[kolbasz]

So today was my first time with prodiamine wdg.

Because I have never used it, I am asking for advice after my first application. A bit out of order, so I am just trying to confirm I did it right.

It's product per 1k regardless of water, right?

So I put 4oz on 6k and the about 4.5oz on 7k. Both with about 4.5gal water.

On the 6k I had a little left so I went back over some known trouble spots.

 

[g-man]

Water is not that important as long as you could apply it without running short or with too much extra.

My only comment is your rate. It seems to be 0.85 oz / k. That seems high for Kbg.

 

[Ware]

Agree, I think you exceeded the max annual application rate for your turf species with a single application. It looks like you were in the 0.64-0.67 oz/k range. Per the label, the max annual rate for KBG/Rye is only 0.55 oz/k, which you would ideally split into multiple applications throughout the year. I don't know what the best answer is now that it's already done, but I would probably shop for a different pre-e for subsequent applications.

You are correct in that the amount of carrier (water) doesn't matter as much as the application rate of the active ingredient. Some products specify on the label how much carrier should be used, some don't. Keep in mind the Prodiamine will need to be activated by at least 0.5 inch of rainfall or irrigation within 14 days following application.

 

[g-man]

Wow, my metal math was way off. I think I calculated 10k instead of 13k.

Too many piña coladas and mojitos during this vacation.

 

[Budstl]

This makes my brain hurt. I need more beer. No more vaca for gman either.

 

[kolbasz]

Well, that sucks. I don't know what I was thinking. I was not paying attention I guess to the grass/vegetation type etc for the application rate. I just opened the book and saw .87 max rate and did 6x.8, backed it off a little and went 4 oz.

At no point did I think about a Max per year. In fact I was thinking since I'm always fighting POA a that I'd do it again in a few weeks...

Guess I'll toss that idea out the window. Good thing my spring app was dimension.

So yeah I guess the question now is what does this actually mean for me, my grass and the yard in general.

 

[j4c11]

I looked and was able to find some information on the effects of various pre-emergents on Kentucky Bluegrass. The whole thing is a very interesting read.

http://citeseerx.ist.psu.edu/viewdoc/download?doi=10.1.1.553.3928&rep=rep1&type=pdf

tl;dr

The maximum rate for KBG is 1.5lbs/acre which is about 1.7 kg/ha.
You applied 2.30lbs/acre which is about 2.6 kg/ha.

The chart below show the "effect of prodiamine on the tiller numbers, rhizome numbers, dry
weight of tillers and dry weight of roots of Kentucky bluegrass as observed 12
weeks after treatment".



So it looks like you should expect poor density, poor root development and poor to no spreading.
I also read somewhere that because of its effects on the roots, necrotic ring spot can be much more prevalent the following season.

 

[kolbasz]

So, what you are saying is that I just totally f-ed myself.

Especially considering that I just liked some POA t and ripped out some bent with plans for the kbg to spread and fill it out.

 

[Redtenchu]

What kind of spray tip did you use? What else was mixed in the tank?

DO NOT WATER IT IN!

I believe after 2 weeks the any Prodiamine that hasn't been washed into the soil should begin to break down and will mitigate the effects of over application.

 

[Redtenchu]

You should also consider mowing a little lower than normal (not a scalp) and collecting the clippings. This will also help to remove some product from the lawn.

 

[g-man]

This makes my brain hurt. I need more beer. No more vaca for gman either.

Vacation is over. Flying back today, hopefully to a fungus free lawn.

 

[kolbasz]

I can turn off the irrigation system, but there is no stopping mother nature.

It was a full cocktail, prodiamine, propocanizole, tenacity and surfactant.

 

[pennstater2005]

I did the same thing, went to heavy, on the first couple thousand square feet. But, I believe mother nature saved me. We had a torrential downpour same today before it completely dried.

 

[g-man]

So yeah I guess the question now is what does this actually mean for me, my grass and the yard in general.

Do what Redtenchu suggested. His advice is spot on. I would consider the intensive nitrogen.

PS I'm going bold the PreM rate in the article.

 

[kolbasz]

So yeah I guess the question now is what does this actually mean for me, my grass and the yard in general.

Do what Redtenchu suggested. His advice is spot on. I would consider the intensive nitrogen.

PS I'm going bold the PreM rate in the article.

I forgot, I also threw down a bag of, 25-0-6

 

[g-man]

How many pounds to the bag? Over the 13k area?

 

[kolbasz]

50# bag marked for 12,500 sqft

 

[kolbasz]

If needed, I do have 9 bags Milo in the garage, which were for later, but whatever it takes not to destroy the lawn

 

[g-man]

Not now. All the fertilizer will need water to activate and we want to avoid water.

 

[kolbasz]

Never thought I'd be saying I hope it doesn't rain