Tuesday, August 27, 2013

                                                                                      



Here is a tree surrounded by healthy trees that appears to be drying up. The leaves wilting as though they have no water.










Pulling the soil from the base of the trees it does appear dry, but a clue to the problem is a tiny gumball exuding from the bark.              


Crown Rot
Cutting away the surface bark reveals gummy brown (dead) wood at the crown of the tree. This is classic Phytophthora Root and Crown rot caused by a fungus. The top of the tree appears drought stressed because the fungus has cut off flow of water from the roots to the leaves.  The rot is a result of excess water that has caused the roots to become stressed from oxygen deprivation and unable to ward off infection by this ubiquitous soil fungi.

This tree happens to be in a low swale and water has accumulated in the soil around it. This is especially a challenge in the foothills where irrigating enough for the hilltops can cause problems for trees in the low spots.

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