Green conditions and upcoming next few weeks of heat/humidity

The heat is finally arriving this week along with some high humidity.  The work we have been doing since last

6 green under severe stress July 2011

fall and through to mid-summer have hopefully put our bentgrass/poa greens in a position to be healthy and survive the rest of the summer. We will now be taking a number of additional steps to protect our turf from this onset of extreme weather that can potentially set in for the next few weeks.

We did a slight raising of our greens mowing height today.  Our walking greens mowers were at .130" which is just barely above 1/8" and will be raised to .135" which amounts to a 3.8% increase.  Just a slight increase in leaf tissue will provide positive increased health to our greens as they begin to suffer through increased ambient and soil temperatures.  Additional leaf surface leads to the potential for more energy production for an already weakened plant.

We will begin to alternate between rolling greens one day and mowing the next in the early part of the week to reduce damage to the plants.  Mowing creates a wound on the tip of the blade which then requires additional plant energy to be produced to heal the wound.  Studies have shown that alternating between mowing and rolling reduces the overall energy required by the plant without sacrificing overall green speed. We will attempt to place an additional roll or two on the greens on Friday/Saturday which will improve ball roll for the weekend.

The disease triangle to the left shows the three factors that must come together to create disease in plants.

The host at the bottom of the triangle is our bentgrass/poa being mowed and played upon at 1/8" and are very susceptible to disease during the heat of the summer.  In some cases, the disease infects parts of the plant during the fall and or spring and if proper maintenance and or treatments are not made, the potential for the disease to explode are possible.  The plants are being grown at a height and in an area of the world where they are not native thus susceptible to certain diseases.

The environment on the right side of the triangle are conditions favoring disease which we are beginning to face.  High temperature and humidity.  This can include high night temperatures where soil temps are not allowed to cool overnight.  Humidity can come in rainfall at the worst time such as an mid-morning deluge followed by over 90 temps.     

The third part of the triangle is the pathogen which is almost always in the soil but its numbers are not to the level where it can impact a plant.  As environmental conditions deteriorate, the pathogen explodes in numbers and over runs the good microbes in the soil and the ability for the plant to defend itself and the onset of disease occurs.  

One of the things we are trying to do is reduce our activities on the turf which can encourage disease or stress to the turf.  At the same time, we walk a fine line in reducing inputs to the turf without compromising your overall ability to enjoy playing on this surface.  This is a difficult task to balance between these two factions.  The enjoyment of our members and guests of their day on the course is foremost in our minds.  At the same time, we must manage the health of our most important resource at the club which is our golf greens in a way to protect them through this stressful period so we can enjoy them for the rest of this season and the future.

Other jobs such as hand watering greens will become more apparent over the next few weeks as needed to supplement irrigation and cool surfaces when warranted.

Chemical input intervals could be shortened slightly over the next few weeks and additional products including seaweed extract will be increased to improve heat stress resistance.  Additional applications of Turfscreen will be applied which is a sunscreen for turf and  reduces overall canopy temperature.  Plant growth regulator Primo will be used which helps to reduce overall top growth of the plant which saves energy consumption as well as reducing top growth which improve ball roll on the non-mowing days.

Hydrojecting and needle tine venting will take place over the next month as well.  Another hydroject venting is scheduled next Tuesday, July 23rd and we will then follow up with a needle tine venting with our verti-drain machine in mid-August.  These two processes open up the turf to exchange good gas(OXYGEN) for excessive bad gas which is (CARBON DIOXIDE).  All living things need carbon dioxide but too much can be fatal.  The holes also help to dry wet areas and allows moisture to get into areas that tend to stay on the dry side.

We've been applying wetting agents and penetrants to assist in moving water through the 4" sand layer of our greens.  This material helps to reduce Localized dry spots(LDS) which is why you might see us concentrating water with hoses on specific green areas in attempting to get moisture to penetrate these areas that repel water.

Probably the most important thing that I have done in my 23 year career took place two seasons ago last summer when I changed our greens mowers over to solid rollers permanently.  Our old practice like many others was to change to solid rollers from grooved rollers during the main stress of mid-July/August.
I decided because of the age of our greens, poa contamination, lack of drainage and improvements in plant health/ball roll with solid rollers to make our switch permanent.  Wiele or grooved rollers do help cut the turf tighter but it also puts severe stress on the turf grass plants and the green surfaces.  We are cutting at a slightly higher height than a few years ago but achieving just as good if not better ball roll and at the same time improving the overall health of the greens.