I am writing this article before I head to the first meeting of the glyphosate drift task force appointed by the Arkansas State Plant Board. This is going to be interesting duty, to say the least.
Everyone agrees that something must be done, but answers are not going to be simple. I will keep you posted as I can, and I welcome any input anyone has. Feel free to e-mail suggestions.
Glyphosate is not the only herbicide we are having drift issues with. I have looked at a lot of Newpath drift to conventional rice this spring. The injury symptoms from glyphosate and Newpath can be very similar.
Actually, where sub-lethal drift rates occur on seedling rice, the plants normally recover from glyphosate injury quicker than from Newpath injury.
I have also looked at fields and taken telephone calls about Permit and Regiment drift to soybeans. In some cases the herbicides have been mixed. Both herbicides can be tough on young soybeans and better awareness on this is needed in the field.
The biggest potential for rice damage from glyphosate drift is right now. There are a lot of late-planted soybeans in the state. Glyphosate will be applied to those soybeans while much of the rice is in the reproductive growth stages.
Seedling rice often recovers from glyphosate if it is not killed outright. However, glyphosate damage on rice during the reproductive growth stages often goes unnoticed until head emergence or even harvest.
If glyphosate gets on rice in the internode elongation stages, it will usually be obvious at head emergence as small malformed heads, parrot-beaked grains and short malformed flag leaves.
When glyphosate gets on rice from late booting through heading, you may never see anything except blank grains or heads at harvest.
I got called to several fields last year where the farmers never had a clue anything was wrong until they put combines in the fields and nothing was there. Believe me, that type of visit is no fun.
Everyone is under a lot of pressure. Farmers are in a survival mode as are a lot of custom applicators and dealers. This has caused some farmers to make bad judgment calls in the name of getting their crops sprayed without properly considering their neighbors.
Almost every custom applicator in the rice area is faced with high fuel costs and less business than in the past. This has caused some to spray under conditions they should not have. We have to do better.
We are also at the time of year when the calls will be coming about what to do with weeds when rice is past the normal cutoff for most herbicides. The cutoff for herbicides such as 2,4-D, Grandstand, Clincher, Ricestar HT and Regiment are green ring to 0.5 inch, depending on the herbicide. This eliminates most of the choices for larger grass and broadleaf weeds.
However, herbicides such as propanil, Blazer, Storm, Aim and Facet can be applied later.
On larger barnyardgrass and broadleaf signalgrass, Facet plus crop oil can be applied considerably later than 0.5-inch internode if the grass pressure warrants the expenditure. Usually suppression is the best that can be expected from a treatment this late.
Propanil, Ultra Blazer, Storm or combinations of these can be applied to control weeds such as coffeebean until the flag leaf has emerged on the rice.
Propanil plus Aim can also be used until this time. Again, control may not be ideal, but these are herbicides or combinations of herbicides that may help some when the weeds have slipped up on you.
Most know they can pretty well knock coffeebean out late with Blazer.
Most of my late calls are on indigo and none of these treatments will be very good on large mature indigo.