[Movingshrub]

I noticed the label states - "Monument 75WG may reduce leaf elongation of bermudagrass
and zoysiagrass and suppress expression of seedheads."

That sounds a lot like a PGR.

Has anyone ever done blanket apps in the spring either way before, or after spring green-up, and specifically chosen monument for the seedhead suppression?

I was unsure how long monument has that seedhead suppression impact and how pronounced/obvious it is.

I tagged you guys since I know you all are applicators.
@Greendoc
@viva_oldtrafford
@thegrassfactor
@high leverage

 

[kur1j]

I wonder if the seedhead suppression is more induced by stress though and not some inherit "PGR like" purpose? I've got some places I sprayed with Monument in my friend's yard to kill some Poa and it was stressed significantly more than other areas of the yard.

Would be curious to know though.

 

[Greendoc]

The suppression is not growth regulation by any means. It is a result of mild metabolic poisoning of the desirable turf. The only SU herbicide with minimal side effects is Halosulfuron(Sedgehammer). All of the others are only marginally selective. Crank up the rate to 4 X and it can kill turf. Other usage of the more potent SU herbicides like Metsulfuron-Methyl and Sulfometuron-Methyl(Oust XP) is as a chemical mowing agent. Spray those at less than lethal rates on roadside or industrial turf, no weeds and also minimal growth of the grass. Grass can look poisoned for the season though. But no mowing or string trimming like what unsprayed grass will need. Other chemical with similar marginal selectivity is Image(Imazaquin). That is one of the products I use to get through the season in Hawaii where it rains for weeks on end, there is no sun and the only things that grow well are Kyllinga or Purple Nutsedge. The lawns not treated are the ones that need to be string trimmed in the pouring rain week after week.

 

[Movingshrub]

Interesting to learn.

My thought was that ALL herbicides are growth regulators in some capacity, and then you've got a special class of PGRs that manage to regulate without killing the plant. With that being said, I wonder if you could kill grass with an overdose of t-nex/primo.

I guess I'm just curious if anyone uses Monument or any other SU herbicides for the seedhead suppression 'benefit'; sounds like the answer is a no.

Thanks Greendoc!

 

[Greendoc]

Yes you can kill grass with Trinexepac. Ask any golf super out of a job what happened when he over regulated the greens at a time when grass was already in a state of slow growth due to weather conditions. I know about that and so do the smart golf guys in my state. They either reduce rates or stop entirely when they hit the time of the year when there is no sun for weeks on end and the Bermuda is hardly growing.

 

[Bunnysarefat]

@Movingshrub are you still having problems with seed heads?

 

[Movingshrub]

Yep, it's what drove part of my question. The seedheads are not as bad as it was before. I'm unsure if the reduction was due to the t-nex app (which has now worn off) or seasonal. Two weeks ago I started applying 1/4lb of N per week. I've made sure the lawn is getting an appropriate amount of water. I sent in a soil sample yesterday to way point just to confirm I don't have any kind of deficiency going on.

So just to be clear - two issues - more seed heads than I expect and then a few areas that aren't thriving. I think the seed heads are likely due to my grass cutting interval and HOC. The second issue is the one I'm more concerned about. I'm unsure if that's due to grubs, winter kill, nematodes, or excess top dressing. The trenches I buried in sand are doing just fine, so I doubt the sand is the cause, but TBD. I plan to spray grub preventative as insurance for the future, while continuing to apply N. I'll evaluate if anything else needs to be done once the soil test results come back.

 

[Greendoc]

T-Nex affects Gibberelic Acid production. Specifically, the ones responsible for vertical growth and length between nodes on stolons. An SU herbicide causes inhibition of Amino Acid synthesis. Cause of death is starvation of the plant. Grass affected by an SU herbicide can react by turning yellow and stunting because there is a small degree of Amino Acid inhibition. What I typically apply is not for spot treatment at all. The only way to avoid the appearance of spots stunted and yellowed is to boom spray the entire lawn. That is only on lawns that have been greened up by appropriate usage of fertilizers and micronutrients. I do spot spray, but that is with guaranteed lethal rates of a combination of Glyphosate, Fusilade, and Triclopyr. This is for weeds not controllable via more selective herbicides. The concept of spot spraying with products that are supposed to be selective but are not because I am doing it to turf in no condition to be treated is foreign to my operation.

 

[Bunnysarefat]

I have trouble with seed heads too. I think TifTuf gets them easier than other strains. I was able to pretty much eliminate them last year for the last part of the summer without PGR. Doing things differently this year and still trying to figure out what works best to keep them at bay. Obviously stress on the grass is a cause and I've stressed my lawn a few times this year. Have you? Or have you been cruising and still getting them?