Donnie Miller and Daniel Stephenson
The lingering effects of winter temperatures and excessive moisture conditions into May will result in much later planting of soybean and cotton than in years past. If anything positive can be taken from this scenario it is the fact that producers have time to scout their fields for ryegrass infestations and the need for control measures in the fall. Ryegrass infestations were very prominent this year in many fields in Northeast Louisiana. As is the case with most situations with ryegrass, infestations began primarily along head lands and drains within the field and appeared to be spreading out from there. Ryegrass can linger into crops until temperatures increase and can cause problems with competition, especially under limited moisture conditions. Effective control of infestations often requires a two-fold approach, with residual soil applied herbicides in the fall followed by POST treatment in late January for escapes. The primary objective is to eliminate seed production and deplete the seed-bank over time. The confirmation of glyphosate-resistant (GR) ryegrass in Mississippi several years ago led to a tremendous amount of research in the programs of Dr. Jason Bond and Dr. Tom Eubanks in identifying effective control measures. These measures have proven very successful in research in Louisiana as well in the absence of GR plants. The fact sheet below developed by Drs. Bond and Eubanks outlines control strategies for GR ryegrass in various cropping systems. It is very important to remember that emerged plants need to be controlled at the time of fall residual application.