See my post on the Fruit & Orchard forum, gabrielita. As I mentioned on that forum to you, this sounds like the rootstock has sent up shoots and is trying take over your grafted scion (that's the "orange" you mention). Nearly all citrus trees are grafted, using a hearty rootstock (most like some trifoliate, which has leaves of three), to the desired variety scion. Just trim those shoots away and prune the top of your tree to remove any dead or damaged branches. Fertilize and see if the top recovers. It should, but you must remove the graft shoots so that the scion (your actual variety of citrus you purchases) has a chance to recover. If you would post a photo of these leaves, as well as a close up as to where these shoots are growing in relation to the graft on the trunk, we can tell you for sure. Just upload your pics to Photobucket, then copy and paste the .html code (NOT the .jpg code) right into your message. Your photos will then show up directly in the body of your message, which makes it very easy for forum members to read and view :-)

Patty S.