The higher the application rate, the longer the control period. A range gives you flexibility for how long a protection period you want. The product label should have that explanation. See section "Application Timing and Rate-Turfgrass" and figure 1 in this pdf:

https://www.domyown.com/msds/PRODIAMINE_65WDG_Label.pdf

 

they include a group of grass types in that category and depending on scenario (newly sprigged, etc) you'll get different maximums. That's how I've always read it.

 

I think its .83 oz / K

 

The label dictates a range based on a number of factors. First, the range relates to the desired length of control. The higher the rate of active ingredient per acre the longer the control. If you refer figure 1: length of control ( I used the Quali-Pro Prodiamine 65 WDG label) the active ingredient ranges 0.5 - 1.50 lbs AI per Acre and the length of control ranges from 3.5 - 8 months respectively. Given your location in Ohio (a southern location as compared to a northern one) you may want to adjust for the length of control. A second factor relates to the recent history of pre-emergent applications to a certain area or lawn. Generally speaking a recurring application rate (on a golf course fairway for instance that is treated yearly) will be lower than an initial rate or a rate if an area that is not regularly treated.

In consulting with the label a solid recommendation for a lawn in Ohio would be to apply 1.15 lbs of AI / A (0.41 oz/ 1000ft2) twice a season. The initial application sometime soon this spring as the GDD tracker for Crabgrass pre-emergent is currently in the target range. ( http://www.gddtracker.net/) and a repeat application in 6 months from the initial application if year long control is desired.

Bear in mind that any overseeding procedures would have to be done before (and germination complete) the application of Prodiamine, or at the very least the area that would be overseeded would have to be physically tilled or disturbed to deteriorate the herbicide barrier after the application made.

Additionally, the product should be watered in fairly soon (preferably immediately) after the application to move the herbicide into the soil profile. The label recommends 0.5" of water.

 

Thanks for the info all. Why don't they just say the annual max for TTTF is 2.3 lb/a or .84 oz/m ? Why is there also the lower range number listed for the annual max?

I'm sure it's just my small brain that can't understand this. I'm not blaming the label at all.

 

Thanks for the info all. Why don't they just say the annual max for TTTF is 2.3 lb/a or .84 oz/m ? Why is there also the lower range number listed for the annual max?

I'm sure it's just my small brain that can't understand this. I'm not blaming the label at all.

Cause then the guy who doesn't read the label details would jump straight to that number and wonder what went wrong !??!? I dunno. I recently gave up trying to explain to someone who kept asking 'how much prodimaine to I mix in 1 gallon of water'... and for the life of me I tried my darnedest to explain its the square footage that matters not the water, to no avail.

 

Bear in mind that any overseeding procedures would have to be done before (and germination complete) the application of Prodiamine...

Labels suggests to wait a lot longer than mere germination to apply after overseeding. This section is a bit farther down, past the rate tables, and possibly gets overlooked.

WHEN TO APPLY PRODIAMINE 65 WDG AFTER OVERSEEDING TURF
Injury to desirable seedlings is likely if PRODIAMINE 65 WDG is applied before the
secondary roots of seedlings are in the second inch of soil (not thatch plus soil). To reduce
the potential to injure overseeded turf, wait 60 days after seeding or until after the second
mowing, whichever is longer, before applying PRODIAMINE 65 WDG.

 

Labels suggests to wait a lot longer than mere germination to apply after overseeding. This section is a bit farther down, past the rate tables, and possibly gets overlooked.

Yep. Despite popular opinion, prodiamine does not stop germination. Prodiamine is a 'root pruner', the delicate baby roots of effected seedlings take it up and it interferes with their development, thereby starving and killing the infant plant. If you overdo the application then concentration in the soil can get high enough that adult plants become impacted.

 

The label dictates a range based on a number of factors. First, the range relates to the desired length of control. The higher the rate of active ingredient per acre the longer the control. If you refer figure 1: length of control ( I used the Quali-Pro Prodiamine 65 WDG label) the active ingredient ranges 0.5 - 1.50 lbs AI per Acre and the length of control ranges from 3.5 - 8 months respectively. Given your location in Ohio (a southern location as compared to a northern one) you may want to adjust for the length of control. A second factor relates to the recent history of pre-emergent applications to a certain area or lawn. Generally speaking a recurring application rate (on a golf course fairway for instance that is treated yearly) will be lower than an initial rate or a rate if an area that is not regularly treated.

