Turf Rising Means Poa Annua Is Waking Quickly

Yes, our turf is rising from it's winter slumber, especially our poa annua. We have a variety on our practice green that wakes up a bit early. I think it awakens early because of a micro climate created by the large parking lot and roadway which is next to the green. The black asphalt absorbs heat which is then transferred onto the green artificially inflating its temperature.  It is also orientated toward the west which gives it a good sun field most of the day.

Interesting note, I just went out and took some soil temperatures of our greens at a 2" depth, 1:15 p.m. Practice green was 54 degrees, #11 which faces to east was 50 in the front but only 43 in the back where it is shaded by the large Pin Oak. 13 green which is facubg west was 51 degrees.

At the tip of the tee is a seed head that has already developed on the practice green. 

Each season, we begin to count growing degree days (average heat accumulation) to determine when to apply specific products to prevent or reduce the effects of weeds, insects and fungus. Yes, scientific models are developed to help us to predict when to apply these products making them more effective. Poa annua seed head development, crabgrass control, broad leaf weeds, beetles and other pests are treated from these various models.

The model we use for poa annua seed head development is the 32 degree model.

Allow me a moment to explain how this model works. The high temp for Friday March 4th was 43. The low was 37 giving us an average of 40. We then subtract the 32 degree base number from the avg. temp for the day which was 40 giving us 8 growing degree days. We then accumulate the days totals until they begin to get near the target number that has been developed over the years by researchers as well as practical experience we have seen on our course.

We use GDD Tracker from Michigan State University. As you can see by the map, we are getting close into the target time for applying the product.

We utilize 2 growth regulators that work in combination to reduce the impacts of seed heads. The predicted outcome is about 50% control which does not seem very good but if we used no control measures, you would come to appreciate at least 50% control. 

We attempt to apply our product when we are trending toward 300 growing degree days. 

Right now we are at 221(we were at 8 growing degree days last year on this date). This week's warm up and rains should shoot us well past the 300 target mark before the end of the week. 

So what does this mean, yes I am either spraying later this afternoon or Sunday morning with rain predictions for most of this upcoming week. We sprayed last year around March 20th or so. We should go past that growing degree number by Thursday of this week. 

What does this mean for the season. Right now we are accumulating heat days about 2 weeks ahead of last year. Will it last? I don't know but we are trending for an earlier season so we will keep our fingers crossed. The weather does have a tendency to average itself out. Of course if we continue this warming trend, that creates tremendous pressure on our staff because everything is sped up, staff are not in place and those problems that come along with too much work and not enough time. Also, applications and sprays get pushed very close together which can create problems for us. Some of our chemicals don't play well together if they are sprayed to closely to one another.

Greens aeration is scheduled for March 21st pulling cores and March 28 contracting a new service called Dryject. More information on this over the next couple of weeks.