Rain Needed For Herbicide Activation

[Jim Meade / Iowa City]

Here is a 2007 ISU study which cites a 1997 UI site.  The chart tells it all.

Bottom line - 1" for full control of foxtails.  1/2" gives 85-90% control.  Up to 1/4" shows about 50% control.

So, it looks like 1/2" gives most of the results but for full results we need an inch. 

http://www.weeds.iastate.edu/mgmt/qtr00-1/dryweather.htm 

[k-289]

Watched an interesting segement on application practices on this weeks  Market  2  Market  ---   

[Blacksandfarmer]

Thanks for the link Jim. I had my corn sprayed a week and a half ago with Roundup and Resolve Q. Some of our beans were sprayed last week with Roundup and Classic. I am already seeing a few weeds starting to emerge in the corn. Our last rain was May 6th if you don't count the five minute shower yesterday that yielded less than a tenth.