herbicide vs too hot

Discussion in 'Pesticide & Herbicide Application' started by RigglePLC, Jun 20, 2012.

  1. cgaengineer

    cgaengineer LawnSite Fanatic
    Posts: 15,782

    In my experience yes. Apply in eary morning when cool. Make sure customer follows irrigation advice. This advice is warm season turf (Bermuda)
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  2. greendoctor

    greendoctor LawnSite Fanatic
    Posts: 9,062

    As long as the lawn is irrigated correctly, warm weather is not a problem. Having said that, I will not not hesitate to hold applications to lawns that are dried out because of mechanical problems with the irrigation system or incorrect operation of the system.

    On a related note, manufacturers need to put a lot of CYA in the labels because there is no guarantee that someone will be as conscientious. I make suggestions concerning tank mixes and applications with the understanding that they are not done to lawns in no condition to tolerate it. Dismiss on a lawn that has not been watered or fertilized, Dismiss + MSO + a partner herbicide on a lawn that has not been watered or fertilized properly. Sure, you will see burn.
     
    Last edited: Jun 28, 2012
  3. RigglePLC

    RigglePLC LawnSite Fanatic
    Posts: 12,118

    As a test, I applied herbicides in hot weather, temps over 90 degrees. Non-irrigated grass(Kentucky blue, rye and fine fescue) in light shade. No significant rain for about 2 weeks. Hudsonville weather station is about 10 miles west of the trial; our city temperatures were a bit higher.
    http://www.enviroweather.msu.edu/run.php?stn=hvl&mod=w_sum

    I added a heavier application test on June 28th. In this test, I sprayed about 5 seconds when using a compressed air sprayer, (Quicksilver, Confront, and Surge), and 7 squirts when using squirt bottles, (T-Zone, Speedzone). This treatment was applied to grass in a 10 inch circle 24 inches above the white labels. Photos taken on the 30th, 48 hours later.

    The only injury was a mild browning from the Confront. Top photo, left. There was slight injury from the T-Zone. The Drive herbicide was omitted on the June 28th test.

    Cnft, Surge.jpg

    Quick,Drive.jpg

    TZone,Speed..jpg
     
  4. RigglePLC

    RigglePLC LawnSite Fanatic
    Posts: 12,118

    On July 6 we experienced temperatures of 100 to 106. I tested 5 weed control products adjacent to a previous test, on a mixture of bluegrass, fine fescue and rye. Shady, and weather was dry for at least two weeks. I sprayed 5 times with squirt bottles, (Speedzone and T-Zone.) I used 3 seconds with hand held compressed air sprayers, (Surge, Confront, and Quicksilver). After 72 hours there was very slight browning on areas treated with T-Zone and Confront.
     
  5. RigglePLC

    RigglePLC LawnSite Fanatic
    Posts: 12,118

    Crabgrass seeds were planted in a small plastic cup in potting soil. After emergence, to about an inch tall, the soil was treated. I applied with 4 granules or about 4 pounds per thousand sqft of Dimension(dithiopyr) 0.13 percent. About 75 percent of the crabgrass was killed.
     
  6. RigglePLC

    RigglePLC LawnSite Fanatic
    Posts: 12,118

    I tested four types of herbicide under high temperature conditions. The grass was Kentucky bluegrass, which was irrigated. Temperature was 83 degrees F. and rose to 94 later in the day. It was 95 on day 2; 92 on day 3, (July 15).
    Products tested were T-Zone, Speedzone, Surge, and Quicksilver.
    T-Zone and Speedzone were applied with "squirt bottles"; sprayed 3 times over and 5 times over. (About 1/40th of an ounce per squirt). Surge and Quicksilver were applied with hand held sprayers, using 2 seconds and then 3 seconds in the high rate spots. The amount recommended for 1000 sqft was added to one quart of water to prepare the spray solutions.

    No visible injury to the grass resulted. Some weeds were killed although there were only a few weeds present.
     
  7. RigglePLC

    RigglePLC LawnSite Fanatic
    Posts: 12,118

    I tested four types of herbicide under high temperature conditions. The grass was Kentucky bluegrass, which was irrigated. Temperature was 83 degrees F. and rose to 94 later in the day. It was 95 on day 2; 92 on day 3, (July 15).
    Products tested were T-Zone, Speedzone, Surge, and Quicksilver.
    T-Zone and Speedzone were applied with "squirt bottles"; sprayed 3 times over and 5 times over. (About 1/40th of an ounce per squirt). Surge and Quicksilver were applied with hand held sprayers, using 2 seconds and then 3 seconds in the high rate spots. The amount recommended for 1000 sqft was added to one quart of water to prepare the spray solutions.

    No visible injury to the grass resulted. Some weeds were killed although there were only a few weeds present.

    Whoops accidental repeat. Please delete.
     
    Last edited: Jul 15, 2012
  8. RigglePLC

    RigglePLC LawnSite Fanatic
    Posts: 12,118

    I tested 4 products on irrigated Kentucky bluegrass On July 13, 2012. Temperature was 83 and rose to 94 later in the day. Temperature highs remained above 90 for the next week.

    Products tested were T-Zone, Speedzone, Surge, and Quicksilver.
    T-Zone and Speedzone were applied with "squirt bottles"; sprayed 3 times over and 5 times over. (About 1/40th of an ounce per squirt). Surge and Quicksilver were applied with hand held sprayers, using 2 seconds and then 3 seconds in the high rate spots. The amount recommended for 1000 sqft was added to one quart of water to prepare the spray solutions.

    At 6 days slight injury was visible on the T-Zone treatment (right)and none on the Speedzone treatment, left, (first picture).
    Distinct browning was visible on the Surge treatment, right; no injury was visible on the Quicksilver treatment, (second picture).

    Possibly this indicates triclopyr can cause injury at high rates. Perhaps Speedzone is a safer procduct at high temperates, or if you accidentally spray in excess. (And Quicksilver, also caused no injury).

    Speed_Tzone.jpg

    Quick_Surge.jpg
     
    Last edited: Jul 19, 2012
  9. frotis

    frotis LawnSite Senior Member
    Posts: 395

    I wonder if the browning would have increased with a spreader sticker added.
     
  10. RigglePLC

    RigglePLC LawnSite Fanatic
    Posts: 12,118

    I did not test it with spreader sticker added. That is a good idea. Coming soon maybe--if the weather is hot enough.
     

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