Laurel Wilt on Day Avocado?

[jc]

Does this look like laurel wilt. Its a Day Avocado beginning to push flowers. Several branches are wilted and the leaves don't fall like an annual molting tree. I dont see any signs of the beetle. Some of the branches look perfect, others not so much. The flower buds are dying on the wilted branches.

[HMHausman]

In its early stages, I don't think you can make the diagnosis from just casual observation.  Laurel Wilt is a fungus that is carried by the Ambrosia Beetle and causes the tree to be unable to uptake moisture to the branches and leaves.  The leaves wilt initially because of loss of hydration.  This is the same situation with some other diseases.....like Phytopthera attack on roots, or even a non-disease process like plain old dehydration from lack of water.  The main difference is that with the diseases, the leaves turn brown and do not drop.  With straight dehydration, there will usually be some attempt by the tree to drop its leaves and limit water loss through the leaves until new hydration occurs.

[jc]

I think I can rule out dehydration due to lack of water. I water  once per week and I have seen dehydration due to lack of water and this is different. Plus when I've observed deyhdration due to lack of water in the past, the avocado trees respond quickly to watering and perk up. This one has not.

Thanks for the insight, Harry.

Several months ago a single lower branch showed the same symptoms and completely died back. Now several branches are showing similar symptoms.

Perhaps there is a root issue. I don't know. 

I still walk around the yard and observe the trees on a daily basis and this wilt came on fast. Seemingly normal branches to wilted in a day or two.

In its early stages, I don't think you can make the diagnosis from just casual observation.  Laurel Wilt is a fungus that is carried by the Ambrosia Beetle and causes the tree to be unable to uptake moisture to the branches and leaves.  The leaves wilt initially because of loss of hydration.  This is the same situation with some other diseases.....like Phytopthera attack on roots, or even a non-disease process like plain old dehydration from lack of water.  The main difference is that with the diseases, the leaves turn brown and do not drop.  With straight dehydration, there will usually be some attempt by the tree to drop its leaves and limit water loss through the leaves until new hydration occurs.

[bsbullie]

I posted this on a different thread.

http://www.freshfromflorida.com/Divisions-Offices/Plant-Industry/Agriculture-Industry/Pests-Diseases/Laurel-Wilt-Disease

[CTMIAMI]

Does not seem to be Laurel Wilt. Usually the beetle will not attack small trees.  Probably over watering or too much fertilizer.

[CTMIAMI]

Does not seem to be Laurel Wilt. Usually the beetle will not attack small trees.  Probably over watering or too much fertilizer. Or just the tree doing its annual leave change.

[jc]

Hmm. Cant say its overwatering. Im in Martin county on high elevation on super sand and only water once a week.

Maybe over fert but I havent done anything different over the past several years. 8-3-9 plus minors and 0-0-22 K Mag lightly on a monthly basis. But I haven't even put down 8-3-9 in the past several months in anticipation of the bloom.

I think I'll submit a sample to be sure.

Does not seem to be Laurel Wilt. Usually the beetle will not attack small trees.  Probably over watering or too much fertilizer.

[CTMIAMI]

Martin County, probably the cold spell we had in late February. I think it will be fine. Is going to shed most leave.
By the way, I fertigate 12 months a year. The no fertilizer for months prior to avocado  bloom is a myth (in my opinion) With respect those that do not agree.