When to Re-Apply Plant Growth Regulator | Growing Degree Days Explained
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- เผยแพร่เมื่อ 4 มิ.ย. 2021
- In this video I take some time to try and simplify the concept of growing degree days and how that helps you understand when you should re-apply plant growth regulator. There is a lot of information out there on what PGRs do and how you should apply them; however, I had not seen much information around when you apply them again beyond it being referenced in passing in a few videos. This information is hopefully helpful in establishing an interval that you should re-apply your PGR to avoid any sort of growth rebound, where the turf actually grows at a rate higher than it did prior to the PGR application for a period of time.
Greencast GDD tool: www.greencastonline.com/growi...
Bentgrass study: turf.unl.edu/research/PGR_GDD...
Bermudagrass study: acsess.onlinelibrary.wiley.co...
![[PLANT GROWTH REGULATORS APPLICATION TRICKS] - T-Nex vs Tide Paclo 2SC](http://i.ytimg.com/vi/ZXREwurnqKs/mqdefault.jpg)
Took me a minute to understand this gdd bit but nowbi think i understand. In my case that number is increasing by roughly 23 per day suggesting in 8-9 daysbi re apply my pgr but will double check the site recommended as i have now bookmarked it and have a shortcut button for it. Thank you for simplifying this. All the best and keepbup the great work
Yup. If you're mowing taller, half inch plus, you may be more on 300-400 reapplication windows. The 200 days discussed in this video is based on greens height grass. Something to just keep an eye on as you watch for rebound.
Look at those sprinklers going in the back round 😍, nothing more relaxing than watering the lawn! 👌🏼
No choice, man. It is pretty relaxing.
I put down my plant growth regulator every 2 weeks at half rate especially if you're putting it down for the first time so you don't burn your lawn. And I just put it down at half rate every 2 weeks for the rest of the season and the results are awesome...
That's close enough if you're mowing short. There are times of the year if mowing taller, though, where that could start to run into some problems. You're also not getting as much in terms of regulation doing that. It'll work and is fine more often than it isn't, but something to consider more closely tracking actual gdd. And it's not hard.
I've been trying to figure out GDD and was totally confused. Thanks Jason for making it simple. It makes sense to me now.
You are welcome. Only thing I forgot is there's mention that longer cut turf is more impacted for longer. So, if mowing higher, just stretch the interval out a bit longer. Unfortunately don't know how much "a bit" is.
@@JasonSeiberlich I back dated my first app and the 200 actually was pretty accurate as to when it wore off and I mow at 2.25 inches.
Oh nice. Good to know.
Great breadown on application timing! Nice sprinklers as well, lawn isn't looking all that bad given the weather conditions we've had
Thanks, man. Only had to water twice so far.
Not bad not bad! I am at about 8 or 9 times.. I'm just waiting for the day my parents get the water bill😂😂
That’s some solid advice, I just started using tnex last week. It really made a huge difference in my mowing schedule since I’ve been mowing between 1/2 - 1” all year. Really saves me a lot of time. UW extension office has so much great content!
It's crazy how effective the stuff is. Makes a huge difference on the green.
I appreciate the effort into the warm season research. Great video!
Thank you.
If using 32F for determining GDD, multiply your 200 times 1.8, which = 360, like you stated. Took me a while to find that little nugget of information. For Anuew PGR and TTTF, I need 630 GDD at 32F. As you can see, the exact numbers for your PGR and location and grass type, causes the numbers to vary substantially. Requires some research, but worth it.
It really does make a huge difference. Mow height also significantly changes the re-apply window.
Where did you find this 1.8 figure BTW?
1. The sprinkler in the back drop was great... Yes, I started watching it and had to rewind...
2. Us poor warm grass guys!!!!
3. So, if I'm hearing right .. this is like a 4 month in-between app timeline until the rebound phase might hit......
I'm up next week w my 1st PGR app....
No growing degree days are not the same as calendar days. At your temps it may be as often as every 10ish days.
