Having Tomato Disease Problems? Identification Key

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Growing tomato plants can be made much easier if, as a gardener, you know how to look for various problems that can arise. Many times a tomato plant can fall under the “spell” of several problems but is misdiagnosed.

  • Some viruses spread to the whole plant, while others do not.
  • Some viruses are geographically centered.
  • Dark brown spots normally indicate bacteria on a plant.
cross section of tomato diseasePin

Indoors or out providing all the information available helps greatly in identifying and diagnosing the potential cause.

Some of the diseases that could hit your tomato plants include:

Learn more about Blight on Tomatoes here.

.. other fungal diseases and other types of wilting caused by a fungus, a pathogen or any plant disease-causing agent.

Early Troubles

When Tomato Seedlings Die

Symptoms: Stems collapse, turn brown, and shrivel at the soil level. Seedlings topple over and die.

Diagnosis: Damping off disease. Infection by this disease is usually from soil that is not sterilized properly.

Treatment: Always use a sterilized soil mix from a reputable supplier. Where seedlings are attacked, control the outbreak with a copper fungicide solution.

When Tomato Plants Topple Over

Symptoms: The base of stem becomes black and shrunken, and plants topple over.

Diagnosis: This complaint is known as foot rot.

Treatment: There is no treatment which will restore the plants to good health. An attack can be brought about if the stem is bruised or damaged. Always take care when pricking out, or potting up the seedlings or young plants.

Flowers And Fruit

Why Tomatoes Fail To Fruit

Symptoms: Flowers fail to set fruit.

Diagnosis: Dry set. This is due to faulty pollination and can be caused by too dry an atmosphere.

Treatment: English varieties are self pollinating and do not need the attention of bees and other insects, but fruit set is encouraged by overhead syringing which creates a moist atmosphere and gently shakes the plants. Overhead sprinkling is best done in the evening or early in the morning.

It is also possible to spray the flowers with a special hormone setting spray, used strictly according to the maker’s instructions. This may be particularly useful early in the year.

Related: What’s The Deal On Tomato Blossom Drop Spray and Flower Dropping?

What Makes My Tomatoes Have Uneven Ripening

Symptoms: The area of the fruit around the stalk or calyx remains green and hard when the rest is ripe.

Diagnosis: Green back. Some varieties seem to be more prone to this condition than others. The cause is thought to be too much sun and a shortage of potash.

Treatment: Shade the greenhouse during very hot, sunny weather and use a high potash, liquid fertilizer when feeding the plants.

Why Do My Tomatoes Have Discolored Fruit?

Symptoms: When most of the fruit is ripe, hard patches remain green or yellow. Vigorous plants seem to be the worst affected.

Diagnosis: Blotchy ripening. This trouble seems to be worse in some seasons than in others. It usually follows when the day temperature is very high and the weather is bright.

Treatment: The exact cause is not fully understood, but the effect can be lessened by careful watering and keeping the plant foods at a high level.

What Causes Falling Tomato Flowers?

Symptoms: Flowers or buds drop from the trusses, causing loss of fruit.

Diagnosis: Plants are too dry at the roots.

Treatment: Carefully control the watering so that the soil never becomes very dry.

Can Virus Distortion Be Cured On My Tomatoes?

Symptoms: Leaves have a light and dark green, or green and yellow mottled or striped appearance. In severe cases, leaves may be reduced to midrib only, with a small fringe of surrounding tissue. Sometimes the leaves are bronzed and curl downwards at the top of the plant, presenting a varnished or oily look. Some plants may produce odd, tendril-like leaves and masses of side-shoots. The fruit may have brown, sunken pits in the flesh.

Diagnosis: Virus disease. Tomato plants grown both indoors and outdoors can be affected. These diseases are usually spread on the hands while working on the crop, or by sap-sucking insects such as aphids.

Treatment: In the main, these diseases are not curable and, if the symptoms are severe, the best remedy is to remove and burn affected plants. Well-grown tomato plants with abundant sources of plant food, however, can survive and minimize the effects of virus diseases.

Tell-Tale Leaves

What Causes A Scorched Look On Tomatoes?

Symptoms: Leaves develop a scorched appearance.

Diagnosis: Water shortage, or too strong a spray used to control pests or diseases.

Treatment: Make sure that the plants never dry out at the roots, particularly those in pots. Shade the glass of cloches and greenhouse if the weather is hot.

What Causes My Tomatoes To Get Speckled Leaves?

