Crop Report – Week of May 24th

Crop Report – May 23, 2024 

Figure 1. Corn is beginning to emerge across the province this week.

Field Conditions 

This past week, much of the province was able to make some progress on field work. Crop Heat Units (CHU) and Growing Degree Days (GDD) are still well above the five-year average across the province. Rain has been sporadic, giving some regions 4-5 days of good weather for planting and field work. Other regions have been delayed but have had some opportunities to get started on lighter ground.


Winter wheat continues to be more advanced than normal, anywhere from 7-10 days ahead, depending on the region. Stripe rust has been reported across southern Ontario. A T3 fungicide application should protect wheat against stripe rust. If it is showing up in fields that are still more than 4-5 days away from T3 fungicide application timing and the variety is susceptible, a fungicide application should be made as soon as possible. If beyond GS 45 or early boot stages, avoid fungicides with Strobilurin. Growers should check with their seed supplier and review the Ontario Cereal Crops Committee performance trials for specific variety ratings ( You can find the stripe rust ratings under the head to head feature or check out the 2016 and 2017 historical reports. Newer Pioneer variety ratings can be found here and C&M’s variety ratings can be found here.

There are wheat fields with powdery mildew. If the crop is nearing T3 timing, fungicide can help with control. Be diligent in reading labels and ensuring that the fungicide choice is best matched for the disease type targeted for control. That information can be found on the Ontario Crop Protection Hub.

Spring cereals continue to be seeded when the conditions allow. Earlier planted fields emerged evenly and are reaching herbicide timing. Weed pressure is persisting in spring cereals, but a timely herbicide pass should be possible to provide adequate control.


Much of the forage rye and the winter triticale has either been harvested over the last week or is currently being harvested. Quality is anticipated to be high in the winter triticale, however, there are some concerns with rye forage quality in relation to a slightly delayed harvest for best feed value.

First cut has not started across the province. Much of the alfalfa is in very early bud, and cutting is expected to begin in the coming week or two. Some fields are reporting high populations of alfalfa weevil. If harvest is not intended in the next 10 days, and populations are over threshold, an insecticide application is recommended. If the crop is less than 10 days from harvest, cutting will control the weevils. Alfalfa regrowth after cutting will need to be watched very closely for alfalfa weevil larvae. Thresholds change with height and can be found here.


The amount of corn acres planted varies drastically across the province. Some areas are reporting only 30% planted while others are anywhere from 70-100% planted. Emergence on earlier planted corn is even and consistent. Much of the emerged corn is between 2 and 3 leaf tips, with the furthest along almost reaching 4 leaf tips. Nitrogen sampling is anticipated to begin in the coming week as we approach corn side-dress timing.


It’s estimated that approximately 20-30% of soybean acres are planted across the province with lots of additional planting occurring this week. Some growers are opting to plant both corn and soybeans simultaneously. Others are planting in order of fields that are ready – some fields intended for corn that aren’t yet fit for planting are being set aside in favour of planting soybeans into intended fields that are fit. It is recommended that after June 1st planting populations should be increased by 10%.

Weed Control

Weed pressures, particularly in no-till fields, are increasing with the sun and warm temperatures, so pre-emerge burndown or early post-emerge herbicide passes are critical going forward.

When planting, be sure to be diligent about trait packages – Enlist, Xtend, Roundup, etc. cannot be sprayed interchangeably. Record keeping is crucial to reduce the risk of errors in spraying and crop management.

Ensuring burndown and residual herbicide programs are applied prior to crop emergence. Some of the crop options have very few effective post applied options so this residual herbicide is critical to success.


The crop planting deadlines are June 30th for soybeans and June 15th for corn. It is expected that significant progress will be made by those dates. The deadline for reporting unseeded acreage is June 15th. The deadline for reporting actual acres of spring-seeded grains and oilseeds and new forage is June 30th. Agricorp encourages farmers to report acres to the Guelph office as soon as they are planted to avoid busy phone lines on the deadline date.

