Crop Conditions – Week of May 15th, 2023

Dandelion Application Timing Chart


Field conditions across the province have improved vastly over the last ten days. With sunshine and temperatures in the high teens to even high twenties in some areas, planting is rolling across a majority of the province. Field work began early last week with lighter soil but by late last week, work on heavier, clay soils was beginning.

Frost is expected this week in some regions of the province, so monitoring will be key. Corn not likely a concern but soybeans will need to be checked after frost if emerged. Lighter soil types tend to be more prone to frost damage. Frost temperature on wheat -2C° at boot stage for longer than 2 hours (lower stem, leaf damage), but it is dependent on crop health, temperature, and length of frost. Likely just leaf tip injury but be sure to give a few days after frost to determine impact.


Winter cereals continue to impress and develop quickly across the province aided by the prolonged warm temperatures. Wheat development in Essex County is 90 GDD ahead and is now heading, with the majority in the southwest at flag leaf. Overall, foliar leaf disease pressure is very low, although powdery mildew is appearing in some very susceptible varieties. T3 fungicide application for FHB is to occur as we reach heading across the province.

Eastern parts of the province are reporting lots of applications of fungicide and PGRs in the last week, with wheat between growth stages 32-34. Spring cereals are emerging well across the province. Stands are thin in areas from either geese damage or where water pooled after the heavy rains at the beginning of the month.


Corn planting is full speed ahead across the province, with many acres being planted over the weekend. Conditions are good and planting is going smoothly. Some of the earliest planted corn has begun to emerge in various regions. Most of it is still at spike leaf. The very southern parts of Ontario estimate there is 70-80% planted as of mid-week, with a hope to have corn planting complete by the weekend.


Early planted beans are emerging, with acres planted varying across Ontario. Eastern and central regions are suggesting anywhere from 0% – 40% of bean acres are seeded, with the southwest reporting double that (upwards of 75-80%). Pre-emerge herbicides are being applied to soybean acres this week as field conditions are appropriate. Weed pressures increased dramatically across the province with rain and warm weather. Herbicide application timing will be critical in the coming days, particularly with no-till acres.


Triticale and rye harvests are progressing in the southwest but have not yet begun in the east & central regions. Harvests are still at least a week away in many areas of the province. First cut of grass hay or alfalfa has not begun yet. Some frost damage is being reported on orchardgrass this week, and with more frost in the forecast, some further damage should be expected.

Weed Control

“Small weeds are easier to kill than big weeds” (Dr. Peter Sikkema). Dandelion’s are large and pressure high across the province which can require higher rates of glyphosate to control larger dandelions:
            For dandelions- 4” – 0.67L/ac glyphosate
                                    6” – 1L/ac glyphosate
                                    8” – 1.33L/ac glyphosate

In preparation for future years controls, dandelions can be applied at the same rate in the fall with better control than spring applications. See charts below.

Dandelion Application Timing Chart

Winter Canola

Winter canola has flowered across the province and stands that survived the winter are looking strong. Flowers are sensitive to cold temperatures, and recent frost events may have caused some damage, but serious economic losses are unlikely as temperatures didn’t drop significantly below freezing. Check out this article for photos displaying the Impact of Late Spring Frost on Winter Canola – Field Crop News. Monitoring for cabbage seedpod weevil has begun across the province. More fields across the province have received white mold fungicide applications. Applications should be targeted between 20-50% flowering.

Weather DataMay 8 –14, 2023

LocationYearHighest Temp (°C)Lowest Temp (°C)Rain (mm)Rain (mm) April 1stGDD 0C April 1stGDD 5C April 1stCHU May 1st
10 YR Avg. (2011-20)19.66.820.521405187186
10 YR Avg. (2011-20)
10 YR Avg. (2011-20)19.95.514.615354145166
10 YR Avg. (2011-20)20.45.625.526358148163
10 YR Avg. (2011-20)18.73.317.31728993127
Mount Forest202325.42.50.00358178125
10 YR Avg. (2011-20)18.33.914.31427890127
10 YR Avg. (2011-20)18.92.917.217301104143
10 YR Avg. (2011-20)19.14.517.918318123150
10 YR Avg. (2011-20)16.90.512.51315947101
10 YR Avg. (2011-20)17.41.818.1181905597
Thunder Bay202327.5-0.31.111927093
10 YR Avg. (2011-20)15.6-0.911.6121522879
Fort Frances202325.23.237.337243114160
10 YR Avg. (2011-20)17.6-0.415.3151864496
Report compiled by OMAFRA using Environment Canada data. Data quality is verified but accuracy is not guaranteed. Report supplied for general information purposes only. An expanded report is available at

Breakfast Meeting Minutes

Ridgetown Ag Breakfast Meeting – May 16th, 2023


  • Planting wrapping up
    • Excellent conditions for planting, but will be looking for moisture soon
    • 70-80% in now, 99% done by weekend
    • Clay ground now being planted after waiting for drier conditions
  • 188 CHU vs 204 last year as of May 1
  • Early planted corn – up now, looks healthy but slow to emerge


