Turfgrass Disease Education

Cool and wet weather continues. Because of these conditions, we are witnessing outbreaks of different minor turf diseases here at Potowomut. Turf disease is more prevalent after periods of wet weather because these conditions favor development of the fungi that damage turf.

Please note that none of these diseases we will discuss today are severely damaging to the overall health of the golf course. I am not writing today to raise alarm; my purpose is to raise your awareness of these issues, and to further your turfgrass education!!

DOLLAR SPOT

On fairways, turf disease Dollar Spot is caused by the pathogen Sclerotinia homeocarpa. (See picture below) Annually, this is the most common disease we see on fairways during the growing season in our climate. Dollar Spot shows itself as silver dollar sized spots of damaged turf. If left untreated, Dollar Spot will coalesce into larger areas and kill turf plants, leaving an ugly playing surface that will need to be re-established. This disease is the focus of our preventative fungicide program on fairways all season long.

Our fairways have been treated twice for Dollar Spot, yet the damage we see this spring has "leaked" through preventative fungicides. Eventually, damaged plants will recover. Damage we see is aesthetic and not a huge concern, but rather a reminder that Mother Nature is always in charge!!

To help fairways heal faster, we will suspend the next scheduled growth regulator treatment planned for later this week. Allowing fairway turf to grow at its normal (faster) rate will hasten the healing process. Also, last week's fairway fertilizer application will help turf recovery, as dollar spot is a rare disease that is slowed by higher nitrogen soil fertility. Most turf diseases spread aggressively with nitrogen fertilizer applications.

LEAF SPOT

Another disease present (in roughs) is called Leaf Spot. It is caused by many different fungi from the Helminthosporium species. Leaf spot is present as partly circular patches one to two feet in diameter. (see picture below) Leaves of infected turfgrass have small brownish areas of damage evident. Again, we are seeing leaf spot this year because of the weather conditions we have seen. Warmer weather will stop the damage on plants, and turf should recover nicely during later June and July. Damage has not spread to greens, tees or fairways because all these areas have been treated with fungicides this year. Leaf spot present in roughs is not a serious situation that warrants expensive fungicide treatments.



FAIRY RING

Fairy rings are present annually and show up on greens and fairways around June 1st. Named from European fokelore because "inside the circles is where the fairys danced." Fairy rings can be both small (6 inch to 12 inch) or larger areas (up to 60 feet in diameter) of circular darker green areas of turf. The fungi use, then release excess nitrogen to the turf. The turf roots find the nitrogen giving the infected areas darker green turfgrass. Sometimes, toxic mushrooms also grow within the darker green circles.

We treat to control fairy rings on greens only, due to potential uneven putting conditions if left untreated. This year, fungicides were applied on May 28th. Fairy rings on fairways are not treated, due to expensive $ 1,500.00 per acre cost for fungicide treatments that would be necessary for successful control.

RED THREAD

Finally, we have seen a few patches of disease Red Thread this spring. Red thread is fascinating in that turfgrass infected has vibrant pink or red strands growing from mowed leaves. It tends to be injure turf in 4 to 18 inch sized circular patches of damaged turf. If left untreated, Red Thread can damage fairways severely, but we are safe because of the two fungicide treatments during 2009.

GOLF has been GREEN for a long time....

We have again added bales of barley straw to the ponds on 2 and 18. Some biologists observe that barley straw's presence can reduce the populations of certain types of algae growing in ponds and waterways. Apparently, as it degrades, a chemical is released that hampers algae growth.

The rough has been in many conversations this spring. We won't further delve into the severity of the rough at this time. However, because of the health of the rough, a significant positive change can be reported and celebrated.

First, a little background information is needed.

Integrated pest management (IPM) is an environmentally friendly management method for maintaining plants (and golf courses) that relies on less dependence of pesticides, irrigation water, fertilizers or any artificial methods that aids plant health. The IPM philosophy says that healthy soils will produce healthy plants that can withstand stresses from insects, disease, heat, drought and weed invasions. We employ IPM ideas constantly to give us a healthier golf course, a golf course that uses less inputs of pesticides and irrigation water than if not under IPM management.

