I do not post pictures so I am sorry I cannot answer the invisible browse button question. Regarding the other question, you can see some photos in these articles about Phytophthora Fungal Infections from North Carolina State University and Virginia Tech

Luis

Luis:

Good links, thanks!

Phytophthora cactorum causes the central vein of a leaf to turn brown and the discoloration extends to the petiole on tender new growth. The infections spreads outward from the midrib tissue and the leaf wilts. Infections are more severe on azaleas. Some varieties of rhododendrons are vulnerable (Chionoides, Catawbiense Album, Nova Zembla) and some are resistant (Roseum Elegans, Scintillation, PJM). Control of the disease is difficult. Since the infection goes from the roots to the tips, when you see the symptoms it is too late. To prevent it, use a raised bed with lots of sphagnum peat moss. Prevention with fungicides and careful control of exposure to high humidity may be practical.

Here is a link that might be useful: Common problems of Rhododendron and Azaleas

Here's the damage I referred to above:

Here is a link that might be useful: {{gwi:396277}}

It is rhododendron dieback which is usually caused by Phytophthora cactorum. Many other fungi can be involved such as Botryosphaeria or Phomopsis and others, all of which produce similar symptoms.

Phytophthora cactorum

Phytophthora ramorum

Phytophthera citricola

Botryosphaeria dothidea

Phomopsis

Here is a link that might be useful: Rhododendron Diseases by Harold Greer

Those are terrific informational links rhodyman.

Thank you very much, I appreciate it.

I'm still trying to save them by pruning off below the diseased parts. I might stay ahead of it, we'll see . . .

glasser