Lemon Tree Damage
What we are seeing is bird damage.
This typically occurs in the spring from young crackle birds.
They are either pecking at the fruit to be a nuisance or possibly collecting some type of nutrition from it.
So start netting the trees early, when the fruit is marble size with bird netting.
Also, the tree looks somewhat pale in color.
Make sure you are fertilizing with copious amounts of fertilizer such as Osmocote in early March, early June and half strength in early September. A weekly application of a water soluble fertilizer throughout the growing season would be beneficial as well.
David Rodriguez -Extension Horticulturist
Texas A&M AgriLife Extension Service
Bexar County -San Antonio