i'm noticing that one of my plants is having some yellowing and mottling on the lower two leaves, and curling of he upper ones

the downward curl is evident in some of my other plants too

any idea what could be causing this?
TurnyBright Reviewed by TurnyBright on . unhealthiness i'm noticing that one of my plants is having some yellowing and mottling on the lower two leaves, and curling of he upper ones the downward curl is evident in some of my other plants too any idea what could be causing this? Rating: 5