Suspected poa triv not lighting up (white) from Tenacity

[southern-ct-4]

I have a few spots that I'm pretty sure are poa triv, but they aren't turning at all white from Tenacity. Is it possibly the time of year and/or the crazy up/down weather we've been having affecting this, or is it more likely just not poa triv? I've only hit it once about 2-3 weeks ago.

[MorpheusPA]

You can certainly try another light shot, but it's most likely simply not P. triv. It should be turning ghostly pale after 2 weeks.

[southern-ct-4]

Thanks. So far it's just remaining light/bright green (possibly turning brighter). I'll try one more light dose and see what happens but perhaps I was wrong and it's not triv.

[MorpheusPA]

If not, post a photo and we'll see if we can ID it.

[southern-ct-4]

I think some of it is actually starting to finally turn white.

I'm wondering if shelf-life is an issue here, as my tenacity is probably 5-6 years old, and stored in my garage which gets very hot/cold...

In any case, if I order new tenacity, what are you guys buying these days in terms of the original vs. a generic...?

Thanks!

[northeastlawn]

I have been through this myself. I used to think my Tenacity was no good because I didn't get instant whitening after a week.

I did a blanket 4 oz/ac Tenacity app to mark out any poa-a and triv in my lawn. I wait 10-14 days and I'll get some lightning and color changing, but don't get a ton of suspicious area bleaching white like magic in 10 days.

In my experience it can take a few apps to get mature poa-a to the point it bleaches white and then starts to brown and die off. especially in the spring when the weather is per4fect for it.

Ill usually do my 1st app as a blanket app (4oz/ac), then about a week later start spraying spot apps (2oz/ac) whereever I seed poa-a seed heads or suspicious grass that is light green. Tenacity definitely speeds up the poa-a going to seed.

By the 2nd spot app (3rd week) the poa-a is withering or is bleached.

I used to be very regimented about a spraying schedule, and found it impossible to follow one in teh spring when its always raining.

Now I take more of a relaxed approach. i spray once a week in small doses (2oz/ac). Trying to keep an eye on my 16 oz/ac annual tenacity limit. I will also stop spraying if the KBG looks like it is taking too much damage or I get to memorial day.

I have gotten to the point where i dont expect to kill all the poa-a I am spraying, A bunch of it will recover and be back, but if i can surpass enough for the KBG to take over, I did the best i can with what i have available.

[MorpheusPA]

I don't even want to tell you how old my Tenacity is (actually, I bought it the first year it was available; I still have about 1 Tbsp left in the jar). So far, I haven't found a use-by date that's actually applicable.

[Green]

They don't even put the manufacture date on it anymore.

[southern-ct-4]

The triv definitely turning white now, just took longer than I remember. In any case, should I be hitting it with glyhpo asap, or wait for it to get a bit warmer? After several 70/80 degree days, we're back to 50s/60 during the day and 40s at night. Thank you.

[MorpheusPA]

If you're going to hit it with glyphosate... I usually let the Tenacity do its job and kill it out on its own. But PA isn't CT.

[Smolenski7]

I spot sprayed Tenacity about a week ago. Some triv is absolutely turning white, but what I suspect is poa-a bc of the crazy number if seed heads doesn't seem to be effected, at least not yet. How long should I wait to spot spray again?

[MorpheusPA]

Technically? Two weeks. If you're VERY VERY SURE, you can do it now. If you're not very, very sure, you can also do it now, but you may find even good grasses turning rather pale.

[Green]

Sometimes, I think when energy is going to produce seeds, as Poa annua is now, it takes grasses longer and/or takes a higher dose of herbicide to impact them. Maybe there is less translocation going on. I've also seen the inverse: Triv switching to more seed production after hitting it with Mesotrione or Sulfosulfuron and stressing it.