Ontario Field Crop Report
October 9, 2008
by OMAFRA Field Crop Specialists

For emerging issues, questions or to provide feedback on this report, contact the CropLine at 1-888-449-0937.  Technical information can also be obtained at the OMAFRA Field Crops Webpage at www.ontario.ca/crops and Crop Pest Ontario at www.omafra.gov.on.ca/croppest/.  Referenced OMAFRA Publications include Publication 811 Agronomy Guide for Field Crops ($20), 812 Field Crop Protection Guide ($15), 75 Guide to Weed Control ($15), and 505 Ontario Weeds ($15).  These can be obtained from your OMAFRA Resource Centre, or by calling 1-800-668-9938.

Corn

Crop Heat Unit (CHU) accumulation from May 1 to September 30 has been greater than the 30 year normal at Windsor (3741 versus 3582); near normal at London (3152 versus 3106) and significantly lower in Barrie (2644 versus 2949).  The general trend is for the corn crop in the south west to be mature and drying down reasonably well.  As you move north and east crop maturity becomes more delayed.  Fortunately, near normal CHU accumulation in September and a lack of a killing frost in these areas has allowed the crop to push towards maturity.  Delayed silking (August) and grain filling late into the season often results in somewhat lower test weights.

Considerable concern exists in the province over stalk quality, and the strength of the root anchor especially were cob weight is large or were disease, extended dry conditions, or saturated soils during the growing season have weakened the plant.  Moderate weather to date has contributed to the absence of any significant lodging.  Be aware of declining stalk quality and identify fields that should be first to harvest.

Initial field scouting has provided evidence to suggest some concerns with ear moulds in the southwest and that these declined as you moved east.  Increased ear moulds tend to be correlated with physical damage to ears and husks caused by hail, insects and birds.  Fields with extensive ear moulds should be tested for mycotoxins.  Farmers harvesting grain corn for on farm feeding should prioritize fields to keep for feed.  Combine set-up can only have a marginal impact on mycotoxin levels in the grain sample.  If possible, set concave and cylinder speed to leave small infected kernels on the cob tips unshelled.

Winter Wheat

Wheat planting has been closely following bean harvest, but wet conditions and late maturity bean crops have slowed progress.  Chances of reaching a 1 million acre crop are dwindling with every storm front.

Early wheat has emerged with excellent stands.  Many growers have skipped the fall burndown in favour of getting wheat planted.  This will necessitate different management in the spring for weed control.  There is little that growers can do for fall weed control once wheat has emerged without negatively impacting yields. 

Many growers are now questioning when it is too late to plant wheat.  Trials undertaken over the last several years prove that excellent wheat crops can be grown even with wheat planted in November.  The key is to plant into good soil conditions.  Yield potential is reduced somewhat, but 90 bu/ac wheat is still a reasonable yield goal in mid October.  As planting dates move later, seeding rates should be increased.  Target 1.5 million seeds/acre until mid October, 1.8 million seeds/acre in late October, and 2.0 million seeds/acre if planting into November.  Remember to check the last fall planting date for your area with Agricorp if this will impact your planting decision.

Soybeans

Soybean harvest is proceeding quickly, ranging from 30-60 % complete depending on the area.  Yields are quite variable, ranging from 30-40 bu/ac in low rainfall areas to 45-60 bu/ac being more typical in the majority of soybean growing areas.  Moisture is generally in the 13-14% range.

If soybean cyst nematode is suspected, now is a good time to soil sample to determine the presence of this pest.  Knowing if you have soybean cyst nematode and its population level helps you plan management strategies for the next growing season, including appropriate crop rotation and selection of resistant soybean varieties.  Submit one soil sample per 20-25 acres consisting of numerous cores that are well mixed.  A more accurate indication of the pest population is achieved with a sampling of fewer acres for each sample.  Sample both suspect and non-suspect areas for comparison.  Samples should represent similar cropping history and soil type in the field.  Sampling technique is similar to taking a regular soil sample.

Growers who plan on harvesting and storing their own soybean seed for next year need to keep a few points in mind.  For the highest quality seed, select the best disease free fields.  The longer in the fall that soybean seed is exposed to wet-dry weather cycles, the greater the deterioration in quality.  Thus producers should harvest those fields to be saved for seed first.  There are a number of seed borne disease fungi that develop any time harvest is delayed.  These diseases reduce seed quality, with the main seed borne disease being phomopsis.  Phomopsis is more prevalent this year.  The fungus will grow on soybean seed giving it a white fuzzy appearance.  Seed may also be shrivelled and cracked.  Stems and pods develop small black dots from the fungus.  The disease is favoured by wet weather from rains or heavy dews and delayed harvest once soybeans reach maturity.  The disease reduces the germ and vigour of seed.  The fungus can continue to grow in storage, when the seed moisture is greater than 14%.  Storage temperatures below 10°C (50°F) and relative humidity below 60% slow fungal growth.  Seed treatments are available for use on soybeans to control Phomopsis.  However, don’t expect seed treatments to increase germination of diseased seed by more than 15-20%.  Clean seed prior to storage and handle gently.  Monitor storage and maintain moisture below 14%.  Seed that is very low in moisture (below 12%) is prone to splits and mechanical damage.  Run augers full and slowly to minimize mechanical injury.

Edible Beans

Harvest continues, with white/black bean harvest over 75% complete, and other coloured beans at 50-75% harvested  Yields have varied from a high of 30 cwt/ac to 10 cwt/ac and quality continues to be good.  Rainfall over the last week has improved seed moisture, although re-wetting of pods increases pod splitting.  Reports of anthracnose in white and black beans have been few, and seed infection has generally been low.  Common Bacterial Blight (CBB) was widespread, but has only increased pick in a few cases.  Only retain seed from field that was inspected for anthracnose and CBB.  Seed beans should be tested for both Anthracnose and CBB which can be carried over to next year on infected seed.

Forages

Many parts of Ontario have had a killing frost marking the end of the “Critical Fall Harvest Period for Alfalfa”.  The risk of alfalfa winterkill decreases after growth is stopped by a killing frost because root energy reserves required for winter survival will not be used up by re-growth.  Killing frost occurs when temperatures reach -4°C for several hours.  Cutting now should still be weighed against the immediate need for forage.  Keep in mind that top growth can be important for winter survival.  Fall growth, in combination with snow, provides insulation to the crown which enables the plant to avoid winter temperature stresses.  After a killing frost, alfalfa feed value declines as leaf loss occurs and rain leaches nutrients quickly.  Leaving a six inch stubble will help trap snow to insulate the alfalfa crowns during cold weather.  Stubble will also protrude through winter ice sheeting, should that occur.  Late-autumn harvests may also result in increased chance of frost heaving of alfalfa.  Refer to “Risk of Alfalfa Winterkill” at www.omafra.gov.on.ca/english/crops/facts/91-072.htm

Heavy stands of grasses or red clover can sometimes smother over the winter because the top growth forms a dense, leafy mat.  In contrast, alfalfa loses most of its leaves as soon as there is a hard frost, and the remaining stems do not pose any risk of smothering.  Cool, dry, late-fall conditions encourage good alfalfa winter hardening.