This is the second part of our "Stepping Up Your Managment Game" series, designed to focus on steps and practices we can do to intensify our management and help our bottom line.
With all the business of harvest, its not always convenient to start thinking of the next step. With some rain in the forecast for the next week, we thought now would be a good time to put a bug in your ear. Its time to start thinking about fall burndown. This blog will cover benefits of a fall burndown, timing and limitations for a fall burndown, and some recommended products.
Benefits of a fall burndown
Fall applications of herbicides can provide a large benefit by reducing levels of winter annual and perennials and help save time and money in the spring. Utilizing fall burndown not only provides weed control that extends into planting, but subsequently widens the window of application for postemergence applications. We can think of the impact that weeds have this way: a growing weed is using water and nutrients that should be reserved for the plant. With the past two growing seasons as dry as they have been, it is imperative that we conserve as much soil moisture as possible. Every little bit that we can keep in reserves and not use to fuel weed growth will go towards getting corn and soybeans off to a good start. With high levels of weed pressure, fall burndown typically provides a higher level of control than spring applications. Additionally, applying herbicides in the fall can reduce a producer’s risk of drift onto sensitive crops and off target movement.
With a fall burndown, we are targeting our winter annuals. These include henbit, chickweed, marestail, and tansy mustard. While some of these are “easier” to control, a fall application will help provide more intensive management to some of the more challenging weeds such as marestail. A fall application will also result in an application while the plant is at a smaller size, providing much more uniform control. If the plants are allowed to overwinter, they will begin growing earlier the next spring and further impact soil moisture and nutrient levels for the next crop. This additional growth will result in weeds forming a thick carpet or mat, which does not allow the soil to warm as rapidly in the spring, or dry out in wet conditions, and generally does not provide as nice of a seed bed for planting.
Studies have shown that a burndown can occur at a more timely interval when conducted in the fall than in the spring. Spring field conditions are often harder to deal with and result in late or delayed herbicide application. Fall conditions are often more suitable for sprayer traffic and helps to distribute the workload throughout the year.
We don’t need to be concerned about volunteer corn at this point. The winter temperatures will provide the control we need for the next growing season. That is not to say more corn plants won’t germinate in the spring, however, winter temperatures should provide excellent control for all that are germinated.
Timing and Limitations for a Fall Burndown
Our timing for fall burndown is generally mid October to mid November. We can sometimes extend our applications past this point even, depending on the temperature trends and growth of the plant. Essentially, to apply, the plant must be exhibiting some growth for a fall burndown to be effective. Applications can extend past several frosts, as winter annuals are built to withstand these temperatures and still be capable of normal growth and development. However, applications themselves should generally occur when air temps are in the 50s for optimum herbicide activity and ease of tank mixing.
Be aware that herbicides labeled for fall applications will have timing restrictions that should be followed. If no residual will be used in the mix, then the application should occur after that maximum amount of winter annuals have emerged but prior to dormancy of these plants. If a residual is included, be sure to check the planting intervals to insure you are able to plant corn or beans at the correct time the next spring.
Fall burndown will not provide control for summer annuals. Any residual from a fall application will not last long enough to impact summer annual levels. The next step in our weed management plan will be used for summer annual control.
Recommended Products
A fall burndown should not be expensive. Keep this application cost down. Our goal is to knock out a maximum amount of weed pressure and save some money for more challenging weeds to control, such as some of our summer annuals like waterhemp and palmer amaranth. Generally, a mix of our common herbicides can provide the best control for the winter annuals. For those not interested in a residual, a 2,4-D, dicamba, and roundup mix can provide excellent control for our wide range of winter annuals. If considering a residual, add Basis Blend or Atrazine to that mix to extend our control all the way to planting. The residual not only suppresses living winter annuals but will also provide control for any winter annual seeds in the seedbank. Basis Blend has been shown to provide control from applications all the way to May. These lower cost options can be some of the most impactful dollars you can put towards your operation. Contact one of the Pederson Seed Team for a customized recommendation and rates to best fit your operation and restrictions.
Resources