Tomato pests and diseases

Tomato pests and diseases

Tomato plants are very easy to grow from seed. They require little care and produce delicious fruit. If you want to grow tomatoes at home, you should start them indoors in early spring or late fall. Plant tomatoes in a sunny spot to get the best harvest. 

The easiest way to grow tomatoes is to plant seeds directly into the soil. Tomato seeds germinate within 2 weeks after being planted. When they sprout, you should thin out the seedlings to allow only two or three to survive.

You can also grow tomatoes from seedlings. These are usually started in trays filled with peat moss or perlite. Once the seedlings reach 3 inches tall, transplant them into individual pots.

The seeds should be planted in a pot or tray filled with soil. After germination, the plants should be transplanted into larger pots or trays. Water them regularly until they reach 6 inches tall.

Tomato crops are one of the easiest vegetables to grow at home. They require little maintenance and produce abundant yields. In addition to being delicious, they also provide vitamins, minerals, antioxidants, and fiber.

How to Grow Tomatoes From Seed

1. Start Seeds Indoors

Tomatoes need about 8 hours of direct sunlight each day. This means that if you live in an area where it gets cold during the winter, you will have to start your tomato seeds indoors.

Start your seeds 4-6 weeks before planting time. You can use either small celled plastic trays or flats. Fill the trays or flats with moistened garden soil. Sprinkle the seeds evenly on top of the soil. Cover the seeds with more soil, making sure there are no air pockets underneath. Make sure the soil is not too wet or dry. The soil should be damp but not soggy.

Start Seeds Indoors

2. Germinate Seeds

Place the trays or flats inside a warm room (75 degrees F) for 10 days. Check the seeds daily. Remove any seeds that have germinated. When all of the seeds have germinated, remove the trays or flats from the heat source.

Germinate Seeds

3. Plant Outdoors

When the weather turns warmer, place the trays or flats outside in the full sun. Keep the soil moist by watering every other day. It takes 5-7 days for the first true leaves to appear.

Plant Outdoors

4. Transplant Into Pots

When the plants reach 12 inches tall, transplant them outdoors. Space plants 18 inches apart. Place the pots in a sunny location. Mist the plants regularly so they don’t get too hot.

Transplant Into Pot

5. Harvest

Harvest when the fruits begin to ripen. Pick the fruits when they are fully ripe. Cut off the stem just below the blossom end. Store the tomatoes in a cool, dark place.


Pests and diseases of tomato plants

Tomato plants are highly sensitive to environmental conditions. They require high temperatures during their growth period. This makes them vulnerable to cold weather. In addition, they are prone to various diseases.

The tomato plant is highly susceptible to various diseases. They require high temperatures for growing. This makes them vulnerable in cold weather. In addition to this, they are prone to several other problems such as bacterial wilt, powder mildew, leaf curl, and fruit rot.

Wet weather, humid weather, and moist weather make the roots more susceptible to diseases as it encourages fungal growth.

The tomato plant is susceptible to many pests and diseases. Common diseases include bacterial diseases and fungal diseases like tomato spotted wilt virus (TSWV), bacterial spot disease, tomato mosaic, fusarium wilt, Tobacco mosaic virus, Leaf mold, black spots, Pythium root rot, brown leaf spots, blossom-end rot, Gray mold, Yellow halo, Green mottling, sooty mold. 

Tomato plants are attacked by insect pests such as aphids, whiteflies, thrips, mealybugs, leaf miner, spider mites, tomato hornworm, and other insects. Mealybugs are found on the undersides of leaves. These pests cause damage to the plant by sucking out the liquid from the leaves, causing them to wilt and turn yellow.

The best way to prevent these pests from attacking your tomato plants is to keep them away from the plants by planting them in pots or raised beds.

Choose biological control agents to keep the pests away.

Infected plants should be attended to as soon as possible. Early detection of diseases will help save your plants. 

Bacterial Wilt

Bacterial wilt is caused by bacteria called Ralstonia solanacearum. This disease causes wilting leaves and stems, which eventually lead to plant death. The best way to prevent bacterial wilt is to avoid planting soil that has been contaminated by water from infected plants. If you do find yourself in such a situation, remove all affected plants immediately and thoroughly clean up any soil around them.

Bacterial Wilt

Powdery Mildew

Powdery mildew is a fungal disease that affects both indoor and outdoor crops. It initially starts on the upper leaves. Powdery mildew appears as white spots on the upper surface of the leaves. The symptoms usually develop after the leaves become infected. Powdery mildew spreads quickly. It can cause significant damage to the foliage.Powdery Mildew

Leaf Curl

Leaf curl is a disease caused by viruses that infect plants. The virus causes leaves to curl up and turn yellow. This disease affects all types of plants, including vegetables, flowers, trees, shrubs, and grasses.

Leaf curl affects the entire plant. Leaves become curled up and brown. The plant may wither and die. Prevent this problem by keeping the soil moist. 

Leaf Curl

Fruit Diseases

Fruit rot disease is caused by fungi such as Botrytis cinerea. The fungus infects fruit through wounds made during harvesting or packing. Symptoms include softening of the skin, discoloration, and rotting. The best way to prevent fruit rot is to wash fruits thoroughly after harvest.

The fungus attacks fruit when temperatures are high and humidity is low. The best way to prevent this problem is to keep fruits away from direct sunlight and air currents.

The fruits become soft and mushy. The color changes from green fruits to red. The ripe fruit eventually falls off the plant. 

The brown spot on the bottom of the tomato fruit is due to calcium deficiencies in the soil.

Fruit Diseases

Tomato yellow leaf curl virus

Yellow leaf curl virus is a viral disease. The virus causes severe damage to leaves, stems, flowers, fruits, and seeds. Symptoms include wilting, stunted growth, and deformed fruit.

Tomato yellow leaf curl virus

Bacterial leaf spot

Bacterial Leaf Spot is caused by bacteria called Xanthomonas campestris. This disease affects pepper plants, tomatoes, eggplants, cucumbers, peppers, beans, and other crops. The symptoms include dark spots on leaves, stems, fruits, and flowers. If left untreated, the plant may wilt and die.

Early blight of tomato

Tomato plants infected with early blight have concentric rings on the tomato leaves. The disease causes leaves to wilt and turn brown, then fall off the plant. If left untreated, the entire plant dies.

Early blight of tomato

How to prevent pests and diseases of tomato 

Preventing pest problems starts with choosing healthy plants. Choose disease-resistant varieties that have good resistance to common pests.

Plant in well-drained soils. Moist conditions of soil will promote diseases. 

Keep weeds under control.

Maintain proper irrigation. Ensure proper air movement in the garden.

Remove and destroy diseased plants and infected leaves at an early stage.

Keep your garden free of debris.

Remove weeds near the base of the plants.

Use organic methods whenever possible.

Water properly.

Avoid overfertilizing. Overfertilization will encourage more pests.

Check plants daily for signs of insects.

If you notice any bugs, remove them immediately.

Dispose of the infected plant debris away from the garden.

Organic gardening techniques include using natural and biological control methods such as ladybugs, praying mantis, and predatory wasps. Use sticky traps to control the pest populations.

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Buy tomato saplings

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Extra reading 

Plant insects

Mosquito repellent plants 

Get rid of mealybugs

Beneficial insects in gardens


Happy Gardening!

Dr. Vandana K.