Winter wheat harvest has now wrapped up across much of the province. While yields and the overall season are still fresh in mind, it is a good time to reflect and assess what worked well and where improvements or changes can be made for next year’s crop. Post winter wheat harvest is also an excellent time to incorporate a cover crop into the rotation and control challenging weeds.
Reflecting on Performance
Reflecting on how varieties performed under certain management strategies and growing conditions on your farm can be a helpful tool for improving future success as it enables you to select the most suitable varieties for the upcoming fall planting season. More information on how varieties performed in 2024 will be available shortly at GoCrops.ca.
Asking yourself questions such as, was there lodging and if so, was the variety grown prone to lodging (Figure 1), does that field have a high risk of lodging due to a history of manure or was the rate of nitrogen applied too high without splitting the application or using a plant growth regulator (PGR), can help you in fine tuning your lodging management strategies for next year. Reflecting back on other early season challenges such as disease pressure can also provide insights into the types of varieties you should be looking for or fungicide programs you should be considering. If powdery mildew for example was a challenge on your farm, selecting a variety with good resistance against that disease may be something to consider. If a fall herbicide was not applied, was weed pressure a concern? Was a herbicide applied in a timely manner in the spring or were certain weed species such as chickweed, dandelion or bluegrass a challenge? If so, consider a fall herbicide application to help mitigate those challenges in the spring with timely and effective herbicide applications. A fall herbicide application can also provide more flexibility in the spring when having to make fungicide and PGR applications. Nutrient deficiencies are another critical item to reflect on so that you can make adjustments to your overall fertility programs and be prepared to respond early in the winter wheat growing season.
Figure 1: Lodging across different winter wheat varieties in 2024 performance trials. Selecting a variety with a low lodging score is a critical part of managing lodging in intensively managed winter wheat.
Post Wheat Harvest Weed Management and Cover Crops
Post wheat harvest is also an excellent window for incorporating a cover crop into the rotation and managing weeds. Cover crops are an effective tool for maintaining and improving soil health and for livestock producers, provide an opportunity to increase feed supply. They are also excellent for reducing weed seed production and dispersal in the soil. Cover crops can be of particular benefit when trying to manage glyphosate resistant weed species such as Canada fleabane and waterhemp (a relative of redroot pigweed). Fall planted cereal rye in particular has shown to reduce glyphosate resistant Canada fleabane biomass by as much as 96% on sandy soils in one University of Guelph study and in another University of Guelph study, reduced Canada fleabane biomass by 57% on heavier textured soils. It has also reduced early season summer annual weed emergence (including waterhemp) by 41% the following season.
While cereal rye is effective in suppressing weeds, it can be a challenging and intimidating cover crop to consider, especially when new to planting cover crops; so oats are an excellent cover crop option. An oat cover crop seeded at 30-60 lbs/ac is generally cost effective, can be used for forage on livestock operations, is easy to establish, and provides comparable weed suppression to cereal rye. However, if using oat cover crop for livestock forage, consider seeding 65-100 lbs/ac.
If winter wheat was underseeded to red clover and annual weeds are a concern, allow the red clover to grow as long as possible to maximize its ground cover and nitrogen credit. An effective but labour-intensive method is to “clip” or trim the top of the red clover which will ‘chop off’ the weed seed heads at the same time. OMAFA and the University of Guelph have experimented with applications of MCPA to manage broadleaf weeds in a red clover cover crop. There are three key learnings from this work:
- The ester formulation of MCPA causes significantly less plant damage then the amine formulation.
- Red clover biomass is initially stunted during the first week after application but does recover within 2-3 weeks.
- Targeting broadleaf weeds when they are smaller will result in better control. If annual grassy weeds are predominant, then the application of MCPA Ester will be insufficient and clipping is a better option to minimize weed seed dispersal. This is because grassy weeds are usually too large to be controlled by grass herbicides.
