Rice weed situations complicated
Jun 8, 2007 3:28 PM,
By Ford L. Baldwin
Practical Weed Consultants, LLC
Last week I wrote that it would be interesting to see if weed control in the later-planted rice would be as easy as in earlier-planted rice. Well, it has not been in the fields I have walked and for farmers who have called me.
When the weather turned dry, a lot of fields were either ready to fertilize and flood or too close to being ready to flood for the farmers to have time to flush. That usually meant the weeds were too drought-stressed to kill prior to flooding and there was not time to flush before spraying.
In Clearfield rice, some of the same situations exist, but a lot of the Clearfield fields are caught in a different situation with the same result. A lot of Clearfield rice has been planted where surrounding crops are complicating things. Three straight weeks of southwest winds have meant only fields that required a southwest wind could be sprayed.
Many other Clearfield fields are ready to flood with no second application of Newpath on them.
Often there are no easy answers for the situations I’ve described. I do not like flooding a field that has grass in it. However, in a lot of these situations there is no choice.
In the conventional rice fields, I have generally recommended putting a shallow flood on the field and spraying. As dry as it has been, I figure the water level will drop quickly, exposing weeds.
To keep a postflood situation from turning into a full-blown salvage situation, you have to get the application out quickly after the flood. If you don’t, the rice is going to close the canopy and you cannot get coverage on the grass until it blows out the top.
Therefore, you have to get the water on, let it drop to expose the grass, then spray it and get the water back up all before you lose the fertilizer. That is complicated and why I do not like postflood situations if I have any other choice.
In the situations above, I have recommended a lot of Regiment where the grass was barnyardgrass only. A 0.6-ounce rate of Regiment with the approved adjuvant is cheaper than some of the alternatives.
I have also recommended some Ricestar HT plus Facet where the farmer preferred Ricestar over Clincher. Ricestar HT alone is fine on sprangletop but needs Facet in it postflood if other grasses are present.
I generally recommend Clincher over Ricestar postflood. After the past two years, however, I have a lot more confidence in Clincher if it is mixed with Facet.
In Clearfield rice, a lot of fields have been flooded with only one application of Newpath applied. To get the second application of Newpath applied in the flood, you have to walk the same tightrope as described postflood for conventional rice. Usually the red rice is stunted from the first Newpath application, so it is down in the canopy. If the canopy closes before you get the Newpath applied, then you are stuck until the red rice comes through the canopy at midseason.
In most of the situations described above I would much rather recommend Beyond instead of Newpath early postflood. However, the current label only allows a Beyond application following two Newpath applications. I do not know how fast BASF is moving on a Beyond label with some better flexibility, but it is not fast enough for me.
Some Clearfield situations involve grasses and broadleaf weeds in addition to red rice. Many of those call for tank mixtures.
There are no easy answers for the situations described here. Feel free to call with your individual situation.
e-mail: ford@weedconsultants.com
