Zinc was supplied to trees of ‘Delmas’ pecan (Carya illinoensis (Wang. K. Koch) by means of Zn saturated bentonite paste implanted into the limbs. Five treatments, 0, 56, 107, 133 and 213 mg Zn per limb in the form of Zn-bentonite paste were applied to 5 years-old trees in a commercial plantation at the beginning of the growing season. Almost all the Zn was released during growth into the transpiration stream and increased the Zn-leaf concentration. No visual damage in treated limbs was caused by implantation per se, although the highest rate of Zn reduced leaf growth somewhat. The optimal dose of Zn was 107 mg/limb equivalent to only about 2-3% of the Zn usually supplied by commercial spraying.