Every gardener who independently grows tomato seedlings has at least once encountered mass lodging of seedlings. The cause of plant death is infection by certain types of fungi or bacteria. Visible symptoms are united by a common name - black leg. Simple prevention methods will help prevent the disease.
Dressing containers and substrate for seedlings
Bacteria and fungal spores, the causative agents of blackleg, are always present in the soil and remain viable for several years. Therefore, special attention should be paid to disinfecting containers for seedlings. Used pots and cassettes should be washed with soapy water and any remaining soil should be removed. After this, treat with a solution of potassium permanganate or soak in a fungicide.
The soil can be processed in two ways:
- shed with fungicide or potassium permanganate;
- steam in a water bath for at least 30 minutes.
You may find recommendations to calcinate the soil before sowing, but temperatures above 200 °C lead to the death of not only harmful, but also beneficial microorganisms. They will have to be added to the substrate to prevent the development of mold.
Pre-sowing seed treatment
Self-collected seeds, as well as unprocessed purchased ones, can be contaminated with spores and require dressing. There are 3 available processing methods:
- Soaking in a pink solution of potassium permanganate for 15-20 minutes.
- Treatment with fungicides according to the instructions on the package.
- Soak in hydrogen peroxide for 20-30 minutes. You need to process seeds that have been previously soaked in plain water for 10-15 minutes.
Conditions for growing seedlings
The key to successful prevention of blackleg is growing healthy and strong plants, because weakened seedlings are often affected by the pathogen. Creating optimal growing conditions and proper agricultural technology are especially important during the period from opening the cotyledons to planting seedlings in open ground or greenhouses.
Too high (above 25 °C) or too low (less than 15 °C) soil temperature in combination with high air humidity is a trigger for the reproduction of blackleg pathogens. Therefore, when growing seedlings in an apartment, containers must be protected from hypothermia on a cold windowsill or due to slightly open windows. Plants in greenhouses should be ventilated regularly. If the pots with seedlings are covered with film, it needs to be opened slightly several times a day.
Attention should also be paid to proper watering and lighting. Do not allow the soil in the pots to become waterlogged. It is recommended to regularly but carefully loosen the soil and, if necessary, deoxidize it with ash. It would be useful to provide additional lighting to the plants.
Recommendations for the prevention of blackleg are simple and easy to implement, and following the rules of agricultural technology will allow you to get strong and healthy seedlings the first time.
