As combines rolled across fields, several reports originating from the combine seat shared that there was already a green carpet of winter annuals established in fields.
This is not entirely surprising, thinking back to our spring; many fields had challenges in controlling winter annuals. Some fields were not successfully burned down until the winter annuals had produced viable seed. Fields, especially no-till, were awash with color as the winter annuals flowered in April and May.
What options do farmers currently have with these problem fields? For those considering a fall herbicide application, fall applied herbicide treatments can normally be applied from mid October until early December. Greatest success takes place when daytime highs exceed 50 degrees for several days post application. Products that do not have appreciable residual activity in soil (glyphosate, 2,4-D, Gramoxone alone) should be applied late enough so that weed reemergence after application is minimal.
The addition of metribuzin to these burn down programs extends residual activity in the fall. This added residual from metribuzin is especially beneficial in fields with high populations of Marestail. When using herbicides in the spring or fall, be sure to read the herbicide label to insure that the product is approved for the intended application.
For farmers who have yet to decide on their planning intentions for 2018, addressing the issue in the spring, while often not as effective, will provide flexibility in switching crops. If we experience a colder than average winter, with limited snow cover, the winter annuals could suffer. However, a mild winter will allow the weed population to flourish. In that scenario, farmers can expect dense population of winter annuals in the spring, forming a “mat” in the field. This often slows soil drying and warming and interferes with planting and tillage applications in the spring.
Tillage operations through dense stands of winter annuals rarely provide adequate control with a single pass. Before the snow flies, check your fields for “greenness” and be prepared to have a fall or spring management plan in place to manage weeds before planting the 2018 crop.
Several upcoming dates for your calendar:
• Private Pesticide Applicator Training and Testing Clinic takes place Dec. 13, at Celebrations 150 Ltd., located at 740 E. US Hwy. 6, Utica. Pre-registration required. Register at www.pesticidesafety.illinois.edu or call 877-626-1650. Check-in starts at 7:30 a.m. Cost is $40 per session.
• Bureau, LaSalle, Marshall and Putnam Counties Unit will host four Testing-Only Sessions at Henry, Ottawa, Oglesby/IVCC and Princeton. For more information, call the main extension office at 815-224-0889.
• Feb. 21 is the Northern Illinois Crop Management Conference in Malta, a great lineup of speakers and the opportunity for eight continuing education units for Certified Crop Advisors.
Until next time, from the farm fields in northern Illinois, this has been your commercial agriculture educator with the University of Illinois Extension, Russ Higgins.
Russ Higgins is from the University of Illinois Extension, Northern Illinois Agronomy Research Center.