So I have a seedling that's about 2 weeks, transplanted into 3gal's. One seedling that just got it's set of leaves and a third that seems to be struggling a little, yellowing along the edges. Looks like N deficiency (i doubt it), maybe heat stress (possible but temps been nice lately) and the last thing I could think of is the bug's causing this? I found ONE fruit fly, killed it. Then found ONE fungus gnat/mosquito type bug on two separate occasions (Just one at a time). Temps on the high end but acceptable (sometimes) 30C (86F) , usually good around 26C (78C). Humidity seems to be okay I think. Should i spray neem oil on the poly walls? On the plants? Soil? Just leave everything how it is and keep a close eye?
Myself, if they are just getting leaves I would use a little pyrethrin spray at a distance to keeep it under control and start with the neem extract after the plants have a few branches. Young leaves are sensitive to sprays and insects. The good news is there aren't enough leaves yet to harbor a large infestation. Sticky traps work Ok for white flys and gnats. Temp does seem a little high for that young of a plant.