Winter wheat is advanced by 10-14 days in southern Ontario compared to other years, particularly in early planted fields. Fields in Essex are now at the early boot stages. Regions of the province further north and east as well as later planted fields are not as advanced and are at the first to second node (GS31-32) growth stages. As fields continue to advance, herbicide applications should be wrapped up. Many weeds being targeted in fields such as chickweed, fleabane, Shepherd’s Purse and dandelion are already past their targeted window and should be controlled in the fall. If fields are at or approaching flag leaf, dollars should be saved for fungicide applications instead of herbicide applications.

Figure 1: Winter wheat at the flag leaf stage. To confirm flag leaf emergence, split the leaf sheath above the highest node. If the developing head is present and no additional leaves are contained inside, then the last leaf emerged was the flag leaf.

Early planted fields with high stem counts may be at risk of lodging, especially if the variety being grown is prone to lodging or there is a history of manure applications. A varieties lodging score can be found at To help manage lodging in those high-risk fields, a plant growth regulator application can help reduce lodging risk and can be applied up to the flag leaf emerging (GS 37). Sulphur deficiency is appearing in fields, particularly in the south (Essex, Chatham-Kent and Lambton) where sulphur was not applied along with nitrogen. An application of 10 lbs of sulphur per acre, even after flag leaf, can be applied to correct a deficiency. Manganese (Mn) deficiency is present in some areas in the south as well, predominantly on sandier knolls within fields. A foliar application at 2 lbs of Mn per acre using manganese sulphate powder will provide correction of the deficiency. Make sure to scout your fields, as not all yellow spots are the same!

Figure 2: Sulphur (S) deficiency in winter wheat. S and Mn deficiency are appearing in fields: S deficiency appears as yellowing on the whole leaf starting with new growth. Mn deficiency will show a distinct striping pattern with necrotic areas, on new growth.

Winter barley in southern Ontario is now at the boot to early heading stages. Spring wheat, oats and barley seeding continues.

True armyworm moths have been found at low levels along with aphids and cereal leaf beetle adults. Fields are well below thresholds but should continue to be scouted as the season progresses. The Great Lakes and Maritimes Pest Monitoring Network ( provides weekly true armyworm trap counts.

Slow planting progress has been made to date due to wet conditions. A few fields with lighter soils have been planted and are starting to emerge. Soybeans are very sensitive to soil compaction so waiting for soils to be fit before seeding is more important than planting date.

Many soybean fields have now received an herbicide burndown and fertilizer application. The use of Enlist (E3) soybeans has become more widespread. Keep careful records of which fields were seeded with which herbicide trait. Sadly, every year some soybean fields are destroyed by mistaken herbicide application. Enlist soybeans are not tolerant to Dicamba. IP soybean acreage is up this year. With recent warm weather weeds are growing extremely quickly. Canada fleabane is about to bolt. Two or three modes of action should be used for control. Using just a glyphosate burndown is not effective. Use high water volumes and a surfactant. There are no post emergent control options in IP soybeans for Canada fleabane.

Good soil fertility is important to achieve excellent soybean yields. A 50 bu/ac crop will remove 40 lb/ac of phosphorus (P) and 70lbs/ac of potassium (K) in the grain, but in-season plant uptake of K is twice that amount. If soil test values are below 20 ppm for P and 120 ppm for K soybeans will respond well to a spring applied fertilizer. The lower the soil test the greater the likelihood of a yield gain from applied fertilizer. If soil tests are below 10 ppm for P and 100 ppm for K a response of 5 bu/ac or more can be expected from spring applied fertilizer. Broadcast fertilizer works equally well for soybeans compared with banding. Keep in mind that soybeans are sensitive to fertilizer burn so no dry potassium or nitrogen (N) fertilizer should go in-furrow. The maximum safe rate for a 2X2 band is a total of 90 kg/ha of N + K20.

Corn planting has been concentrated mainly on lighter textured soils due to sporadic showers across the province. In a few counties up to 10 percent of the crop has been planted and some growers have almost finished. Although Ontario trials have shown that the highest yields often result from planting during the last week of April or the first week of May, planting into fit soils is more important than the exact planting date. Uniform emergence is much more important in corn than soybeans. It is important to note that research has also shown that there is still a 95% yield potential available even when seeding as late as May 25th in much of Ontario. Switching to shorter season hybrids is not warranted at this calendar date. Switching to shorter season hybrids is not recommended until May 15-20th in areas less than 2800 CHU, May 20-25th in areas 2800-3200 CHU and May 30th to early June in areas over 3200 CHU. General recommendations are to reduce hybrids 100 CHU for every week after these dates.

