Usually, there is no single reason why a pecan tree fails to produce a crop or produces poor quality nuts. The following are common problems and some suggestions for correcting them. For example, a variety such as Schely will rarely produce a good crop when trees are unsprayed because the trees are extremely susceptible to pecan scab, a fungous disease. In contrast, varieties such as Elliott, Jenkins, McMillan or Syrup Hill, which are currently recommended for home planting, are quite resistant to pecan scab and aren't usually seriously damaged.
Pecan trees grow best on sandy loam soils with well-drained subsoil.
Growth and production is often poor on heavy clays, poorly drained soils and on deep sands unless an intensive irrigation and fertilization program is maintained. Inadequate lime or fertilizer- Lack of lime, nitrogen fertilizer and zinc are common limiting factors in pecan production. Fertilize according to soil and leaf sample recommendations. Apply half ammonium nitrate in April, half in June. Broadcast fertilizer on the surface in a circle twice the branch spread of the tree.