Signs of Injury

As I mentioned in an earlier post, we have been playing around with some experimental treatments to help eradicate the Perennial Ryegrass in our Bentgrass fairways.

The first visible signs of treatment began to show up after six days following the initial application. Symptoms of the treated areas began to show up as a chlorotic effect on the turfgrass.

Chlorotic Effect Shown of Fairway

Ten days after treatment another indicator that something was going also started to appear. Smaller patches of the Ryegrass are beginning to turn reddish and are giving the appearance of dying. Not all of the Ryegrass is showing the same effect, but several areas are reacting more effectively to the treatment.

Ryegrass Checking Out

As Hot As It Gets

After 17 straight days with temperatures in the 90’s, the forecast is not showing any signs of improvement. This year is currently the fourth driest on record and if weather patterns remain the same, this will go down as the driest year on record.

The previous record for consecutive days 90 or above is 18 days, which was set back in 1874. This record is likely to be passed by without blinking.

With all the talk of how hot and dry it is, the golf course continues to be in great playing condition. We picked a great year to allow for brown being an acceptable color on the golf course in efforts to improve playability. This year especially, the shortcomings of the irrigation system are on full display for all to see. The outer lying rough areas are under great stress while the core of the course remains green while not being overly wet.

The Bentgrass fairways have not been phased one bit by the heat and are actually thriving under these conditions. The fairways have been treated all season long with PGR’s for Poa Annua control and they are hands down out competing the Poa. As the Poa is weekend by the effects of chemical suppression and the heat, the Bentgrass is moving laterally and taking over in the fairways.

Ball Mark Recovery

The additional fertility that has been applied to the greens is helping with ball mark recovery. If you look closely at the ball marks that were actually repaired, you will se new growth forming and beginning the fill the mark back in. Additionally other un-repaired ball marks are beginning to fill in as well, from the fertility and use of PGR’s.

The plant growth regulators help the turf by increasing plant density and production of additional tillers. This additional growth is mostly in the form of lateral movement which helps grow over and into old ball marks. This type of lateral spreading is the normal growth habit of the Pencross Bentgrass, but this movement is enhanced with the use of PGR’s.

Close Up Of a Recovering Ball Mark

Bentgrass Seedlings

If you look closely in the fairways, you will see many Bentgrass seedlings becoming established. The fairways were overseeded back in the middle of April and with the cooler than normal temperatures this spring, wide spread germination was delayed. With the recent consistent rains the seedlings finally started to germinate and become visible. Normally germination of Bentgrass takes between five and seven days, were as this spring it took nearly three and a half weeks to occur.

Now that the seedlings are fighting for establishment, bi- weekly foliar fertilizer applications will be made to help provide the nutrients necessary for maturity. These foliar fertilizer applications will be made in conjunction with PGR applications that will target the Poa and further allow the Bentgrass to take hold.
Visible Seedlings in Verti-Cut Lines
Seedlings Coming Up In a Divot

Growth Regulators

Growth regulation products are commonly applied to many of the playing surfaces on the golf course such as, greens, tees and fairways. The use of PGR’s or plant growth regulators consistently improves overall turfgrass quality by promoting a smooth uniform playing surface, aides in color enhancement and improves stress tolerance.
Spraying PGR's on Fairways

PGR’s are generally classified into two different categories type I and type II. Type I PGR’s suppress plant growth by inhibiting cell division and help with the prevention of seedhead production. These products are typically foliar absorbed by the plant. Type II PGR’s suppress plant growth by limiting cell elongation and Gibberellin production which reduces growth rate. These products are can be either foliar or root absorbed.

The use of specific growth regulators also helps with controlling Poa Annua populations by weakening the Poa and allowing the desired grass species a competitive advantage. When the Poa is targeted for suppression it can be severely injured and or killed if that is the desired effect. When proper rates and application timing of PGR’s is done they can be one of the best agronomic tools available for Golf Course Superintendent’s.
Close up of Injured Poa Annua