Friday, July 15, 2011

LDS not LSD

No you're not hallucinating there is something funky on the greens. Sometimes with the heat (and usually after an aeration) the greens can develop dinner plate sized spots which can sometimes coalesce into a nice paisley patterns that cover large areas. The spots are a result of the turf being water stressed and are called Localized Dry Spots (LDS). There is multiple reasons why these occur including too much thatch, soil compaction, steep slopes, insects, disease, and the obvious one, poor irrigation coverage. Also, a sandy root zone that has accumulated enough organic molecules on a number of sand particles can eventually reach a point where the moisture content is so low that the growth media change from wettable to non-wettable resulting in the eventual turf decline.

LDS spot at the T-handle
End of the Soil Probe

Within LDS the sand is powder dry. I took two plugs, one from a LDS and one directly next a LDS to demonstrate.

Plug with Adequate Moisture
Versus Plug from LDS

We deal with these spots in a couple of ways. First, we spike the green surface to help break the surface tension that develops over the LDS. The equipment we use is nothing more than a series of "ninja throwing stars" lined up on a shaft which rotates as we pull it over the green.

Spiker Kit

The holes created are about one inch deep and hardly disrupt the surface.

Spiking Aftermath

To take full advantage of the perforations in the green surface the second thing we do is spray a class of product called a wetting agent. This product also has the characteristic of decreasing water surface tension as well as acting as a surfactant that allows the interaction of the dipolar water molecules with non-polar organic molecules coating some sand particles with the end result of making the once hydrophobic sand particle hydrophilic.

Usually, we can get a few months between treatments but a lot of that has to do with the weather (as usual) and how dry we let the greens get in between watering cycles. The easy thing to do would be to never shut the water off on the greens but that makes for some squishy greens so if it heats up more and we keep the greens dry you may see these spots before you eyes again before the season is up.



Thursday, July 7, 2011

More aeration

What to write about when nothing seems new? I guess I could do a quick review of the past couple weeks. We continued with aerating other spots once the greens where done. I made mention of why we aerate and top dress the collars and aprons in the past (see aerating collars) and the same reasons still hold true this time out.


Puchin' #13 Approach

We also took the time to aerate select spots on the certain fairways. We've done this many times in the past during early summer and it has resulted in better conditions during the remainder of the season for those select spots. We choose areas that a prone to drying out and, as a result, require extra work to keep them playable and looking good. We try to punch as many holes as possible and then overseed those areas with a blend of bluegrass/rye grass seed. I like to reuse the cores we collect from the spring greens aeration mixed with one part Nature's Gold (commercial compost composed of ..... you don't want to know but if you know someone in Kelowna chances are pretty good some of their "business" is on our fairways) and one part sand. We lay it on pretty thick with the hope of filling the newly created holes. The top dressing will also cover the seeds which helps give a better catch.

Aerating and Cleaning Cores
at Lone Pine

The next area to see the aerator will be the tees but I think everybody needs a bit of reprieve so chances are we won't be doing tees until the end of July.

One more quick comment about the greens aeration. I can see with the benefit of hindsight that the greens at KGC didn't really respond the way I had hoped. Although they are growing well with lots of grass and new roots are starting to appear they are still too soft. With the heat arriving last weekend I was happy with how well they coped, however, that was short lived and now we are having to hand water LDS (Localized Dry Spots) like crazy. Ultimately, the greens will be better off but my preference would be to not deal with the problems we are facing now. This falls aeration will not be as aggressive as I alluded to in the last post but more likely a repeat of the 2010 fall aeration (2010 fall aeration)

4 Green Surface