If you notice a change in the color of the stem of tomato seedlings, do not hope for the best or varietal characteristics. Most likely, the shoots were affected by a fungus.
Usually in such cases they talk about black leg. This is not a horror story, but a fungal disease that can quickly mow down all the achievements of a gardener.
Reasons
If we talk about seedlings on the windowsill, then most often the fungus spreads through poor-quality soil, even purchased in a store. Dense planting, which reduces lighting and ventilation, contributes to the development of the pathogen.
If the soil is constantly waterlogged, the container with seedlings is in a cool room, and the soil is quite dense, then you should prepare for trouble in advance.
How to fight
First, do not forget about prevention. Before planting, seeds must be treated, and the soil must be disinfected with boiling water, potassium permanganate or baked in the oven, otherwise the fungus spores cannot be destroyed.
Secondly, it is important to follow agricultural practices – loosen the soil, provide drainage in the container, and follow the watering schedule.
Thirdly, if the disease has presented a fact, then the only thing left to do is to use fungicides. Usually, Bordeaux mixture, copper or iron sulfate, phytosporin are used.
Don't forget to repeat the treatment after 14 days.
