The province experienced weather extremes. Southern Ontario saw warmer conditions that supported corn and soybean growth and helped dry fields still awaiting planting. However, wind and scattered rain complicated weed control efforts. In the Northeast and Northwest Ontario, temperatures neared 0°C, raising concerns about frost damage to emerged soybeans and white beans. Field assessments are ongoing.

Field Corn

In general, corn stands across the province have been good. Crop staging varies significantly across the province. A majority of the crop is in the V3-V5 stage (5-8 leaf tip), while the earliest planted corn will be at or beyond V6 (10 leaf tip) and close to canopy closure. Most of the corn crop is in the critical weed-free period (V1 to V10 or 3-12 leaf tips), making weed management a top priority. Side dressing is underway where crop staging, and soil conditions allow.

Tar Spot is expected to be an issue again this season and may be found in new areas in Ontario. The disease was detected in Northern Indiana last week in early planted corn, which timing is consistent with 2024, although incidence levels are lower than in 2024. There were other Tar Spot confirmations last week in Iowa, Illinois, Kansas, and Missouri (refer to: CPN Tar Spot Map). Early plant corn fields with a history of Tar Spot should be scouted first. Since 2021, Tar Spot detection in Ontario has occurred during the first 2 weeks of July in the southwest. A new risk prediction tool can be found at https://cropprotectionnetwork.org/crop-disease-forecasting. This tool replaces the former Tarspotter App and provides weather-based forecasting and risk assessments for various crop diseases (including Tar Spot, Northern corn leaf blight (NCLB)), helping farmers, crop advisors, and agricultural researchers to make data-driven decisions. If not equipped to spray corn at tasseling, it is best to contact your local crop protection retailer or custom applicator to inquire about their capacity and to secure a spot. This will ensure that if the risk of Tar Spot disease is high, you are able to preventatively manage it.

Soybeans

Most of the acreage has been planted. Of the remaining unplanted acreage, progress has been made in areas where there wasn’t any appreciable precipitation over the past week, while other areas receiving rainfall have been delayed further. While there are plenty of examples of good soybean stands, deep planting into cool soils combined with crusting, heavy crop residue, and seed corn maggot have caused poor stands that had to be replanted. April planted soybeans are close to flowering and in the fourth to fifth trifoliate stage, while soybeans planted around the middle of May are in the second to third trifoliate stage.

Cereals

Most of the winter wheat is past the optimum stage for fusarium head blight protection. It is estimated that most acres received a T3 fungicide application for fusarium head blight. This will also provide around 14 days of protection against stripe rust. It is predicted that stripe rust could become more prevalent across the province. Looking towards next season, growers are advised to consider choosing varieties that are less susceptible to stripe rust, and budget for a fungicide application to preventively manage this disease. More details are available on FieldCropNews.com: https://fieldcropnews.com/2024/05/effectively-managing-stripe-rust/

Cereal leaf beetle and aphid populations have been high in some fields. While they cannot be managed in winter wheat at this point (due to insecticide preharvest intervals), they will begin to move into spring cereals and should be monitored so action can be taken if they reach threshold prior to heading.

Edible beans

Most of the dry bean acreage has been planted. The majority of fields look good and are at the unifoliate stage. Some replanting has occurred where planting was done on the early side and into cold soils. Many have commented on seeing “bald beans” emerging. These are beans with no unifoliate leaves or growing point. This is most likely caused by dry, crusted seedbeds, cracked seed coats, or herbicide injury. If there is any kind of growth at the shoot tip, then the plants should recover. Fields should be scouted for weed escapes regularly since any post-emergent herbicides are only effective when they are applied to very small seedling weeds (e.g., 2 to 4 leaves).

Canola

Winter canola seed pods are still green but will begin the ripening process imminently. Some have commented that in fields with thinner stands earlier in the spring, plants have branched out significantly, and the crop looks very good.

Some spring canola fields in northeastern and northwestern Ontario have been sprayed for flea beetles. Once canola reaches the 4-leaf stage, growth should outpace flea beetle feeding if the crop is growing vigorously. There have been a few frost events in the Northeast, but most of the canola has survived.

Forages

In areas that received little to no rainfall over the past week, a lot of cutting and harvesting for dry hay has occurred. There has been a push to put up forage crops ahead of forecasted rain.

