TOMATOES

One of these disruptive factors causes a reduced level of calcium in the calcium pectate layer between cells. The blossom end is the last to develop and this is where the deficiency manifests itself. With reduced levels of calcium, the structure between the cells begins to collapse, thus rupturing these small, thin-walled cells. The surrounding cells have increased physical stress and they rupture (like a line of dominos).

Blossom end rot is usually seen on the first crop.

Control:

• In May/June, when tomatoes are very tiny, apply a preventive spray of Calcium Chloride, which is sold commercially by several names such as "Tomato Saver" or "Blossom End Rot Preventer." Spray 2-4 Tbs/gal at blossom stage/tiny fruit stage and once per week for next 3 weeks.
• Use mulch to maintain even soil moisture.
• Water plants with 1-1/2" to 2" per week.
• Use the Calcium nitrate form of fertilizer in proper amounts; excess fertilizer may encourage blossom end rot.
• Plant resistant varieties if you've had problems before: Homestead or Walker.
• Wait: problem often levels off/corrects itself after several fruit clusters have set fruit.

Tall, spindly plants: Overdoing nitrogen? Insufficient sun? They prefer 8 hours of sun.

Poor Production: If seeds grown while temperatures are too cool, the main stem will harden and result in poor production. Tomatoes require 70 degree soil temperature.

Care when using chemicals: Tomatoes are very sensitive to some chemicals, especially 2,4-D.

Blossom Drop: Some varieties will set fruit only within a rather narrow range of night temperatures. Many varieties require night temperatures above 55 degrees for fruit set, and night temperatures above 75 degrees inhibit fruit set, causing blossom drop.

All vine and no fruit: Less likely to be excessive nitrogen than to be lack of fruit set. When the blossoms drop, the plant continues in the vegetative state. When weather conditions improve, the plant is likely to set fruit. Fertilize only in recommended amounts.

Improving fruit set: Pollen is shed most abundantly on bright sunny days between 10 am and 4 pm. In the middle of the day, tap and shake the plant gently or hand pollinate with a small paintbrush.

Fruit cracking: Radial cracking usually occurs when the plant undergoes extremely rapid growth, as when rainy periods and high temperatures follow a long dry period.

Hard white blotchy tissue in tomato: A physiological disorder that is not clearly understood. There is no satisfactory control; some species are less affected than others, but no varieties are immune. Ok to use fruit with small to moderate amounts of blotchiness.

Leaf Rolling: Usually not a disease problem. The greater the ratio of fruit to leaf area, the more leaves will roll. Pruning off leaves and shoots will intensify rolling, as will moisture shortage. Some varieties are more prone to rolling than others.

"The Leaves On My Tomatoes Are Turning Yellow And Dying!"

1. Nitrogen deficiency. (10-10-10 fertilizer lasts 4-6 weeks, depending on weather.)

2. Leaf-spot pathogens. There are several fungal pathogens causing diseases on the leaves of tomatoes (Septoria leafspot, Early Blight, Late Blight, etc.). In the early stages of these diseases, a few small (1/16") brown-tan necrotic spots will be seen on the leaves. As the disease progresses, the spots will increase in size and number, and the surrounding tissue will often begin to yellow. Finally the affected leaves will begin to drop off. All of these diseases are favored by hot moist weather and poor air circulation. Control: Staking: provides improved air circulation. Sanitation: All diseased and fallen leaves should be removed from the garden during the growth season; remove entire plant at end of season and dispose of them away from garden. Fungicides: Daconil or Maneb will not remove existing lesions but will prevent new lesions from forming and spreading the disease. These materials should be applied every 10-14 days after the first lesions are seen, which is usually in May or June. (Sulfur, the usual organic alternative, will not control these diseases.)

3. Wilts. All are soil-borne diseases and all are fatal. Once infected, there is no effective chemical treatment. The soil should not be used for tomatoes for several years. Plant resistant varieties in a different area next year. Some of the wilts have a rapid onset and death of the plant, while others have a gradual onset and decline. Diseased plants should be removed and destroyed.

4. Nematodes. Root Knot Nematodes - To diagnose: Pull up a dead/affected plant and inspect the roots for galls that look like a string of beads. Control: Plant resistant varieties. If you have had nematode problems in the past, use Clandosan 2-4 weeks prior to planting. It MUST be incorporated to the depth of the root area, 6-8".

5. Phytopthora Root Rot. A fungal disease that is much encouraged by poor drainage. A wide variety of plants is susceptible (azaleas, rhododendrons, camellias, boxwood, etc.) Do not replant the same plant in the same spot; improve drainage before planting anything in the affected area.

What to do: Not much this year: Usually a diseased plant cannot be cured; therefore control must be based on prevention and avoiding spread of any disease already present. (The exception is the fungal leafspot diseases if control spraying is begun early.)