Since many of you are about to start your “burndown” herbicide applications, I would like to provide a few tips on some troublesome weeds to make sure we are successful. The photo on the left is of a great 
cover crop with triticale and clover. However, if you look really close (you may not be able to see at this resolution), there are wild radishes and Italian ryegrass present. Identify what weeds are present. Below, is a list of five troublesome weeds that can be difficult to terminate with a burndown herbicide application. And remember…..START CLEAN STAY CLEAN!!!!
- Cutleaf evening primrose and wild radish can be very troublesome to control. 2,4-D alone or with a Roundup tank mixture (Roundup+Valor) works well for control. If a grower does not want to use 2,4-D in the sprayer, they can rely on Liberty or Roundup+Valor. If this option is used, expect 70%-80% control of pre-blooming primrose. Control can be increased by about 15% if primrose and radish are allowed to reach full bloom. I observe 1 to 2 fields a year that have high populations of false chinch bug feeding on 1 leaf cotton. This phenomenon is usually patterned with high populations of cutleaf evening primrose.
- Italian Ryegrass has proven to be a very troublesome weed in Turner County in some places. If you have a field that has this weed in it, here are some tips. Use a high rate of roundup and you may possibly have to follow up with select. If a farm has a history with this weed, It may be beneficial to use some PREs in your small grains over winter. Italian ryegrass grows a massive root system that can make strip tillage very difficult.
- Successful bermudagrass burndown can be obtained by making multiple applications that are timed according to the chart at the botton of the blog. Dr. Prostko provided us with the chart below that shows where spring emergence of bermudagrass can be correlated to control. Also, Dr. Prostko did some work that showed where two split applications of glyphosate at a medium rate can control bermudagrass better than one high rate. Growers should also consider the use of select later on after crop emergence.
- Nutsedge control in a burndown can be extremely difficult. Roundup may not provide the level of control you are looking for. In this case, tillage may be your only answer.
