Ontario field conditions on the upswing, so too the weeds

Conditions

Field conditions across the province have improved vastly over the last ten days. With sunshine and temperatures in the high teens to even high twenties in some areas, planting is rolling across a majority of the province. Field work began early last week with lighter soil but by late last week, work on heavier, clay soils was beginning.

Frost is expected this week in some regions of the province, so monitoring will be key. Corn not likely a concern but soybeans will need to be checked after frost if emerged. Lighter soil types tend to be more prone to frost damage. Frost temperature on wheat -2 C at boot stage for longer than 2 hours (lower stem, leaf damage), but it is dependent on crop health, temperature, and length of frost. Likely just leaf tip injury but be sure to give a few days after frost to determine impact.

Cereals

Winter cereals continue to impress and develop quickly across the province aided by the prolonged warm temperatures. Wheat development in Essex County is 90 GDD ahead and is now heading, with the majority in the southwest at flag leaf. Overall, foliar leaf disease pressure is very low, although powdery mildew is appearing in some very susceptible varieties. T3 fungicide application for FHB is to occur as we reach heading across the province.

Eastern parts of the province are reporting lots of applications of fungicide and PGRs in the last week, with wheat between growth stages 32-34. Spring cereals are emerging well across the province. Stands are thin in areas from either geese damage or where water pooled after the heavy rains at the beginning of the month.

Corn

Corn planting is full speed ahead across the province, with many acres being planted over the weekend. Conditions are good and planting is going smoothly. Some of the earliest planted corn has begun to emerge in various regions. Most of it is still at spike leaf. The very southern parts of Ontario estimate there is 70-80 per cent planted as of mid-week, with a hope to have corn planting complete by the weekend.

Soybeans

Early planted beans are emerging, with acres planted varying across Ontario. Eastern and central regions are suggesting anywhere from 0 – 40 per cent of bean acres are seeded, with the southwest reporting double that (upwards of 75-80 per cent). Pre-emerge herbicides are being applied to soybean acres this week as field conditions are appropriate. Weed pressures increased dramatically across the province with rain and warm weather. Herbicide application timing will be critical in the coming days, particularly with no-till acres.

Forages

Triticale and rye harvests are progressing in the southwest but have not yet begun in the east & central regions. Harvests are still at least a week away in many areas of the province. First cut of grass hay or alfalfa has not begun yet. Some frost damage is being reported on orchardgrass this week, and with more frost in the forecast, some further damage should be expected.

Weed control

“Small weeds are easier to kill than big weeds” (Dr. Peter Sikkema). Dandelion’s are large and pressure high across the province which can require higher rates of glyphosate to control larger dandelions:
For dandelions- 4” – 0.67L/ac glyphosate
                                6” – 1L/ac glyphosate
                                8” – 1.33L/ac glyphosate

In preparation for future years controls, dandelions can be applied at the same rate in the fall with better control than spring applications. See charts below.

Winter canola

Winter canola has flowered across the province and stands that survived the winter are looking strong. Flowers are sensitive to cold temperatures, and recent frost events may have caused some damage, but serious economic losses are unlikely as temperatures didn’t drop significantly below freezing. Check out this article for photos displaying the Impact of Late Spring Frost on Winter Canola – Field Crop News. Monitoring for cabbage seedpod weevil has begun across the province. More fields across the province have received white mold fungicide applications. Applications should be targeted between 20-50 per cent flowering.

– Click here to read the full field crop report for May 15, 2023 at the Field Crop News website