# Tenacity/Prodiamine/Specticle for pre-emerg?



## silvercymbal (Sep 17, 2018)

Wondering which you would use for cool season turf? I have used Tenacity for post emergent with amazing results and love the product but for planning for this year I am wondering which to use. I also have seen Specticle, but it says discontinued on do my own? Most of what I am looking to control is crabgrass and poa. Thank you kindly.


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## Movingshrub (Jun 12, 2017)

Specticle isn't labeled for cool season.

I would think prodiamine, dithiopyr, or pendamethalin would be the go-to options.

Tenactiy has a soil residual for a few weeks.


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## g-man (Jun 15, 2017)

^+2

Tenacity is good at seeding and it last 30days. Using tenacity instead of a real prem not advised since the weeds will build resistance.


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## silvercymbal (Sep 17, 2018)

Thank you. It sounds like prodiamine will end up being a safe choice. I use the tenacity for post emergent treatment as needed. I am planning to use the Turfex 80 walk behind sprayer. I will have to work on calibrating it and using the right nozzle to get it all dialed in correctly.


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## Green (Dec 24, 2017)

Prodiamine more aggressively inhibits lawn roots than Dimension, I believe.

Dimension is ideal for use after Tenacity because of the above and due to its early post emergent effects (less likely to get breakthrough or resistance to Mesotrione).


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## Greendoc (Mar 24, 2018)

Green said:


> Prodiamine more aggressively inhibits lawn roots than Dimension, I believe.
> 
> Dimension is ideal for use after Tenacity because of the above and due to its early post emergent effects (less likely to get breakthrough or resistance to Mesotrione).


Other way around. Prodiamine stays closer to the surface vs Dimension. Pendimethalin goes even deeper than the first two. The deeper a Pre works into the soil with rain or irrigation the more it affects roots. 
This is according the BASF, who makes Pendimethalin. They also say that Pendimethalin provides some of the most aggressive weed control.


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## Jayray (Aug 8, 2018)

Greendoc said:


> Green said:
> 
> 
> > Prodiamine more aggressively inhibits lawn roots than Dimension, I believe.
> ...


These pre-emergents slow the growth of existing turf grass roots? In the case of KBG it would effect the winter recovery? Do any of these do anything for POA? It almost sounds like for smaller lawns it might be better to roll the dice and deal with whatever germinates after the fact but have a thicker lawn. If I had to pick one over the other I'd rather have a few weeds and a thicker lawn than a thin lawn with no weeds. The only other factor being POA control. Crabgrass or dandelions and other broadleaf weeds are easy to identify and remove, POA not so much.


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## Greendoc (Mar 24, 2018)

Those all do pretty well for Poa. However, here is a good video concerning usage of Pre and Poa control. What I can add to it is that I deal with low cut warm season grasses that are sensitive to the effect of PRE. I minimize adverse effects by using split applications of a Pre rather than trying to apply enough that one application will do it. https://www.youtube.com/watch?v=NVS8jTiWFo8&lc=z231cvpa1vaeifessacdp432iinf4jvhy0uzf2fubsxw03c010c.1549747950266901


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## Green (Dec 24, 2017)

@Greendoc, thanks for revising the root inhibition post; I was not 100% certain if I had the order right on that.

Also, I'm surprised about Pendi. At the rates Scotts labels list, it only lasts about 2 months. Where are the heavier rates listed? It'd be nice to have a reference sheet for granular apps for this AI. I might consider using it again if I had that.


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## Greendoc (Mar 24, 2018)

The heavier rates are on the Pendulum Aquacap and Pendulum G labels. I just looked at the Scotts label. It is applying a 1.5 lb of AI per acre rate. The Pendulum labels call for more if used against weeds other than Crabgrass or if a non split application is desired. The Halts label applies the low rate with reapplication allowed 2 months later. Good idea. Out of all the Pre's familiar to both warm and cool season areas, Pendimethalin is the harshest. I spray areas infested with tall grasses with RoundUp and Pendulum at its max rate. 6 months later the area can be bare dirt. If I apply Pendulum in my low cut warm season lawns, there is a reduction in vigor. Stolons have trouble grabbing onto the soil. This is a problem because stolons taking root along their length is how a warm season grass repairs itself. I use the split application program for Barricade and do not have that kind of side effects.


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## Green (Dec 24, 2017)

Greendoc said:


> Those all do pretty well for Poa. However, here is a good video concerning usage of Pre and Poa control. What I can add to it is that I deal with low cut warm season grasses that are sensitive to the effect of PRE. I minimize adverse effects by using split applications of a Pre rather than trying to apply enough that one application will do it.


Matt has done it again. I really enjoy listening to this higher level stuff as a hobbiest. Now the question is, what can I do as a ool season residential DIY guy on a budget? I've almost always used Dimension, and had this rotation and resistance question in the back of my mind all these years. But now I see alternating with Prodiamine or Pendimethalin won't help. The last few years, I've used Tenacity as my "round 1" because I was overseeding or had some other use for it. I wonder what else I can do to help prevent Dna resistant weeds from propogating.


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## Greendoc (Mar 24, 2018)

What is the weed you are most concerned about?


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## Green (Dec 24, 2017)

Greendoc said:


> What is the weed you are most concerned about?


Crabgrass (May-Sept.). But also dandelion and other broadleafs starting in April...just as much a concern. Spurge and Purslane during the Summer as well...very hard to prevent with what I've been using (Dna pre-Ms). In fact, I think I'm going to have a spurge infestation in one area this year based on last year. At least 3 of my adjoining neighbors' lawns have a lot of seeds, not to mention other properties nearby in the wind path...all types of seeds.


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## Greendoc (Mar 24, 2018)

In that case, I would rather see Gallery used. The amount and type of DNA pre is harsh on grass. Think max rate Pendimethalin. What I use is the mid rate of Prodiamine with Gallery. Spurge is epidemic in Hawaii. No other broadleaf is an issue.


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## Green (Dec 24, 2017)

@Greendoc thank you. I started a new thread.

@silvercymbal, hope you find it helpful, too.


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