Field Observations

October 10, 2024

The past week saw exceptional harvest weather. Soybean harvest continues, while corn harvest is beginning to ramp up in some regions of the province. Winter wheat planting is continuing.

Corn

Corn harvest has begun in areas with shorter day hybrids, areas with low moisture causing plant dry down earlier, and/or fields that might have been impacted by diseases such as tar spot (which caused plant death). Later planted corn is close to or at black layer. Aim to make alternative plans, such as silage, for corn that will not reach black layer prior to plant death.

Over the past two months, tar spot has severely impacted some corn fields. As fall harvest approaches, it will be critical to prioritize infected fields for early harvest. Stalk integrity is deteriorating, and fields that were unsprayed and impacted should be harvested first, followed by fields with more susceptible hybrids (lower tolerance to tar spot). Keep track of yields, moisture, test weights and grades. Depending on when the plants were impacted can greatly determine yield loss and low-test weights. Keep notes on hybrid differences and how fungicide spray programs helped (fungicides give protection for a certain length of time). For more information on stalk integrity, please visit the Grain Farmers of Ontario Factsheet.

Some corn fields are seeing ear tip back in the fields this year. Tip back is when corn kernels do not extend to the tip of the corn cob and have missing or incomplete kernels. Typically, there are two main reasons for tip back: poor pollination (causing the absence of kernel formation) and kernel abortion (smaller kernels that have been shut down early). If tip back is being seen in the field, take some time to assess the main contributor.

Silks that emerge from the tip of the cob are the last to emerge through the husk, and these kernels are also the last to fill during the grain fill period. Any significant stresses before, during and right after pollination will impact these kernels. Delayed or late silking is when silks emerge when there is little to no pollen left. Corn rootworm beetles can also clip silks, resulting in poor pollination as well.

Kernel abortion is mainly caused by stresses that reduce plant photosynthetic output (drought or disease can cause this) during the first several weeks following pollination and through the R3 (milk) growth stage. Also, many days of cloudy weather can reduce plant photosynthesis and cause kernel abortion.

Watch the newly released GrainTALK Webinar: Management Strategies and Innovative Research on Corn Rootworm, with MSc. candidate Tuesday Kristianson as she shares the corn rootworm lifecycle, current tools, best management practices and her research on Entomopathogenic Nematodes to manage corn rootworm, which is funded by Grain Farmers of Ontario.

Soybeans

Soybean harvest is 60 to 100 per cent complete, depending on the region, with most soybeans coming off the field dry or close to dry (10 to 16 per cent moisture). Fields planted later are seeing slightly lower yields, and areas planted into less-than-perfect field conditions are also showing lower yields due to emergence issues and/or water ponding after planting issues.

Cereals

Winter wheat planting is still occurring as conditions and calendar dates allow. Winter wheat that was planted earlier in the season is staging from emergence to the seedling growth stages (GS 10 to 19). Wheat needs 80 GDD to germinate and 50 more GDD per 2.5 cm of seeding depth to emerge. With warm temperatures in the past weeks, wheat emergence and development have been rapid.

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October 3, 2024

Soybean harvest continues across the province, with steady progress in the north and east, while the southwest has been in a holding pattern due to the remnants of Hurricane Helene last weekend. Corn harvest is slowly starting as dry areas have reported corn moistures down to 20 per cent. Winter wheat planting continues; pay attention to seeding rates as the season progresses.

Corn

Corn harvest will begin soon as fields dry down. At this point in the year, it can be expected that grain will dry down slower than in September. On average, in the fall, it’s typical to expect three days per point of moisture. Tar spot has impacted many fields in western Ontario and has caused earlier plant death. Impacts to test weight and yield will depend on hybrid susceptibility, fungicide application and the crop’s growth stage when tar spot started development.

So far, many have escaped killing frosts with warm temperatures occurring, but in the coming month, there will most likely be hard frosts arriving in regions of the province. Frost injury can more easily harm leaves than the stalk, leaving leaves to look water-soaked before the leaf turns brown and die. If the grain has not reached maturity (black layer), yield and test weight can be reduced. To learn more about the impact of frost damage on corn, visit here.

Gibberella ear rot produces the mycotoxin DON in corn and is beginning to be a topic in corn fields; learn more here. Be prepared to manage infected fields with a timely harvest, drying the grain quickly and storing it separately from non-infected grain. The Ontario Grain Corn Ear Mould and Deoxynivalenol Mycotoxin Survey will be published later this month.

Seed selection season is coming up. Check out the Choosing the right seed factsheet for more information on how to make seed selection decisions.

Soybeans

Soybean harvest has continued, as conditions allow, with 15 to 30 per cent complete, with moistures from 11 to 16 per cent and average yields.

With many late-planted soybeans this year, there may be some discussion on spreading treated wheat seed on standing soybeans. This is NOT recommended.