Winter canola grown in southern counties is now beyond fungicide application timing for white mould prevention and pods are forming. North of Guelph, winter canola is in early bloom stages and advancing quickly. Canola can advance from first flower to 30% bloom (petal drop) in 6 to 10 days. White mould infects plant tissue when flower petals colonized with mould spores land on stems and leaves. The window for fungicide application for white mould prevention closes at 50% bloom, which is when there are greater than 20 open flowers on the main stem and pods are forming.

Spring canola seeding has begun and is ongoing. In northern regions (north of Muskoka) seeding is just beginning as wet soils are now starting to dry out.

Winter triticale and rye are quickly approaching forage harvest. Timely harvest is critical for forage quality so growers should continue to monitor to avoid missing the optimum harvest window. Alfalfa weevil have been found in southwestern Ontario. The action threshold to manage weevils changes with crop height. Details on weevil management are available on

Agriculture Breakfast Meeting Minutes.

The following minutes are from individual regional Agriculture Breakfast meetings

  • Winter wheat is advanced by 10-14 days in early planted fields. In regions further north or in later planted fields, winter wheat is not as advanced and are not catching up to early planted fields. Many weeds being targeted in fields such as chickweed, fleabane, Shepherd’s Purse and dandelion are already past their targeted window and should be controlled in the fall. Dollars should be saved for fungicide applications instead.
  • Early planted fields with high stem counts may be at risk of lodging, especially if the variety has a high lodging score. A plant growth regulator application may be warranted in those fields.
  • Winter barley is in the boot to early heading stages.
  • There has been planting activity in Bruce, Huron and Perth counties on lighter soils.  It was suggested that up to 10 percent of the corn has already been planted in Huron County and 3% of the soybeans.  Most of the rains to date have been warm rain events but growers should ensure the soils are fit before planting. With warm temperatures and no rain in the forecast planting is expected to pick up.
  • Canada fleabane is quite large in fields and is about to bolt. If planting IP soybeans, two to three modes of action are needed for control, using just a glyphosate burndown is not effective. Use high water volumes and a surfactant to stick to larger plants.
  • The likelihood of success for double crop soybeans goes way down after July 10th. Double crop soybeans are hard in this geography and often do not mature north of Highway 8. There are growers that do make it work consistently but it is usually after winter barely, hay, or peas. These growers are very dedicated to the system and manage to plant in good time. Growers should be aware that there is not a maturity that is short enough north of highway 8 to get consistent results, with 00 not being good enough for Elora or Stratford. Double crop soybeans are also not covered by insurance due to the unreliability. Growers should consider planting a cover crop after wheat. IP soybeans should not be planted as a double crop.
  • Agricorp reported they have received minimal damage reports this spring. A reminder that the deadline for adding or removing crops, or any changes to production insurance is May 10th.
  • Rainfall is very sporadic – some areas only got 5mm on the weekend, others got 25mm.
  • Reports of winter crop damages/losses are minimal, but winter wheat seeded into canola stubble seems to keep the geese off the wheat field entirely.
  • There are low levels of insect activity in cereals but will monitor spring cereals going forward.
  • Not all spring cereals are planted in the east, but many growers have at least some of their intended acres in. There are some growers switching intended cereal acres to corn or soybeans based on the 14-day forecast.
  • Alfalfa stands are good, but growers are still opting to keep older stands. Current forecast is not conducive to new seeding, so there may be more summer/fall seeded acres.
  • Some older stands are planned to be terminated and planted into corn or soybeans following first cut. Some alfalfa did go in the ground in mid-April, and it has emerged and is looking good.
  • Estimates in the area are 5-10% of intended corn acres have been planted. Some areas a 0% with others 30% or higher.
  • Some discussion on variety changes based on maturities, but seed companies are holding off until later next week, as the forecast still looks like we will get some windows.
  • Soybean acres planted are even less – maybe 2%, and only in areas where the soybeans fields are fit before the corn fields.
  • Winter canola that came through the winter looks phenomenal, even the later planted stands.
  • Most spring canola is planted and beginning to emerge.
  • There are concerns about weed pressures – emerging weeds are growing rapidly with the rain and warm weather, so be sure to have an effective herbicide plan in place.
  • A reminder that the Wheat Staging Guide is available through GFO for free, and the website has launched with all of the crop committee data.
