Not sure where to start... but here goes..First, I'm not sure if I have a Lisbon or Eureka. Maybe by my pic's, you will be able to tell.. My problem is, the leaves are falling off, the fruit is turning brown before ripening, (they also have a squiggly line on them, and by them I mean we only have 3 on the tree), some leaves have black stuff on them, while others are wrinkly. the tree is approx 3-4 years old.. Last year the same thing happened, no fruit and leaves falling off in great quantity. We fertilized with what the citrus grower gave us (little small beads). We thought that was our problem so this time around we used 6-6-6. (we fertilize every 6 months) We spray our leaves with malathion. We also have other fruit trees, and they don't have any problems. If more info is needed, please don't hesitate to ask.. I'm desperate.. Shelley sorry if pic's are blurry.
Leaf miners and scale would be an estimated guess. I haven't had much experience with them - trawl through this forum and read posts on them, especially the scale, and see if it matches. the black bits can sometimes be from scale - they leave a sticky residue that attracts gross black mold stuff! if it is scale, get rid of them quick.
First, if you are fertilizing your tree every six months using 6-6-6, and if your lemon tree is 3 years old, you are UNDER fertilizing your tree by 50 percent. The proper fertilizing of a 3 year old citrus tree, growing in central Florida using 6-6-6 formulation would be four (4) applications of a 6-6-6 fertilizer per year, applying 2 to 3.75 lbs of fertilizer at each application. The squiggly lines on the fruit are just wind scar,caused by the fruit rubbing against branches during a windy period, and nothing to worry about. The wrinkly leaves are caused by an insect called "Citrus Leaf Miner". In Florida, there is not a lot you can do to control it, unless you constantly spray the new foliage growth. Use the words "leaf miner" on the search function on this forum, and you will be able to read a LOT of information concerning leaf miner "control". To increase bloom/fruit on your lemon tree, be sure to fertilize the tree one month BEFORE you expect the tree to begin blooming. Then be sure to follow the correct fertilizing schedule. The black on the leaves is probably either sooty mold or an insect, however I cannot tell as the picture is blurry. In either case it can be washed off. You should purchase a 40 page booklet that is published by the University of Florida titled "Florida - Your Dooryard Citrus Guide" by Jim Ferguson. Reading this excellent publication will supply you with all the information you (and your tree) need to obtain successful crops. Copies are available from IFAS Extension Bookstore, UF/IFAS Communication Services, PO Box 110011, Gainesville Florida, 32611-0011, or by telephone at 352-392-2411. I highly recommend you get yourself a copy. Good luck. - Millet
