Hektar

Symptoms of the Disease

1. Blackish-Brown Spots on Stems:

   • The disease starts with the formation of dark spots (4-6 mm) on the stem, which can encircle the entire stem.
   • As the infection progresses, the affected tissue becomes necrotic, leading to bark exfoliation and rot in the stem.

2. Withering of the Plant:

   • The rot hampers the circulation of sap, causing the plant to wither and die.

3. Attack on Upper Stem, Leaves, and Petioles:

   • The infection can also spread to the upper part of the stem, including the underneath of leaves and petioles.

4. Fruit Rot:

   • Fruits may be attacked, starting from the peduncle (stem of the fruit) and moving toward the apex, resulting in brown or dark brown spots that extend into the flesh.
   • Over time, the fruits rot, and seeds from these affected fruits can serve as a primary source of future infections.

Factors Favoring the Disease

1. Environmental Conditions:

   • The disease thrives in greenhouses and solariums, with less prevalence in open fields.
   • It is favored by specific environmental conditions:
     • Temperature: 18-21°C
     • Atmospheric Humidity: 85-90%
     • High Soil Moisture

2. Spread of the Disease:

   • The fungus spreads during regular maintenance activities like pruning and handling of plants.

Prevention and Control Measures

1. Soil Management:

   • Improve the soil structure by ensuring proper drainage, as heavy clay soils retain water and keep the base of the plant cooler, promoting fungal growth.
   • Use products like Transformer to improve soil infiltration and water drainage. Recommended dosage: 10-15 liters/ha applied in successive doses of 5 liters/ha every 15 days.

2. Soil Disinfection:

   • In cases where the soil in solariums becomes a potential source of infection (from pathogens like Didymella lycopersici), it’s essential to disinfect the soil with products like Metam sodium. For example, Nemasol 510 can be used at 700 liters/ha, following the recommended technological flow.

3. Preventive Foliar Treatments:

   • Especially in cooler years with high cloud cover, foliar treatments with systemic fungicides are crucial. Recommended products include:
     • Thiophanate-methyl (systemic)
     • Folpet-based products: Folpan 80 WDG 0.15%
     • Captan-based products: Merpan 80 WDG 0.15%; Captan 80 WDG 0.15%
     • Bio-stimulants: Copfort 0.2% + Mimox Zn 0.3% or Algiforte 0.3% + Altosan 0.3%

4. Tomato Hybrid Recommendations:

   • To reduce the impact of this disease, selecting disease-resistant tomato hybrids is highly recommended. The Moldoveanu F1 tomato hybrid from the Hektar portfolio is an excellent choice due to its robust resistance and productivity. You can find more details about this variety here.

Conclusion

Implementing proper soil management, disinfection practices, and preventive treatments are crucial for controlling this disease in tomatoes, particularly in protected environments. By using resistant hybrids like Moldoveanu F1, you can further minimize crop losses and maintain a healthy harvest even under adverse conditions.