As summer thunderstorms roll across the province, growers are reminded to scout alfalfa and alfalfa/grass mixes for potato leafhopper. Leafhoppers blow into Ontario on storm fronts. By the time “hopper burn” or feeding damage from leafhoppers is visible, economically significant damage has already occurred. Action thresholds change with alfalfa height. More details are available on FieldCropNews.com: https://fieldcropnews.com/2025/04/how-do-i-manage-potato-leafhopper-in-alfalfa/

Weed Control

Ryegrass (Lolium spp.) is out in head and easily found at this time of year. It has been found in wheat, corn, and soybean fields. Ryegrass can be a particularly hard species to control as it hybridizes easily, making it very adaptable to its environment. Most specimens tested for glyphosate resistance have been positive. All specimens identified so far have had a perennial life cycle. A combination of tillage (ploughing) to destroy established ryegrass clumps, and effective residual herbicides to prevent new seedling emergence in both the spring and fall will be necessary to make control headway on this species. If you do come across clumps in your field, it is best to dig them out if possible.

Breakfast Meeting Notes 

Exeter Breakfast Meeting Minutes

Cereals

• Most winter wheat fields in the area received a T3 fungicide to protect against fusarium head blight and stripe rust.
• Those that applied a T1 fungicide ran out of protection for stripe rust by the time they got to the field for a T3 fungicide. A lot of T2s or flag leaf fungicide applications were missed because the timing coincided with corn and soybean planting and/or spraying. The weather was also poor at T1 fungicide timing, so many opted not to apply a T1 fungicide.
• According to research out of Australia, yield loss from stripe rust is significantly influenced by varietal susceptibility. Highly susceptible varieties see a yield loss as high as 85%. Moderately resistant varieties see a 25% yield loss. In previous stripe rust years in Ontario, yield loss has been as high as 80% on susceptible varieties that did not receive a fungicide application.
• In fields that were on the early side of a T3 fungicide application (around May 30^th), some stripe rust pustules are being found. If they are not bright in colour, they are dead. The fungicide is going to give control for at least 14 days, and with warmer temperatures, the latency period is now closer to 4 days. If you get 14 to 18 days of control from the fungicide and add 4 more days on due to the latency period before first pustules are found, then you are 18 to 22 days through grain fill, and the benefit of an additional fungicide is not likely there. 
• According to Australian data, if you get beyond mid-heading there is only a 12% yield loss from stripe rust. If the canopy is still green, then it may be worth spraying, but if no leaf tissue is left, then it is not worth it.
• Stripe rust samples have been collected from various fields across the province to determine if the pathogen has changed and adapted to overwinter in Ontario. Varieties that were historically resistant to stripe rust are more susceptible, while varieties that were believed to be susceptible appear to be more resistant.
• In the future, if stripe rust arrives early in Ontario, growers are advised to spray a fungicide to protect against it. Retailers are pushing to get fall herbicides on so they can do a better job of timing their plant growth regulator (PGR) and T1 fungicide applications.
• In forages, stripe rust drops palatability. If growing cereals for forages, a fungicide application should be considered to manage stripe rust, and in oats to manage crown rust.
• A lot of T3s went on when it was windy, and a lot of drift occurred. It is likely that some fields did not get good coverage down into the canopy.
• Cereal leaf beetle and aphid populations have been high in some fields. Those pests will begin to move into spring cereals, so those fields should be monitored closely.

