Field Observations
FALL 2026
October 8, 2026
Soybean harvest and winter wheat planting continue across the province. Overall, the fall harvest season has started exceptionally well. Corn continues to mature and dry down.
Corn
Corn harvest has barely begun in areas where shorter-day hybrids were planted early. An early harvest may result from limited rainfall causing plants to dry down sooner, fields affected by diseases such as northern corn leaf blight, which has been observed frequently this year and can cause plant death, or early-maturing hybrids. Later-planted corn is nearing black layer where earlier hybrids were used. Full-season corn planted late still needs heat to finish filling kernels. Consider alternatives, such as silage, for corn that will not reach black layer before plant death.
Although Halloween is still a few weeks away, some are reporting “ghost corn”: random dead corn stalks among plants that appear unaffected. Several factors may contribute to this phenomenon. However, one possible cause appearing more frequently this year is crown rot. Crown rot may appear early or later in the season, although it is more common when plants are close to maturity.
As fall harvest approaches, it will be critical to prioritize fields for early harvest as stalk integrity deteriorates. For more information on stalk integrity and how to determine whether a field should be a higher harvest priority, visit the Grain Farmers of Ontario factsheet.
Some cornfields are showing ear tip back this year. Tip back occurs when kernels do not extend to the tip of the cob, leaving kernels missing or incomplete. Two main causes typically apply: poor pollination, which prevents kernel formation, and kernel abortion, in which smaller kernels stop developing early. If you see tip back in a field, take time to assess the main cause.
Silks from the tip of the cob are the last to emerge through the husk, and their kernels are also the last to fill during the grain-fill period. Significant stress before, during, or immediately after pollination will affect these kernels. Delayed or late silking occurs when silks emerge after little or no pollen remains. Corn rootworm beetles can also clip silks, resulting in poor pollination.
Kernel abortion is mainly caused by stresses that reduce a plant’s photosynthetic output, including drought or disease, during the first several weeks after pollination and through the R3, or milk, growth stage. Prolonged cloudy weather can also reduce photosynthesis and cause kernel abortion.
Watch the recorded GrainTALK webinar, Management Strategies and Innovative Research on Corn Rootworm. Tuesday Kristianson, MSc, discusses the corn rootworm life cycle, current tools, best management practices, and her Grain Farmers of Ontario-funded research on using entomopathogenic nematodes to manage corn rootworm.
Corn ear moulds are appearing. Scout for Aspergillus, Diplodia, Fusarium, and Gibberella ear rots. Gibberella ear rot can produce DON in corn. Find more information about DON in corn here. Prioritize fields showing any corn ear moulds for harvest.
Soybeans
Field Progress, Grain Farmers of Ontario’s weekly estimate of planting and harvest progress by district, reports that soybean harvest was 44 per cent complete across the province as of Wednesday, October 7, 2026.
Soybean harvest progress varies by region and depends on crop moisture. Most soybeans are coming off the field dry or close to dry, at 10 to 16 per cent moisture. Overall, yields are average. However, some areas are seeing exceptional yields following timely rain, particularly in early September, which helped produce large soybeans. Other areas experienced dry conditions and are seeing the effect on yields.
There have been reports of green stems, making soybean harvest more challenging because the plant material is tougher to cut and process through the combine. Green stems may result from variety, environmental conditions, or fungicide use.
After heavier rain in some parts of the province, watch for mud tagging in muddy fields, especially on identity-preserved soybeans.
Also, be aware that operating equipment on saturated ground can increase compaction. Learn more about soil compaction and damage in the Grain Farmers of Ontario factsheet.
As you harvest soybeans, review the Crop Protection Network’s soybean disease loss estimates for Ontario. Which diseases affected your crop, and what can you do next year to help mitigate those losses?
Watch the recent GrainTALK webinar, Managing crop residue and soil compaction, featuring Ian McDonald of OMAFA. McDonald encourages farmers to be curious, observant, conversational, and questioning when considering these topics this fall. He also shares research and insights from across Ontario to help farmers manage soil compaction and crop residue. Farmers can use a range of practices to reduce compaction and manage crop residue in the short and long term.
Cereals
Field Progress, Grain Farmers of Ontario’s weekly estimate of planting and harvest progress by district, reports that winter wheat planting was 52 per cent complete across the province as of Wednesday, October 7, 2026.
Winter wheat planting continues as field conditions and calendar dates allow. Winter wheat planted earlier in the season ranges from emergence to the seedling growth stages, GS 10 to 19. Wheat needs 80 growing degree days to germinate and another 50 growing degree days for every 2.5 centimetres of seeding depth to emerge. Warm temperatures in recent weeks have accelerated wheat emergence and development.
Fall weed control tips
Fall weed management can be highly beneficial for controlling winter annual, biennial, and perennial weeds. In this Ontario Grain Farmer magazine article, OMAFA’s Mike Cowbrough shares fall weed control tips.
