Two weeks ago we experienced a fairly good frost. I had already sprayed my Bearss lime with Cloud Cover antitranspirant; however, I should have moved the tree under the eaves of the roof that night as well. I didn't. A couple days later I noticed a leaf on a tender new branch had turned soft and brown at the base. When I touched it, the leaf and petiole easily seperated from the branch. A few days later, I noticed the bark around where this leaf had been attached was brown. The brown spot appears to be slowing increasing in size. Today I sprayed the tree with Cooke brand Kop-R-Spray, but the rainy season finally started in earnest today, so I'm not sure how effective this application was.

Should I just let it go and see what happens or should I take some other preemptive action?

Kent

http://pg.photos.yahoo.com/ph/keh_bier/detail?.dir=a75a&.dnm=7436.jpg

http://pg.photos.yahoo.com/ph/keh_bier/detail?.dir=a75a&.dnm=a151.jpg

This looks to me like a fungal disease that has entered the stem at a a damaged leaf node. It may have been initiated by frost, but this usually shows first on leaves and at the tips of new growth rather than further down.
Left alone this will probably spread down the twig. Certainly the portion above will die. I would cut off the damaged branch at a healthy leaf node well below the infection.

Citrange,

Thanks for the reply!

It's certainly starting to look like surgery is necessary. The next higher leaf has now dropped and the youngest growth at the tip is beginning to droop.

When I cut the branch, should I treat the exposed cut in any manner?

Kent