Conditions
Some sporadic rains have occurred across the province this last week. In areas where planting is mostly complete, these rains have generally been well received. Temperature swings between stretches of very warm and cooler weather has continued this spring, though crop heat unit (CHU) accumulation is similar to slightly ahead of normal.
Cereals
Emergence of winter wheat heads is slowly occurring across the province. In the longest season areas and in fields planted early, heads have emerged, and fusarium head blight (FHB) fungicide applications (T3) have just started. Applications are expected to start in earnest this weekend and progress over the next week or two as winter wheat approaches the ideal growth stage (anthers emerging from the middle of the wheat head) across the province.
To help time your fungicide applications, Day 0 occurs when 75% of heads on main stems are fully emerged. Day 2 is typically when anthers have just started to emerge from the middle of heads (start of anthesis) and has traditionally been the optimum timing for fungicide efficacy against FHB. Fungicide applications can still reduce DON levels as late as days 6 to 8.
Corn
Except for corn to be planted after first cut hay, corn planting is nearly complete. Some of the remaining corn to be planted on heavier soils has or is close to wrapping up. In most cases, emergence and stands are reported to look excellent. Some of the earliest planted corn may be approaching V4-V5 stage, while corn planted during the week of May 9 to 15 is generally around V2-V3. Some early sidedress nitrogen applications are just starting and are expected to get underway in earnest in some areas the end of this week and into next.
Uniform plant emergence and development is an important foundation for high yields. Early vegetative stages are an excellent time to investigate corn stands for missing or late emerging plants to troubleshoot for any issues that may have led to these (Figure 1).
Soybeans
Soybean planting continues this week. Progress is highly variable depending on area, soil type and rainfall, but may be about 75% complete overall. Planting is now in full swing in many of the heavier textured soils and is expected to near completion this weekend.
Depending on tillage and planting depth, dry soil has been a concern for some. Planting deeper has been required to find moisture, especially in rougher or drier seedbeds. In general, planting 1.5” is ideal for soybeans, while planting deeper than 2” on tougher or heavier textured soils can be a challenge for emergence. While most have reported excellent stands for beans that are emerging, rain has or will be welcome to complete germination and emergence.
Forages
First cut alfalfa for dairy-quality hay has just started this week, especially on operations where more than 3 cuts are made each year. Alfalfa appears to be slightly delayed (e.g. some fields still not in bud as of late last week), likely due to the cool start this spring. Grasses have been heading out, so cuts should be made on grass hay if targeting quality. Insects should be monitored now in forage crops. Alfalfa weevil has been reported at high levels in some areas. Harvesting is typically the recommendation for populations approaching thresholds. If populations are high but harvest is more than 7-10 days away, control may be warranted, though crop protectant products can also negatively impact beneficial insects. Given recent weather fronts and thunderstorms in some areas, potato leaf hopper scouting should also begin. Details on scouting and thresholds for alfalfa insect pests are available on FieldCropNews.com.
