[Green]

For those who have used granular Prodiamine (doesn't matter if you're warm or cool season):

-What percent AI are you using?
-How many lb/K ?
-What month was it applied?
-How long did the Pre-M barrier last?

Granular Prodiamine only, please. Thanks.

 

[Green]

Here's my response:

-0.37%
-2 lbs/K
-Late Summer
-Not sure

 

[Pete1313]

Here's my response:

-0.37%
-2 lbs/K
-Late Summer
-Not sure

I don't use granular prodiamine, but the rate of AI you put down (11.84 oz AI) would have given you a roughly a 3 month barrier.

 

[Green]

I don't use granular prodiamine, but the rate of AI you put down (11.84 oz AI) would have given you a roughly a 6 month barrier.

Good to know! I was kind of hoping it would last a while. Do you know if the rates act in a linear fashion as they're increased/decreased?

 

[Pete1313]

I don't use granular prodiamine, but the rate of AI you put down (11.84 oz AI) would have given you a roughly a 3 month barrier.

Good to know! I was kind of hoping it would last a while. Do you know if the rates act in a linear fashion as they're increased/decreased?

My apologies, I was doing the math while I was getting ready to leave work. Double checked it and it is only a 3 month barrier for 2lbs/k of .37% prodiamine. Just changed it in my previous post. It is not linear.

 

[Green]

My apologies, I was doing the math while I was getting ready to leave work. Double checked it and it is only a 3 month barrier for 2lbs/k of .37% prodiamine. It is not linear.

3 months...still pretty long.

Just curious, how are you calculating how long the barrier will last?
Or are you going by experience/using a table to determine how long a certain number of ounces of AI lasts?

 

[Pete1313]

My apologies, I was doing the math while I was getting ready to leave work. Double checked it and it is only a 3 month barrier for 2lbs/k of .37% prodiamine. It is not linear.

3 months...still pretty long.

Just curious, how are you calculating how long the barrier will last?
Or are you going by experience/using a table to determine how long a certain number of ounces of AI lasts?

Used the chart from my 65 WDG label

.5 lbs/acre of 65WDG (.325 lbs AI/acre) is 3 month barrier.
For .37% prodiamine, 2lbs/k (.0074 lbs AI/k) multiply by 43.56 to convert to acre and you get .322 lbs AI/acre.

So ~4 lbs/k of .37% would get you about 5 months coverage, ~6lbs/k get you about 8 months coverage.

 

[thegrassfactor]

Granular Pre... ARGGGGHHHHHHHHHH

 

[Green]

Granular Pre... ARGGGGHHHHHHHHHH

Not a fan?

 

[thegrassfactor]

Granular Pre... ARGGGGHHHHHHHHHH

Not a fan?

Do you see the inconsistency in the 2 bags? So frustrating. How do I trust it. I'm having an existential crises over granular pre.

 

[Green]

That's crazy. I had no idea the two halves in the spreader were supposed to be the same product until you said it. Thought maybe one was Pendimethalin and the other was something else. Were those both your bags, and from the same batch?

 

[Green]

Btw, Grassfactor...I just watched your video on Screamin' Green 16-2-3, a fertilizer that I bought about two years ago, and was super excited about, as well. Problem was, I haven't been able to find it since then. Thanks to this forum, I found out that SIteOne sells it, so I plan to use it again this year. I liked seeing your enthusiasm and the technical details about the product in your video.

Edi: just found your granular pre-M video. Watching it now for more details on what you posted above.

 

[g-man]

Pretty much all of the lawn lawn chemicals we apply that last months follow an exponential decay curve.

For spring, Purdue recommends an 0.65ai/acre rate. You could split it in two apps within the spring app.

 

[Green]

Pretty much all of the lawn lawn chemicals we apply that last months follow an exponential decay curve.

For spring, Purdue recommends an 0.65ai/acre rate. You could split it in two apps within the spring app.

Thanks. 0.65 (of what unit?) per acre?
Do they have a recommendation for late Summer or early Fall as well? At this point, that's the only time of year I use Prodiamine, and only on areas that used to have an annual bluegrass issue. (I use Dimension in the Spring.)

 

[g-man]

This study only did 09Apr and 01Jun with combos of prodiamine, dimension and pendi
https://turf.purdue.edu/report/2011/PDF/15_AGRY_Patton_sequential%20apps.pdf

 

[GrassFarmer]

what i dont understand if you use .38 and a second app of .38 like purdue that only leaves you with .22 ai/acre left for fall POA premergence and be under the kbg max yearly rate. Is .22 enough for fall?

 

[FuzzeWuzze]

what i dont understand if you use .38 and a second app of .38 like purdue that only leaves you with .22 ai/acre left for fall POA premergence and be under the kbg max yearly rate. Is .22 enough for fall?

People that want full year coverage use different products, like Dithiopyr to span the gaps.

 

[g-man]

@GrassFarmer Their report is around crabgrass and not around Poa Annua. You do bring a good point of something I have thought about in the past. I came up with this plan:

I follow their treatment 9 - first app in march of dimension (granular) 0.25 rate+ second app late May of prodiamine (0.38 ai rate). This leaves me enough to do a 0.5 rate in mid august. I found zero Poa in the mow I just did last weekend.

The last table in the report does give some insight into the effects in fall. The split app had an 87 % control in September. That is pretty good and even the single app had a 73%. One thing to keep in mind is that they did this in plots that had history of crabgrass problems. Must of our members are keeping the yards in top shape, so the crabgrass pressure is lower. I think it is balancing act between poa A and crabgrass. I think a good approach could be 3 apps of just prodiamine at 0.3ai/rate in March, Mid June, 01Sept; but I dont want to use my yard for the experiment.

 

[Catlettsl]

What does AI mean in this thread?

 

[Green]

What does AI mean in this thread?

Active Ingredient. But I'm not sure what people mean in this thread by:

"0.38 active ingredient rate"

or

"0.38 active ingredient per acre"

or

"0.38 active ingredient / rate"

I've never heard any of those 3 terminologies before. To me, there are units missing. Hopefully someone will clarify. Maybe I'm just being stubborn, but it doesn't make sense.