Resources
GoCrops: https://cereals.gocrops.ca/
Vanhie, TR (2020). An Integrated Weed Management Strategy for the Control of Canada Fleabane (Conyza canadensis). http://hdl.handle.net/10214/17968
Cholette TB, Soltani N, Hooker DC, Robinson DE, Sikkema PH (2018) Suppression of Glyphosate-resistant Canada Fleabane (Conyza canadensis) in Corn with Cover Crops Seeded after Wheat Harvest the Previous Year. Weed Technol 32:244–250. https://doi.org/10.1017/wet.2018.19
Cornelius CD, Bradley KW (2017) Influence of Various Cover Crop Species on Winter and Summer Annual Weed Emergence in Soybean. Weed Technology 2017 31:503–513. https://doi.org/10.1017/wet.2017.23
Weather Summary: Thursday, July 25 to Wednesday, July 31, 2024
| Location | Highest Temp (°C) | Lowest Temp (°C) | Rain for Week (mm) | Rain Since April 1st (mm) | GDD0C April 1st | GDD5C April 1st | CHU May 1st |
| HARROW | |||||||
| 2024 | 30.5 | 12.7 | 5.6 | 324.6 | 2166 | 1559 | 2239 |
| 2023 | 29.4 | 13.0 | 53.4 | 342.6 | 1949 | 1355 | 2008 |
| 2022 | 28.2 | 13.6 | 0.3 | 301.3 | 2013 | 1437 | 2157 |
| 10 YR Norm (11-20) | 28.0 | 16.8 | 27.2 | 380.7 | 2019 | 1411 | 2176 |
| RIDGETOWN | |||||||
| 2024 | 30.3 | 9.8 | 2.2 | 435.2 | 2048 | 1445 | 2105 |
| 2023 | 30.7 | 11.0 | 38.2 | 412.9 | 1852 | 1267 | 1871 |
| 2022 | 28.7 | 12.8 | 1.5 | 211.3 | 1895 | 1326 | 1990 |
| 10 YR Norm (11-20) | 27.4 | 14.4 | 33.6 | 335.6 | 1898 | 1293 | 2027 |
| SARNIA | |||||||
| 2024 | 30.4 | 11.9 | 5.0 | 379.4 | 2035 | 1434 | 2071 |
| 2023 | 31.9 | 14.2 | 30.3 | 301.5 | 1815 | 1231 | 1799 |
| 2022 | 30.1 | 13.4 | 0.0 | 190.2 | 1887 | 1323 | 1946 |
| 10 YR Norm (11-20) | 27.5 | 15.7 | 19.4 | 338.8 | 1859 | 1257 | 1986 |
| LONDON | |||||||
| 2024 | 30.5 | 11.3 | 5.3 | 470.5 | 2025 | 1420 | 2091 |
| 2023 | 29.8 | 11.7 | 69.3 | 400.4 | 1844 | 1259 | 1868 |
| 2022 | 27.8 | 11.8 | 2.8 | 228.7 | 1838 | 1277 | 1933 |
| 10 YR Norm (11-20) | 27.3 | 14.7 | 16.9 | 341.7 | 1877 | 1276 | 2009 |
| BRANTFORD | |||||||
| 2024 | 30.7 | 11.2 | 9.9 | 418.4 | 1973 | 1373 | 2040 |
| 2023 | 29.6 | 11.5 | 62.0 | 339.4 | 1834 | 1248 | 1857 |
| 2022 | 28.9 | 11.2 | 0.3 | 229.9 | 1843 | 1272 | 1889 |
| WELLAND | |||||||
| 2024 | 30.6 | 12.5 | 0.6 | 392.9 | 2035 | 1431 | 2127 |
| 2023 | 29.6 | 12.6 | 77.8 | 360.7 | 1853 | 1261 | 1879 |
| 2022 | 26.8 | 12.0 | 14.6 | 263.3 | 1890 | 1311 | 1996 |
| 10 YR Norm (11-20) | 27.3 | 14.7 | 14.8 | 322.3 | 1885 | 1283 | 2022 |
| GODERICH | |||||||
| 2024 | 29.2 | 10.0 | 4.0 | 266.5 | 1841 | 1244 | 1886 |
| 2023 | 29.3 | 10.6 | 8.0 | 238.2 | 1698 | 1130 | 1706 |
| 2022 | 27.7 | 11.8 | 0.0 | 178.4 | 1720 | 1162 | 1785 |
| 10 YR Norm (11-20) | 24.9 | 13.4 | 30.0 | 299.1 | 1697 | 1105 | 1811 |
