Crop growth and conditions continue to be variable across the province. While crops look good in areas that were able to be planted either early or as per normal and into decent soil conditions, other areas have been delayed significantly by continued rainfall. Understandably, this has been a difficult time for those growers. There is optimism that most of the unseeded acreage will be planted this week with above normal air temperatures to speed up the drying of soil.  


Crop growth and conditions continue to be variable across the province. While the earliest planted corn is approaching canopy closure, there is significant acreage that was planted this week. Side-dressing of nitrogen is being done to corn planted on the earlier side. Soil applied herbicide programs have largely worked well but may be coming to the end of their residual effectiveness, and there may be a new flush of seedling weeds. Timely control of these new flushes is important, especially with difficult to control species like waterhemp (Figure 1). 

Figure 1. Seedling waterhemp at the 2 to10 leaf stage in 6 leaf corn. Control must be prioritized since herbicide effectiveness will be reduced as this weed gets bigger.  


Planting has continued this week in areas where soil conditions have prevented earlier planting. Re-planting has also occurred where soil crusting has prevented good emergence. Seedcorn maggot and slug feeding are also prevalent this year. Soybeans have an impressive ability to compensate for thin stands under good growing conditions. Soybean plants can fill spaces up to 30 cm (12 inches) within or between rows with relatively little yield reduction. Research has shown that a final stand of 90 000 plants per acre in 7.5 inch rows provide a yield potential of 90%. Field experience has shown that more plants per acre are needed on clay soils. A minimum stand of about 110 000 plants/acre on heavy clay soils is required to achieve good yields. When thickening a poor stand, use the same variety. Soybeans that were planted during the first part of May are approaching canopy closure and are beyond the 3rd to 4th trifoliate stage of growth. 

Dry beans 

Most of the dry bean acreage has been planted. Emergence has been variable, and poorer than normal due to soil crusting in some areas.


The broad use of T3 fungicides across the province has appeared to slow the stripe rust threat. Fusarium head blight is visible in some fields but for the most part remains at low levels. Growers are encouraged to continue scouting their fields leading up to harvest for signs of Fusarium Head Blight (FHB) infection. With previous rainfall events and storms late this week, some fields have lodged, but still remains minor. Again, doing field preharvest evaluations for FHB, lodging, etc is important to prioritize harvesting order. 

Winter wheat continues to be further advanced than normal with harvest expected to start within the next 10 days in the southwest. Despite the recent warm temperatures, yield potential looks excellent. Winter barley has also matured more quickly than normal, and harvest has begun in the southwest.  Lodging has been observed in areas affected by the mid—week storm front. 

Spring cereals are also looking good with many fields just reaching the heading stages.    

Figure 2. Winter wheat variety trial at C & M Seeds, Palmerston, Ontario. June 17, 2024.

Winter canola

Harvest is imminent with desiccation just beginning in parts of southern Ontario. This may offer an opportunity to double crop soybeans in those areas. 

Weed control 

Big weeds continue to be the story of the 2024 season. With a mild winter, many winter annual and perennial weeds were more advanced than normal at the beginning of the spring. An advanced growth stage to start the spring, coupled with weather conditions that prevented prompt spraying, has resulted in poor control. All that one can do to minimize the impact of such big weeds is to apply the highest labelled rate of the selected herbicide, ensure good coverage of the weed by increasing water carrier volumes (especially with contact herbicides) and if possible, avoid early morning or late evening applications when ambient air temperatures and the leaf orientation of the weeds are less conducive to herbicide uptake. Moving forward, weed management programs that combine tillage, cover crops (cereal rye), residual herbicides and fall weed management, often have fewer of large winter annual and perennial weeds.  

Herbicides that have the active ingredient “dicamba” cannot be applied when air temperatures exceed 30 degrees Celsius during application as it increases the risk of off-target drift by volatilization.  

The risk of crop injury increases when herbicides are applied to IP (Identity Preserved), non-GMO soybeans or dry beans during “hot” conditions (above 30 C) that have occurred over the past week. The decision to wait for less stressful conditions for applying herbicides or to accept some increased risk of crop injury but target smaller, more susceptible weeds can be a difficult to make in the moment. In general, it is often better to prioritize weed control at the sacrifice of crop injury.  It is best to consult the herbicide manufacturer for product specific guidance when such decisions must be made.  


Upcoming deadlines:  

For Production Insurance coverage, crop planting deadline is June 30th for soybeans. The unseeded acreage coverage provides one-third of a farm’s average farm yield if a crop is not planted by the planting deadline.

The deadline for reporting actual acres of spring-seeded grains and oilseeds or new forages is June 30th. Growers are encouraged to report acres as soon as possible to avoid busy times at the deadline. Reporting can be done online or by calling the Guelph office (+1 888-247-4999).

Upcoming Events:

July 3rd & 4th – Southwest Diagnostic Days, Ridgetown Campus, University of Guelph. Register before June 25th here. 

