sir_isOanswered grow question 4 years ago Not sure I understand your question...
Those pics are imo meaningless without any context. If a specific plant doesn't get thrip problems easily, it is likely due to the terpene profile and its health. Specific terpene combinations will be more effective against certain pests than others.
If your seedlings are not growing,could be a number of factors. Firstly,root growth isn't always visible, and sometimes plants are biased to root growth initially.
Lots of things can affect that, watering, nutrients, heat, light.