The condition of the seedling leaves is an indicator of the health of the plants. Yellowing indicates problems.
There could be several reasons.
Most often, the mistake lies in improper care of the seedlings.
For example, if there is a lack of moisture or an excess of fertilizers, the color of the leaves may change.
If plants lack manganese, light yellow spots appear on the leaves. In this situation, it is necessary to fertilize with manganese sulfate.
If the seedlings need iron, the leaves will be yellow, but the veins will remain a rich green color. It is optimal to carry out foliar feeding with iron chelate.
When fragile plants suffer from a lack of potassium, the edges of the leaves begin to turn yellow and dry out. It is enough to add any potassium fertilizer to correct the situation.
Plants also need nitrogen. When there is a deficiency, the leaves of seedlings turn yellow uniformly. The situation can be saved by adding mineral or organic agents. For example, urea or herbal infusion will do.
