We’ve had a warm, wet late winter in Mississippi and vegetation has emerged on many acres. This past winter should come as no surprise. The advent of effective burndown options has allowed winter weed control to become the norm versus wide-scale tillage in late spring. There are lots of ways to obtain clean fields, but the main point is to not delay your choice, particularly burndowns.
Many want to apply a burndown plus a residual and start clean. Given our spring rains, however, a timely burndown even with a residual added many times will not carry us to planting. With corn and rice it is more likely, but other crops are not as consistent.
Regardless of your choice, residuals will do a good job holding additional emergence, but under adverse conditions they may not hold a second flush prior to planting.
Another approach is a two-step program. It will allow you to overlay or get a pre out before or right behind the planter to aid in control of spring weeds.
If you have a ryegrass issue and did not address it earlier this fall, it will require the addition of a post grass product in your burndown or as a separate application. In most cases, ryegrass is not a whole-field problem. Some border treatments, whether residual or a post treatment, for a couple of years can reduce this problem greatly.
In the case of marestail (and we must consider it resistant), prolonged emergence or a second flush following a wet spring has been an issue. It will take a three-way mix to hold/control resistant marestail, but escapes may still occur.
Regardless of the downside, using early burndowns is an essential practice. I have had conservations with growers who are considering eliminating an early burndown and applying them at planting. This can work, but emerged vegetation will just get bigger and be more difficult to control. Ground void of vegetation will dry and warm faster. Although rare, the reverse can happen and vegetation will wick soil moisture in a dry spring.
The recent heavy rains have caused delays on some acres. Once fields drain, get burndowns applied. Many times we tend to hold off, hoping to run a ground rig, but the calendar is at a point where we can delay no longer. The drop dead date has passed; get your burndowns applied now.
Early burndowns will put you more in control of planting. As soils dry faster, you can plant earlier. To increase or make high yields, early planting is essential. We are not afforded many days to plant in March/April, so we need to take advantage of every day it is dry. In most years, nothing is going to be ideal/perfect, but the negatives associated with early planting (regardless of crop) far outweigh the results from later planting dates.
The take home message is do not skip on burndowns. Budgets are tight, but this is one area that will allow you to be more in control of when you plant, and for that reason it is an essential practice.
Alan Blaine is a former Mississippi Extension Agronomist/Soybean Specialist. In 2008, he co-founded Southern Ag Consulting with Mitt Wardlaw and Brian Ward. In 2009 he also co-founded Alliance Ag Risk Management.