October 1, 2026
Open weather across much of the province has allowed soybean harvest and winter wheat planting to progress rapidly. Corn is maturing and drying down. Seasonably warm temperatures and sunny days will support continued dry down.
Corn
Corn harvest still appears to be some time away, as some fields remain exceptionally green. However, limited harvesting of high-moisture corn is underway. As fields dry down naturally or following frost or disease, harvest will begin to pick up. In most cases, that still appears to be a few weeks away. At this time of year, grain typically dries down more slowly than it does in September. On average, expect one percentage point of moisture loss every three days in the fall.
So far, many areas have escaped a killing frost because of warm temperatures. However, some parts of the province have already experienced frost this season, including a hard frost in some northern areas. More hard frosts will likely arrive across the province in the coming month. Frost injury can damage leaves more easily than stalks, causing leaves to appear water-soaked before they turn brown and die. If the grain has not reached maturity, or black layer, yield and test weight can be reduced. To learn more about the effects of frost damage on corn, visit this resource.
Gibberella ear rot, which produces the mycotoxin DON in corn, is becoming a concern in some fields. Learn more about DON in corn. Be prepared to manage infected fields by harvesting promptly, drying the grain quickly, and storing it separately from uninfected grain. The Ontario Grain Corn Ear Mould and Deoxynivalenol Mycotoxin Survey will be published later this fall.
Seed selection season is approaching. Review the Choosing the right seed fact sheet for more information about making seed selection decisions.
Soybeans
Field Progress, Grain Farmers of Ontario’s weekly estimate of planting and harvest progress by district across the province, reports that soybean harvest was 31 per cent complete as of Wednesday, September 30, 2026.
Moisture levels in harvested soybeans range from 11 to 15 per cent. Dry, sunny conditions have resulted in lower harvest moisture levels than in some previous years.
Be sure to reduce the risk of contamination from treated seed. If equipment is used to handle both treated seed and harvested grain, review Grain Farmers of Ontario’s Handling treated seed fact sheet for more information.
Fall is a key time for soil sampling. Weather can skew soil test data. Learn more about the challenges of collecting a representative sample and how soil moisture can influence potassium levels and soil pH in this crop report.
Cereals
Winter wheat planting remains in full swing where ground conditions allow. Field Progress reports that winter wheat planting was 36 per cent complete as of Wednesday, September 30, 2026.
Wheat planted a couple of weeks ago is emerging. However, some areas are trending dry, and limited moisture in the upper soil profile is delaying emergence. A Visual Guide to Winter Wheat Staging can help identify crop stages and includes key yield components, scouting tips, and more.
As a reminder, the Ontario Cereal Crops Committee publishes a guide to Ontario’s optimum winter wheat planting dates. In areas where the optimum planting window has passed, there may still be time to plant before the Agricorp 2026 planting deadlines for fall-seeded grains. Increase seeding rates accordingly by adding 200,000 seeds per acre for each week after the optimum planting date, to a maximum of 2.2 million seeds per acre.
Cover crops planted after wheat are looking great as fall arrives.
GrainTALK Webinar
Watch the recent GrainTALK webinar, Managing crop residue and soil compaction, featuring Ian McDonald of OMAFA. McDonald encourages farmers to be curious, observant, conversational, questioning, and more when considering these topics this fall. He also shares research and insights from across Ontario to help farmers manage soil compaction and crop residue. Farmers can use a range of practices to reduce compaction and manage crop residue in both the short and long term.
Field Progress, Grain Farmers of Ontario’s weekly estimate of planting and harvest progress by district across the province, reports that soybean harvest was 31 per cent complete and winter wheat planting was 36 per cent complete as of Wednesday, September 30, 2026.
September 24, 2026
The fall season is upon us, and soybean harvest is ramping up. Corn has reached maturity and is drying down in some areas, while in others, the milk line is progressing toward black layer. Winter wheat planting is moving quickly behind the soybean harvest.
Corn
DON in corn
Corn ranges from black layer to half milk line in most areas. Warm days over the past couple of weeks have helped advance the crop, and moderately warm days in the forecast will help it continue toward maturity and dry down. In exceptionally warm, dry weather, grain moisture could decrease by one percentage point per day. The long-range forecast suggests some areas of the province will receive very little rain, while others could see a rainy start to fall. As October approaches, cooler weather and showers often mean it takes an average of about three days to remove one percentage point of moisture.
Do you have lodged corn plants in your fields? Was corn grown in the same fields last year? Are the roots small or pruned? Now is the time to diagnose why the crop might not look as good as it should. Corn rootworm, poor root development caused by compaction, and poor hybrid selection can lead to standability concerns. Take time to determine which factor is affecting corn stands so you can make better choices for next year. Learn more about managing corn rootworm resistance in this fact sheet. Assess your fields for stalk strength by consulting this Grain Farmers of Ontario fact sheet on stalk integrity.