Breakfast Meeting Minutes

Exeter Breakfast Meeting – May 21, 2024
  • Alfalfa weevil is at high levels in some fields. To date there have been no reports of insecticide applications but growers are planning to harvest as soon as possible. If it is not possible to harvest within 10 days, a spray may be warranted. Regrowth will need to be watched closely if there are lots of weevil larvae present.
  • In the last couple of days, significant corn planting progress has been made but is still quite variable. In Bruce and Perth counties planting progress is at about 20% where they have received persistent rainfalls and are on heavier soils.  In Waterloo, Wellington, Brant, Dufferin and Peel planting progress is at about 90%. Perth is variable and Huron is 80% or more. It was noted that in this part of the province planting progress has been quite good compared to southern Ontario and Quebec.
  • Corn emergence has been excellent. There have been some reports of corn leafing out underground (5% of plants) that went into good soil conditions but overall are not requiring replants.
  • There have been discussions amongst growers on dropping corn population as planting is delayed. It was suggested that if any change to population was made,  to only slightly drop the population (1000 plants per acre). The final population should not be under 30,000 plants per acre.
  • There have been some calls about switching out corn to soybeans but for the most part growers in this area are sticking with their original plans until May 25th. Further south in less livestock dominated areas there is more discussion about switching corn to beans.
  • Nitrate testing is expected to begin soon and levels are expected to be good given the warm soils.
  • Soybean planting progress is at about 20-30% and is emerging nicely. The ground has been fit with little or no crusting reported so far to hinder emergence. If soybeans are planted by the end of this week very little yield has been lost. As planting is delayed beyond this week, yield potential starts to go down.
  • As planting is delayed for soybeans, populations should increase as the vegetative window is not as long. This reduces the number of nodes per plant.  Increasing the plant population helps to increase the number of nodes per acre in the field. Populations should be bumped up by 10% once it is June 1st.
  • As planting date is delayed, soybeans do not respond to starter fertilizer applications as much, but overall it largely depends on the soil test levels. In fields with adequate soil test levels, a recent U of G high yield experiment showed there was only a 1 bu/ac response to 500 lbs/ac of starter fertilizer (included nitrogen, phosphorus (P), potassium (K), sulphur (S), boron (B), magnesium, zinc, etc.) if the soil tests were adequate for these nutrients.  If the soil test levels are low, there is a 5-7 bu/ac response to P and K with very little response to B and S on loamy or clay soils. Sandy soils are more responsive to S.
  • Phosphorus is 5 times more available at 20 degrees than at 5 degrees Celsius. As temperatures increase, it is less likely to see a response from starter.  Soybean response to starter fertilizer is still largely dependent on soil test levels.  Low soil tests are much more likely to respond.
  • On higher yielding soybeans there is a 1-2 bu/ac response to spring time fertilizer application but it is tough to sell when planting date is delayed. A s l test is still the best predictor of yield response.
  • There are a lot of growers looking for dry beans and a lot that have never grown them before.
  • Winter wheat continues to be about 10 days ahead of normal in some areas and 7 days ahead of normal in areas further north in the region. For the most part wheat continues to look excellent. Some fields are showing signs of sulphur deficiency where none was applied or lower rates were used.
  • Stripe rust appeared in southern Ontario last week. Lots of growers are making T3 fungicide applications in that area and should be protected against stripe rust.
  • If it is showing up in fields that are still more than 4-5 days away from T3 fungicide application timing and the variety is susceptible a fungicide application should be made as soon as possible. If beyond GS 45 or early boot stages, avoid fungicides with Strobilurin. Growers should check with their seed supplier and the Ontario Cereal Crops Committee performance trials for specific variety ratings ( You can find the stripe rust ratings under the head to head feature or check out the 2016 and 2017 historical reports.  Newer Pioneer variety ratings can be found here and C&M’s variety ratings can be found here.
  • Stripe rust is acting very similar to previous years. It can cycle in 5 days when warm and under cool conditions can be closer to 2 weeks.
  • Growers are encouraged to look for little yellow patches in fields. Once it goes through its life cycle it will sporulate and spread further into the field. Scout fields every 5 days and avoid walking through the entire field after walking through patches of rust.
  • Yield losses from stripe rust can occur without seeing it sporulate on the leaf. Yield losses can be as high as 70% if left untreated.
  • As fungicide applications are underway in wheat it is important to ensure the sprayer is being cleaned out properly before spraying wheat. There have been reports of Valtera injury in wheat. It can be sticky in the tank and is important to use ammonia to clean the tank and take Valtera out. More information on cleaning your sprayer can be found here.
  • T3 fungicide applications are highly recommended, particularly on a year like this when disease levels are high and conditions are conducive for Fusarium Head Blight (FHB). From a DON perspective the data is saying that slightly later in the T3 application window is better than too early from an FHB and DON perspective. The newer T3 fungicides are more forgiving on the later end allowing growers to sightly delay applications to allow for those later heads to emerge.
  • In addition to timing, wind speed matters as well as droplet size. A coarse droplet is needed to paint the head. The forward-backwards nozzles are not effective is using medium droplets. The boom should also be 10 inches off the crop canopy. If it is raised to 20 inches off the canopy, you will not get good head coverage.
  • Fields that did not receive a fall herbicide application or applied a herbicide late this fall are seeing heavy chickweed and dandelion pressure.
  • Winter triticale and rye harvest is underway. Yields to date have been reported as being excellent. Quality in winter triticale has been good but quality in rye is expected to be poorer as it was harvested late.
  • Herbicide burndowns went on in decent time for the most part and have had good activity. Many are seeing more annual bluegrass or roughstalk bluegrass that already had burndown on. Down in Essex there tends to be more annual bluegrass and around Elora and north there is more roughstalk bluegrass with everything in between being a combination of both.
  • Fleabane is starting to bolt in fields that received a late herbicide and are intended for IP soybeans. There are limited options for fleabane control in those fields.
  • Winter canola looks excellent and has awesome potential for a 4th crop in the rotation. The early order deadline for seed is June 15th. Planting date is the last week of August and first week of September.