Corn

• Overall, corn stands are good, but weed control has not been perfect. Some herbicide programs have been less effective than anticipated.
• Zinc deficiency has been identified in some fields where zinc was not included in the starter. Other fields have multiple nutrient deficiencies showing up, which is a sign of poor root systems and the plant growing fast. Some varieties will stripe more readily. With the cold weather and overall conditions this spring, zinc uptake is suspected to have been low. Some sandy fields have a very short radicle. It was also noted that any herbicide application 24 hours before or after those cold nights could have dinged the corn and caused some of these symptoms.
• Volunteer alfalfa has been a challenge to control this spring. When there is dry weather for 6 to 8 weeks, fields need to be terminated early. Good weather over the last two falls has also resulted in strong root systems in the alfalfa. Conventional tillage needs to happen at least 3 weeks after a group 4 and glyphosate application to give the herbicide time to work. 
• Those that are planning an aerial fungicide application on corn should get that lined up now, as it will fill up quickly. Tar Spot was found in northern Indiana last week, so we will likely see it move into Michigan and then into Ontario. In 2024, it was found on June 26^th, which means it is likely infecting right now, and the first symptoms will likely be seen in a week or two. Corn is a little behind where it was last year, so infection timing is going to be early. Fields should be assessed and monitored to try and get to the R1-R3 window. The hope is that genetic tolerance can carry fields through to the ideal timing.
• The Tarspotter app is no longer available on the phone but can still be accessed through the University of Wisconsin-Madison and the Pest Management Coalition. If the map shows high pressure, the symptoms may not be in the field, but will show where the pressure is going to be.

Soybeans

• The soil is very hard this year, resulting in poor soybean emergence and thin stands in some fields. Residue impacts have been horrendous, and no-till soybeans are delayed compared to tilled fields. With the large amounts of snow this winter, there was little breakdown of the residue.  Early planted no-till fields have suffered the most from large amounts of residue. Warm temperatures will help those fields tremendously over the next week.
• Some indicated that most of their problem calls have been on sandy or lighter soils. Heavier soils in this area have good stands for the most part. There have been replants on the heavier ground in North Huron and South Bruce. Those areas are extremely dry.
• In fields that have areas with poor stands, careful assessment of the whole field is necessary before deciding to replant. If the impacted areas are less than 10% of the field, they should leave it as replanting those areas will delay maturity and ultimately winter wheat seeding.
• Some fields on sand have herbicide damage and experienced cold soils early in the growing season. Deeper planting of the sandier soils may be part of the reason stands are thin on lighter parts of the field compared to heavier soil types. There have also been seed quality differences, which, combined with the spring, have added to plant stand issues.
• Some fields have bad seedcorn maggot.Normally, there is one flush of seed corn maggot, and then it is done; however, some wondered if there is a second flush this spring. Many are seeing lots of seed corn maggot flies, even over the last few days. Slugs have also been bad.
• Pre-emergent herbicides have been working well. There has been some group 15 herbicide injury, particularly on sandier soils.
• Residual herbicides that have been down for a long time are going to be challenged, as there is no soybean canopy yet.
• With the forecasted rainfall, IP soybean herbicides need to be applied.

Edible beans

• There are some fields of edible beans in various classes with bald beans or beans with no cotyledons. This is likely due to dry seedbed, or the seed coat was cracked. If there is any kind of growth at the tip, they will come out of it. There may be some variability in maturity where this is occurring. Adzukis do not bring their cotyledons up.
• Where there is cotyledon to 1^st leaf pigweed or ragweed with many weeds still to emerge, herbicide applications should be applied. Reflex can be applied 21 days after soil disturbance. Reflex does have some residual activity and will control those weeds that have not yet emerged. Fields should be sprayed according to weed size and not the crop stage.

Weed Control

• Soil applied herbicides have already been on field for 6 weeks with no corn or bean canopy.
• There have been Group 27 and Group 14 weed control issues in strip still situations. There was a discussion about whether the atrazine has antagonized the glyphosate a bit as there is volunteer wheat still existing in those fields. 
• Weed control with glyphosate has been slow this year.
• The group discussed ryegrass control, and it was noted that there have been situations where ryegrass received a 2 L application of glyphosate with various other products and was not controlled well and was confirmed being susceptible to group 9 herbicides. While in other situations that same mixtures completely controlled the ryegrass. It is suspected that the variability in control may be related to when the frost occurred in relation to the herbicide application.
• Ryegrass is susceptible to glyphosate; however, if the ryegrass is in the stem elongation phases it will not be controlled well. It is best to control is when it is small or when it is heading.
• There are some issues with roughstalk bluegrass as well. Where it was sprayed with a glyphosate mixture and didn’t kill it but when it was sprayed two weeks later with the same mixture it was controlled well. Simplicity sprayed in November in some wheat fields did a good job of controlling the bluegrass.
• Growers in group 4 tolerant herbicide programs are lacking residual herbicides, and these grasses are becoming more of an issue.