Gibberella ear mould has appeared, or may begin to appear, in some locations, particularly those that have experienced heavy dew or rain over the past two to three weeks and where wet conditions are expected to continue. Much of the crop appeared free of ear mould until now. The crop is often infected during pollination, when moderate temperatures and humidity favour infection through the silk channel. That may be the case in some fields this year, although other factors may also be involved. Conditions after infection determine whether the visible symptoms of ear mould develop, and those symptoms are only now being observed.
As noted above, mould development may involve more than favourable weather at pollination. Increased pressure from corn rootworm beetles clipping silks, along with feeding by western bean cutworm, corn earworm, and other pests, has been observed in several cornfields. This feeding creates wounds in the cob where mould-causing pathogens can enter.
Morning fog and heavy dew over the past few weeks have increased humidity in the canopy, fuelling disease development. Areas where fields do not dry quickly, such as those near tree lines and buildings, should be scouted first. Fields and hybrids with open husks will have drier conditions, which can limit disease growth. Check tight-husked plants for mould. Identify fields of concern, prioritize them for harvest, and dry the grain quickly to limit DON production. Wet, cool conditions favour DON production. Read more about DON in corn.
Sound sampling protocols for testing for DON are crucial to obtaining consistent, accurate test results.
As noted in previous editions of E-News, tar spot may also be appearing, but given the crop stage, it should have little effect on yield in most cases.
Soybeans
Field Progress, Grain Farmers of Ontario’s weekly estimate of planting and harvest progress by district across the province, reports that soybean harvest was four per cent complete as of Wednesday, Sept. 23, 2026.
Soybean harvest is underway across the province as weather and crop maturity allow. The extended hot, dry period leading up to harvest could result in soybeans being harvested below 13 per cent moisture. Harvesting below the optimum moisture level can reduce revenue through lower delivery weights, shatter loss, and splits. Timely rain, should it arrive, can help soybean seeds return to a more desirable harvest moisture.
Ensure chaff is spread evenly from the combine. Several harvested fields have a very uneven spread pattern, and an even residue spread is essential for good winter wheat establishment.
Early harvest offers several advantages, including timely wheat planting, less soil compaction than is typical in wetter fall soils later in the year, earlier fall tillage, and the ability to switch to corn harvest sooner.
Some grain-growing areas of the province have been under frost warnings. So far, it appears that most have received only light frost.
The SCN Coalition has designated Oct. 5, 2026, as National Nematode Day to raise awareness of this yield-robbing pest. To learn more about soybean cyst nematode, visit the SCN Coalition.
Cereals
Field Progress reports that winter wheat planting was five per cent complete as of Wednesday, Sept. 23, 2026. Overall, conditions are close to ideal for planting. However, some areas may be a little too wet, while others may be too dry. A timely rain could help provide enough moisture for wheat to germinate, especially in drier areas.
In several regions, the optimum planting date has passed, while in others, it is approaching. As the optimum date approaches, seeding rates should increase. For early planting, the recommended rate is 1.4 million to 1.6 million seeds per acre. Add 200,000 seeds per acre for each week of delay after the optimum date, to a maximum of 2.2 million seeds per acre. The later winter wheat is planted, the fewer tillers it will develop, and a higher seeding rate will help compensate for reduced fall tillering.
Spring cereal harvest has mostly wrapped up, with just a few acres remaining.
Driving around the countryside, it is apparent that many fields have volunteer wheat that will need to be managed. Read more here.
Watch the recently recorded GrainTALK webinar, Reflecting on 2026: Setting the stage for the 2027 winter wheat crop. Joanna Follings of OMAFA reviews the 2026 season and explains how to prepare for planting winter wheat this fall, with a focus on mitigating and managing barley yellow dwarf virus, optimizing planting dates and seeding rates, and more.
Join OMAFA’s Ian McDonald on Wednesday, Sept. 30, at noon as he shares insights on managing crop residue and soil compaction this fall. Register now.
Research helps Ontario farmers stay ahead of herbicide-resistant weeds
Herbicide-resistant weeds pose a major threat to Ontario crop production, with potential losses estimated at up to $1.6 billion annually if they are left unmanaged. Dr. Peter Sikkema, now retired, Dr. Isabelle Aicklen, and other collaborators have spent years studying herbicide-resistant weeds, with funding from Grain Farmers of Ontario and other partners. Through more than 3,000 field experiments in grain crops and dry beans, as well as more than 500 presentations to farmers, researchers have provided practical, science-based strategies to control resistant weeds, protect yields, and reduce economic losses. Ongoing research continues to help Ontario farmers respond to emerging weed challenges and maintain a resilient, productive crop sector. The University of Guelph recently published an article describing some of the effects of herbicide-resistant weed research across the province. Read more here.
