This blog talks about the major diseases of the tomato crop, the symptoms to identify these diseases also the preventive measures one can take to avoid them.

One of the main factors limiting tomato production is diseases. Unfortunately, several pathogens have the potential to infect tomato plants and cause disease.
Remember that healthy, well-cared-for tomato plants are more likely to demonstrate resistance to tomato plant diseases. As a result, you must make sure your tomato farm has enough moisture and good, fertile soil.
Let’s discuss some of the most prevalent tomato plant diseases today and discuss how to manage and avoid them.

Major diseases in the tomato crop are

• Damping Off
• Septoria leaf spot
• Early Blight
• Fusarium wilt
• Late blight

Major disease	Characteristics symptoms	Favourable circumstances	Control
Damping Off	– Seedlings die at the pre-emergence phase. – Infested tissues swell and take up water.	– High humidity – High soil moisture – Low temperatures below 24° C	– Avoid excessive irrigation. – Use raised beds.
Septoria leaf spot	– Tiny, rounded irregular spots with a dark border and a grey center.  – Leaves become wilted. – Total defoliation of infested leaves	– Plants have low vigour. – 25 °C Temperature. – High humidity or persistent dew.	– Eliminating and destroying the damaged plant parts
Early Blight	– Small, black spots, primarily on the older plants. – A bull’s eye pattern of concentric rings.	– Warm, cloudy, and wet conditions.	– Crop rotation.
Fusarium wilt	– Discolouration of the leaves. – Petiole and leaves begin to drop and wilt quickly.	– High soil temperature and moisture levels.	– Wilt plants should be checked frequently   – Remove and destroy the impacted plants.
Late blight	– Spots grow in size and turn brown. – White moldy growth close on the underside of leaves  – Dark brown lesions on the fruit’s upper half.	– Humid circumstances persist along with mild temperatures.	– Use disease-free seeds and transplants. Avoid growing tomatoes next to potatoes. – Rotate fields to prevent tomato planting patterns.

1. Damping Off

Symptoms

• Seedling pre-emergence and post-emergence phases are the two stages of tomato damping off.
• The seedlings are killed at the pre-emergence phase shortly before reaching the soil’s surface.
• The young radical and plumule are killed, and the seedlings completely decay.
• The young, immature tissues of the collar at ground level become infected during the post-emergence period.
• The diseased tissues swell and take up water. The seedlings collapse or topple over.
• The Primary source of survival and spread is through water, seeds, and soil.
• The Secondary source of the spread of disease is through conidia caused by wind, rain, or splash.

Favourable circumstances

• The perfect conditions for infection and disease development are high humidity, high soil moisture, cloudiness, and low temperatures below 24° C for a few days.
• Overcrowding of seedlings, high rainfall-induced moisture, poor drainage, and abundant soil solutes prevent plant growth and worsen pathogenic damping-off.

Management

• Use raised beds: 15 cm height is preferable for water drainage, or use pro-trays for raising seedlings.
• Excessive watering and portions of the field that are poorly drained should be avoided.
• Applying a fungal culture on seeds. The only preventive strategy to control pre-emergence damping off is Trichoderma viride (4 g/kg of seed) or Thiram (3 g/kg of seed).

2. Septoria leaf spot

Symptoms

• Usually, less resilient plants are impacted.
• There are tiny, rounded irregular spots on leaves with a dark border and a grey center.
• Spots typically begin on lower leaves and move up the leaves over time.
• Spots accumulate, and the leaves become wilted.
• Total defoliation of the harmed leaves.
• Flowers and stems are occasionally affected.
• Fruits rarely come under attack.
• The primary source for survival and spread of disease is through Mycelium or conidia in pycnidia on solanaceous weeds or diseased plant waste.
• The secondary source of survival and spread of disease is through Conidia from wind or rain splashes, as well as from sticky conidia adhering to tomato pickers’ hands and clothing.