  • Planting
    • 70-80% to be in by weekend
    • Clay ground – just getting started at
  • Early planted soybeans – some crusting occurring as beans are emerging after a few weeks


  • Some wheat in Essex in head, most at flag leaf stage
  • 90 GDD ahead of normal
  • Some sulphur deficiency showing up more than usual
    • Cool weather early in season leads to less S mineralization
    • Some stripping in fields evident, even where spread with airflow
  • PGR should be wrapped up, can go up to GS 39, but best management has it on by GS 37
    • Shorter than normal crop, may lead to less lodging, although stem counts are very high in some cases
  • Disease has been fairly low, some powdery mildew in susceptible varieties
  • Winter barley – short stature
    • Some awns are kinked in head
  • Some lodging occurring in fields with manure
  • Thin leaf cuticles have led to some leaf burn, but very variable


  • Triticale/rye harvest ongoing
  • Keep an eye on timing for best feed quality


  • No supply issues, but extremely busy week may have lead to some logistical issues as far as timeliness getting to farm


  • Frost forecast for Wed night
    • Potential for damage to horticulture crops especially
      • Fruit tree crops – especially apples
      • Tomato planting has been stopped with at least one processor
    • -2C at boot stage in wheat for 2 hours + can cause injury
  • Soils drying out, need some moisture by weekend

Weed control

  • Weed size has increased rapidly with warm weather
    • Small weeds are easier to kill
  • Dandelions are out in full force this spring
    • Control with glyphosate depends on weed size
      • 4” – 0.67L/ac
      • 6” – 1 L/ac
      • 8” – 1.33 L/ac
      • Classic in soybean very nice addition
    • Residual weed control may be limited by dry soils
    • Scouting critical in early season
    • Glyphosate – slow acting with cool temps, faster with warmer temps


  • Lots being applied now
  • Conditions have been good for incorporation right after
  • Important to have manure sampled for nutrient value
    • pH needs to be included as well
      • High pH – more ammonia loss with pH over 7.5, especially in sunny conditions

Agricorp update

  • Damage reported in 2023 Winter Wheat for Southwest Region, South Central (Simcoe) and Niagara Region:
    • Number of Customers Reporting Damage for 2023 Winter Wheat: 77
    • Number of Acres Affected: 6,035 acres
    • Damaged Acres as a % of Total Insured Acres for the 3 Regions: 1.81%
  • Please note that a damage report does not always result in a claim payment.

Cobourg Ag Breakfast Meeting – May 16th, 2023

  • Ideal conditions for field work this past week means that planting is progressing rapidly across the region.
  • Frost injury has been reported on orchardgrass, but rapid grass growth rates mean this is not a serious issue.
  • Winter wheat is expected to reach flag leaf in many fields this week.
  • Estimates are that about 50% of corn acres have been planted in the region, but this varies widely by location.
  • Soybeans are 30-40% complete.
  • Cutworm moths have been found in larger numbers than usual.

Mount Forest Ag Breakfast Meeting – May 17th, 2023


  • Most soil conditions are good, if not optimal. Some complaints of less than ideal seedbeds in the Elmvale area, due to the ground not working up well.
  • Reports of soil erosion in fields in Bruce, Huron and Perth counties – rill and sheet erosion is primary
  • Some areas looking for a bit of rain as soil is starting to get dry.


  • It’s estimated most of the corn acres in the area will be wrapped up by late this week or over the weekend. Some corn at Cookstown is emerged within two weeks of planting.
  • Many growers waited an extra day for conditions to be ideal, so corn was planted into proper seed beds.


  • Many growers planting soybeans this week.
  • IP acres are being planted and pre-emerge herbicides are down on plenty of IP acres
  • Most growers waiting for the cold weather mid-week to pass before really starting into the soybeans.


  • Winter wheat continues to look phenomenal
  • Some reports of rye grass pressure in wheat stands
  • Lots of herbicide and fungicide applications on Winter cereals in the last week. No concerns with injury because of warmer temperatures
  • Some flag leaf in Guelph area and south, but not all at flag yet
  • Acres with PGR applications up from last year

Weed Control

  • Concerns about lack of rain in the forecast and soil applied herbicides – rain is needed to activate many of them.
  • Efficacy of soil applied herbicides with 1” of rain within 7 days is often upwards of 95%
  • Herbicides that are applied are working but slowly.
  • Lots of dandelion pressure across the region. Not many perfect options for spring dandelion control when they’re large. Fall control on them is optimal
  • Some reports of alfalfa pressures in corn – Lontrel is a good option.


  • Lots of potatoes in the ground – over 50% completed.
  • Planting in the Holland Marsh is well underway

Lots of orchards working this week.