  • Rainfall – Ranged from 5 mm to 0.3 mm in the Elgin – Niagara area
  • Field work – Lots of field preparation on light-textured soils to almost nothing on clay soils. There are sandy soils with standing water and these wet sands need to be managed to avoid compaction.  The past few weeks soils have not been fit to plant, but good for fertilizer and herbicide applications.  Custom application now will help limit the bottleneck when planting begins in earnest. Growers with their own sprayer equipment need to watch tank clean out because the pressure for timely application will be intense, and farmers need to be reminded about importance of sprayer clean out.
  • Patience in spring is a virtue.  Planting into the wrong conditions could result in a 20 to 50-bushel yield hit, especially with big equipment.  Best to have a plan and be ready to amend it based on conditions.
  • Different winter/spring conditions result in different weed pressures.  This year weeds are advanced – especially sow thistle.  Walking fields to scout for herbicide misses, herbicide resistant weeds or new un-identified weeds is important for problem weed management.  Take a weed specimen to local retail to help with identification, if needed.
  • Wheat – Flag leaf has fully emerged for early October planted wheat, while mid-October planted wheat has not reached flag leaf stage.  Lots of advanced weeds in wheat fields. Many fields had herbicides and fungicides applied but fields without weed control to now will need to wait for post-harvest since weeds are too advanced for cost effective control.
  • Pesticide applications ahead of wide temperature fluctuations should ideally wait 48 hours. Observations for 2-way tank mix applied to wheat with < 0oC low to double digit highs showed minor injury that wheat grew out of.
  • Blue grass pressure – used to be a Niagara area issue but has also become a problem weed in other counties (e.g.  Elgin, Middlesex). Bluegrass likes cold-clammy soils, so 2024 mild winter conditions were good for bluegrass survival. From windshield scouting bluegrass looks like chickweed – an unpleasant surprise for some growers. The herbicide Simplicity (pyroxsulam) applied before flag leaf stage on blue grass less than 10 cm will give good control. Applied to bluegrass at 20 cm will provide weed suppression. Field where glyphosate was fall applied has far less bluegrass than fields with no control.
  • More purple nettle in fields this year – function of mild winter or is this a weed that is spreading?
  • Herbicides Prominex (spring/winter wheat and spring barley) and TruSlate (cereals and grasses) both contain Lontrel and have a 10-month residual – waiting period therefore can not double crop soybeans after wheat where these herbicides are used.
  • To avoid costly replants by spraying the wrong product “Just Ask”, especially when it comes to seed traits and herbicides. Enlist represents 78% of seed trait beans Woodstock to Niagara region. (55% pre-plant market in Ontario). Also ask when it comes to identifying an unknown weed.  
  • Corn planting well underway in Norfolk (70%) and started in Oxford (10%) but only a few acres on clay soils. Lots of questions about switching varieties. Seed switches should occur no earlier than after May long weekend. Interest in earlier variety switching stems from experiences with drying and carbon tax costs from last fall. More interest in growing shorter day varieties that will cost less to dry. Farms with on-farm drying capacity are at an advantage and are more aware of the costs. Carbon tax influence combined with low crop prices and high land rent.
  • Forage harvest – cereal rye or triticale pea mixes are being harvested. Thick stands and some lodging.  Alfalfa forages came through winter well with no reported winterkill. Observations from 4th year forage stands that stem counts from last fall to this spring are significantly reduced where there is a thick stand of chickweed. Less stand reduction where there are dandelions or Shepard’s Purse.
  • More IP beans than ever, but proper residual herbicide planning and use is important. New growers often don’t know field history – and upfront chemistry will save money from tramping mature beans with pre-harvest burndown. Increasing weed resistance will make weed control IP and dry beans more difficult to grow in a few years.
  • Agricorp – May 10 deadline for adjusting or changes to crop production insurance. Only 2 wheat fields reported in Niagara region to be replanted.

Weather Data – Tuesday May 2- Wednesday May 8, 2024

LocationHighest Temp (°C)Lowest Temp (°C)Rain for Week (mm)Rain Since April 1st (mm)GDD0C April 1stGDD5C April 1stCHU May 1st
10 YR Norm (11-20)20.16.420.1118.2338149109
10 YR Norm (11-20)
10 YR Norm (11-20)
10 YR Norm (11-20)19.85.816.1110.129111197
10 YR Norm (11-20)
10 YR Norm (11-20)17.74.410.889.42457366
10 YR Norm (11-20)18.63.815.8113.42366875
10 YR Norm (11-20)18.13.513.2100.52256475
10 YR Norm (11-20)17.92.514.2101.62165874
10 YR Norm (11-20)18.61.315.5104.22457584
10 YR Norm (11-20)
10 YR Norm (11-20)16.71.414.5104.61403252
10 YR Norm (11-20)
10 YR Norm (11-20)
10 YR Norm (11-20)15.8-1.712.264.21141643
10 YR Norm (11-20)18.5-0.89.655.21442857