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produce a good crop when trees are unsprayed because
the trees are extremely susceptible to pecan scab, a fungous disease. In
contrast, varieties like 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.
Poor
soil- 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
fertilizer in March on large trees. For young trees, fertilize in March
with 13-13-13, lime and zinc. Apply half ammonium nitrate in April, half
in June. Broadcast fertilizer on the surface in a circle twice the
branch spread of the tree.
Too
much or too little water-
Waterlogged soils where water stands do not provide aeration for roots.
Lack of water, especially during dry periods of summer, frequently
results in reduced yields and quality, and in weakened trees that may be
less productive in following years. Choose well-drained soil, provide
drainage for excess water and keep trees watered during dry periods.
Poor
pollination- A
single isolated pecan tree usually won’t be effectively pollinated,
since most varieties shed pollen either too early or too late to
pollinate the female flowers of the same tree. If a number of seedling
pecan trees or trees of several different varieties are already growing
within a few hundred yards, a tree for pollination is probably
unnecessary. Another reason for poor pollination is wet weather during
April and May. Rain washes off pollen and may restrict movement of
pollen by wind.
Overcrowding-
Pecan trees must have good exposure to sunlight to produce good crops.
When limbs begin to overlap limbs of neighboring trees, remove the least
desirable trees to prevent overcrowding.
Disease
and insect pests-
Pecan scab seriously limits production on unsprayed pecan varieties.
Even varieties previously resistant to scab are being affected. Several
other diseases can cause early leaf drop and decreased production.
Elliott, Gloria Grande, Owens, Jenkins, McMillan and Syrup Hill are
recommended varieties with good disease resistance.
Aphids,
pecan weevils, hickory shuckworms and several other insects can limit
pecan production. Removing and destroying fallen leaves, shucks, nuts or
twigs are sanitary measures that aid in control of many insects and
diseases. Spraying may not be feasible for growers with only a few
trees, but spray recommendations for controlling pecan pests are
available from the Alabama Cooperative Extension System office in your
county.
William
Goff is with Auburn University. |
