White County
 Gardening
Podcast
May 8, 2008
Managing Tomato Diseases (Series 1 of 3) (2:53 minutes)
Audio/Video Script:
Sherri Sanders
County Extension Agent - Agriculture
Hello this is Sherri Sanders, County Extension Agent in White county.
Tomatoes suffer from numerous infectious diseases and physiological disorders
and are regarded as among the most sensitive plants to herbicide drift injury. I
will be conducting a three part series in tomato diseases with this first one
dealing with physiological disorders that can affect tomatoes.
Blossom-End Rot - This is caused by a deficiency of calcium in developing
tomato fruit. This may due to a lack of calcium in the soil or extreme
fluctuations in watering, which can decrease calcium uptake. Over fertilization
with nitrogen can increase this problem.
Early symptoms include a slight water-soaked or sunken area at the blossom
end of the fruit. This area soon develops into a large brown to blackish spot
that constantly increases in size until the fruit ripens. Affected tissue may
shrink inward and have a dry, leathery feel.
For management - Have the soil tested. Apply lime if pH is low. Agricultural
lime or gypsum may be used but should be applied several months in advance of
planting. A soil pH of 6.5 - 6.8 is ideal for tomatoes. Apply a calcium chloride
product such as Stop-Rot, Tomato Saver, or Blossom-End Rot Preventer to plants
beginning at early fruiting. Mulch plants and irrigate regularly to avoid
extremes in the water supply. Remove affected fruit when first observed to
encourage formation of new, healthy fruit.
Catfacing - This is caused by cold nights during early fruit set and
development.
Fruit is grossly deformed at the blossom end during growth. Management
practices include spreading out planting dates, avoid planting too early and
protecting the plants during cool nights with cloth or plastic covers may help.
Fruit Cracking - Cracking is usually caused by rapid fruit development, too
frequent watering, or over-fertilization. Some varieties appear to be more
susceptible, especially tomato types with high sugar content. Affected fruit
becomes callused or cracked, usually vertically. Avoid over watering and
excessive fertilization.
Lack of Fruit Set - This is sometimes caused in Arkansas by hot temperatures
at night (over 75 degrees F) during flowering to early fruit development and may
also be caused by drift injury from various herbicides. It is best to space
plantings at 2-4 week intervals to avoid high temperature injury to all plants.
Use hot-set tomato varieties like Heatwave or Solar Set, if available, in at
least some of the plantings. Follow herbicide label directions carefully if
using around tomatoes.
Next we will discuss the bacterial diseases that affect tomatoes in Arkansas.
That will be on the second of the three series of these podcasts. This has been
Sherri Sanders with the Cooperative Extension Service in Searcy.
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