Nitrogen deficiency causes the plant's lower leaves to turn yellow, while excessive amounts delay maturity, causing increased vegetative growth and decreasing cold-hardiness. Nitrogen is needed in all parts of Texas to maintain healthy plants. However, in most situations, phosphorus does not increase blooming in a fruiting plant. Phosphorus fertilization is needed most in sandy soils, since clays and loams ordinarily have adequate amounts for perennial plants. Many areas have problems with iron deficiency even though adequate amounts are present in most Texas soils.
Zinc deficiencies are a problem in pecans in most of the state.
Leaf veins have a band of green on each side, giving the leaves a striped appearance. Because Texas has such variability in its soil types, a single broad fertilizer recommendation is not applicable in all cases. The best means of determining your individual soil need is to have a soil test done by the Texas Agricultural Extension Service's Soil Testing Laboratory. Information on sampling techniques and prices is available from your county Extension office. Where soil tests are unavailable and a general recommendation is needed, use the following guidelines.