Monday, January 12, 2015

Entomosporium Fungal Leaf Spot

Today I went to Chamley Landscape where I gave pesticide safety training to the employees.
After the training session my good friend Paul Smith and I visited sites in Shady Canyon and Corona Del Mar to look at different landscape and plant conditions.  The plant in the photo is  Lantana camara "Fiery Skipper".  The spots are seen are caused by Entomosporium mespili or Entomosporium maculatum.  The disease is commonly known as fungal leaf spot.
It's caused by water on the leaf surface during a humid weather period. 
You can treat it by spraying a broad spectrum fungicide with the active ingredient chlorothalonil or copper.  If I was inspecting a nursery with this condition I would likely recommend spraying.  But the fact is the spots will not go away or spread. Spraying will prevent other diseases and the chlorothalonil is not systemic. It's a protectant fungicide therefore, it must be applied before the disease occurs.  So why spray? In a commercial setting there is liability involved and spraying shows a desire to take action and prevent the spread or remediate the condition.  This equates to job security for a production manager in a large nursery. 
As a homeowner or small landscape contractor don't do anything. If you are really bothered by the spots, pick off the leaves. In a large setting trim the stems and leaves that show damage. Eventually the leaves with the spots will just fall off. 

Lantana camara is a hardy plant that takes all types of soil from sandy to heavy clay. It requires little water once established. It blooms profusely when the air temps are over 65. In So Cal that's most of the year. It grows to a height of 3 to 4 ft but can be trimmed hard to keep it low and grows back quickly after it's trimmed. Lantana responds to nitrogen fertilizers containing iron which will give the leaves a beautiful deep green color.  
I like this plant for dry conditions or reducing water. It has few pests or diseases. This might be the only disease I've ever seen on Lantana in my 40 years or so of looking at plants. 

No comments:

Post a Comment