White County
 Gardening
Podcast
February 11, 2008
Pecan Management - (Part 3 of 3) (3:11 minutes)
Audio/Video Script:
Sherri Sanders
County Extension Agent - Agriculture
Last time we talked about fertilizer and zinc recommendations. This time we
will discuss pecan insects and diseases. Hello this is Sherri Sanders, County
Extension Agent – Agriculture with the White county Cooperative Extension
Service.
We will begin with pecan insects that offer a challenge to pecan growers in
Arkansas and it’s a long list. The Pecan Nut Casebearer, Caterpillars, Aphids,
Mites, Borers, Spittle bug, Pecan weevil and the Hickory Shuckworm are all
worthy adversaries to our pecan crop. However, many of our calls each year refer
to the “Big Three” in Pecan insects. They are the pecan phylloxera, plant bugs,
and the twig girdler.
Pecan Phylloxera
The Pecan Phylloxera is a small, aphid-like insect that is rarely seen, but
the galls it produces are prominent and easily noticed. Severe infestations
cause malformed, weakened shoots that finally die; such infestations can destroy
entire limbs.
Plant Bugs
Pecan nuts may be attacked by stink bugs and other plant bugs. They feed on
the nuts, causing black pit and kernel spots. Black pit is indicated by
darkening of the inside of the immature nuts. The spots on mature nuts are very
bitter. There insects live in groundcover in or adjacent to pecan orchards. Most
of the time, poorly managed orchards are the ones attacked. Therefore, orchard
sanitation is the best control.
Twig Girdler
The Twig Girdler lays eggs in twigs, and girdles limbs to stop growth. The
trees are severely pruned when the insects are numerous. The best solution is
good orchard sanitation.
Pecan Diseases are just as detrimental to Arkansas’ pecan crops as insects.
Pecan Scab
Pecan Scab is caused by a fungus and is the most serious disease in Arkansas.
Scab is characterized by numerous, irregular black spots on leaves and nuts. The
infection occurs during rainy periods in the spring and early summer. Scab
lesions appear about two weeks after infection. The fungus produces spores and
numerous infections may result.
Downy Spot
Downy Spot is another fungal disease. It appears first in the spring and
resembles frosty spots on the lower sides of leaves. The appearance is due to
the production of spores by the fungus. Spots later become greenish-yellow about
1/8 inch in diameter and then turn brown. Downy Spot causes premature
defoliation.
Powdery Mildew
Powdery Mildew may become serious in periods of heavy rainfall and high
humidity. It looks like a uniform, powdery, white covering of the leaves and
fruit. Some people refer to it as looking like “talcum powder”. Other diseases
include Blotch and Brown Leaf Spot.
For control recommendations for insects and diseases consult your county
Cooperative Extension Service for current information.
As a side note, we will be conducting a Pecan workshop in Prairie County at
the old Hazen Armory on February 26th from 9:00 a.m. till noon. Fertility, weed
control, disease control, insect control and grafting will be the topics
discussed at this workshop.
This meeting is free and open to the public and you are encouraged to contact
the Prairie county office at (870) 998-2614 for additional information and to
pre-register for the workshop.
This has been Sherri Sanders for the White County Cooperative Extension
Service in Searcy, Arkansas.
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