July 4th – Forage Expo West, Gorrie, ON. No pre-registration required. Find more information here  

July 11th – Weeds Tour, Elora Research Station. Register here before July 4th.  

July 10th & 11th – Eastern Ontario Crop Diagnostic Days, Winchester Research Station. Register before July 2nd here 

July 12th – Forage Expo East, St. Isidore. No pre-registration is required. Find more information here.  

July 25th – 27th – Northwest International Ag Expo, Emo, ON. Find more info & register here. 

August 27th – Soil Health Day, Sunderland Co-op Oakwood. Registration is available here

Upcoming agricultural events across the province can be found on OMAFA’s Dateline calendar

Weather Summary for Thursday June 13 to Wednesday June 19, 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)27.312.014.4237.110766781002
10 YR Norm (11-20)26.710.617.9209.6999604923
10 YR Norm (11-20)25.710.421.5219.9956564862
10 YR Norm (11-20)26.810.413.5225.5982592910
10 YR Norm (11-20)26.610.99.6229.9982590903
10 YR Norm (11-20)24.79.520.6197.6868486774
10 YR Norm (11-20)
10 YR Norm (11-20)25.18.618.7212.2849478782
10 YR Norm (11-20)
10 YR Norm (11-20)26.77.310.9218.0876497799
10 YR Norm (11-20)
10 YR Norm (11-20)24.67.610.1197.2732414708
10 YR Norm (11-20)24.16.410.4179.8666370654
10 YR Norm (11-20)
10 YR Norm (11-20)23.46.423.8188.1604297553
10 YR Norm (11-20)23.69.627.7191.2702376673
Weather Summary compiled by OMAFRA using Environment Canada weather station data provided by Agriculture and Agri-Food Canada. Data quality is verified but accuracy is not guaranteed and should be used for general information purposes only.  

Ag Breakfast Meeting Minutes 

Exeter – Tuesday, June 18

  • Overall, crops in this area look good (Huron and Perth) but there are corn fields showing the symptoms of being planted into wet soils (patchy, tile run, nutrient deficiency, uneven growth, sidewall compaction, etc.).
  • Frequent rains have helped these crops along so far. 
  • Early planted soybeans are in the 4th trifoliate leaf stage. There is replanting underway due to crusting, seed corn maggot and slug feeding.  Still lots of soybeans being planting for the first time in Lambton, Dufferin, Halton, etc. 
  • Considerable acreage still needs to be seeded.  Hopefully these growers will get a chance this week. 
  • Winter wheat is about 10 days ahead of normal so there is lots of interest in double cropping this year.  There is no crop insurance coverage for double cropped soybeans.   
  • The crop insurance deadline for reporting is June 30th. Make sure you know what your coverage is. 
  • This is an insect and disease year.  
  • Some hail damage reported north of Stratford with some replanting. 
  • Pre-emergent herbicides are working well this year. Lots of herbicides being applied this week. Pre-emergent herbicides are just starting to break now. 
  • Not many re-sprays have been needed this year. 
  • Do not add any additional surfactants with all this heat. Weeds have not hardened off. 
  • Enlist soybeans still requires a two pass approach. Due to the weather, too many fields are relying on a single post-emergent application this year.  
  • Use only the Choline formulation of 2,4-D on Enlist soybeans – not the Ester formulation. 
  • 2 effective modes of action have worked well on Canada fleabane control this year. 
  • Crop injury from herbicides is being reported this year. Bleaching on corn from Group 27, leaning/floppy corn syndrome from group 4 herbicides.  
  • Nitrate levels: Chris Roelands, Honeyland Ag Services, is finding lower than expected nitrate levels from organic additions last fall (manure, clover). This is surprising but suggests keeping normal N rate applications (or do a test).  
  • Stabilize top-dressed urea. Recent data from Dr. Joshua Nasielski, University of Guelph, from a 3-year study at Ridgetown, Elora, and Winchester, showed much higher loss risk of top-dressed urea than Y dropped 28%. Across site years (including US sites) average loss urea surface applied 40 lbs/ac, urea surface with inhibitor 14 lbs/ac, UAN surface 10 lbs/ac, UAN plus inhibitor surface 7 lbs/ac, UAN injected 3 lbs/ac loss.  So, stabilize any top-dressed urea! 
  • Injury reported from 28% streamed on corn. Get it between the rows. 
  • Reports continue of army worm in wheat, even in Exeter area.  
  • High temperatures do have an impact on cereals: critical period is 10 days prior to 14 days post anthesis. We are past that stage. However, we are currently accumulating 25+ GDD/day. The previous weather pattern was about 15 GDD/day. We will shorten grain fill, UK research suggests yield reduction of about 3 bu/ac/day of lost grain fill.

Simcoe – Wednesday, June 19


  • In general crops are growing well and responding to heat.   
  • Insect pressure is higher than average with more seedcorn maggot, cabbage maggot, slugs, leafhopper, and thrips in field and vegetable crops.   
  • Slug damage is higher than most years, especially on lighter soils and fields with less or no tillage.   
  • A few fields have been replanted more than once due to slugs.   There has been some slug baiting with mixed results where pressure is extremely high. 
  • Thunderstorms brought variable amounts of rain to some areas and none to most of the region.   


