So, after a decade I have finally discovered the problem that devastates my tomato plants is the Potato Psyllid. It causes Psyllid Yellows as well as Candidatus Liberibacter solanacearum that really cripples the plant and production. So the trick is to prevent the Psyllid and its nymphs from biting my plants, easier said than done.

I am open to any suggestions to how to prevent damage, but now I am asking if anyone has tried or has information on interplanting other species to repel biting insects. I am even thinking Neem trees and Citronella grass, but don't know if interplanting is at all effective.

I am considering spraying with 0.5% neem oil once a week or so, but since the psyllid likes the new growth the best I am thinking that fast growth leaves the tops neem-free and unprotected, hence the idea to repel the insects from even wanting to hang around my precious tomato plants. I tried making fierce faces at them, but to no avail ;P