old shielded leaves. If it is not progressing up the plant or elsewhere, ignore it.
if it is creeping up on the plant it's a nitrogen deficiency.
plants to shed this sort of leaf... will suck it down before falling off on its own.
The first picture is a bit different. Burning around serated tips points to a potassium deficiency. if some interveinal chlorosis coincides, that'll help verify. If moving slowly i'd let it present itself more clearly.. Diagnosing from visible symptoms is not 1:1.. it is indiscrete stuff. But it is also a lower, well-shielded leaf... this is something a plant can and does shed.