Aerial or broadcast spreading of treated wheat seed over a standing crop of soybeans is not recommended because:

• Tolerance for treated seed in a grain shipment is 0 per cent. Any treated kernels found in a shipment will see the entire load rejected. Fines and penalties can be imposed when grain safety standards, including grain contamination tolerances, are not met.
• Treated seed can land on the standing soybean plants and rest in the branches of the plant. Harvesting the soybean crop with seed on the plants will undoubtedly lead to treated kernels ending up in the harvested grain.
• Air reels can blow treated seed into the header, allowing for treated seed contamination of the soybeans.
• Wheat seed placed on the surface will have lower germination rates and potential for a very uneven stand of winter wheat with a variable population as seed will only germinate where conditions are favourable, such as areas with higher surface moisture or will be dependent on rainfall for germination. Seed-to-soil contact is key.
• Broadcast or aerial seeding over the surface results in shallow roots and surface crown root development. This leads to higher stand losses due to freeze damage in winter or heaving during the spring heaving cycles.
• Broadcasting with a tractor and spreader tramples soybean rows if tram lines are not already in place, lowering the soybean yield. If conditions are wet, compaction will occur.

Be sure to reduce the risk of treated seed contamination. If equipment is used to handle treated seed and harvested grain, review the Grain Farmers of Ontario Handling treated seed factsheet for more information.

Cereals

Winter wheat planting is still going strong, as ground conditions allow. Wheat that has been in the ground for a couple of weeks is emerging. A Visual Guide to Winter Wheat Staging is a great way to know what stage crops are at, and it shares 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. For areas that have passed the optimum winter wheat planting window, there may still be time to plant before the Agricorp 2025 Planting Deadlines for fall-seeded grains. Just ensure that seeding rates are increased accordingly; 200,000 seeds should be added to the equation for each week delay after optimum, with 2.2 million seeds being the per acre maximum rate.

Spring cereal harvest is wrapping up in the northern area of the province.

Cover crops planted after wheat are looking great as fall arrives.

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September 26, 2024

The soybean harvest saw a good few days of productivity last week and into the weekend, but rains have put harvest and winter wheat planting on hold for much of the province. Pay particular attention to optimum winter wheat planting dates and increase seeding rates accordingly.

Corn

Corn is anywhere from a black layer to 1/4 milk line in most areas. Warm days in the past couple of weeks have really helped advance corn. With exceptionally warm, dry weather, grain moisture could decrease by one point per day. As October approaches, with cooler weather and some showers, it will be common to need approximately three days to remove one point of moisture.

Are there lodged corn plants in your fields? Was corn grown in the same field last year? Are the roots small and look pruned? Now is the time to diagnose why things might not look as good as they should. Corn rootworm, poor root development from compaction, and poor hybrid selection can cause standability concerns. Be sure to take the time to determine which factor is affecting corn stands and make better choices for next year! Find out more in the managing corn rootworm resistance factsheet.

Gibberella ear mould has appeared in some locations. Most of the crop has looked to be free of ear mould, until now. The crop was infected during pollination with ideal moderate temperatures and humidity, aiding in infection of the silk channel. Conditions after infection will lead to the actual development of the visual symptoms of ear mould that are just now being observed.

The past few weeks of morning fog and heavy dews have led to higher humidity in the canopy, which fuels this disease. Areas where fields do not dry out as quickly, like around tree lines and buildings, should be the first place to scout. Fields and hybrids with open husks will have an environment of dryer conditions, which will limit disease growth. Look for the tight-husked plants to find if mould is present. Identify fields of concern and be sure to manage them this fall by prioritizing harvest and quickly drying down to limit the amount of DON that gets produced. Wet, cool conditions will favour DON production. Read more information on DON in corn.

Soybeans

Soybean harvest is continuing across the province as weather and plant maturity allow, with five to 10 per cent harvested. As there was an extended hot, dry period approaching soybean harvest, there were some reports of soybeans being harvested below 13 per cent. Harvesting below optimum harvest moisture can impact revenue through reduced delivery weight and shatter loss and splits. With rain arriving earlier this week, it should help the moisture of the soybean seed return to a moisture that is more desirable for harvest.

Soybean harvest started slightly earlier than some years. There are some great advantages to harvesting early: timely wheat planting, reduced soil compaction from typically wet fall soils later in the year, earlier fall tillage, and the ability to switch to corn earlier are some of the benefits. 

The Soybean Cyst Nematode Coalition has named National Nematode Day October 1, 2024, to increase awareness around this yield-robbing pest. To learn more about SCN, visit the SCN Coalition.

Cereals

Winter wheat planting is occurring, with some areas planting earlier than normal. A nice rain across most of the province will ensure moisture for wheat to germinate, especially in areas lacking moisture.

For several regions, the optimum date for planting has passed, while in other areas, it is approaching. As optimum dates approach, the seeding rate should increase. 1.4 to 1.6 million seeds per acre is recommended for early planting. Two hundred thousand seeds should be added to the equation for each week’s delay after optimum, with 2.2 million seeds being the per acre maximum rate. The later winter wheat is planted into the season, the lower the number of tillers will develop, and the higher the seeding rate will help compensate.

Spring cereal harvest, oats, in particular, is still occurring in the northern portion of the province.