Kiwifruit

Your plant is showing serious nutrient related problems. Note the yellowing between the veins. This plant requires an acid soil in the pH range of 5-6.5. It is also very salt intolerant and can suffer root death. It cannot stand drought or water-logged soil. We do not know from this picture what is going on with the roots, but poor roots can also cause nutrient problems. Our compliments on your careful descriptions by the way. That always helps. The only pest on kiwifruit is the snail, which very much likes the leaves. We could find no mention of a leaf spot disease which would necrose and cause the area to drop out. We strongly advise you to take advantage of your local NC state extension offices for a hands-on appraisal. They also have the ability to do cultures for as yet uncommon problems. The service operates out of your state university and has branches in most counties. Good luck with this problem.