Sunday, August 15, 2010

Ruthless 'er Rootless summer for cool season grasses!!!

Some of the greens are starting to show mostly physiological stress from this season's challenging weather conditions. Today's blog is intended to give a brief explanation as to why and what is happening and what staff has been doing to keep the turf alive to this point and what corrective measures/plans are in place for the quickest recovery...University studies have documented that cool-season grasses such as bentgrass and poa have root mass loss when soil temperatures hit 80-degrees and 72-degrees respectively. When roots die back the plant no longer produces carbohydrates (fuel) while respiration (similar to people sweating) continues to cool the plant. An analogy would be fill your car up with gas and drive until it runs out of gas.

In 2010 we have had more 70-degree nights than any year since 1959. Soil temperatures basically follow the night time or low daily temperatures. July into August set a new record for consecutive days of 80-degrees or above. Near record rains in June and July further damaged root systems.

The greens at WGC have a history of poor subsurface drainage that can be managed to provide a near private club level putting surface (traffic notwithstanding) most every season. Hand watering has been the norm in July so as to not over water. This is critical until the green dries enough to use the sprinklers. Staff has utilized our 'Toro Procore 648' (the best greens aerator in the world) since mid July "venting" or solid-tine aeration to punch tiny holes (smaller than a pencil) and provide increased gas exchange as the July wet weather came around. This procedure has been ongoing with an average of three greens per day being vented providing from 50,000 to 60,000 holes per green. As most green's root system is only an inch or two deep staff has been concentrating sustaining and recovery methods in this zone.

#5 Green with Brown Patch/Rhizoctonia solani disease due to breakthrough from preventative fungicide spray program. Breakthrough was caused by application and equipment issues and exacerbated by these recent prolonged hot and very humid conditions. Greens #12 and #13 which have performed the strongest until last week have slight damage from a fertilizer burn due to the spray gun sticking at times.

#16 Green also with Brown Patch. When climatic conditions change the turfgrass will grow out and through the diseased spots.


Staff will continue venting the greens on a 7-10 day rotation and use prudent hand watering and sprinkler methodology until greens fully recover. Once weather conditions break and return to normal (or below normal for a week or two) from these high temperatures and high humidity the turfgrass should recover just fine in a few weeks. WGC has a 1/3 acre bentgrass Nursery Green that will be utilized once the weather pattern changes and the greens show what recovery is left in their reserves'. This situation brings staff a great opportunity to introduce much newer varieties of bentgrass through seeding and plugging than the varieties these greens were sodded to over twenty plus years ago. Since the technology boom of the 1980's and 90's university turfgrass genetics and plant breeding made tremendous advances. #15 Green has direct evidence built into it. In 2008 the first (and only to date) drain line was installed from the front left of the green to the back right side basically following the swale of the green. Sod from the Nursery Green was used on the drain line. The stronger, much greener turf is easy to see every day if you just look from northeast to southwest as you approach the green.

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