John White is an expert horticulturist. He thinks you need to make sure to add zinc to the proper care of your pecan trees. White advises to buy zinc at your local gardening store and use a garden sprayer to put it on your trees. Older trees and younger trees need to have zinc at different times. When you are spraying make sure to hit all the limbs and leaves. Without proper care your trees will not be as healthy as they would if you follow White's simple instructions. Make sure to follow his advise for a bumper pecan crop!