lower temps, lower moisture

We often say, “it isn’t the heat, it’s the humidity.” Indeed, humidity can be a measure of how nasty it feels outside. However, I also like to use dew point. See, hotter air can hold more water. For example, at 90 degrees F, relative humidity of 62% might not sound so bad. But, the dew point is 75. That is, there is so much moisture in the air that the temperature only needs to fall to 75 for condensation to occur. Dew points above 70 are very uncomfortable. Check out “dew point” on wikipedia and you’ll find more details and a better explanation.


On Tuesday evening the dewpoint here in Manhattan, KS, was 77, and I think that is the worst I have ever experienced.


But, the weather has changed and in many areas we are experiencing some relief, with highs in the low/mid 80’s and lows in the upper 50’s (!!) and low 60’s for the next few days.


Brown patch that was highly visible on putting greens on Tuesday and Wednesday is already fading. The image was taken by my colleague, Dr. Rodney St. John, and it’s my favorite photo ever of brown patch in greens-height turf.

With the temperature change, dollar spot that had been suppressed in the heat is now creeping back in.


Earlier in the week I received a couple more samples of Pythium from fairway height perennial ryegrass. The change in temperatures will help reduce disease pressure. In addition the break in temperatures will allow some cultural practices that superintendents might have been holding back on during the hot conditions.