Grade 8 made a natural pesticide at the farm stay on the Chiang Mai trip. The idea is banana roots and cultures for the fermentation, then just a bunch of naturally bitter or spicy local plants and leaves.
Banana roots- dug up and chopped into smallish pieces
Citronella
Neem
Wormwood
Dried chillies
Tobacco!
A harsh rice spirit!
This was mixed in a big bucket with water and molasses and a starter culture was added and it brewed away for a few days before being mixed 1:20 with more water and poured/sprayed on all the plants in the organic gardens.
We are going to try this with some of plants in the incredible Edibles gardens.