Tomato Anthracnose: Causes, Symptoms, and Management

Tomato anthracnose is consistently one of the top concerns for farmers. It not only causes fruit to rot and drop prematurely but also severely diminishes the quality and yield of the crop. To help farmers proactively prevent and effectively manage this disease, let's explore the information below.

1. Causes of Tomato Anthracnose

Tomato anthracnose is a common and dangerous disease that severely impacts the yield and quality of agricultural produce. The primary causal agents are fungi belonging to the genus Colletotrichum, most notably C. phomoides, C. gloeosporioides, C. dematium, and C. coccodes. These fungi typically spread rapidly in humid environmental conditions and at temperatures ranging from 25–30°C — being especially prevalent during the rainy season or in gardens with poor drainage systems.

It's important to note that tomato anthracnose is not limited to a specific area within the garden; it can spread widely through irrigation water, rainwater, wind, or gardening tools if not thoroughly cleaned. Even improper plant care can inadvertently contribute to the dissemination of disease spores.

Fungal spores are typically cylindrical or slightly curved and colorless, with the ability to adhere to and penetrate plant tissue very quickly. Once favorable conditions are met, they will attack various parts of the tomato plant, such as leaves, stems, flowers, and fruits, weakening the plant and easily leading to complete crop loss if not detected early.

Causes of Tomato Anthracnose

2. Symptoms of Tomato Anthracnose

Tomato anthracnose typically causes the most significant damage when tomatoes are nearing harvest and fruits begin to ripen—this is when the plants are most vulnerable.

• On Fruit: The first easily noticeable signs are small, round, slightly sunken spots on the fruit surface, especially on ripe tomatoes. These lesions then spread rapidly, forming concentric rings that sink deep into the fruit flesh. The flesh around the lesion usually appears lighter in color, while the center is darker and contains numerous fungal spores.
• On Leaves: Lesions on leaves are also round, slightly sunken, and dark brown with a pale yellow halo around them—a fairly typical sign of tomato anthracnose. In humid weather, a light mold layer may appear directly on the lesions, indicating active fungal growth.
• On Stems and Roots: In severe cases, the disease can attack both stems and roots, leading to weakened, stunted, or gradually dying plants. These symptoms are often less noticeable in the early stages but cause hidden damage and severely reduce yield later on.

Symptoms of Tomato Anthracnose

3. Impact of Tomato Anthracnose on Crops

Beyond directly damaging the plants, tomato anthracnose brings about several serious consequences, affecting farmers' yield, quality, and income.

• Reduced Yield and Fruit Quality: Tomato anthracnose causes fruits to rot, lose color, drop easily, and fail to meet commercial standards, significantly decreasing the value of the harvest.
• Economic Impact: Low yield and poor quality lead to reduced income. Treatment costs also increase significantly if the disease is detected late.
• High Recurrence Risk: The fungus can persist in the soil and on plant residues for a long time, making it prone to re-emergence if not thoroughly managed after each growing season.

4. Management Measures for Tomato Anthracnose

Here are effective and practical ways to help farmers proactively protect their tomato gardens from the severe damage caused by fungal diseases.

4.1 Cultural Practices

Prevention is better than cure—this is a crucial principle when dealing with tomato anthracnose. Here are steps farmers should take right from the start of the season:

• Choose Healthy Tomato Varieties: Prioritize varieties with good disease resistance, clear origins, and those that have been pre-treated for fungal pathogens before planting.
• Thoroughly Prepare Soil and Sanitize Pathogens: Plow, solarize the soil, and use biological methods or lime to disinfect the soil, helping to eliminate any remaining anthracnose fungal spores.
• Use Appropriate Mulch and Drainage Ditches: This aims to maintain adequate moisture and prevent waterlogging—ideal conditions for vigorous fungal growth.
• Limit Excessive Watering: Farmers should use drip irrigation systems instead of flood irrigation or overhead sprinklers. This helps keep leaves dry, limiting the humid environment where tomato anthracnose easily develops.

Management Measures for Tomato Anthracnose

4.2 Chemical Measures

If the disease starts to appear or there's a risk of a widespread outbreak, farmers can consider using appropriate plant protection products. Some recommended active ingredients for controlling tomato anthracnose include:

• Mancozeb
• Azoxystrobin
• Thiophanate-methyl
• Dimethomorph

When using these products, farmers must strictly follow the manufacturer's recommended dosage, pre-harvest interval, and instructions. Additionally, it's advisable to rotate active ingredients to prevent the fungus from developing resistance. Farmers should also remember to wear full protective gear when spraying, ensuring their personal safety and protecting the surrounding environment.

We hope that the information shared has provided farmers with a clearer understanding of tomato anthracnose and equipped them with useful solutions to keep their crops healthy and achieve high yields. If you need further consultation or wish to select suitable specific treatment products, don't hesitate to contact Sataka!

SATAKA VIETNAM JOINT STOCK COMPANY
Address: No. 246 Nguyen Kim Cuong, Tan Thanh Dong Commune, Cu Chi District, Ho Chi Minh City
Hotline: 0856.555.585 or 0789.917.927
Website: https://sataka.com.vn/