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Ontario Grain Farmer Magazine is the flagship publication of Grain Farmers of Ontario and a source of information for our province’s grain farmers. 

Field observations


May 24, 2023

There will be an incredible number of acres in the ground by the last week of May, all planted within a very short window. Will it be a record? The week ahead looks ideal for completing #plant23 across much of the province.



Most farmers across the province got to catch up on a couple hoMost farmers across the province got to catch up on a few hours of sleep on the Victoria Day long weekend. A timely rain, bringing anywhere from 0.1” to over 2” across the province, created the perfect rain delay. Up to 80 to 99 per cent complete for corn planting across the province. Most of the corn that is in the ground has germinated or will be shortly with the warm temperatures being experienced. On the heavier clays, there was found to be some crusting, which could cause emergence issues, but the rain this past weekend should help mitigate those issues.

One thing to keep in mind as the corn does emerge is how uniformly it is emerging. If corn was planted this past week, with maximum corn heat unit (CHU) accumulation (30 per day), the corn could be out of the ground in five to six days, which is a lot less time for insects to be active, as well the soil temperatures would move them down in the soil profile (a huge plus for planting into warm soils). Overall, with the cold nights this year, emergence might take a bit longer, with some emerging around nine days. It is not time that gets the crop out of the ground; the heat drives the enzymatic process to get the seed to germinate, and the continued heat helps the cell growth of the developing plant seedling. Pay attention if there is even emergence or not, watching individual rows for differences as well. As the season progresses, pay particular attention. See if the later emerged plants are weaker and smaller. Did they pollinate later? How was the ear size or cob fill? Does emergence timing make a difference in your crop?

With the recent rain, pre-emergent-applied herbicides should have activated. Most herbicides do not claim to have reach-back activity. However, there should be activity on weeds that are germinating. Pay attention to weeds that have gotten past the herbicide due to weed emergence before rains, and come back in and clean up if necessary.

Source: Pub 811, Ontario Ministry of Agriculture, Food, and Rural Affairs.


Up to 85 per cent complete on soybean planting, and after a short rain delay over the weekend, many were moving again mid-week to move the planting progress needle even closer to the finish line.

Soybeans that have been in the ground since last week will emerge shortly. Soybeans are more prone to poor stand establishment than other crops as they need to pull their cotyledons up and through the soil. Once the field has emerged, it is always a good idea to check on emerged plant numbers.


With the warm weather, winter wheat is progressing quickly. Wheat is at boot stage in southern Ontario (GS45-49), while in other parts of the province, wheat has the flag leaf emerging (GS 37). In Northern Ontario, the growth stage is in stem elongation (roughly GS32-33). In the deep southwest, wheat will be heading out soon, with farmers getting ready to spray for Fusarium. Wheat fields that are most susceptible to Fusarium infections are those planted after corn or susceptible varieties. Once 75 per cent of the heads are completely emerged on the main stem (GS59), ideal fungicide timing is approaching. The optimum timing is at the beginning of pollination (GS61) when anthers are visible on the middle of the wheat head. Timing is critical, and the crop will be moving very quickly through stages with all this heat. Be sure that your sprayer has been cleaned out well before fungicide applications.

Overall, leaf dOverall, leaf disease pressure is still low in the field. Fields should still be monitored, though, especially susceptible varieties.  

A wide range of sulphur (S) deficiencies have been identified in this year’s winter wheat crop, even on fields with S applied. S is a mobile nutrient, and with the wet/cooler weather in the early spring, the S could have moved deep within the soil profile, and the cooler weather could have impacted root growth to reach the mineral. S deficiency can often be seen as patches of yellow plants within the field or areas that are stunted, thin or with delayed maturity. S plays a crucial role in photosynthesis and the production of chlorophyll. If a deficiency is seen or found through tissue sampling, it can be corrected. The sooner the mitigation is taken, the better.

