Spraying Tangerines

This is Benidicto, spraying what looks like a good crop of tangerines with a liquid made from local plants.
He is head of pest control on the farms and has developed various concoctions and systems to keep the pests away.
I think maybe he's on the trail of aphids using Tephrosia and sisal.
We have never used chemical pesticides over the past six years, using combinations of smelly and other plants to help.