Rotate And Mix Herbicide MOAs

Josh Cartwright

Josh Cartwright

Josh Cartwright
Bear River Supply, Inc.
Rio Oso, Calif.

My hands-on experience with rice began with a summer job at Bear River Supply – a part of Butte County Rice Growers Association (BUCRA) – while I was attending junior college. Later, I was fortunate enough to be hired full-time after graduating from Chico State. Working with the PCAs at Bear River has been a great asset to me because they also farm rice. Having access to the information from the research facility at BUCRA has helped me gain knowledge, too.

With 2014 behind us, there is a lot of uncertainty going into the 2015 growing season. It’s going to be a challenging year because of the water situation and input costs versus crop value. However, the inputs that we provide are necessary to grow a maximum-yield crop. We can’t cut corners with either cultural practices or inputs and expect to be successful.

GRANITE Herbicide from Dow AgroSciencesControlling resistant weeds continues to be on the forefront out in the field. With no new tools available, we have to closely manage the ones we have. Rotating and mixing herbicide modes of action can help. The most troublesome weeds to control have been resistant watergrass (early and late) and resistant smallflower umbrella sedge. Sprangletop has also been a problem the last couple years.

In these tough situations, applying a base herbicide, like Cerano, Clincher or Bolero, is important. This helps set the stage for an intermediate application of Granite GR, Shark or Regiment for sedges and broadleaves. Cerano followed by Granite GR has been a solid program for us. It takes out early weed competition so the rice can get off to a good start and removes some of the pressure of relying strictly on propanil to clean up dense weed populations later in the season. Cerano followed by Regiment at 4-leaf stage rice is also a program I like to use where we can apply Regiment by air. When it’s time to apply propanil 35 to 45 days after seeding, we’ll include Grandstand at 6-8 oz/A to help with redberry and heat up the propanil mix.

Last year, in fields that were known to have propanil-resistant smallflower, we applied Shark H2O into the water at 2 1/2-leaf stage rice as a direct dry treatment and were very happy with the results. We’ve also applied foliar treatments of Shark and Londax mixtures and have seen some mixed results. Once the weeds get too big, coverage becomes an issue. Coverage is critical with any contact herbicide, so getting the weeds while they are small and using plenty of water increases the chance of success.

It’s still too early to tell how much water will be available this year, and our water allocation has to be balanced with urban and environmental demands. However, California rice growers are very resourceful, and I consider them the best in the world. They are always able to adapt to change, overcome obstacles and produce a great crop.

Screen Shot 2015-03-17 at 11.06.59 AM