Almost every gardener was faced with the problem of yellowed tomato seedlings. And, accordingly, everyone in this situation will have a question - "What is wrong and why does the plant die?"
The reason for the sudden yellowing of seedlings is primarily stressful situations that negatively affect the growth and development of the plant. Stress is the result of the onset of dying off of the plant's root system. In this situation, it is necessary, as they say, to provide first aid to the plant - to fertilize with urea or epin, to make top dressing by means of organic matter or mineral fertilizers.
If the seedlings turn yellow at a slow pace and the plant gradually becomes lethargic, then the reason for this, in most cases, is insufficient light and a lack of nitrogen. In this case, it is necessary to create additional artificial lighting for the plant and regular, weak feeding with urea.
Also, a sharp contrast in weather conditions can contribute to the appearance of an ailment. In conditions of excessive heat, the plant is exposed to harmful environmental factors, which leads to disease. In order to somehow make life easier for tomato seedlings, abundant watering and constant moisture should be carried out, as well as provide the plant with such conditions that direct sunlight does not fall on its delicate texture.
Well, and accordingly, the appearance of a black leg can become the cause of yellowing of seedlings. Root rot is very common, especially if the soil and seeds have not been previously treated.