A Program Approach to Weed Control

My career in the rice industry began in mid-1997 when the company that I was working for registered Stam brand propanil in California. In 2001, the company was purchased by Dow AgroSciences, which had a portfolio of rice products. For many years, I was a Sales Representative for Dow AgroSciences and just recently assumed the role of Market Development Specialist.

Although rice farmers began the 2015 season with another tremendous water shortage, the season itself was almost perfect. Harvest went off without a hitch, and yields were outstanding because of good growing conditions. In 2016, the water situation is better than last year – but not as good as it could be.

GRANITE Herbicide from Dow AgroSciencesIn addition to managing water and fertility, a program approach to weed control is a crucial element in California rice farmers’ overall production strategy. The No.1 weed that growers have to contend with is watergrass, which infests about 99 percent of our rice acres and can be a huge contributor to yield loss. Other yield-robbing weeds that we commonly fight include sprangletop, ricefield bulrush and smallflower umbrella sedge. Aquatic broadleaf weeds, such as California arrowhead, ducksalad and monochloria, are less of a problem – but, in some instances, can be very troublesome. We also have redstem – a broadleaf weed that appears later in the season and is easy to control with Grandstand.

The best way to control weeds in California rice fields is to use a program approach. A typical weed-control program that Dow AgroSciences promotes is to apply Cerano on the day of, or the day after, seeding to control sprangletop. When rice reaches the 2½- to 4-leaf stage, apply Granite GR in a sequential format. The advantage of this strategy is that the farmer has flooded the field, seeded the field, applied clomazone in the flood and maintained the flood until he applies Granite GR.

The significance of this scenario is that the flood itself suppresses weed growth and germination, which all comes back to water management. Herbicides such as clomazone and Granite GR are dispersed in the flood and delivered via the flood to the weeds that we are trying to control. Dow AgroSciences recently announced that a new rice herbicide with a new mode of action is in development and potentially could be registered for the California market in 2019. Stay tuned for more details.

As far as insect pests, the worst outbreak of armyworms that we have seen in recent years occurred in 2015. Pyrethroids were not working well, so the California Rice Commission in cooperation with Dow AgroSciences secured a Section 18 crisis exemption for Intrepid 2F, which provided outstanding control of armyworms.
Overall, California rice farmers do a terrific job of using technology effectively to grow their crops, working with their PCAs and producing high-quality rice that is sought after in world markets. The Sacramento Valley is just a good place to grow rice.

Rick GeddesRick Geddes
Market Development Specialist, Dow AgroSciences
Yuba City, Calif.

  •  B.S., Plant and Soil Science, Southwest Missouri State University. M.S., Agronomy, University of Arkansas
  • As Market Development Specialist for Dow AgroSciences, Geddes is involved in bringing to market new technology and new uses for existing products, mentoring younger people in the field and assisting with product launches.
  • Member of California Association of Pest Control Advisers (CAPCA)
  • Regularly attends Rice Technical Working Group meeting
  • Past board member of the California Weed Science Society
  • Married to wife, Cindy. Two sons: Tracy and Travis
  • Enjoys boating on California mountain lakes and camping with the family