I need help identifying and fixing some problems. I circled and labeled them in each pic.
First plant is dragon fruit. It shot out new growth last month, which is the only part of the plant affected by the following:
A) Weird gray fuzz. It's kinda sticky. Just appeared this morning. Some kind of fungus maybe? Greenhouse leaks a bit so it gets very humid after rainfall.
B) This area looks a little strange to me as well. Slightly gray and very fuzzy. Probably nothing.
C) Small pinhole. What could have made this? There are many small spiders in my greenhouse that I allow to web on my plants. Bad idea?
D) Some strange sap leaking from here. White fuzz on it. Never seen this plant secrete anything. Maybe related to the slight sunburn it got the other day?
Next plants, some prickly pears. They are affected by the following:
E) Two small plants have a single red pimple. Got these plants last month, hasn't spread. Rust fungus?
F) Very old plant that I bought yesterday. Owner had left it outdoors for 15 years without much maintenance. Has very bad rust fungus. How can I fix this on a tight budget? It is affecting pads that I don't want to remove.
Looking forward to hearing your advice!