Photos of the week - the stress index and grubs
October 12, 2015
| | The Stress Index (also known as the Wong Gray Leaf Spot Index - developed by Dr. Frank Wong) is the sum of the maximum air temperature (F) and the minimum relative humidity. This graph provides a comparison of the cumulative stress index for 2014 and 2015. Stress started earlier in 2015 compared to 2014 and has yet to stop accumulating. The result was severe gray leaf spot in ryegrass and kikuyugrass stands in addition to weakened poa annua…