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ball field herbicide - mixed bag of weeds and turfgrass

Discussion in 'Pesticide & Herbicide Application' started by Coachbob, Jul 29, 2017.

  1. Coachbob

    Coachbob LawnSite Member
    Messages: 110

    im a coach and take care of several fields on my own. We are in Southern California where a typical school field is a mixture Bermudagrass (mostly), Poa Annua, Kikuyu, Ryegrass, and a lot of other weeds. On one field we had good success with Trimec last February, but now we are dealing with crabgrass issues and Poa Annua demise in may areas. I would like to establish a cultural system that will deal with the common issues on a school budget. We mow the outfield to 2.5 inches typically. Right now the large bare patches where the poa and other cool season grasses have died are quite bare. I can't decide if we should try to eradicate the Poa or try to love with it because during g the Spring season it's easy to keep green.

    So questions are as follows:
    Field 1 - primarily Bermuda, good stand with not much Poa or Rye. Significant crabgrass at various stages. Do I treat the CG or wait until spring for pre-emergent? Is dimension a good option here?

    Fields 2-4: significant patches of cool season grass demise in primary bermudagrass. Variety of broadleaf weeds as well. I have no idea what to do first on these fields. Do I try to get the Bermuda to fill in first? Kill the broad leafs? Kill the cool season? Use pre-emergent for the Poa?

    Any advise would be appreciated, and if I didn't post enough info, I will gladly post more. Thank you.
  2. Tidewater Greenworks

    Tidewater Greenworks LawnSite Member
    Messages: 83

    Irrigated or not?
  3. Coachbob

    Coachbob LawnSite Member
    Messages: 110

    Yes, all fields are irrigated with decent quality reclaimed water.
  4. Todd KSD

    Todd KSD LawnSite Member
    Messages: 34

    I'm also at a school district but in SE Wa. The budget struggle is real. No justification for the spent money, no profit to show for the work. Just a "hey, nice green grass"

    so with that in mind...

    Field 1 - cheaper to treat with pre emergent. We've had good results with dimension as well as good results with prodiamine. I think prodiamine is a little cheaper. If you can live with the crabgrass for the rest of the year I would do that. If not, get some quinclorac and maybe just treat infields?

    Fields 2-4, treat broadleaf now. Overseed with Kentucky blue, ryegrass blend once temps start to drop for the season.

    If you're interested in getting rid of the Bermuda, you can try pylex. 3 year, 3 apps per year program but it's worth it. Cost is probably around $100 per acre per app. If that's too much you could always just do infields.

    We only have a little bit of poa on 1 field. Haven't done anything about it yet. Next spring is our goal for that. Bonus though, prodiamine and dimension are labeled for poa control. So either one would help with that.
    Coachbob likes this.
  5. grass4gas

    grass4gas LawnSite Senior Member
    Messages: 655

    Timing is the critical part for poa annua. Being on the "right" coast of the country, this is what I have done. Here we need to treat for it late summer. If it is a new client and I see it in the lawn in the spring, I will apply a pre in august-seems to be the best time frame for me to control it. However, this may throw seeding out the window. Some on here have said that they have done seeding after a pre has been applied and it has worked. I am planning on doing my own experiment this fall to see how well it works or works at all.

    The following year I apply prodiamine at a heavier rate to make sure control will last into early sept just to be on the safe side and then you can seed with no problem.

    I'm sure you will have to adjust your timing based on your area

    Good luck...
    Coachbob likes this.
  6. Tidewater Greenworks

    Tidewater Greenworks LawnSite Member
    Messages: 83

    Here in SE Virginia poa will germinate from the end of August all the way up to early November. I've used monthly applications of Tenacity to stave it off during seeding season. Any long-residual pre that blocks poa will also stop fescue germination, so if you're overseeding, (and here it's almost mandatory to repair damage with the level of fungus pressure we have during the summer) Tenacity or the older Tupersan is the only way to go.

    Bermuda is much easier; just do an app of prodiamine in August if you're not overseeding or control it postemergently with low-rate glyphosate before overseeding with rye in mid October. Healthy bermuda turf is too dense for poa to really outcompete in the first place, and it's a lot easier to control cool-season grass in warm season turf than to selectively control cool season grass in different cool season turf.

    Not sure what your budget is, but might be cheaper, (initially anyway) to just hire someone to maintain the turf rather than buying all you would need to treat just 2 fields throughout the year. If that's not in the budget I wouldn't try to get fancy with the overseeding. Keep it all bermuda, fertilize the hell out of it in summer, (at least 1lb N per 1k per month from early May to August) so it fills in any holes. Spray 3-way, (generic Trimec) in October and April, apply prodiamine at max rate in Feb/March as soon as forsythia begins to bloom to keep it free of crabgrass. Spray anything green in December/January with generic glyphosate.
    Coachbob likes this.
  7. Coachbob

    Coachbob LawnSite Member
    Messages: 110

    Thank you for that TG (and all who are helping me with this):

    My gut feeling is to try this last approach. We have some significant bare spots where the Poa and other cool season grasses are. Would you recommend doing anything in these areas prior to fertilization to make it easier for the Bermuda to run? pull cores and sand? or? We have at least two more months of warm season growth in our area, so I would like to try to see what I can do.
  8. Tidewater Greenworks

    Tidewater Greenworks LawnSite Member
    Messages: 83

    Yeah, if you have bare spots now I imagine they're filled with crab? Get some quinclorac and kill that off. If the areas are small, use one of those hand-tool cultivators and rough up the soil to loosen it. If big, pull cores with an aerator, running over the same area at least 3-4 times and spread a bit of compost. Fertilize the hell out of the bermuda these next 2 months. You can safely go as high as 1.5lbs N per 1k, do that asap and then another app of 1.5lbs N in 30d. At least 30% slow release N, sulfur-coated or poly-coated.

    Mow as low as possible as often as possible. If you can mow twice a week, take it down as low as you can get without scalping. If you can only mow it once a week, 2.5 is likely as low as you're going to be able to go and keep the grass looking green. Keeping the bermuda cut low, fertilized and the soil in the bare spots loose will help it to spread as much as possible.
  9. Coachbob

    Coachbob LawnSite Member
    Messages: 110

    Ok, got it. Question, since we have irrigation, might we use Ammonium sulfate for quicker release? or a combination quick and slow?
  10. Tidewater Greenworks

    Tidewater Greenworks LawnSite Member
    Messages: 83

    Best would be .75lbs N Ammonium Sulfate, followed 2wks later with 1lb N slow release, 0.5lbs AS 2 wks after that, and 1.25 slow release 2wks after that one, and then a final 1lb slow release 60d after the very first app; but you really need to be mowing more than once a week if you're going to go that route, the grass is going to explode out of the ground and look like it needs to be cut every 2-3 days.

    2 applications of 1.5lbs slow release 30 days apart would be much simpler to do and not require so much mowing. I'd only go the first route if I wanted to really impress a new customer and I knew they had the ability and desire to mow that often, and all the weeds were already under control.
    Coachbob likes this.

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