Physiological fleck is also showing up in some fields, caused by prolonged cloudy days. More info is available in this Field Crop News article.  

So far, pest pressure is low this year. A common pest to the region is armyworm, which commonly shows up with thunderstorms coming from the south; no major storms from the south lowers the incidence of their arrival. Cereal leaf beetle numbers also, at this point, have been low.   

Looking at winter barley, it is currently heading out with low injury from last week’s frost. Be on the lookout for Barley yellow dwarf virus. More information can be found on the Crop Protection Network website.

Spring cereals have emerged and are roughly at GS 11-13 (seedling growth). In some fields, there was frost damage from last week; however, nothing detrimental. •

May 17, 2023

A better week for planting could not have been asked for these past seven 7 days across most of the province. A lot of crops have gone into ideal or close to ideal conditions. However, it was not perfect for everyone, as regions of northern Ontario experienced some snow early this week.


Seventy to 90 per cent of corn has been planted across the province. Soil conditions dried up very quickly, allowing many acres to get planted in a short window of time with no forced breaks.

There is a potential for uneven emergence due to variable moisture content and drying of the soil across fields. It will be clear to see seed that was planted into moisture and seed that was not. Overall, corn is slow to emerge with cool soil temperatures during planting and the days after. Some corn planted during the warm weather in mid-April has been seen to have crusted soil due to heavy rains after planting and then drying out. A rotary hoe might be needed in these situations to help free the emerging corn from the crust.

If you are still planting corn with dry conditions, remember to plant into moisture; a 2.5 to three-inch depth is ok if you need moisture. Also, something to keep in mind: do not fluff the soil but keep the seedbed firm to retain the moisture. Those who have run packers behind their cultivators might be wise this year to keep soil moisture in the soil.

Cooler temperatures/frost was seen across much of the province earlier in the week. With corn still not having emerged, there is little concern over the frost affecting the plant. And if the corn has emerged, the growing point is still below the soil surface.

Rain in the forecast for this weekend will be beneficial to crop management. If rain does not arrive, fields that have had a pre-emergent herbicide applied will need to be monitored for weed control in the coming weeks. Some pre-emerge herbicides do need rain to activate the herbicide. Scout and be prepared to take action if cleanup is needed. Managing weeds in the early stages of crop growth is crucial for yield; the same goes for soybeans. •


Like corn, soybeans acres have rocketed into the ground without delay. Acres planted are around 40 to 70 per cent in regions.

Soybeans planted in April that have emerged are at the VC (cotyledon) stage; with the cool weather that was experienced this week, there could be some frost damage on soybeans that emerged on lighter soils or muck soils as those soils hold less heat, during cool temperatures.


Winter wheat is staging up to GS 37 (flag leaf just visible), however the deep southwest might be seeing some wheat roughly at GS 41 (booting). If split applying nitrogen GS 32 to 39 is the optimum application window.

The flag leaf accounts for over 50 per cent of photosynthates used for yield. T2 fungicide applications have been occurring to keep the emerging flag leaf clean, where warranted, overall disease pressure has been low. However, be on the lookout for Powdery mildew and Septoria; disease infection is varietal specific. Take note of which varieties fare better than others. Fungicide applications should be decided based on the severity and presence of the two leaves immediately below the flag leaf. T3 timing (to protect the head) for some fields will be just around the corner.

With the cooler temperatures experienced earlier this week, there has been some concern about spraying. Be sure to read the label or speak with an agronomist if you are unsure if you should spray a certain product.

Similarly, with the cooler temperatures, give wheat a few days after the frost to scout and see if there is any damage. There might be some leaf tip burn but hopefully not much else. When wheat is in the boot stage (GS 41-49), there can be some injury if the temperature remains low for an extended period of time. Not to jinx anything, but the next full moon is on June 3. Let’s hope that it is cloudy for all crops’ sake. •

May 11, 2023

Sporadic rains across the province over the weekend delayed fieldwork in some regions, while other areas were full steam ahead at the beginning of the week. Areas that were still waiting for ideal soil conditions should get rolling shortly. Some may have noticed a haze in the sky due to wildfires in Alberta. This haze could slow the drying of fields slightly, as it impacts sunlight, but with promising forecasts, spring planting will soon be occurring widely across the province.


