In The Field with Randy

Annual Sedge Control in Rice

As I write this Eye On article on April 14th, we’re off to an incredible planting start. A whole lot of rice, soybeans, and corn have been planted. The days of planting these crops in a certain order are a distant memory. It wouldn’t be unheard of to see all 3 crops being planted on the same day on the same farm. This is clearly one of the fastest starts I can ever remember. As I’ve been telling everybody the last few days, the good Lord has a way of humbling us when we have a start like this. But who knows, we may stay on the fast track all summer and end up getting to harvest a lot of crop in August. That would be nice, especially if it turns out to be a good crop. This month I want to review annual sedge control in rice. The annual sedges have become a major problem due to becoming resistant to the ALS herbicides and the increase of a couple of formerly uncommon sedges that we’re having to deal with.

You have to be able to identify what you have. First, you must distinguish between yellow nutsedge and the annual sedges. Yellow nutsedge has thicker stems and broader leaves especially early on. You may or may not be able to find the tuber (nut) when you examine the root system. If you do, that’s a dead giveaway that you have yellow nutsedge. The root system is a complex underground network of vegetative structures including bulbs from which the shoots arise, rhizomes, tubers, and a fibrous root system extending up to 4 feet deep. The annual sedges have a much simpler root system.

The surest way to identify rice flatsedge is to crush the leaves between your fingers. If you smell a cedar-like odor, that is a sure way to know you have rice flatsedge.

The annual sedge that seems to be increasing the fastest is white margined sedge. The best identifier for it is the whitesilver look to the backside of the leaves. Also, the roots are a rusty red color.

Another annual sedge that we can see is smallflower umbrella sedge. The seedlings of this weed have needle-like leaves with the first leaves forming a V-shape.

Control can vary somewhat between these sedges. Sharpen and Bolero both have decent preemergence activity on rice flatsedge and white-margined sedge. Sharpen has good activity on smallflower umbrella sedge. Propanil, Basagran, and Loyant are effective against rice flatsedge and smallflower umbrella sedge from a postemergence standpoint. Whitemargined sedge is most effectively controlled postemergence by Basagran and Loyant.

For more information, feel free to contact me through Farmers Supply Association by cell at 870-318-0739 (cell) or by e-mail at randychlapecka@gmail.com N