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MisterBreeze
07-14-2012, 08:50 AM
I put down 2 apps of Dimension, 1 in late Feb, 1 in early April. I am starting to see crabgrass coming up. WTF?

Duekster
07-14-2012, 08:52 AM
you missed a spot? It did not get watered soon after the app? Not watered in enough? You put down too little?

Smallaxe
07-14-2012, 09:47 AM
Around herenpeople apply way too early to get all their lawns done on time... then they start the second round and do them all again... heavy rains/irrigation wash away the herbicide, the grass is cut too short and bakes the surface where CG is the only thing that grows... Not sure what should be done in NC but you might want to rethink the cultural habits of lawncare for your area...

Duekster
07-14-2012, 11:36 AM
While improving cultural habits is a given priority, Pre-ems help break a cycle. Most have enough residual effect if applied properly and moved onto the soil ( avoiding UV breakdown) to become active will last 3 month or longer depending on the rate. You can apply early to stay ahead of crabgrass.

The purpose of the OP's split app was to extend the seasonal coverages and to stay well under the seasonal limits. This is a normal activity in warm season areas. I have seen crabgrass in many relatively thick lawns. I do not want to get into all the in's and out's of Bermuda grass in this thread.

cgaengineer
07-14-2012, 12:33 PM
We do two split apps here since our growing season is so long, I would think NC would be similar. My main reason for splits is because I use low volume to apply, but it's better anyway...better for cg prevention and safer for the root system in my opinion.
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Duekster
07-14-2012, 02:40 PM
Since we are talking, My understanding of the label is like two apps per year, say Spring and Fall. The split app is actually taking the spring App dividing it in 1/2 but while you are doing that, you can increase the strength slightly.

So you get something like this

1/2 recommended rate ( which is less than max rate /2) late Summer / Fall
then 1/3 of Max rate Late winter
followed by 1/3 of Max rate. Mid Spring

You will put down less than the maximum allowable rate like this and get extended CG control on warm southern regions.

Duekster
07-14-2012, 02:57 PM
So for our States, NC/SC/GA/TX

Fall / Late Summer is applied at Program 3 rates of 1.2 pints per AC to control Poa and winter weeds.

Then we use Program 2 rates - 1 Pint per AC split into two apps ( .5 Pints ) 5 to 10 weeks apart.

This actually uses 2.2 pints per AC which is far below that maximum rate of 6 Pints per year and 2 pints per Application.

If you did the program 2 with two apps, you would be at 2 pints per AC....

Brett Thomas
07-15-2012, 01:05 PM
what were your rates

Brett Thomas
07-15-2012, 01:13 PM
hopefully its not this bad. I took this pic yesterday at a pool house u can tell exactly where the spreader with pre m went

Duekster
07-15-2012, 01:40 PM
Never in my life have I seen pre of any type work well as a granular product as well as a spray.

Brett Thomas
07-15-2012, 03:29 PM
I def agree with that and why the z spray helps so much

Duekster
07-15-2012, 03:54 PM
I def agree with that and why the z spray helps so much

Dimension is a very good pre-emergent but I believe it requires a minimum of 2 gallons per K plus some watering in too

Brett Thomas
07-15-2012, 03:59 PM
yes but thats y I run the the irrigation for a few right after I put down the pre emergent and I can tell u it makes a huge difference.

cgaengineer
07-15-2012, 08:20 PM
Never in my life have I seen pre of any type work well as a granular product as well as a spray.

I don't think it has to do with how it's applied, I think it's about how it's made. Since a granular pre is mostly filler, the AI is coated to the prills in the outside so that it's first to come off with irrigation. I suspect that much of the AI is worn off the outside of the prill in either the packaging or the shipping. I'm guessing that a bag of granular pre probably has a good bit of powder in the bottom of the bag when opened and emptied into a hopper. If this is the case than some areas get more and some get less AI if any at all.
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greendoctor
07-16-2012, 04:54 AM
If this is pre applied to fertilizer blends, there is not much holding it on to the granules. Really easy for it to become the yellow dust or musty smelling dust at the bottom of the bag. Never had a problem with adding pre to a liquid fertilizer load and spraying it out. I also agree with irrigation right after application. Many of the AIs are either volatile or degrade in light. It would be silly to leave them not watered in and about to be mowed off. A short cycle of say, 10 minutes per zone should do it.

Duekster
07-16-2012, 11:58 AM
If this is pre applied to fertilizer blends, there is not much holding it on to the granules. Really easy for it to become the yellow dust or musty smelling dust at the bottom of the bag. Never had a problem with adding pre to a liquid fertilizer load and spraying it out. I also agree with irrigation right after application. Many of the AIs are either volatile or degrade in light. It would be silly to leave them not watered in and about to be mowed off. A short cycle of say, 10 minutes per zone should do it.

Exactly - The 2 EW label says to apply with 2 gallons per 1000 SF at recommended AI rates then water in with 1/2 of water. Unlike Barricaid ( IRRCC is 2 weeks) it does not say how long the window is for getting that water on it.

I have had few problems with it working as a result of the HO not watering enough.

WestGaPineStraw
07-16-2012, 12:43 PM
We ran pendimethalin at 60% rate on round 2, liquid. Then we followed it up with dimension .15% granular. This was trial and error. No one ever needs to use this formulation in there application schedule, very poor control.
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RigglePLC
07-16-2012, 02:56 PM
That is a good question. Can you use two different types of crabgrass control a few months apart? What if they have different modes of action? Suppose one attacks the roots and the other the grass tip?

Duekster
07-16-2012, 03:49 PM
That is a good question. Can you use two different types of crabgrass control a few months apart? What if they have different modes of action? Suppose one attacks the roots and the other the grass tip?

If I switch up is because of lack of control of different types of weeds.

lawns Etc
07-16-2012, 04:30 PM
Around here most run two apps 1st late March is Pre M second late April is Dimension .15 and works pretty good