremely wet April, May, and June. For some, it was the wettest spring ever recorded. For example, Simcoe County received almost double the rainfall it usually receives during that 3-month period. And, even more challenging rains were sometimes extremely intense over a short period of time, with over 150 mm (6 inches) being reported by some growers in a single rain event. The Toronto Airport has reported that 2024 was the wettest year on record with 1054 mm (41.5 inches) being measured so far in 2024. This tremendous amount of rainfall made spring field work including spraying a real challenge. See picture #1. Some growers were unable to seed until late June or even early July, especially on clay soils in Lambton County.
Picture 1. A flooded soybean field near Stratford Ontario on July 15, 2024. Source: Horst Bohner
Variety Selection
The most important management decisions to achieve maximum profitability is variety selection. Large yield differences are common between soybean varieties. Yield differences of over 10 bu/ac can be found within similar maturity groups in the 2024 Ontario Soybean Variety Trials. Ontario now has an updated web page dedicated to third-party variety and hybrid performance trial data. It can be found at GoCrops.ca. “Go Crops” stands for Growing Ontario Crops.
Two Spotted Spider Mites
Dimethoate resistant two spotted spider mite populations continue to be found in southern Ontario and are also building tolerance to other miticides used on other crops. Research is underway to better understand the dynamics at play with this resistance, while also exploring more sustainable management tools to implement for control in soybean and dry bean production. If you find that dimethoate applications are not effectively managing two spotted spider mites, contact Tracey Baute, OMAFA so that collections can be made to test for insecticide/miticide resistance.”
Mites use their sucking mouthparts to extract sap from leaves. Damage is visible in the form of white stippling (dots) on the leaf. See picture #2. Leaves with heavy mite infestations turn yellow, curl, bronze and die. The underside of the leaves appear sand blasted.
Picture #2: Leaves with white stippling damage from spider mite feeding. Source: Horst Bohner
Phosphorus, Potassium, and Sulphur
An above average crop means that additional nutrients were removed from the soil in 2024 compared to normal. Regular soil testing is the most effective way to manage soil nutrients. Ontario research has shown that fields low in both P and K can yield up to 20 bu/ac less than fields with adequate soil fertility. A number of public and private trials have been conducted over the last few years to assess if soybeans need sulphur. To date, trials on clay or clay loam soils have shown little or no significant yield advantage to the addition of sulphur. However, in 2024 sandy soils again responded extremely well to the addition of ammonium sulphate (AMS). At one sandy soil trial conducted by Maizex Seeds, soybean yields increased an astounding 22-27 bu/ac with the addition of 100 lbs./ac of AMS. These results are a strong indication that sulphur may now be necessary on sandy soils in Ontario.
Herbicide Resistant Weeds
Farmers and agronomists submitted samples of weed species that were not adequately controlled by herbicides in soybeans to determine if they were resistant to the applied herbicides. New fields continue to show populations of common ragweed resistant to group 14 herbicides (e.g., Reflex, Ultra Blazer). In Lambton County, one population of common ragweed was found to be resistant to three different modes of action (see Table 1). Waterhemp remains the most frequently tested species for herbicide resistance. Resistant waterhemp populations were identified in five counties, with resistance to three different modes of action being the most common (see Table 1).
Growers are encouraged to include fall-seeded crops, such as winter wheat and winter canola, in their crop rotations. These crops often create environments that are inhospitable for weeds like waterhemp. Additionally, maintaining adequate soil fertility to ensure crops canopy quickly and seeding cover crops such as oats or cereal rye after harvest are proven cultural practices that help minimize weed populations.
| Weed Species | Resistant to | County |
| Common ragweed | Group 14 (e.g. Reflex, Ultra Blazer) | Huron, Lambton |
| Common ragweed | Groups 2 (e.g. FirstRate), 5 (e.g. Aatrex) and 14 (e.g. Reflex, Ultra Blazer) | Lambton |
| Waterhemp | Groups 2 (e.g. FirstRate) and 14 (e.g. Reflex, Ultra Blazer) | Ottawa, Leeds and Grenville |
| Waterhemp | Groups 2 (e.g. FirstRate), 9 (e.g. glyphosate) and 14 (e.g. Reflex, Ultra Blazer) | Essex, Huron and Norfolk |