Results with Quinstar and Sledgehammer on Orchard Grass

I had a local coop spray my orchard grass with quinstar for foxtail and crabgrass at the rate of 1/2 pt per ac and I spot sprayed nutsedge at the recommended rate.  The quinstar was applied on 8/6, the sledgehammer on 8/9.  Since there has been a fair amount of interest in the topic I thought I would post my results to date.  

 

Weather/moisture

First of all it is fairly dry but there is moisture in low flats draws and other likely places.  On 8/6 weeding was still fairly easy.  There was guaranteed rain on 8/7 which did not occur, and highly probable rain on 8/10 which also did not occur.  We got a decent rain finally last night so things may look different in 4-5 days from now.

 

Nutsedge

Sledgehammer was applied at the recommended strength to wet but not running off on isolated clumps of nutsedge.  As expected, all the nutsedge is in areas with better soil moisture and non treated areas of orchard grass are not showing any signs of stress from lack of moisture.  Within 2 days of application the nutsedge started turning yellow without any visible sign of change to the surrounding orchard grass.  As of today, the same conditions were observed.  Pic included.  Sorry for the lighting, it was evening when I took it  .  Also noticed from the other pics I took that it is really difficult to show what is desired even with a good camera and lens.  So borrowing any significant reversal, the sledgehammer appears to be a real success and I can gradually eliminate the nutsedge a little at a time.

 

Quinstar

Not such great news with the quinstar.  Where there is still adequate soil moisture, the impacts on the orchard grass appear minimal but the impacts on the crabgrass are highly varied even over very short distances.  There will be crabgrass that is clearly stressed and looks to be fading and 5 feet away it is still going strong.  Makes no sense to me.  The foxtail does not appear to be rapidly fading but does not appear to be growing either.  So I am not sure if it is arrested as it was or what is going on.  Perhaps after the rain we just had it will be clearer in 4-5 days.    In the areas where soil moisture was becoming or had become limiting, some of the orchard grass is stressed and some appears to be dying off.  Now it may come back with rain, it may not.  There appears to be more control on the crabgrass areas in the moisture stressed areas than in the adequate moisture areas.  

 

So, if I was making a decision at this point, the quinstar should not be applied at this time of year when moisture stress happens frequently.  Perhaps right after first cutting after a rain is a better strategy.  Will report more as I see it.

Results with Quinstar and Sledgehammer on Orchard Grass