Forages

• Overall yields have been excellent. A lot of growers are pushing to get dry hay right now before the forecasted rains tomorrow.
• There has been some lodging in the alfalfa crop and appears to be variety and environment dependent. It was noted that last year’s cut was even heavier but there was less lodging than this year.  It was also noted that there is significantly less lodging in cereals compared to this time last year.

Canola

• The early order deadline for next years seed was June 16^th. The seed size is small at sub 2lb to the acre. Although the seed is small, the germination is good. 
• Canola is an amazing crop, even where the stands were very thin, plants have branched out and overall look good.

Winchester Breakfast Meeting Notes – June 18, 2025

Winter Cereals

• A lot of fungicide went on late last week, as much of the winter wheat has finished pollination.
• Much of the area is entering grain fill now but won’t like the forecasted heat and lack of rainfall in the coming week.
• There are reports of some stripe rust in the Spencerville/Morrisburg/Wolfe Island/Lancaster area. Pressures are low and the fields received T3 fungicide last week.
• There is some concern of stripe rust moving from winter to spring cereals if temperatures get back down below 25 degrees.
• Pest pressures are low, moth counts/catches are very low (TAW)

Spring Cereals

• Getting ready for N, coming nicely
• Much of the area has reached stem elongation, second node.

Forages

• Lot of first cut harvested and then planted into beans. Stands planted into forages look decent – planted into moisture, had a rain, and are coming along nicely.
• Reports are varied – close to 50% reporting average yield, while 50% reporting high yields. There is not a lot of concern around any average yields due to high inventories locally.
• Regrowth on first cut is going to be quite slow/is quite slow, due to a lack of rain and warm temperatures.
• No potato leafhoppers appearing yet, populations quite low.

Corn

• Side dress has started, lots of 7-8 leaf corn, starting early canopy.
• Not a lot of N testing going on. Fields that have been sampled are seeing soil N levels a little lower than usual. It’s suspected it’s due to the cooler, wet weather earlier in the spring.
• Some volunteer wheat, grasses not being controlled with early herbicides. A lot of volunteer wheat pressure in corn that blew through early herbicide applications and is heading out now.

Soybeans

• 98% done, still the odd seed tote going out.
• Not seeing aphids yet
• It has been too dry to have huge white mould impacts.
• Already complaints of mixing up Xtend and Enlist varieties and weed control programs.
• If you are rushing to make a recommendation, take a breath, communicate, make the phones calls to confirm. If you’re not sure what you planted, it’s recommended to stick with a non-trait specific program (i.e. Freestyle, pursuit, etc). If you don’t need the dicamba or enlist system, it’s not a bad thing to go back to the RR programs.

Weed Control

• Reminder that weather forecast isn’t conducive to dicamba applications – the potential for volatilization loss/movement is extreme with the coming heat.
• Volunteer corn coming ahead, pay attention to what type of herbicide you’re using since volunteer Enlist corn won’t be controlled in soybeans with quizalofop (e.g. Assure II).

Simcoe Ag Breakfast meeting notes – June 18, 2025

Planting status 

• All corn was planted by June 15 Agricorp deadline, and all but a few fields of soybeans are planted (or re-planted). 
• Soil temperatures are warm which is helping for quick crop emergence.
• A decent gentle rain along with the current warmer days and nights would help advance the crop (but also the weeds). 

Agricorp

• Damage reports for the clay soils in Haldimand-Niagara region have resulted in replants.  Most of the replants were planted into good soil conditions. Crops planted prior to May 21-23 heavy cold rains followed by cold temperatures were almost all replanted.
• Dilemma for growers with low population soybeans stands (65,000 – 100,000 ppa) that have emerged but are struggling. They also want to plant wheat in the fall so must decide between rotation benefits and yield.  Most are deciding to stick with wheat this fall since they know the importance and benefits of wheat in rotation for clay soils.

