White County
 Gardening
Podcast
May 23, 2008
Managing Tomato Diseases (Series 2 of 3) (3:20 minutes)
Audio/Video Script:
Sherri Sanders
County Extension Agent - Agriculture
Hi this is Sherri Sanders, County Extension Agent in White county. This is
the second in a series of three podcasts dealing with tomato diseases. Today we
will discuss a few of the bacterial diseases that affect tomatoes in Arkansas.
Bacterial Speck - This disease is favored by cool, wet weather and is
more common during the spring months in Arkansas. It is spread primarily on seed
or infected transplants and is moved about by splashing water, workers or
machinery. It can survive in infected crop debris for several months and can
live on various weeds.
Symptoms - This disease causes small round, dark spots on leaves.
Young spots do not have a halo (light border) but older spots can. Spots may
grow together, killing larger areas of leaf tissue. Spots can also form on
stems, branches, and fruit. Fruit spots are very tiny dark specks and can be
slightly raised or sunken, depending on the age of the spot. A dark green halo
may surround some fruit spots.
For management - Use only bacterial speck-free seeds or transplants
from a reliable supplier. Seed disinfection with 1 percent bleach solution for
10 minutes should be used when the seed source is suspect. Eliminate all nearby
weeds or volunteer tomato plants. Rotate tomatoes to new soil areas every two
years and plant rotation crops like corn or beans in old production areas.
Bactericides containing copper can be used but should be applied following the
label directions at the first sign of disease. These materials will wash off
periodically and must be reapplied every 1-2 weeks.
Bacterial Wilt - This disease can cause rapid death of infected plants
but usually only attacks a few plants within a planting. It can infect many
other plants, including potato, tobacco, eggplants and others. The bacterium can
survive in the soil for months, especially in well-drained soils. It is spread
by soil and water movement, or by diseased plants or infected debris.
Early symptoms are a slight wilt of the youngest leaves, followed by a rapid
wilt within 2 to 3 days. New above - ground roots may appear just above the soil
surface growing out of the stem. The inside of the stem becomes brown and stems
cut cross - wise may ooze a thick off-white to yellowish liquid. Sticking the
cut end of an infected stem partially into a glass of water reveals a
milky-white stream of bacteria into the water within 3 to 5 minutes. The root
system may also develop a brownish rot as the plant dies. Symptom development is
favored by hot, dry weather.
Use only free transplants from a reliable supplier. Rotate to clean areas as
soon as possible. Do not use peppers, eggplant, Irish potatoes, sunflowers, or
cosmos in the rotation areas. Grow resistant varieties, if available. Neptune
and Tropic Boy are considered partially resistant. Rotation soils should be
fallowed 1 to 2 years between crops, with frequent tillage. Remove infected
plants and destroy immediately. Grow on raised beds to promote drainage.
We will discuss fungal diseases on the final podcast of this three part
series. This has been Sherri Sanders with the Cooperative Extension Service in
Searcy.
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