Poa annua confirmation and mesotrione regimen

[wpstrassburg]

During my second mowing today noticed a few odd looking gems throughout some of the lawn. Lots of lime green tufts which I think are just kbg taking off more so than others and a few teal green patches that are already going to seed.

I believe these are Poa Annua based on google and searching here, but wanted confirmation from the group.

Mowed at 3” and didn’t touch any of these patches with seeds.







From a few articles and others treatments it seems now is a good time for treatment as long as temps stay up a bit more than some of the nights we have had dipping down into the 40’s and high 30’s occasionally. If I have a significant amount my question is how much meso will my fescue and rye tolerate before I do more damage than good. 5oz/year is the label limit for those, but some of the turf studies looked to apply well beyond the 8oz/year on kbg, but not an even comparison since it sounds like kbg is a bit more tolerant. Does anyone have rates and frequency they have had success with in rye and fescue? Will 2oz/acre as an initial application be enough to lighten the Poa for diagnosing how much a actually have? Will two more 1.5oz/acre be enough to knock it out? Five 1.6oz apps looked to be the minimum in the turfgrass trials that gave substantial eradication.

[wpstrassburg]

Did some rereading and looks like 16oz/acre is the yearly limit, so that opens up the quantity of apps I can do. Will rye and fescue tolerate 2oz per week apps or when should I expect issues with those? Obviously can monitor for signs of stress, but being aggressive on the Poa seems to be the only way to get real success against it.

[MorpheusPA]

Rye's going to show stress. Fescue's going to show A LOT OF STRESS. I used that to knock back the neighbors' fescue in the area that's his but that I maintain...but I probably shouldn't tell you that.

Fescue stresses at way under anything close to 16 oz/year. I was more close to 5 oz/yr in that zone and I think that killed it off, if I remember correctly. Rye survival levels weren't great. KBG just turned pale green but came back just fine.

[northeastlawn]

I can also confirm FF hates Mesotrione, I had a few isolated poa-a patches in a FF shade mix last year. All I did is a few quick weekly sprayer of Tenacity in FF and it it took a beating. Some of it died, but the poa-a didnt do great either.

FF also doesn't like mesotrione at seeding time, I have learned to not use tenacity with FF and northern seed mixes.

[wpstrassburg]

Looking through the area it appears it is just in the side yard for now and not too many large patches so I way do a 3-4oz / acre dose to highlight and then go after it on a spot basis if there isn’t a ton. If the rye & Ff thin out too much most of the Poa looks to be in a sunnier location that I could get kbg overseeded this fall to fill in. Once the wind dies down I’ll get a dose down and see how things look in a few days.

[wpstrassburg]

Rye's going to show stress. Fescue's going to show A LOT OF STRESS. I used that to knock back the neighbors' fescue in the area that's his but that I maintain...but I probably shouldn't tell you that.

Fescue stresses at way under anything close to 16 oz/year. I was more close to 5 oz/yr in that zone and I think that killed it off, if I remember correctly. Rye survival levels weren't great. KBG just turned pale green but came back just fine.

Yeah, no idea why just one side of my neighbors lawn doesn’t have any dandelions….

What was your rates and frequency? Looked like more frequent low dose rates were more effective against poa, but wondering if it’d still have the same effect on the ff & rye. It survived 16oz over 1.75 acres the fall of the year I planted it in the spring when I was over seeding, but that was about 4 weeks apart on two doses. Good weather the rest of the week so first app will hopefully go down tomorrow.

[MorpheusPA]

I tend to be low end app levels, but every ten days to 2 weeks until it dies painfully. At the moment, there's no remaining triv in the lawn, it's gone. I won't spray again, so May 11th is past the end date (May 1st was about the last spray, so I really only sprayed 3 times).