In consulting with the label a solid recommendation for a lawn in Ohio would be to apply 1.15 lbs of AI / A (0.41 oz/ 1000ft2) twice a season. The initial application sometime soon this spring as the GDD tracker for Crabgrass pre-emergent is currently in the target range. ( http://www.gddtracker.net/) and a repeat application in 6 months from the initial application if year long control is desired.

Bear in mind that any overseeding procedures would have to be done before (and germination complete) the application of Prodiamine, or at the very least the area that would be overseeded would have to be physically tilled or disturbed to deteriorate the herbicide barrier after the application made.

Additionally, the product should be watered in fairly soon (preferably immediately) after the application to move the herbicide into the soil profile. The label recommends 0.5" of water.

Thank you for that information. Regarding the GDD tracker, should I use the Proxy/Primo timer or the Crabgrass PRE timer?

 

Crabgrass pre

 

Not to highjack, I have my prodiamine coming from domyown and some spray tips from barndoorag(local to me). We have gotten quite a bit of water in the past few weeks. It rains about everyone other day it seems like, not torrential down pour but steady drizzle all day. We have rain in the forecast for the next two weeks. I applied .3 of N/1000sqft (Ammonium Sulfate) b/c I knew rain was in the forecast.

Is it stupid to apply preM in the rain, lol? We do have a few dry days coming between the rainy days and don't know how immidiate the preM needs to be watered in.

Sorry to hijack the thread.

 

Also, I see on the label it gives oz/per 1000 and then states .5 gallon water @ a minimum. What is everyone spraying rates at?

I was going to shoot for .5-1 gal per 1000 with the tips I'm getting. Also was going to do a 3-4 month application.

With split apps, how long do you wait between apps? 45 days?

 

Read g-man take on this. Go to the Grass Daddy website. The lower rate is for 3 months protection, the higher goes up to 9.
If I decide to seed same fall I will try to time (use the right amount) so I can have 'clear' shot for my seeding.
Another point @g-man discussed few times, is that, it is better to do 3 min rate apps instead of one big one. The third being end season for winter grass suppression.

 

Is it stupid to apply preM in the rain, lol?

That would probably depend on how hard it's raining.
Rainwater isn't going to hurt prodiamine of course, and it needs some water to carry it down off the plants and into the soil. Light rain is probably not an issue if you can't find a dry time to get out there.
If the ground seems fully saturated, or if there's any standing water, or if it's raining enough that you're getting runoff, then definitely wait. You want the product watered into the soil, not washed away.

 

The label dictates a range based on a number of factors. First, the range relates to the desired length of control. The higher the rate of active ingredient per acre the longer the control. If you refer figure 1: length of control ( I used the Quali-Pro Prodiamine 65 WDG label) the active ingredient ranges 0.5 - 1.50 lbs AI per Acre and the length of control ranges from 3.5 - 8 months respectively. Given your location in Ohio (a southern location as compared to a northern one) you may want to adjust for the length of control. A second factor relates to the recent history of pre-emergent applications to a certain area or lawn. Generally speaking a recurring application rate (on a golf course fairway for instance that is treated yearly) will be lower than an initial rate or a rate if an area that is not regularly treated.

In consulting with the label a solid recommendation for a lawn in Ohio would be to apply 1.15 lbs of AI / A (0.41 oz/ 1000ft2) twice a season. The initial application sometime soon this spring as the GDD tracker for Crabgrass pre-emergent is currently in the target range. ( http://www.gddtracker.net/) and a repeat application in 6 months from the initial application if year long control is desired.

Bear in mind that any overseeding procedures would have to be done before (and germination complete) the application of Prodiamine, or at the very least the area that would be overseeded would have to be physically tilled or disturbed to deteriorate the herbicide barrier after the application made.

Additionally, the product should be watered in fairly soon (preferably immediately) after the application to move the herbicide into the soil profile. The label recommends 0.5" of water.

Has anyone converted 65 WDG weight measurement (dry ounce) to volume measurement (teaspoon/tablespoon)?

Or is the product (granules) not consistent enough for that and better to stick with weight measurement?

 

The label gives conversions for Lbs/Acre to Oz/1k to tablespoons/1k . You can open the label in a PDF reader and search for tablespoons. It is on page 15: http://www.greencastonline.com/current-label/barricade%2065wg