  • Questions are starting to come in regarding what happens if a crop is not planted. The crop deadlines are June 30th for soybeans and June 15th for corn. It is expected that significant progress will be made by those dates.
  • The deadline for reporting unseeded acreage is June 15th.
  • No significant damage on fall seeded crops. There are some replants for winter wheat, canola, sugar beets and peas.
Winchester Breakfast Meeting
  • Rainfall extremely variable – further north received 30+mm, while areas along the St Lawrence and south of Winchester received less than 5mm.
  • Reports of powdery mildew in winter wheat – fungicide timing will be critical to help control this.
  • Winter wheat is almost at flag leaf stage.
  • Corn is 60-70% planted, with some growers closer to 30% and some growers are 100% done corn.
  • The furthest staged corn is approaching 4 leaf tip, with the majority of the emerged acres being 2-3 leaf tip.
  • It is estimated approximately 30% of soybeans are planted to date.
  • As we progress through May, it is recommended that plant populations get increased by 10%.
  • There are some soybeans emerged in the area, and concerns for crusting to date are low. There are some concerns for crusting going forward if the forecast stays hot and dry, but for now, it is a low-priority concern.
  • Herbicide applications are not behind, but growers are opting to continue planting over switching to the sprayer.
  • Herbicide timing on corn is going to be variable – with some acres approaching 4 leaf tip it is reaching herbicide timing, however, the acres that are just planted or being planted are going to be over a week behind for herbicide application timing. Individual field management will be something to be diligent about with products and label rates in how they relate to corn staging.
  • There are low concerns on availability for herbicide and insecticide products from suppliers at this time.
Simcoe Breakfast Meeting – May 22, 2024

The spring season, so far, is the best in memory for the heavy-textured soils in Haldimand and Niagara. Farmers have generally waited for soil conditions to be fit and have waited the 1-3 days extra days.  In many fields soil conditions in the top 2 inches is ideal for planting, but wet soils below limit equipment carrying capacity.  June planting is not uncommon, so this seems relatively early. As of May 21, about 45-50% of corn is planted on the clays and on lighter soils corn is about 80-90% planted and beans about 50-60%.  Without any additional rain, most of the crop could be planted by the weekend.