Good stuff Jason! Quality info.
Thank you.
Thanks for the research Jason! Much appreciated!
Absolutely. Hope it's helpful
Great info. Thank you Jason
Thank you.
Great content. I had the same question when i started using PGR. I made up a growing degree cal. In excel that tracks the same way you are. I use the Awnue PGR and can get 300 GDD . With out any issues in cool season grass.
Thank you. That's awesome. I did see in one of the things I read that Aneu was the longest acting PGR of the I think 3 tested in that particular study.
Yes and i have not experienced any yellowing as i have hurd from T-nex users
OK, I am still confused. I add 200 to what number? And what do I do with that number then?
The number I highlighted is the year total. The day you apply, add 200 to that. Then check the year total periodically until it reaches that number and apply again at that time. So, say the day you apply the year's gdd total is 600, you're going to watch for it to get to 800 and apply again.
@@JasonSeiberlich ahh. Ok. That is making more sense now. I need pictures. 😂
Realistically should have walked all the way through an example.
@@JasonSeiberlich well that helps me. Looks like maybe in a week or so I will have apply some more now it looks!
I want to try at some point PGR but for what I have the bottle is too much for me... need to seed if someone will be nice to split some. I heard Lawn Forum sometimes helps, do you know any other place? Thanks - Nice Video
Boy have I got a video for you lol. That pramaxxis mec product is only $34 for 8 oz. More expensive per ounce, but much lower barrier to entry. Did a video on the "cheapest" pgr not too long ago.
4:59 So using a 0°C base you say 200 GDD's, but if you use 32°F base use 360 GDD's? It's the same temperature, why are GDD's different? Thanks
Because there are more degrees with Fahrenheit since the numbers are bigger. For example, 72 farenheit is 40 degrees above base but thats only 22 C or 22 degrees over base. Honestly, just use Celsius. And, something I didn't know at the time of this video, if you are mowing taller you can stretch to 300 or even 400 gdd based on the Celsius calculation.
@@JasonSeiberlich - Thanks, I just had to sit down and work it out. It now makes Sense. 200 GDD's using 0°C base and then switching to 32°F base and using the 360 GDD target, they equal the same "time period" and end on the same day. My math shows if you add 80% to the 0°C target you get the correct 32°F target: 200 +80% (160)= 360. I think the terminology messes me up. They should call it Growing Degree Units. 😄
This is the same program I’m on that I found from Purdue University. What rate do you use for your bent ? 4 Tsp per thousand works great for my .5” PRG.
I'm only doing my putting green, which is bent at 1/8 and the label rate is an eighth of an ounce per 1000. Not sure what that is in tsp.
Great video. Where did you find 200 GDD for Tnex? I had read 300 GDD. Thanks
200 is from a bentgrass green study. For longer grass, 300 to even 400+ is more ideal.
So this is my first time and I’m confused. I have the GDD +200. But how do I find the date for reapplication?
I want to first clarify something I didn't know when I made this video. 200 gdd is for grass that is sub 3/8". If you're using in normal cool season type grass mauntained at 2"+ it may be closer to 350-400 or even more before you have to reapply.
So, with that out of the way. Note the day you make the first pgr application and what the season total of gdd has been on the Syngenta website on that day. Say you apply on 5/20 and the current gdd total for the year is 350 days. So, the next application will be when the gdd total for the year passes 550 days. It's just checking in on the gdd total until it crosses 200+ days from the application day total.
I wanted to give PGR's a try but for some reason they are banned in NY for some of the products I have been researching .
Interesting and unfortunate
January to March was 0, April 30 and May 40 so that stuff would work forever up here.
Historical data did say August has 200 gdd.
Interesting. Realistically you wouldn't even apply during those months since the grass isn't growing.
@@JasonSeiberlich Having never read the chart before it was only to say what I saw.
🇺🇲🇺🇲🇺🇲 Freedom units. 🇺🇲🇺🇲🇺🇲
I still don't get it.
Math is hard.
😕
What's up, my guy?