Relentless July and August Leads to Major Turfgrass
Problems
16 August 2016
Turfgrass Disease Solutions, LLC
Over the past three
weeks, I have visited more than 65 golf courses in Delaware, Maryland, New
Jersey, New York and Pennsylvania and there is one common theme,
stressed turf due to the relentless weather since mid to late July. The recent
high day time temperatures, warm nights, humidity, intense sunlight, wind and
then spotty thunder storms have placed incredible stress to all cool season fine
turfgrass areas. The weather has not discriminated amongst private nor public
clubs, high budget or low budget courses - every golf course is showing signs
of stress in some regard. It has been a brutal season to try to maintain green
speeds, manage moisture and playing conditions. Due to the varying climates,
budgets, ages, and designs throughout the region, golf courses should not be
compared to one another. The growing season of 2016 is bringing chronic issues
such as air movement, drainage, shade and weak species to the fore front.
The most common problem
I have encountered, especially in regions that are receiving rainfall, is
severe wet wilt to fairways, tees and greens. Wet wilt is a physical problem in
which the soils are saturated and the grass cannot transpire water to cool
itself because of poor air movement and high humidity levels. This has been
most commonly observed in low lying areas of fairways, tees and greens. Most
commonly, it is complete decline or the only live grass is in aeration holes
from this spring or last fall. Wet wilt is very difficult to manage and can
take up to 10 days to fully show up, especially on higher cut tees and
fairways. Typically, you will see that golf cart tire tracks wilt quickly and
then decline even when the soil moisture is adequate. If you are experiencing
wet wilt, be conservative with mowing heights and use solid front rollers.
Rolling greens is a significant stress to thin turf. On fairways, in the short
term, limit cart traffic and restrict to roughs or paths. Don’t be afraid to
preventively syringe turf that is showing signs of wilt with adequate soil
moisture. Long term, explore options to improve drainage and air movement.
Dry wilt is also a
problem for many golf courses not receiving rainfall in some regions. This
places an incredible load on the staff to manage moisture with hoses and
overhead irrigation, which is tough in the heat. If you are in a dry period, be
sure to check that irrigation heads are properly functioning. Far too often an irrigation
problem shows up when the stress shows up and with the heat we have
experienced, it’s a slow road to recovery. Beyond lack of water or too much
water, is decline in the poorest growing environments. Air movement is the most
important growing environment consideration during warm, humid periods. Air
movement is needed for fine turf to be able to cool itself following light
applications of water (i.e. syringing). If there is no air movement, the turf
in that environment can be 8-12ᵒF warmer than turf receiving air movement naturally or
through fans. Fans have completely changed greens management in areas where
trees and underbrush cannot be removed. Air movement is the key for syringing
to work. If the turf does not dry in between syringing, the effects are minimal
and the turf will begin to thin.
Mechanical stress is
showing up throughout the region, especially in shaded areas. Mechanical
stress, although self-inflicted, is tough because superintendents are trying to
produce a playable golf course. The two most common mechanical issues I see are
roller damage to the collars or mower stress from turning or to the edges
(clean ups) of greens. Be sure to watch staff turn mowers and use rollers to be
sure they are properly completing the task and adjust heights if mowing is
skipped. Skipping mowing may be needed during droughty or wet conditions but if
skipping mowing, be sure to assess the height of cut and not remove too much
tissue in a single mow. You will be able to work the height back down in time,
but the initial scalp can cause issues under the current environment.
Disease pressure has
been extremely high and every major turfgrass disease has been observed. Brown
patch and Pythium pressure has been high for the past three weeks. For those of
you maintaining perennial ryegrass, I have confirmed gray leaf spot over the
past week- this disease can be incredibly damaging under stress. In some of our
trials, we are seeing tighter spray intervals and high rates work best but
nothing will provide 100% control in extreme conditions or saturated, humid
conditions. Preventive fungicides should be applied as needed. If curative
control is attempted, be sure to have the disease properly identified and use
the best course of action. Annual bluegrass weevils have been significantly
damaging bentgrass fairways and tees for the past 3 weeks. We have found early
instar white grubs in some of the untreated plots in our research trials so be
sure to scout for them if you are seeing wilt or unthrifty turf. Be sure to
scout for insect pest and treat accordingly.
In a quick outline,
these are just a few of the major observations I have had in my recent visits.
Other common themes include: elevated amounts of phytotoxicity
(injury from commonly used plantprotection agents), elevated plant parasitic nematode levels, physical injury from aggressive golf shoes
and damage from venting or spiking greens and/or sand topdressing on weak and/or stressed turf. For
those of you considering aerification in the near future, please assess the health of the turf before aeration
or use a less aggressive technique. Aeration should not be looked upon as a tool to renovate weak turf,
but rather a tool to promote long term health. Aerification of weak turf in August can lead to weak turf in
September and October which are two of the most important golf months in the Mid-Atlantic region.
Feel free to reach out with a phone call/text (610.633.1878) or
email
(turfgrassdiseasesolutions@yahoo.com).
Steve
McDonald
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