2010 Tomatoes – wet, cool conditions result in problems SG


While at the State Fair, the Master Gardeners had several questions about Blossom End Rot on their tomatoes and bell peppers. I thought many of my readers may also be concerned about that and other common tomato problems.

Therefore, I am reprinting the following article in hopes it will answer your concerns too.

BACTERIAL SPECK: The fruit and leaves will have many tiny (pinhead size) and slightly raised brown-black specks. If you look closely on the fruit, these specks are bordered in white. On leaves, the border will be yellow colored. This problem is often mis-identified as bacterial spot.
Bacterial speck thrives in temperatures of 65° to 75°F that follow heavy rains.

The bacteria overwinter in the soil and may be carried on tomato seed. When the first
signs of this disease appear, it is time to control. Use a fungicide spray containing maneb
or basic copper sulfate. And, like all fungicide applications, repeat sprays as long as
weather conditions are favorable for the disease. Additional means to control this problem are: avoid overhead watering, do not work in wet plants, and do not save seeds

BLOSSOM END ROT: This is caused by sudden changes in soil moisture or lack of calcium in the plant. It appears as a sunken, dark brown or black leather spot. To reduce this problem, provide a normal supply of moisture and/or lime to the soil to a pH

HORNWORMS: These fat green or brown worms, up to five inches long with white diagonal stripes, have a red or black “horn” that projects from the rear end. They eat leaves and fruit, leaving only midribs.

2010 Tomatoes – wet, cool conditions result in problems SG

Hand pick the worms or use a chemical control to reduce hornworms. If you scout for eggs, look for small, smooth, round and light green-colored single eggs laid on Remember, upon discovering this pest, if its back is covered with many little
white cocoon-like objects, don’t destroy them. These are a result of a beneficial wasp
laying her eggs on the hornworm and this worm’s days are numbered.

LATE BLIGHT: This is caused by a fungus. Bluish-gray, water-soaked patches
appear on leaves and stems. During humid weather, a white downy mold grows on the
Grayish-green, water-soaked spots appear on the fruit. These turn dark brown,
become wrinkled and cork-like. Dying plants have an unpleasant odor. Use a fungicide
and remove all plant debris from your garden after harvest. This will help reduce late

FRUIT CRACKS: Fruit cracks occur during rainy periods when temperatures
are relatively high (above 90o), especially when rains follow a long dry period. Also,
tomatoes exposed to the sun develop more cracks than those well-covered with foliage.
Lastly, remember to read and follow all label directions.

I hope this article will help you to get to enjoy your vine ripened tomatoes.