My lemon trees are approximately 7 years old. They have consistently produced a lot of fruit, but every year the lemons shortly after they get to golf ball size, begin to show scarring or scabs. They taste fine but are not pretty. This year, in addition to the scarring, the leaves are not looking good, some yellowing and some as the picture shows. I feel we have neglected the trees a little this year and perhaps did not fertilize them enough; however, as I say, the fruit looks like this every year. Help!!

Thanks.