We have touched on these IPM ideas previously without actually identifying them as IPM. Discussions that have centered on improving soil's health by adding lime and deficient nutrients is straight out of the IPM handbook, as healthier soils will support stronger, more reliable turfgrass with fewer inputs. Aerification of turf areas is an IPM method that provides air for improved soil/oxygen exchange. Providing the sharpest cutting blades for the cleanest cut prevents disease from entering poorly mowed leaf blades is IPM. Barley straw in ponds, rolling greens, thatch removal, using sand topdressing, and increasing sunlight penetration for turfgrass are all methods of Integrated Pest Management employed that lessen dependence on pesticides, fertilizers and water. (I could write for hours about how we use the IPM philosophy to manage Potowomut.)

Back to my original point, my apologies as I seemed to have wandered a bit.

Turfgrass in the rough is greatly improved after applying appropriate fertilizers the last few years as directed by Soil Scientists as a result of soil testing. During 2009, much less herbicide (weed killer) has been utilized to eliminate weeds, simply because there are fewer of them. IPM says healthier soils will provide stronger turfgrass plants that will choke out weed plants and their lateral movement, slow or stop germination of new weed seeds, and we are seeing those benefits this spring.

Ramblings

Thursday's miscellaneous ramblings....

Today we applied to fairways sulfate of potash fertilizer, with an analysis of 0-0-50 (the numerical analysis refers to amounts of nitrogen, phosphorus and potassium, listed as a percentage of weight in each bag.) Potassium helps prepare turf for the stresses of summer heat and drought. Research shows that potassium helps to toughen plants by strengthening plant's cell walls, improve the plant's response to disease potential, and also helps plants to use water as efficiently as possible. Fertilizer particles will slowly degrade during summer, allowing plants to uptake the nutrient when it is needed most. Potassium was applied to greens and tees last week.

Also applied this week were soil deficient nutrients manganese, magnesium and calcium to greens and tees, and a complete fertilizer to practice tees (30-5-10.)

You may notice some darker green streaks on putting greens this week. The streaks were caused by overlapping sprayer passes of a nitrogen based fertilizer applied last week. I expect these streaks to disappear early next week.

To improve 60 yards of right side rough on #7, two sprinkler heads at 145 and 168 yards were changed in irrigation programs this week. Instead of running infrequently as rough heads, they will now run more often since we designated them as fairway heads in the computer.

We hope to see you out tomorrow, or during the holiday weekend!!!

ROUGH

Admittedly, the rough has been extra penal this spring. Sincere apologies from your golf course staff. Let me explain why the grass is extra long and feisty and tell you what is being done.

Let's start with a mini review of the problems with rough's soils.
1. Rough soils are extremely deficient in many important nutrients. Soils are deficient in plant available calcium, magnesium, and potassium. Soil pH is low, as are soluble salts. In summary, the supply in the soil for plant available soluble nutrients, or put another way, the amount of "gas in the soil's tank" for proper turfgrass growth is on empty. Let me provide quotes from March 2009 soil reports provided us by Harris Labs of Lincoln, NE.
a. "Immediate attention is required. Root growth has stopped...resistance to heat stress is poor, and membrane function is failing."
b. "Plant functions are in jeopardy of failing. Stomate (a plant cooling mechanism) is minimal so expect poor movement of water and nutrient throughout the plant."

To correct soil nutrient deficiencies, applications of proper fertilizer materials have been made, both last fall and again this spring. As these materials are slowly released to soils, plants are using them. Turfgrass in the rough is reacting positively or negatively, depending on your point of view, by actively growing with increased vigor during April and May.

Obviously, our long term goal is to improve the chemistry of rough soils. When soil can provide the nutrients plants need when they are needed, the rough can perform by providing an excellent playing surface for our members and guests.

Combined with fertility, the wet spring also aided aggressive growth of rough turf. 7.78" of rain has fallen on Potowomut since April 2, twice the normal amount.