Symptoms: Yellow speckled markings appear on the leaves, which quickly become bronzed and dry. Small reddish mites can be seen on the underside of leaves, with the aid of a magnifying glass. In severe attacks, masses of thick webbing are formed over the leaves.

Diagnosis: Red spider mite. These mites breed very rapidly, especially in hot, dry conditions.

Treatment: Spray plants with neem oil. Make at least two applications, the second one being 5 10 days after the first. This pest is hard to control once the population has built up.

What Causes Blisters On My Tomatoes?

Symptoms: Greyish white blisters on the under surfaces of the leaves.

Diagnosis: Oedema or dropsy. This condition is caused by too much water being taken up by the plant, which is unable to lose it through the leaves.

Treatment: Give more ventilation in cloches or the greenhouse and withhold water for a time.

What Causes Yellow Blotches On Tomatoes?

Yellow blotchy markings on the upper surface of leaves are usually the first-noticed signs of leaf-mold. On the undersides of the leaves, the yellow marks correspond with patches of a grey mold.

Treatment: Spray with zineb, paying particular attention to the undersides of the leaves.

Note: Stem Diseases because of pruning wounds and leaf scars, botrytis is usually found attacking the main stems of tomato plants. The young plant suffering from foot rot often turns black and start to shrivel just above the roots.

Root Problems

What Is The Reason for Wilting Tomatoes?

Symptoms: Plants wilt in the daytime and recover during the night, to ook healthy in the morning. The trouble gets worse as the plants get older – on sunny days the bottom leaves wilt first and may even die off. If the plants are pulled up, the roots look brown and decayed.

Diagnosis: Root rot. The condition is enhanced by unsuitable soil conditions such as extreme wetness, poor aeration, or bad drainage.

Treatment: Plants that, are badly affected should be pulled up and burnt. Older plants can be encouraged to make new roots by raising the temperature in the greenhouse to 77 degrees Fahrenheit for 14 days, to check the activity of the fungus, and top dressing the soil with a layer of moist peat, into which new roots will form.

With care the plants can be saved by keeping the soil on the dry side and syringing the plants with water.

Why Is The Growth Of My Tomatoes Dwarfed?

Symptoms: Growth of plants retarded, small trusses formed and leaves, particularly lower ones, dry up and die.

Diagnosis: Eelworm. These are microscopic creatures that enter the roots of plants. The most common one is the “root knot” eelworm.

Treatment: There is no treatment suitable for use by the home gardener. Where the pest is known to exist in the soil, plants are best grown using the ring culture system. Tomatoes are grown in pots filled with clean materials and isolated from the soil by polythene sheeting or a layer of concrete.

Fungus And Insects

What Is The Grey Fluff On Tomatoes?

Symptoms: Areas of the plant attacked turn dark brown in color, later a fluffy, grey growth develops. Any part of the plant above ground can be attacked, including flowers and fruit.

Diagnosis: Botrytis or grey mold. Occasionally, outdoor plants are attacked as are those under cloches, but it is more prevalent in greenhouses.

Treatment: Adequate ventilation is necessary to maintain a free circulation of air. All leaves or side shoots removed during pruning should be removed from the house and any part which is diseased, including fruits, should be burned. It is difficult to control the disease by means of a spray.

The main control depends on preventing leaf scars and pruning wounds from becoming infected by the disease, by covering them with captan, helps stop the spores from entering.

Why Do My Tomatoes Get Purplish Marks On The Leaves?

Symptoms: Dark purplish areas appear on the leaves, stems, and developing fruit, which afterward rot.

Diagnosis: Potato blight. This disease is common on outdoor crops.

Treatment: As soon as the first signs appear, spray the plants with copper or zineb. Repeat the treatment every 14 days, or more often if the weather is excessively wet.

What Causes The Chewed Leaves On My Tomato Plants?

Symptoms: Leaves, stems, and fruit are attacked and damaged by caterpillars.

Diagnosis: Tomato moth. All tomato plants, whether indoors or; outdoors. can be attacked.

Treatment: Bacillus Thuringiensis (Bt) a biological control applied as a dust or spray will quickly control this pest if applied in good time.

What Are The Insect Clusters On My Tomato Plants?

Symptoms: Green or greyish insects are found singly or in clusters on the plants, particularly on the new growth, which is often distorted.

Diagnosis: Aphids or greenfly.

These pests can be a nuisance outdoors as well as under cloches and in the greenhouse. They are capable of transmitting virus diseases from infected plants to healthy ones qnd multiply in number very rapidly.

Treatment: Spray the plants with neem oil.

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