Stripe rust has been identified on wheat north of London (in addition to already being identified in Essex, Kent, and Elgin counties). So far, the disease is limited to a small pocket of the field, but can spread quickly, especially with the recent foggy, humid mornings, ideal for disease transmission.

The risk of scouting fields with disease brought up the issue of biosecurity and taking measures to prevent the spread of easily transmissible diseases.

Many fields in the area are at heading and are close to T3 application timing to prevent FHB. Wheat southeast of London that was planted Oct 1 is at GS 59 (75% of field has heads fully emerged), while wheat planted Oct 5 is at GS 57 (¾ of the head emerged above the flag leaf ligule). With disease pressure this year there is lots of priority to get T3 applied, but with busy planting window it is easy to miss. Avoid applying any fungicides from the strobilurin class of fungicides as these have been shown to increase DON levels in winter wheat when applied at the T3 timing.

Winter barley has headed and there is some lodging.

With a compressed spring season where planting, fungicide application and weed control are happening simultaneously, there are a lot of green fields (weeds not crops). Fleabane is getting big and dandelions are growing fast and becoming a problem. Some weeds are beyond the label directions. Will need to look to tank mixes and higher water volume to hit big weeds. Scouting is critical along with being able to identify weeds and stage them correctly.  The critical weed-free stage is important, therefore, applicators must know which products and at what stage. For fields that have not been planted yet, burn-downs with residuals will give better control options. And, for fields going into soybeans, do not forget to ask about trait information.

Blue grass is everywhere – London to the Peninsula and getting worse. Blue grass was big when people went to spray and the products used in cereals are not the best on bluegrass and now, if sprayed too late will provide suppression only.

On the heavy textured soils – Niagara /Haldimand, intended acres of corn are about 50% planted. Soils are in better shape than many years partly because there have not been pounding rains. However, soils are not drying quickly this year. Some growers are taking corn acres out of the rotation due to profit opportunity – high input costs, low corn prices and lower yield potential.

Surprisingly, a lot of growers are staying with the intended rotation. Not much talk yet about switching acres to soybeans and almost no wheat replants this year. June planting is not uncommon, so this year planting seems relatively early. If the weather stays dry there is a lot of planter capacity and most corn and soybean planting could be completed by the weekend.

Forage harvest has started. Fields are in early-mid bud and many have high alfalfa weevil pressure. Cereal forages (rye, triticale) have headed and if cut now will have greater volume but reduced quality.

Many fields will be getting manure applied after forage harvest. Some will plant corn and apply manure between planting and side-dress, since the opportunities for applying manure have been limited and growers have been more aware of compaction issues.

It is important to have manure tested for nutrients.  A grower that applied high rate of hog manure wondered how long planting needed to be delayed after application. With finisher hog manure salt content is often very high and if planting immediately after application the corn will suffer from salt injury (ammonia burn) and reduced plant stand.  Incorporation of manure helps, but for salt to dissipate into the soil, it is suggested to wait about 3 days after application unless soils are bone-dry in which case the wait should be extended.


This year is boiling up to be a good year with record low wheat calls. Specialty crops are all good and with night temperatures forecast to be above 10 degrees Celsius for the next 2 weeks everything currently looks promising. Tobacco acres are up significantly.

Weather Summary for Thursday May 16 to Wednesday May 22, 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)22.49.517.8159.8536278331
10 YR Norm (11-20)
10 YR Norm (11-20)21.37.615.7137.8461209263
10 YR Norm (11-20)22.77.815.3143.2476225295
10 YR Norm (11-20)22.46.914.5158.6481229293
10 YR Norm (11-20)
10 YR Norm (11-20)21.44.918.6151.0399161236
10 YR Norm (11-20)21.35.515.4135.4388157233
10 YR Norm (11-20)21.54.315.3133.1376147230
10 YR Norm (11-20)
10 YR Norm (11-20)22.75.312.3145.8438200276
10 YR Norm (11-20)21.83.614.0134.3292114194
10 YR Norm (11-20)
10 YR Norm (11-20)19.51.520.8133.025679150
10 YR Norm (11-20)19.3-0.226.799.623668158
10 YR Norm (11-20)