Farmers using BASF’s NewPath herbicide and Clearfield 161 rice have seen remarkable results controlling yield-choking red rice weeds this year.
But, LSU AgCenter scientists say water – an old ally in the battle against red rice – remains critical. In fact, keeping rice fields damp in between applications of the chemical NewPath can be a big factor in slowing or stopping red rice seeds from germinating from 1-inch deep or more beneath the soil.
“You’ve got to use all the water you can to your best advantage,” said Eric Webster, an LSU AgCenter weed scientist who has studied red rice control. “You’ve got to manage your water.”
The timing of two separate chemical applications to control red rice is another factor. LSU AgCenter researchers now recommend a total postemergence use of the herbicide. Farmers using that method have seen 99 percent control of red rice in their fields in the past year.
Webster explains how it works:
In a drill-seeded situation, the first application of NewPath herbicide should go on at emergence of plant material from the seed.
“You assume you’ve got red rice coming as well,” Webster said. In water-seeded rice fields, the first shot of chemical goes out at “pegging,” when a tiny root emerges from the seed.
A second application of the herbicide should go out about 14 days later to catch larger red rice plants.
Between the two chemical applications, the trick is to keep fields moist, Webster said. If the area starts to dry out, either pump water on or stop pumping rain water off, he said.
“Use that water to your advantage. You don’t want the soil cracking. You just need to manage the water a little closer. With a good rainfall, hold that water on the field a little longer,” Webster said. “Managing your water is probably more important now than it’s ever been – even with the Clearfield technology.”
The LSU AgCenter and the LSU College of Agriculture