Corn

• Side dress applications are underway, however 28% UAN is in short supply. Farms that had pre-paid or ordered ahead are generally okay. An alternative from local retailers is urea or AMIDAS (a nitrogen-sulphur product) mixed with PurYield (½ – ½), which can be applied with high clearance equipment with drop tubes to prevent leaf burn.
• Corn on sandy soils showing variability in growth and some herbicide damage. Both symptoms are probably from the days with frost and near frost.  Potential impact of pH and nutrient availability or plant’s ability to metabolize herbicides. High aluminum in low pH soils could limit phosphorus availability could also cause poor plant growth.
• Tar Spot infection is happening now for fields have inoculum present from last year.  Tar Spot may not be an issue if weather conditions remain dry, however with frequent moisture that results in leaf wetness in the crop canopy the disease will begin to show up in the first 8 days of July. It is important to line up application equipment (ground or aerial) well ahead of time.

Soybeans

• Seed corn maggot damage on soybeans on sand was most evident with delayed emergence in cool soils combined with previous crop of rye.  Seed treatments probably lost effectiveness in the time since planting and seeds have been vulnerable due to cool temperatures and slow emergence.

Winter wheat

• Wheat crop looks good.
• Stripe rust is not an issue in the Norfolk, Haldimand-Niagara region.
• T3 application sometimes occurred during higher than ideal winds due to very few low-wind days. How well did the fungicide cover the wheat heads?

Canola

• Winter canola looks good. All field operations for this crop are about a week behind last year.

Weed Control

• Time for dicamba application has passed. When daytime temperature reach or are forecast for 28-30^o C, spraying should not occur, even in early morning. Read and follow label.
• Residual weed control applied in April/early May are starting to “run out of gas”. Crop canopy will be key for weed control.
• Some group 15 herbicides applied to IP beans are showing drawstring damage.  Visual symptom that doesn’t affect yield.
• For IP beans, growers should check with buyers to ensure some group 15 herbicides can be used.  In some cases, for example to control water hemp, the residuals will warrant use.
• Weeds are starting to “harden off” and become more difficult to kill.  It is important to follow label instructions for use of surfactants and adjuvants.  With limited 28% as a carrier for some group 2 herbicides, the use of an alternative could affect herbicide efficacy or could result in reduced effectiveness if there is herbicide antagonism.

Other crops

• Frost in early June impacted strawberries, tobacco, and watermelons mostly.  Tobacco and watermelon seedlings for re-plants were available. Affected strawberries will have lower fruit yields.
• Fresh market tomatoes handled the frost quite well.
• Tobacco transplant shock was worse than normal, but most plants have come out of it.
• Some growers have used products such as Megafol and nutrients like zinc to try to help protect plants from cold stress.  Not enough research currently on this question.
• Some peppers have herbicide injury. Chemicals applied to sandy soils sometime behave differently under prolonged cool temperatures. It appears that metolachlor may have been taken up by the peppers.

Mark your calendar November 12, 2025 at Renton Greens for a fall meeting to follow up with spring issues and how they impacted yield and to discuss other current issues.

Events

• AgSpray Expo – July 23^rd, Jasper, ON – register at eocac.ca
• New Liskeard Diagnostic Day – July 17^th – register here