  • Stripe rust was evident across the region, but most fields did get a T3 application.  
  • There is also some evidence of fusarium, however the current heat wave will help reduce its progression. 


  • Areas that received a lot of rain are showing yellow corn due to roots sitting in wet soils.   
  • Not all yellow corn is due to nitrogen shortage. There is also magnesium deficiency, however warmer weather will help crops grow out of some deficiencies.   
  • Nitrogen side-dressing is occurring with 50-75% doing by injecting 28%.  Y-drop seems to be more popular on larger farms.  PSNT tests have been coming back with lower-than-normal soil nitrogen levels – mostly due to continued wet soils a few inches below the surface. 
  • Diseases have been early this year.  Tar spot could show up in the next couple of weeks and with a wide variation in crop planting dates, will result in a wide range of tasseling/silking dates for fungicide applications if necessary, especially in later planted corn where disease could have a bigger yield impact.  


  • Replant decisions are difficult in many soybean fields.   
  • Where stands are thin, they will range from 0 to 40,000 plants/ac in some areas of the field and 70,000 – 90,000 plants/ac in other areas.   
  • Replant decisions are difficult when stands in most of the field range between 60,000 – 70,000 plants/ac. Uniformity of the plant stand will factor into decisions.   
  • Lower populations may be more acceptable in fields where wheat seeding is planned for fall.   
  • Vigor of the stand will also factor into replant decisions, depending on how long the soybeans have been struggling in tough soils.  
  •  Just because the plant is there doesn’t mean it has yield potential. It is important to ensure the viability of these plants.


  • Most dairy farms have completed 1st cut. Potato leafhopper pressure is high enough that some fields are being sprayed where 2nd cut is still several weeks away. 

Horticulture crops

  • Horticulture crops are growing well for the most part and are 1-2 weeks ahead of normal. 
  • Vegetable growers prefer dry seasons where moisture can be controlled with irrigation.  Asparagus is nearing completion.   
  • Sweet corn harvest will begin in early July.   
  • Farms growing cucumbers are on their 2nd planting.   
  • Strawberry harvest has been good to date, but current heat may impact yields.  Yields have also been affected in fields that have experienced continued rains.   
  • Thrips in onion fields have never been this early and could get worse with heat. 
  • Tobacco side dress is a week earlier than normal.   
  • Phytophthora   is being found earlier than expected in ginseng fields. 

Weed Control: 

  • With 25% of acres with enlist soybeans it is important to check and double check to ensure the right products are used for weed control.   
  • Generally, fields are way too weedy to be controlling weeds on June 20th.    
  • There needs to be more herbicides with residual activity in rotations. There seems to be too much reliance on post options.   
  • As early applied residuals start to lose effectiveness, it is important to scout for resistant weeds such as water hemp.   
  • If resistant weeds are found, there is a need for farmers/industry to be upfront and share information/problems. 
  • With the prevalence of sensitive horticulture crops in much of the region, caution with spraying of some of the post herbicide options is advised. High temperatures are problematic for both the efficacy and crop safety of some of these products. 

Kemptville – Wednesday, June 19


  • Kemptville reporting 250 mm of rain since April 1.
  • Some ponding, some claims for excessive moisture.  
  • Some later planted corn not looking as good. 

Winter Wheat 

  • Wheat is done flowering, and majority has reached milk stage. 
  • A little bit of disease but nothing overall concerning.  
  • Quebec has a Fusarium Head Blight predictive model that can be useful. 

Spring Cereals 

  • In Renfrew and St. Isidore area, the spring wheat has headed out. Early no till spring wheat may flower next week. 
  • Other spring cereals at flag leaf stage. 
  • Most fungicide in spring cereals applied at T3 (heading). 


  • Some corn samples brought in showing difference between no fertilizer corn and no herbicide, significant differences. 
  • Eastern Ontario 20% ahead of other parts of the province, crop development. 
  • Corn being switched for soybeans in Western Ontario, London, Chatham area and going to shorter beans. 
  • Sidewall compaction in corn in some areas. 
  • Row crop cultivation has an impact on yield, breaking up the soil in between the rows – some growers are looking into this for crusting concerns.  


  • Replanting reported in Eastern Ontario, mostly caused by crusting or soybeans sitting in water. 
  • Soybeans are advancing quicker than other years. Most fields have lots of rain after planting. We have had lots of heat and moisture.
  • Some weedy soybean fields, it has been hard to spray because of weather. 
  • Biological trial being done at University of Guelph, Ontario Crops Research Centre – Winchester.  It will be a stop at Diagnostic Day July 10-11, 2024.


  • Quantity is good. 
  • There are no symptoms yet but there are a high numbers of leafhoppers found in lots of fields. Many fields nearing threshold are with in 7 to 10 days of being cut, or are right at threshold.