Crop Conditions – Week of April 22, 2024

Field Conditions

Light rains and cool temperatures this past weekend and early this week slowed field drying and limited opportunities for early planting of field crops. While it is generally too wet for field work, conditions are variable depending on rainfall received. The remainder of this week was mostly sunny, but expectations are tempered by widespread rain forecast for the coming weekend and early next week for most of the province.

Ontario Agriculture Breakfast Meeting Summary

(Exeter, Simcoe, Kemptville)


Winter wheat stands look good across most parts of the province. Acreage being terminated is generally similar or lower than normal.

Wheat fields broadcast-seeded into soybeans are in good condition due to early seeding and mild winter. Heaving losses are minimal. Tire tracking at soybean harvest that is aggressive enough to move germinated seedlings can result in stand loss. Despite appearances this spring, broadcast seeding wheat is not a recommended practice as there is too great of a risk of contaminating soybeans with treated wheat seed. Broadcast-seeded fields must be inspected prior to receiving crop insurance coverage.

Nitrogen (N) application progress is variable depending on soil type and rainfall. At least 50% of N has been applied in most areas, with some areas as much as 80% or more. Most applications at this point will be single applications. Most N applications have included some form of sulphur.

Tiller retention is important for wheat yields. Where N applications are delayed due to wet conditions, the impact is likely bigger on later planted wheat than earlier planted wheat, as early planted wheat likely already has established tillers. Solar radiation following tillering has a significant impact on tiller retention – more solar radiation (sunny days) improves tiller retention. Fields that received AMS or nitrogen in March appear to have more biomass and tillers.

Plant growth regulators (PGRs) are being applied in areas that have reached stem elongation. Those applications are anticipated to continue in the coming week as temperatures increase, and wheat progresses more quickly.

Powdery mildew has been found in some fields. Scouting for this disease is important, particularly after a mild winter. Stripe rust is being found in various U.S. states and will be monitored for moving into Michigan and Ontario.

Fields that received a fall herbicide application continue to be clean, but it was often difficult making those applications due to a wet fall. Dandelions are beginning to flower and fleabane and shepherd’s purse are beginning to bolt, so the window for effective weed control is closing. As growers continue to make their PGR, herbicide and fungicide applications it is important to consider the timing of those applications and what is being achieved. Ensure these applications are timed properly as much as possible. For those considering a 3-way tank mix,[O(1]  consider making those applications once temperatures are on the warming trend, particularly night temperatures. Cold temperatures increase risks. Biologicals should not contribute to tank mix risks.

Spring cereal planting has been spotty in most areas due to wet conditions. Some areas estimate only 1/3 of intended acres are planted. With warming temperatures, planting will resume. 

Growing degree day accumulations in 2024 continue to be well ahead of 2022 and the 10-year average but are getting closer to the GDD accumulated to date in 2023. In many areas, GDD accumulations are about 200 GDDs ahead of the 10-year average (Fig. 1).

Text Box: Figure 1: Growing degree day (base 0°C) accumulation (2024 and historical) at various locations in Ontario.

Winter Canola

Winter canola survival has generally been good, but some winter survival issues are reported in Eastern Ontario. Stands are still being assessed in that area.

Winter canola is flowering in the far southwest of the province this week. With warmer temperatures forecast, flowering is expected to progress across other parts of the province.

When planting canola ahead of corn, it is a good idea to plant an oat cover crop after harvest to promote mycorrhizae fungi growth. Canola does not support mycorrhizae which can sometimes cause corn to struggle.

Winter canola is very sensitive to imazethapyr herbicide (e.g., Pursuit) carryover (22-month replant interval, more if dry or lower soil pH). Soybean herbicides should be considered when selecting winter canola fields.


Corn planting is expected to be essentially zero. Given current economics (corn prices), there may be some small reduction in corn acres, particularly in corn-on-corn rotations or soils where corn is less competitive than soybeans.

In Eastern Ontario, it has been reported that some non-GMO corn growers have moved away from non-GMO production due to pest issues (e.g., European corn borer). There is more monitoring of European Corn Borer this year. If you experience ECB pressure, please contact Tracey Baute or Jocelyn Smith.[O(2] 

Given the forecast, there have been some questions around whether corn should be planted if ground is fit but there is rain in the forecast. It is difficult to reliably predict risks, but they tend to be greater where:

  • the weather event includes cold temperatures and risks of cold rain or snow.
  • the water the seed will imbibe in the first 24 hours could be cold.
  • soil conditions are not great prior to the rain event.
  • the hybrid planted is known to have poor early season stress tolerance.
  • the soils and tillage/seedbed conditions can be susceptible to crusting.