Favourable circumstances

• Plants have low vigour because of insufficient nutrition or the late season.
• At 25 °C, high humidity or persistent dew.
• Humid conditions with sporadic showers.

Management

Eliminating and destroying the damaged plant parts. Thiram or Dithane M-45 (2 g/kg seed) seed treatment can help prevent seed-borne disease.

3. Early Blight

Symptoms

• This specific tomato disease can affect plants at any stage of growth.
• The fungus destroys the plant, resulting in blight and typical leaf spots. Small, black spots, primarily on the older plants, are the first plant symptoms of early blight.
• As spots grow, a bull’s eye pattern of concentric rings can be observed in the center of the diseased area by the time they are one-fourth inch in diameter or greater.
• The skin around the spots may become yellow. Much of the plant is killed if excessive temperatures and humidity are experienced at this time.
• Similar to leaf infections, stem infections can occasionally encircle the plant if they develop close to the soil line.

Continuity and spread

• The fungus overwinters in infected plant waste in or on the soil, where it can survive for at least a year and possibly longer. It might even be seed-borne.
• In addition, the spores are dispersed by machinery, water, wind, insects, and other creatures, including humans.
• Once the initial infections have taken place, they turn into the most significant source of fresh spore production and are in charge of the quick spread of disease.

Favourable circumstances

Warm, cloudy, and wet conditions.

Management

Eliminating and destroying the damaged plant parts. Crop rotation is a technique that reduces the occurrence of disease.

4. Fusarium wilt

Symptoms

• The disease’s initial signs are the clearing of the veinlets and the discolouration of the leaves.
• Younger leaves may drop off one after another, and the entire plant may wilt and die in a matter of days. Petiole and leaves begin to droop and wilt quickly.
• The symptoms in young plants include veinlet clearing and petiole drooping. Lower leaves yellow first in the field, and then the affected leaflets wilt and die.
• Subsequent leaves continue to exhibit the symptoms. Later on, the vascular system begins to brown.
• Stunted plants eventually die.
• The source through which disease spreads is ground and tools.

Favourable circumstances

High soil temperature and moisture levels.

Management

Plants affected with wilt should be checked frequently in the nursery. It is necessary to remove and destroy the impacted plants.

5. Late blight

Symptoms

• Late blight develops when humid circumstances persist along with mild temperatures for an extended time.
• When the right circumstances are present, diseases spread quickly and cause significant economic losses.
• The lesions on the leaves are initially asymmetrical, fairly big, greenish-black, and wet.
• These spots quickly grow in size, turn brown, and, in humid environments, produce a white moldy growth close to the edges of the sick area on the underside of leaves or stems.
• Under humid conditions, the disease spreads swiftly and devastates extensive tracts of tissue.
• Fruit lesions appear as prominent, green to dark brown lesions, usually on the fruit’s upper half, though they can also appear elsewhere. Fruits may develop white moldy growth under humid conditions.
• The disease affects both the plant’s leaves and fruits. Because spores fall on fruit from above, symptoms on the fruit typically start on the shoulders of the fruit.

Control

• Use disease-free seeds and transplants, avoid growing tomatoes next to potatoes, and rotate fields to prevent potato or tomato planting patterns.
• Adopting specific preventative actions can also manage the disease. First and foremost, the disease-free territory should be used to source the seed material.

Role of fasal in identification and prevention of tomato diseases

• Tomato infections can have a negative impact on fruit quality, production, and growth.
• With Fasal’s technology, diseases like fusarium wilt, early blight, late blight, damping off, and Septoria leaf spot need not be a threat to pomegranate production. The technology developed by Fasal, founded on the idea of precision agriculture, provides crop, time, and location-specific solutions that are appropriate for the particular site in issue.
• While reducing the risk of infection with tomato diseases, our technology also keeps an eye on rainfall, humidity, temperature, canopy level forecasts, and an ultra hyper-local macroclimatic forecast to warn farmers when levels approach the perfect range for disease development.