Areas of the province have finally dried up enough for further manure applications and tillage to start at the beginning of the week. Planting and any pre-plant/pre-emerge herbicide applications soon followed.


Soybean planting has begun this week as well. As the weather holds favourably over the remainder of the week, there will most likely be a number of acres planted.

The increase in daytime and nighttime temperatures will drive corn heat unit accumulation resulting in rapid plant growth (both weeds and crops). Burndown herbicide applications will now see faster-acting herbicidal activity as plants develop quicker as temperatures rise. Some weeds, such as winter annuals, have continued to grow during the past few cool weeks. Canada fleabane has already progressed and is ready to bolt with these warmer temperatures. Be timely with burndown applications, as bigger weeds are harder to control and may need additional measures for effective control.

As planting really ramps up, remember to take breaks. Working while tired leads to avoidable mistakes and accidents. Be sure to get home safely to your family every day.

Depending on which regions of northern Ontario fields are located determines field activity. Areas such as New Liskeard have dried up nicely with fieldwork and planting occurring; others, such as Cochrane, received heavy rains and will take another week or two to dry up. With the calendar date being where it is, much focus is on spring grains but will quickly change to silage corn and soybeans. Overall, the forecast is looking favourable.


Winter wheat in Ontario is around the second node (GS31-32) up to flag leaf emergence (GS37, flag leaf just visible). Wheat has moved quite slowly this past month with the cooler temperatures.

Herbicide applications need to cease by flag leaf so as not to cause head injury. If spraying is done in cool conditions, many have focused on only using one product in the tank to prevent wheat injury. Second applications of nitrogen have been applied, especially where flag leaves are starting to emerge. Burn from a fungicide/herbicide application can impact yield, so use caution when applying in cold weather. Be sure to speak with your agronomist to determine which herbicides are easier on wheat if temperatures dip toward zero.

Some winter wheat fields have been or will be terminated in northern Ontario due to winter kill.

Keep an eye out for pests in fields; cereal leaf beetle can show up around this time in fields. The Pest Manager app is an excellent source of information on all pests. Grain Farmers of Ontario supports much of the research that is used in the app. It applies to pests, weeds, and disease and is updated regularly based on current research data.

May 4, 2023

It has been a slower week across the province, with heavy rains and/or snow this past weekend and into the start of the week, causing equipment to remain parked.


Any planted corn is slow to emerge due to cold temperatures. The radicle (first root to emerge from the seed) on some planted corn can be seen. Insect feeding damage may occur. Corn seed typically requires 165 to 175 CHU for emergence. Looking at accumulated CHUs for the Ridgetown area this year, there have been only 66 CHU since April 15, 2023.


Cool weather has slowed the growth and development of winter wheat; the approximate staging for wheat is around the Growth Stage 31 – 35 (stem elongation). Information on how to identify which Zadocks stage wheat plants are at can be found in A Visual Guide to Winter wheat staging, pages 25-26 show in-depth pictures and descriptions of stem elongation at GS 31.

Many fields have now received a first pass of nitrogen. Those that are still waiting on the application might be showing N deficiencies (the oldest leaf will be paler than others, with yellowing beginning at the tip and moving downwards). Some wheat has been showing manganese deficiencies, predominantly in sandy and loamy soils. There have also been some Zinc deficiencies on clays and some sulphur deficiencies as well. Be sure to get out and scout so that corrective action can be taken if needed.

In northwestern Ontario, fields have dried up enough in some areas that spring cereals are getting seeded.


