lower leaves turning yellow and stem turning red

Hello! Then there are two causes. The first is that simply, the first two leaves have reached a certain age and are starting to die, but (second reason) is that to see the dark green color of the whole plant, in addition to the slight purple coloration of the central stem and leaves, there is a slight overfert of nitrogen, which causes less PK assimilation! In fact, the burnt outlines of the leaves can be attributed to this deficiency