We've recently moved to a new house which has a lemon tree in the backyard in dire need of some TLC -- but we're not quite sure what exactly is wrong with it. Two primary problems, which may or may not be related:
1) Lemons are covered to varying degrees in narrow black-brown scabby spots that come off when scraped. Sizewise they look kind of like insects, but there's no obvious infestation of anything living. The inside of the fruit is fine, and this seems to primarily affect the side of the fruit that doesn't get direct sunlight.
2) The leaves have yellow-brown spots, and in bad cases are dried-up and crinkly.
We're in Sydney, Australia, which is warm and fairly humid, but neither of these seems to match up very well with the descriptions here. Melanose, perhaps, but doesn't look quite the same...?