Over the last several years, problems with ducksalad and roundleaf mudplantain have increased. Additionally, in the past year, a number of calls have been received regarding a strange nutsedge that was not controlled with Permit. This nutsedge is actually smallflower umbrella sedge and is common in California. This was also the first rice weed to develop resistance to the ALS herbicide Londax.

It appears that this is the same situation, and this nutsedge also appears to be resistant to the other ALS chemistries including Permit and Grasp. In Missouri, this nutsedge also seems to be associated with zero-grade, water-seeded fields- which is similar to California production practices.

To date, our research has indicated that propanil provides good control of smallflower umbrellasedge, and to date, all of our control complaints have come from fields where no propanil was used. Basagran appears to be providing good control of the large escapes; however, we are recommending traditional, early-post propanil applications and according to our counterparts in California, this propanil is "the recommendation".

In a small study we did in 2005, it appeared that Storm and propanil provided good control of roundleaf mudplantain.

In my thesis project, we are finding some carryover of the herbicide Newpath when we rotate back to conventional rice. However, we are not finding damage where Beyond was used. We want to stress that a Clearfield-to-conventional rotation should not be used- unless the producer is certain that there is no red rice present in a field. These types of rotations can result in the Clearfield trait crossing into red rice and would render the system useless.

We are conducting some renewed research on the herbicide Bolero, but find that it still requires critical water management. With current economics and more forgiving herbicides, Bolero still has a limited fit.

2006 Field Day Report