OMAFA Weather Summary: Thurs June 12—Wed June 18, 2025

Location	Highest Temp (°C)	Lowest Temp (°C)	Rain for Week (mm)	Rain Since April 1st (mm)	GDD0C April 1st	GDD5C April 1st	CHU May 1st
HARROW
2025	26.2	13.2	39.4	275.8	1012	639	174
2024	33.9	10.3	0.3	206.8	1216	819	191
2023	25.3	10.1	46.0	138.5	1025	641	139
10 YR Norm (2011-2020)	27.6	12.7	24.4	236.8	1045	652	176
RIDGETOWN
2025	28.2	11.0	45.2	197.5	956	586	169
2024	32.3	8.6	0.2	253.6	1135	742	182
2023	24.9	7.4	39.5	179.0	963	588	118
10 YR Norm (2011-2020)	27.0	11.0	18.7	206.1	968	581	162
SARNIA
2025	30.4	11.6	22.6	228.8	907	543	151
2024	33.0	10.5	0.2	194.4	1115	726	172
2023	25.3	7.0	21.4	159.4	926	551	114
10 YR Norm (2011-2020)	26.1	10.3	22.9	217.0	926	541	156
LONDON
2025	27.5	12.8	22.1	232.1	941	582	171
2024	31.9	9.2	0.0	240.0	1117	722	171
2023	25.5	8.0	46.7	227.1	968	593	118
10 YR Norm (2011-2020)	27.3	10.6	16.6	222.4	950	567	159
BRANTFORD
2025	29.4	11.9	43.0	251.0	942	580	164
2024	31.8	8.7	13.3	206.8	1061	671	164
2023	25.7	9.0	30.6	183.7	955	579	134
10 YR Norm (2011-2020)	28.9	10.3	19.2	218.1	935	554	160
WELLAND
2025	28.5	12.6	1.9	143.6	953	587	172
2024	31.5	8.6	4.2	237.2	1108	714	170
2023	24.6	9.3	26.5	170.6	951	569	133
10 YR Norm (2011-2020)	27.1	10.8	15.4	228.5	951	566	160
GODERICH
2025	28.8	11.5	27.2	156.1	861	505	161
2024	31.2	9.3	0.0	185.8	995	612	166
2023	22.8	6.9	8.3	128.5	848	490	93
10 YR Norm (2011-2020)	24.8	9.8	24.1	195.6	838	463	145
ELORA
2025	27.8	11.1	3.2	202.3	853	502	156
2024	32.2	9.0	16.4	201.0	981	600	163
2023	25.2	7.9	21.0	154.0	869	510	121
10 YR Norm (2011-2020)	25.9	9.2	14.9	220.6	834	464	143
MOUNT FOREST
2025	28.1	11.2	9.4	178.9	849	501	159
2024	31.9	8.8	3.1	225.2	968	591	164
2023	25.4	7.4	26.5	179.3	863	509	110
10 YR Norm (2011-2020)	25.3	8.9	21.8	210.4	818	456	142
BARRIE
2025	26.5	9.0	0.0	182.3	821	475	142
2024	30.6	6.9	21.1	305.0	932	554	150
2023	24.9	7.3	56.0	211.6	850	490	121
10 YR Norm (2011-2020)	25.8	8.5	17.9	211.8	798	438	138
PETERBOROUGH
2025	28.8	6.7	0.0	195.5	857	501	142
2024	31.9	5.1	27.8	234.9	957	574	141
2023	24.5	7.4	36.3	183.5	877	506	131
10 YR Norm (2011-2020)	26.9	7.6	18.5	215.3	847	476	140
KEMPTVILLE
2025	29.6	6.4	0.3	153.7	910	551	143
2024	31.3	5.2	16.3	252.5	1015	632	145
2023	27.2	7.8	14.0	217.4	923	557	148
10 YR Norm (2011-2020)	27.5	9.4	18.2	216.0	885	515	146
SUDBURY
2025	27.1	3.8	0.0	142.4	701	387	111
2024	32.0	5.1	4.9	287.0	837	484	138
2023	25.5	6.2	34.8	249.8	767	449	113
10 YR Norm (2011-2020)	25.2	8.2	15.1	197.8	703	394	138
EARLTON
2025	27.6	0.8	1.1	138.1	661	364	106
2024	32.5	3.0	25.2	244.7	823	477	134
2023	25.5	4.3	22.7	193.0	754	435	109
10 YR Norm (2011-2020)	24.8	6.6	19.8	179.6	638	351	128
SAULT STE MARIE
2025	26.2	5.7	0.5	165.5	674	352	110
2024	25.3	5.2	44.2	267.3	779	411	122
2023	27.5	6.7	50.0	177.9	742	422	84
10 YR Norm (2011-2020)	23.8	6.2	17.6	202.6	613	305	115
THUNDER BAY
2025	26.8	-0.2	45.6	173.5	591	298	106
2024	24.1	4.4	45.1	207.8	685	341	120
2023	26.5	4.4	0.0	129.8	658	361	117
10 YR Norm (2011-2020)	23.6	5.2	16.4	178.7	578	280	113
FORT FRANCES
2025	26.9	1.2	6.9	123.0	752	424	121
2024	26.7	4.5	61.1	236.9	740	386	137
2023	27.2	3.5	1.7	114.7	818	514	121
10 YR Norm (2011-2020)	23.6	6.3	31.7	185.5	674	357	131

This weather summary is compiled by OMAFA 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.  For additional locations and weather analysis, visit the OMAFA Pest and Weather System (PAWS)