It has still been a bit too cool and wet for many areas to begin spraying herbicides. Once annual weeds have further emerged, there will be herbicides sprayed as the weather cooperates. Winter annuals are growing quickly. Watch that they do not get to a stage where they are too large to control easily; adjust rates to get good control.

April 27, 2023

As the end of April creeps closer, cool weather, rain, and snow have hindered field operations. But never fear; there is lots of time left to get into the fields. A few good drying days can change a lot.

Corn and Soybeans

A very small amount of corn and soybeans went into the ground across Ontario during the unseasonably warm temperatures experienced in mid-April. Ground conditions were very good for these earlier planted crops; however, most farmers focused on spreading manure, fertilizer and getting nitrogen down on wheat. Showers and cool weather have slowed down fieldwork. Looking at the long-range forecast, there appears to be several rain showers headed for Ontario, but this can change.

It is important to note that it is still very early in the spring season. When planting corn and soybeans, it is great if they go into warm soil and the first moisture that is taken into the seed is also warm (relatively speaking – they don’t need 80-degree shower water like we do!) The first 48 hours after planting are critical to avoid cold/chilling injury. The first drink the crop gets should be warm. Cold water taken into the seed the cells do not allow the cell the same elasticity as if it had warmer water. Depending on the conditions and the crop, different cell damage can occur, causing damage to the new sprouts and resulting in poor and uneven emergence that will affect plant stands and, ultimately, yield.

True armyworm and black cutworm have been caught in traps. Other pests are also becoming active with the warmer weather. Good soil temps help plants emerge quickly, with less chance of insect feeding on seeds.

Above all things, planting into fit soil, with both temperature and moisture taken into consideration, is crucial for good emergence.


Similarly to the above crops, some spring cereals also went into the ground in mid-April.

With the above-average warmth, winter wheat really took off. Farmers took advantage of the beautiful weather to apply the first pass of nitrogen (N) on the wheat crop. Overall, wheat crops look very good, especially those that have had a first shot of N, especially if the N was applied during the warm conditions. There are, however, some poor stand areas within fields where water has laid during the spring melt.

Cooler weather this past week has slowed down growth stage progression allowing a bit more time to get everything applied in a timely manner. Fields are staging around the Growth Stage (GS) 30-31, the beginning of stem elongation and the first node (GS31), the stage where the Yield Enhancement Network participants are getting their first tissue sample for analysis. As temperatures increase, be on the lookout for leaf disease within the next week or two. With dense canopies, stem elongation is an important time for T1 fungicide timing (if pressure and disease timing are sufficient), weed control and N applications. It is also the start of the optimum window for most plant growth regulator (PGR) applications. Read more about what PGRs are available on the market and optimum timings in this Ontario Grain Farmer article on PGRs. It is a good idea to keep in mind that GS 32-39 is the recommended window for a second pass of N. Herbicide applications will also be approaching. Remember to avoid temperatures below 5 degrees Celsius the day before and after spraying.

Have a great spring. When things do get rolling, remember to take breaks and stay safe.

April 13, 2023


Winter wheat has come through the winter looking great across much of the province. There are a few yellow spots where water laid a little too long last week with the 3-inch rain.  Many fields are staging around four to six tillers (GS 24 to 26). With good populations and potential thick stands, if you are managing for higher yields and have experienced lodging in the past, a plant growth regulator (PGR) application during stem elongation might be something to consider for those intensely managed acres. Split nitrogen applications can also help in managing later lodging concerns.

If a winter wheat field is not looking as good as it should, as fields green up, it is a great chance to assess survival. Read more in this Field Crop News article: Assessing winter wheat stands for winter survival.

Along with the warm and dryer weather, early nitrogen applications will be going down across fields this week. Optimum nitrogen (N) rates and timing are key to producing top-yielding wheat. The question of split applied N is a common one most years. More information on split applying N can be found in this Field Crop News Article: Should I split apply nitrogen in winter wheat?  

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