| ELORA | |||||||
| 2024 | 29.2 | 9.7 | 12.5 | 358.6 | 1836 | 1243 | 1904 |
| 2023 | 29.1 | 10.5 | 26.8 | 320.6 | 1695 | 1124 | 1706 |
| 2022 | 27.7 | 9.0 | 0.0 | 196.2 | 1684 | 1126 | 1728 |
| 10 YR Norm (11-20) | 26.1 | 12.1 | 22.9 | 338.7 | 1689 | 1101 | 1794 |
| MOUNT FOREST | |||||||
| 2024 | 29.9 | 9.5 | 7.5 | 340.1 | 1819 | 1229 | 1889 |
| 2023 | 28.6 | 10.2 | 28.3 | 316.8 | 1694 | 1128 | 1712 |
| 2022 | 26.9 | 11.6 | 21.5 | 259.7 | 1686 | 1134 | 1760 |
| 10 YR Norm (11-20) | 25.6 | 12.6 | 24.5 | 347.7 | 1669 | 1089 | 1790 |
| BARRIE | |||||||
| 2024 | 28.8 | 11.1 | 0.0 | 501.4 | 1781 | 1191 | 1863 |
| 2023 | 29.3 | 9.2 | 6.7 | 381.9 | 1680 | 1108 | 1697 |
| 2022 | 27.9 | 9.9 | 0.0 | 261.5 | 1655 | 1093 | 1724 |
| 10 YR Norm (11-20) | 26.5 | 12.4 | 17.1 | 305.0 | 1653 | 1075 | 1768 |
| PETERBOROUGH | |||||||
| 2024 | 30.3 | 10.6 | 3.8 | 355.9 | 1832 | 1238 | 1881 |
| 2023 | 29.5 | 8.7 | 40.1 | 333.9 | 1720 | 1139 | 1694 |
| 2022 | 27.8 | 9.9 | 0.2 | 261.9 | 1701 | 1129 | 1764 |
| 10 YR Norm (11-20) | 28.1 | 12.2 | 20.3 | 303.1 | 1716 | 1126 | 1800 |
| KEMPTVILLE | |||||||
| 2024 | 31.2 | 14.1 | 12.4 | 395.0 | 1928 | 1335 | 2036 |
| 2023 | 29.1 | 9.1 | 56.0 | 356.7 | 1843 | 1266 | 1843 |
| 2022 | 27.6 | 13.0 | 1.1 | 384.4 | 1820 | 1231 | 1908 |
| 10 YR Norm (11-20) | 28.3 | 13.9 | 12.4 | 329.4 | 1800 | 1212 | 1916 |
| SUDBURY | |||||||
| 2024 | 29.4 | 10.9 | 3.7 | 420.1 | 1661 | 1093 | 1762 |
| 2023 | 28.6 | 9.4 | 22.6 | 424.1 | 1593 | 1060 | 1644 |
| 2022 | 25.5 | 13.0 | 9.2 | 256.8 | 1538 | 1006 | 1656 |
| 10 YR Norm (11-20) | 26.8 | 13.2 | 11.9 | 311.0 | 1546 | 1018 | 1699 |
| EARLTON | |||||||
| 2024 | 29.9 | 10.6 | 4.7 | 360.9 | 1637 | 1076 | 1729 |
| 2023 | 27.4 | 8.2 | 7.3 | 262.5 | 1567 | 1033 | 1609 |
| 2022 | 28.5 | 11.6 | 25.7 | 276.6 | 1536 | 1012 | 1647 |
| 10 YR Norm (11-20) | 25.8 | 12.0 | 11.6 | 282.4 | 1442 | 936 | 1587 |
| SAULT STE MARIE | |||||||
| 2024 | 27.8 | 10.7 | 4.3 | 390.7 | 1529 | 948 | 1557 |
| 2023 | 27.3 | 9.2 | 25.5 | 266.1 | 1518 | 983 | 1530 |
| 2022 | 24.9 | 11.1 | 23.5 | 303.9 | 1315 | 786 | 1325 |
| 10 YR Norm (11-20) | 25.5 | 9.5 | 21.7 | 322.9 | 1383 | 855 | 1457 |
| THUNDER BAY | |||||||
| 2024 | 31.8 | 7.9 | 0.0 | 278.1 | 1439 | 881 | 1448 |
| 2023 | 31.4 | 8.2 | 13.1 | 211.8 | 1407 | 894 | 1476 |
| 2022 | 28.7 | 8.9 | 21.9 | 409.6 | 1311 | 815 | 1370 |
| 10 YR Norm (11-20) | 26.7 | 11.1 | 14.8 | 312.5 | 1357 | 840 | 1451 |
| FORT FRANCES | |||||||
| 2024 | 30.1 | 7.7 | 19.9 | 365.1 | 1513 | 944 | 1557 |
| 2023 | 31.5 | 6.3 | 23.1 | 253.6 | 1566 | 1047 | 1672 |
| 2022 | 28.6 | 8.3 | 17.2 | 522.5 | 1388 | 894 | 1515 |
| 10 YR Norm (11-20) | 27.0 | 10.4 | 14.5 | 310.1 | 1484 | 948 | 1608 |