For many of us, fall is about seeing the “payoff” from all our hard work during the past season. While harvest does allow us to make observations and summarize our findings from the past season, I’d encourage you to also consider preparing your seed bed for next year. For some of you that means tillage, for others who do not intend to till their acres, this means controlling those fall emerged weeds.
While this past growing season was hot and dry for many of us, the recent fall rains have provided the moisture necessary for winter annual and perennial weed populations to thrive. Those same weeds will not only be tougher to get sufficient control of next spring, but will inhibit us from getting our 2017 crop established and off to the best possible start.
Fall is an excellent time to control many of these troublesome winter annual and perennial weeds such as marestail, dandelion, chickweed, henbit, field pennycress and purple deadnettle. Herbicides applied in the fall have a wide window of application as we have from harvest up until the ground freezes. After the ground freezes, herbicide effectiveness is reduced due to limited translocation to the root system of the weeds with the cooler temperatures.
The most important thing we need to accomplish with these applications is to control the fall emerged weeds. Of these weeds, the most critical to control in Ohio is marestail. Marestail will germinate and emerge almost year round, but the majority emerge in the fall and approximately 70 to 85% of those will survive the winter. The fall germinated weeds are much more difficult to control in the spring versus in the fall. Generally, the use of residual herbicides in the fall has not proven to be economically beneficial. These products increase management costs but have not proven to consistently offer much aid in the suppression or control of weeds in the spring.
Benefits of clean fields in the spring include:
- Less opportunity for pests and insects to lay eggs
- Easier to control spring germinated weeds consistently
- Soils will be dryer in spring with less ground cover for sunlight to penetrate
- Less ground cover in the spring will result in warmer soil temperatures
- More consistent stand establishment due to less competition for sunlight/nutrients
- Earlier planting on corn, resulting in dryer corn at harvest
- Earlier planting consistently results in increased yields (see PFR study results below).
2015 PFR Corn Planting Date Study, Ohio. For full study details, click here.
2015 PFR Soybean Planting Date Study, Ohio. For full study details, click here.
Beck’s three-year Practical Farm Research (PFR) Corn Planting Date study in Ohio reflects that the April 16 to April 30 planting window represents the highest average yield of all trials planted at various times throughout late April to early June.
To ensure our best chance of successful weed control and maximize our greatest yield potential for 2017, we must control weeds that germinate this fall. We can achieve effective and successful weed control in the fall at minimal costs, resulting in cleaner fields in the spring that will provide us with the opportunity to get 2017 off to the best start possible.
For more Agronomic News from Luke Schulte, please visit his blog.