Traditional wisdom is to avoid planting 48 hours prior to cold rain events. In recent years (e.g., early May 2020), some growers successfully planted closer to these events with little issue, but this has typically involved environments where soil conditions were excellent prior to the stressful event and initial precipitation was not enough to saturate to seed depth. Hybrids that don’t tolerate early season stress are often most susceptible to stand issues. Plant to plant variability can drive yield loss and late immature ears which can increase DON risks.


Soybean (including IP soybean) acres are generally expected to be up slightly this year due to lower corn prices.

There have been questions around sulphur on soybeans. There were some large responses to S noted in 2023, but this was often on sandy soils and may have been partially a year effect (early planting and growth, significant rainfall/loss potential in some cases). Soybean response to added S in most years tends to be quite small. Growers are encouraged to do test strips to build confidence in decision making. Dr. John Lauzon at the University of Guelph is developing a sulphur soil test to help identify where S applications are more likely beneficial and is interested in on-farm trials in 2024.

The importance of keeping track of soybean seed and weed control traits has been stressed by many this spring, especially Enlist versus Xtend traits. Fields should be carefully tracked and communicated when spraying. Extra caution is needed when using up or topping off seed at planting.

Bean leaf beetles (BLB) overwintered well this year with the mild winter. Mortality models suggest less than 25% mortality occurred in Ontario. Expect that beetles will be actively feeding on alfalfa until early planted soybeans begin to emerge. If planting one of the earlier soybean fields in areas with a history of early season BLB, consider using an insecticide seed treatment.

Edible Beans

Black bean contracts are reported to be up this year as many new growers are interested in trying them.

Growers are reminded to fully read their contracts, particularly around biosolid applications. There have been cases where growers intending to plant edible beans in some fields have made changes because of biosolid applications in recent past (3-4 years ago). Some edible bean contracts require fields that have never received biosolid applications.


Feed inventories are reported to be generally good. Alfalfa winter survival appears good across most parts of the province. New seedings are evident around the countryside.

Horticultural Crops

Onions, carrots and some sweet corn under plastic has been reported planted in the Simcoe area.

Weed Control

There has been some discussion around controlling annual ryegrass. Control can be easier in very early spring but becomes very difficult (with glyphosate) once into the jointing stage. It can be more susceptible again once headed out. Surfactants are important.

Glyphosate resistant lambsquarters has been reported in Quebec. Anyone scouting fields should know this when watching for suspected resistance. Genomic testing can confirm resistance.

With tighter margins in 2024, think carefully before cutting weed control costs. Appropriate products, rates and timings are important for maximizing weed control and minimizing crop losses.


Given the drier and warmer late winter and very early spring, there was much more spring soil sampling done than normal.

Manure applications continue, particularly on lighter soils or areas that didn’t receive as much rainfall. Compaction should be top of mind even if fields look dry on top of the soil surface. Ensure soil profile is fit to carry manure tanks.

Be cautious with surface applications of manure on parts of fields where water may run across the surface during heavy rains. These have a high potential for runoff losses. Manage applications for the risk.

Given the warmer than normal winter, there may be higher than normal N availability from fall manure applications, especially those with high organic N content (dairy, poultry). Spring applied manures need to be incorporated to receive full N credits, especially under warm conditions and high pH manures.


See Agricorp website (HERE) for all crop insurance planting deadlines and replant benefit details.

Weather Data – April 15-21, 2024

LocationHighest Temp (°C)Lowest Temp (°C)Rain for Week (mm)Rain (mm) April 1stGDD0C April 1stGDD5C April 1st
10 YR Norm (11-20)14.61.421.146.011834
10 YR Norm (11-20)14.20.317.042.810222
10 YR Norm (11-20)13.50.320.646.89417
10 YR Norm (11-20)13.4-0.521.152.69116
10 YR Norm (11-20)14.2-
10 YR Norm (11-20)11.6-0.921.744.1747
10 YR Norm (11-20)12.2-1.924.355.1674
10 YR Norm (11-20)10.8-
10 YR Norm (11-20)11.2-2.822.947.7540