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Growth regualtors on diff warm season grasses

Discussion in 'Pesticide & Herbicide Application' started by ArTurf, Aug 2, 2012.

  1. ArTurf

    ArTurf LawnSite Gold Member
    Male, from Ark
    Posts: 3,458

    I know it is not uncommon to use growth regulators on Bermuda and I have read several of the threads on this. But what about other warm season grasses such as St Aug or zoysia? I know they are on the label but I would like to hear experiences from actual in the field use on these grasses. Under what conditions did you use them and what were you trying to accomplish? Results?
  2. Ric

    Ric LawnSite Fanatic
    Posts: 11,956


    I have started several thread on LS about PGR on turf and had little or no response. I cut my own Bermuda 8 times last year in South Florida's year round growing season and it was never more than 6 inches tall. St Augustine only needs 4.5 to 6 oz of Primo per acre so the chemical cost is nothing compared to the 33 oz for Bermuda and 44 oz for Bahia. Of course those turfs I use a different more cost effective PGR and get a longer ******ed growth period. Zoysia is 11 oz per acre

    Good Luck, it took me 10 years to get it down to a science where I didn't burn grass or miss spots. Equipment Calibration is the big issue.

    BTW After the PGR wears off the Grass has a SPRING BACK effect were it grows faster than normal. Application timing is critical.

    Since I am now a Chemical Mowing Consultant for a ROW company doing State contracts. I do not feel I can ethically give any more information away.

  3. grassmasterswilson

    grassmasterswilson LawnSite Platinum Member
    from nc
    Posts: 4,548

    Good thought. I have given consideration to offering pgr apps as add ons to customers who want to get a thicker lawn. Figureing out if it's worth it or if i can still convince them on a regular mowing schedule.

    On a side not. I have asked serveral times about using primo on my newly plugged bermuda lawn. There is a thread in the renovation topic called my bermuda plug experiment. I was under the impression that primo would slow vertical growth and push lateral growth. I've gotten a wide range of answers. Some say use it and others say just keep pounding it with fertilizer and mow 2-3 times a week. Was hoping for a consistant answer. I don't think it would hurt, but don't want to risk it. We only have about 6 weeks of good growing season left before it goes dormant.
  4. ArTurf

    ArTurf LawnSite Gold Member
    Male, from Ark
    Posts: 3,458

    I guess no one use PGR on St Aug or Zoysia.

    My guess would be to let the plugs more less fill in on their own by cutting often. Then next year use the PGR to thicken things up.

    I've read your posts on PGR's and know you use glypho on your bermuda. What is a ROW company? Just wondering.
  5. WestGaPineStraw

    WestGaPineStraw LawnSite Senior Member
    Posts: 763

    Right of way
    Posted via Mobile Device
  6. Ric

    Ric LawnSite Fanatic
    Posts: 11,956


    If timed correctly PGR will help plugs grow in'and thicken turf. However timing is imperative. Unless you plan on applying every 4 weeks, don't.

    Glyphosate is but one PGR and I alway bring it up just to blow peoples mind because they think it is only a weed killer.

  7. greendoctor

    greendoctor LawnSite Fanatic
    Posts: 9,064

    There is also imazapic, imazapyr and even imazaquin. All of these are growth regulators on warm season grasses. Most of the sulfonylurea compounds are growth regulators as well. Their MOA is very similar to glyphosate, an amino acid synthesis inhibitor. Compare that to Cutless, Primo and Trimmit, which are gibberelic acid inhibitors.

    I have used Primo on zoysia to control overgrowth caused by too much water, overfertilization or lack of sun. The rates on zoysia are rather low and a double or triple application will show as excessively stunted turf.
  8. Duekster

    Duekster LawnSite Fanatic
    from DFW, TX
    Posts: 7,961

    Most SA will handle Primo in low doses. It is wierd to see the blade so small. :laugh:
  9. Ric

    Ric LawnSite Fanatic
    Posts: 11,956

    Some PGR are herbicides that effect each species differently. Therefore some can be used BOTH as a SELECT HERBICIDE and as a Growth Regulator. Roundup 1/2 oz per thousand will kill St Augustine and is the Release Rate on Bermuda. (RELEASE RATE-- to kill competition will out stunting the desirable plants).

    In ROW work we are looking to stunt growth for an entire season if possible. This is utility ground cover not fine turf. While a total kill out is not acceptable, a brown out is. Roundup won't go the distances.

    BTW there are products and methods that will slow a tree's growth on the Road side while letting it grow away from the road on the other side.

    In Edit: Some PGR are Pre Emerges also.

  10. grassmasterswilson

    grassmasterswilson LawnSite Platinum Member
    from nc
    Posts: 4,548

    Here is the thread to my bermuda plugging....http://www.lawnsite.com/showthread.php?t=380862

    I'm extremely pleased with the amount of spreading I've gotten. Some areas are doing great and others not so much. I decreased the size of some very old beds and that may have caused the soil to be different.

    It's been about 8 weeks and I've got another 6-8 weeks left in the growing season depending on how long the warm weather says. I've been fertilizing at 1lb N every 2 weeks or so(per local university experts) and mowing 2 times per week(lawn isn't as level as I'd like so my mowing height is higher than I'd like...topdress next spring). At this point I'm looking to get as much coverage as possible and then next year concentrate on the spots that are less bare.

    I've gotten great advice here and looking for some more on pgr's that might help thicken up the lawn before winter. I'd like as little soil showing as possible.

    So to try or not to try?????

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