bigbloomer the close up picture is not very good but it looks like Citrus Scale to me. Take a spray bottle and wet that area and see if you can rub them off with a rough rag. Don't worry about hurting it as they have almost killed that branch already. If you can rub them off I would say the branch still has at least a 50/50 chance of pulling through.

After that the next thing to do....

Get some Alaskan Fish Emulsion and put it in a spray bottle. 1-2 tablespoons per gallon of water and spray the entire tree every three weeks. The tops and bottom of the leaves the stems the branches and the truck; spray it all. If that does not work get some Bonide Anytime Dormant oil spray and hit them with that according to instructions.

If you are referring to the branch that is about perpendicular to the trunk, and almost parallel to the ground, then yes, you can prune this branch off without affecting the rest of the tree. From an aesthetics point of view, I'd already have pruned that branch off. I'd also prune it as close to the main trunk as I could without damaging any other branches. The nice thing about citrus, is that the plant will rapidly put on new growth to make up for what you removed. Good luck.

bigbloomer,
Spraying your trees with fish emulsion absolutely works when you want to keep scale off your trees. Clean your branches and leaves with a little veg oil mixed in water with a drop or two of soap. Use a toothbrush if rubbing doesn't work. You didn't mention an ant problem, but I'll bet that you have some ants scouting around to protect the scale. Good luck.

I'm interested in this application of Fish Emulsion.

What is the mechanism by which it treats/prevents scale?

Josh

Hi greenman28, the traditional method of treating Citrus Scale is to use a dormant oil or Neem oil. The oils suffocate the scale and they die. Some times it takes more than one application though.

Mike started a thread not long ago about avoiding pests and keeping your plants green. He said he used Fish Emulsion at 1 Tablespoon per gallon. I did a search on the internet and found that it has been used and sometimes works. Many of us live in parts of the country where it gets really hot in the summer. Dormant oil and Neem oil are less effective in high temps as it causes it to both evaporate more quickly and break down faster.

The oils are a better choice if your temps are not over 85 deg and you spray in the early morning when temps are 70deg or less. However the Fish Emulsion has the added benefit of foliar feeding your trees and making them nice and green.

Seaweed Extract aka Kelp Extract is also a good foliar fed fertilizer that has some affect on Scale and other insects and is often mixed with Fish Emulsion.

Thank you so much for your help, I'm going to do the fish emulsion and get a toothbrush and get to it. My plants are on my patio where I'm unable to spray them down, the humidity is unbelievable here too!! It's been raining nonstop all week and in the high nineties so I'm feeling overwhelmed with trying to keep my plants happy!

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That is my mexican lime next to my concord grapevine. It shows some signs of having that black stuff too. I can't believe that is an insect, I was sure it was fungus. I don't want to lose any of my plants, they have been with my for over three years, all the way from Jersey

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This is a limequat I traded with someone for. When I first got it, it was a little twig with three small leaves. I'm not sure how to prune it or what it going to go to be. I think it was sown from a seed, but I'm not sure. Anyone have anything to say about this guy?? He's started leaning next to my raspberries and blackberries.