# Use T-Zone and Defendor same app?



## Jeff_MI84 (Sep 28, 2020)

Planning my 2022 applications, does anybody use both T-Zone and Defendor at the same time?

The fertilizing company used both on the first application of 2021. Is it really necessary or a bit overkill?


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## macattack (Nov 2, 2020)

Unless i was treating active weeds, I wouldn't plan this in my arsenal. I maybe sprayed some ortho 3-way, (2-4D ester, dicamba, quinchlorac) one time last year as i see them. Did a nutsedge spray (sulfentrazone) later in the year too. Seems massive overkill, unless you are in rough shape to start the year, and already have a lot of post emergent weeds. If you have a strong turf stand to start the year, weeds won't be such a problem.


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## Jeff_MI84 (Sep 28, 2020)

@macattack going into this past spring, I had zero weeds in the front (no crabgrass since early 2019 sod install). The backyard had maybe 6-10 weeds, stuff growing from neighbor's yard. In fact, going into dormancy, almost all weeds were in the flowerbeds, a little bit of clover or creeping Charlie. But nothing that someone like me (OCD) would even care about.

They would spray T-Zone every 6-8 weeks I believe. I used Tenacity on my overseeeding. I bought T-Zone already and would use it every so often if needed. Defendor is so expensive and I didn't think I'd need it. I figured the cocktail the fert guys used was just so they wouldn't have to come back or have fewer apps.

This is what I plan to use in April for my first application, as recommended by the head guy at my Site One, slightly better than what I paid to have put down:


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## macattack (Nov 2, 2020)

I throw down a 6-month app of preemergent around March 2nd, so if I am doing overseed by Labor Day i am fine. Of course, location has lots to do with timing. Lowes has Lesco 0-0-7 0.68% prodiamine ($33). Boy did it do well last year keeping most everything at bay. The grass doesn't need nitrogen that early, so i throw fertilizer down usually several weeks after that when temps rise. I use spreadsheets to plot soil temps, rainfall, and my applications. The less herbicide I use the better.


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## Jeff_MI84 (Sep 28, 2020)

@macattack,
How do you know how long the pre-emergent lasts for? Is it just a rough guess or after years of doing it?

Going off this chart on the label, it says program #1 (what I'd be doing) it says 3-5 months and not to overseed for 12 weeks. That's fine because I'm doing a reno in late July in the backyard, so throwing down in April should give me enough time.

Lastly, the company never did split apps or put down a pre-emergent in the fall, just either Momentum FX2 or T-Zone for post emergents. If I put down x amount of granular pre-emergent in April, would I put down the same amount in the fall?


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## macattack (Nov 2, 2020)

Here is a nice read. I have never used an NPD detector for GC before. I don't guess, I follow procedures.

https://etd.ohiolink.edu/apexprod/rws_etd/send_file/send?accession=osu1242841967&disposition=inline

For prodiamine in my area, I apply at 0.80 # AI/acre for 6 month effectiveness. All pre-emergents break down due to many mechanisms outlined, hydrolysis, photolysis, microbial etc. Surely they have validated those numbers on the bag. I have not had an issue at the stated amounts and time. They extracted the chemicals from the soils and analyzed by gas chromatography. Probably some HPLC methods out there, I havent looked. Obviously the colder it is the slower the degradation, along with sun angle. There is a maximum application per year for these chemicals too. Being further north, you wouldn't want to apply too much to give you time to do overseeding or renovation, if that's the plan for a certain area of the lawn.


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## Jeff_MI84 (Sep 28, 2020)

@macattack thank you. I think I might want to just use a liquid app, separate from fertilizer. It would be my luck that I'd fert too early and waste it.

I'm going to go between either Prodiamine or Dimension. Split apps are done what, like two weeks apart or spring and fall?


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