Weather Data – May 23 – 29, 2022
| Location | Year | Highest Temp (°C) | Lowest Temp (°C) | Rain (mm) | Rain (mm) April 1st | GDD 0C April 1st | GDD 5C April 1st | CHU May 1st |
| Harrow | 2022 | 22.8 | 5.9 | 16.0 | 153.3 | 596.0 | 348.4 | 440.6 |
| 2021 | 30.1 | 6.1 | 27.6 | 102.0 | 673.2 | 396.6 | 423.0 | |
| 10 YR Avg. (2011-20) | 25.4 | 10.5 | 31.1 | 187.8 | 656.7 | 364.1 | 489.7 | |
| Ridgetown | 2022 | 24.3 | 5.2 | 4.2 | 124.5 | 545.2 | 305.5 | 390.0 |
| 2021 | 30.3 | 2.9 | 32.6 | 96.4 | 621.1 | 353.0 | 402.4 | |
| 10 YR Avg. (2011-20) | 25.1 | 8.0 | 26.2 | 163.0 | 603.8 | 316.2 | 447.6 | |
| London | 2022 | 24.5 | 5.7 | 2.0 | 135.0 | 541.2 | 306.0 | 388.1 |
| 2021 | 30.1 | 3.6 | 23.3 | 105.1 | 616.0 | 352.2 | 375.0 | |
| 10 YR Avg. (2011-20) | 25.1 | 8.4 | 25.6 | 168.0 | 592.1 | 308.6 | 444.8 | |
| Brantford | 2022 | 24.9 | 5.8 | 0.3 | 121.1 | 534.9 | 294.0 | 364.1 |
| 2021 | 32.1 | 2.6 | 17.7 | 100.0 | 591.8 | 327.2 | 368.9 | |
| Welland | 2022 | 26.0 | 6.5 | 0.7 | 112.5 | 577.1 | 326.8 | 399.0 |
| 2021 | 28.1 | 3.6 | 17.6 | 71.0 | 601.6 | 333.1 | 366.7 | |
| 10 YR Avg. (2011-20) | 24.7 | 8.8 | 18.9 | 175.8 | 595.7 | 311.0 | 442.2 | |
| Elora | 2022 | 24.2 | 5.1 | 1.0 | 83.4 | 492.4 | 264.2 | 340.3 |
| 2021 | 29.8 | 1.3 | 13.7 | 84.3 | 530.6 | 275.2 | 315.8 | |
| 10 YR Avg. (2011-20) | 23.9 | 7.6 | 16.0 | 165.3 | 508.2 | 237.5 | 374.6 | |
| Mount Forest | 2022 | 23.6 | 4.1 | 4.0 | 117.8 | 499.4 | 277.6 | 365.0 |
| 2021 | 28.6 | 1.2 | 16.5 | 90.4 | 537.7 | 285.3 | 318.0 | |
| 10 YR Avg. (2011-20) | 23.5 | 7.9 | 18.6 | 152.6 | 495.5 | 232.7 | 371.4 | |
| Peterborough | 2022 | 21.4 | 3.7 | 2.3 | 92.3 | 496.2 | 253.5 | 353.9 |
| 2021 | 28.3 | -1.2 | 2.7 | 80.6 | 536.6 | 270.4 | 331.2 | |
| 10 YR Avg. (2011-20) | 24.7 | 6.8 | 18.0 | 149.3 | 524.5 | 253.3 | 396.8 | |
| Kemptville | 2022 | 24.2 | 3.9 | 2.1 | 200.9 | 553.2 | 290.9 | 390.5 |
| 2021 | 28.0 | -0.7 | 0.0 | 78.7 | 620.3 | 348.1 | 374.3 | |
| 10 YR Avg. (2011-20) | 24.8 | 8.2 | 13.5 | 158.6 | 547.8 | 277.9 | 414.9 | |
| Earlton | 2022 | 20.7 | 1.4 | 25.3 | 110.2 | 399.4 | 206.0 | 338.6 |
| 2021 | 24.3 | -4.1 | 6.4 | 63.0 | 499.1 | 252.3 | 302.0 | |
| 10 YR Avg. (2011-20) | 22.7 | 5.0 | 17.8 | 125.6 | 348.6 | 161.9 | 301.3 | |
| Sudbury | 2022 | 18.8 | 3.0 | 25.9 | 133.1 | 405.4 | 202.9 | 316.2 |
| 2021 | 25.6 | -0.7 | 18.2 | 95.9 | 495.7 | 250.3 | 298.7 | |
| 10 YR Avg. (2011-20) | 23.2 | 8.6 | 15.3 | 148.6 | 396.9 | 187.5 | 324.5 | |
| Thunder Bay | 2022 | 23.3 | -3.3 | 11.7 | 273.2 | 265.2 | 99.4 | 197.6 |
| 2021 | 27.0 | -4.6 | 4.3 | 150.0 | 388.1 | 155.4 | 258.1 | |
| 10 YR Avg. (2011-20) | 19.5 | 4.9 | 32.5 | 129.5 | 314.0 | 115.4 | 241.3 | |
| Fort Frances | 2022 | 21.6 | -2.0 | 0.0 | 245.7 | 288.7 | 124.8 | 240.9 |
| 2021 | 26.5 | -4.9 | 0.3 | 107.4 | 431.8 | 193.1 | 335.6 | |
| 10 YR Avg. (2011-20) | 21.6 | 6.5 | 18.8 | 108.7 | 373.9 | 157.2 | 299.7 |