We have two employees who each mow rough almost 40 hours each week. On Monday, we usually begin mowing rough on #11. Going in order they complete the rest of the back nine by Wednesday, and mow holes 1 through 10 Thursday and Friday. Each week, the rough is mowed once. Rough height differs depending on what day it is mowed.

Finally, both mowers' height of cut was lowered a half inch today. This adjustment should improve the situation a bit. We also plan on adding a third machine as time permits. We will do our best to continue knocking down the rough through May and June, when warmer weather should begin to slow growth.

May 8

Just a few notes from the week:

Greens spiking is nearly complete. Only #7 green remains to be done next week. This spiking process took the place of the heavy duty aerification and topdressing we normally do in early May. We spiked all greens in two directions, using our John Deere aerators set up with a slim "bayonet" shaped tine. We did not pull a soil core this spring, the spiking opens up the greens to improve soil and oxygen exchange.

For members who have not seen the greens since spiking, the surface disruption was minimal during this process. Greens are putting close to normal as of Friday evening.

We installed tournament cup liners today. The cup lines is an insert that sits on top of the cup, and simulates the painted cup look common on televised tournaments. Let us know if you like them...or not!!

Rough is extremely penal this spring, due our very wet spring and plenty of soil fertility. 7.63" of rainfall has fallen on our weather station since April 2nd. Waterlogged soil combined with 55 tons of lime and a nitrogen based fertilizer application to the rough last December are responsible. Growth should even out during the next three weeks.

All pre-emergent crabgrass applications are complete, as is a plant protectant applied to control Hyperoides Weevils, a potentially destructive root and crown munching small insect.

Play well!!!

Miscellaneous Ramblings....

Greens aeration will be performed next Monday and Tuesday, weather permitting. As mentioned in an earlier blog entry, we are significantly changing our method this spring. We will aerate with a solid tine, a tine that only pokes a hole into the greens' surface. No soil will be brought to the surface, making this much less intrusive than in the past. We will topdress the greens lightly and roll the greens to return smoothness. If all goes to plan, greens will be back to normal by Friday or Saturday.

This aeration process will help the greens by providing air to soil. A healthy soil is comprised of 50% soil particles and 50% air space. Aeration is our method of returning the air component after golf traffic, equipment and weather compress soils and remove air over time.

Wednesday we aerated over half of our golf course tees. We expect to finish either tomorrow or Friday.

With recent warm weather, soils are warming quickly after a slow start. Warm soil temperatures turn the millions of crabgrass seeds present in soil from not viable to viable, ready to germinate, establish itself and cause headaches for both you and me. We treat 95% of our turf areas with chemical materials to prevent this crabgrass seed from germinating. Earlier than previous years, we are almost finished applying these chemicals to prevent this weed grass. This weekend, after your golf of course, would be a great time to apply pre-emergent crabgrass materials and fertilizer to your home lawn!! Remember to water this material in with a half inch of irrigation or natural rainfall within a few days of application.

Greens were sprayed today for disease Anthracnose, potentially destructive insects hyperoides weevils, and were treated with growth regulator. The growth regulator will help to add speed to greens for this weekend's Phil Tally tournament.

We continue our project of severing aboveground tree roots. This is proving to be a slow moving process, but we will continue to be diligent to get rid of the roots!!

Please enjoy your golf course, and email me if you have any questions!!!!

INVASION!!!

We have become concerned with the ever-spreading cattails (genus Typha) present in our ponds on #2 and #18. Our concern is focused on the cattail's ability to choke off water flow between the two ponds, which would limit the amount of water available to us for golf course irrigation.

To irrigate the golf course, we use the "pump and dump" system. Our 60' deep water well, located near the stone wall bordering Potowomut and Goddard Park, "pumps" ground water and "dumps" it into our pond at the rate of 140 gallons per minute, until it is needed and moved to turf by irrigation pumps located inside the green pumphouse. We have the ability to store around one million gallons of water in our ponds for irrigation.

Because both ponds are utilized for water storage, it is important that water flows continually between them. The invasive cattails potentially could slow, or even stop this water flow, making it necessary for us to begin these control measures. No herbicides will be used; we plan on slowing the spread by frequent cutting back of the shameless invaders.


Thpha invasion!!