+Condition of leaves:+ To produce well filled nuts, nut trees must bear a large leaf area and the leaves must be in good health and vigor. If they are to produce annual crops, the trees must carry their leaves until cold weather in the late fall, undamaged by insects or diseases. The importance of a large leaf area free from injury or abnormal condition is so great that it can hardly be overemphasized in connection with nut production. It can be definitely stated that under normal conditions the size of the crop produced and the degree to which the nuts are filled is directly related to the leaf area and the length of time it is carried by the tree. If the leaf area is to be large, the trees must make good, strong, vigorous shoot growth, and this means that proper attention must be given to fertilization to insure that the trees have adequate amounts of nitrogen, potassium, magnesium, zinc, and boron, as well as all other essential elements. The elements mentioned have been found most likely to be deficient in the soils of eastern and southern United States. In those regions their lack may be expected most frequently to limit tree growth or the filling of the nuts because of their effects on the leaves and the consequent inability of the leaves to make food materials. Deficiency of one or more of these elements results in leaves that are not able to make food materials in anywhere near such amounts as do normal leaves well supplied with all essential elements. In severe cases, deficiency of one or more of these elements results in chlorosis of the leaves, still later in leaf scorch, and finally in premature leaf fall. Trees having leaves in such condition cannot be expected to fill the nuts borne by them. Most nut trees grown about home or farmstead are deficient in nitrogen, as the trees must compete with grass, weeds, shrubbery, or other trees. Frequently there is not enough plant food for all. A deficiency of nitrogen limits the growth and the leaf area carried by a tree. A deficiency of potassium or magnesium very greatly limits the amount of food material made by the leaves and hence greatly decreases the filling and the oil content of the kernels. Zinc or boron deficiency has a similar effect. Hence, to insure the production of well filled nuts, one must be certain that the trees are well fertilized and that the fertilizer elements applied are in proper balance one with the others.