Kaolin clay film

How it works

A fine white mineral film coats the fruit and leaves so insects cannot recognise or grip the host plant, and females will not lay on it. It also reflects heat and reduces sunburn on fruit.

Recipe

Mix kaolin powder per label (typically 30-50 g per litre) and keep stirring - it settles instantly.

How to apply

Olives: begin when fruit reaches about 1 cm, before the fly starts laying, and reapply every 2-3 weeks and after heavy rain. Coverage must be complete and visibly white.

Targets — pests

Olive fly, Psyllid, Codling moth, Thrips

Targets — diseases

Not recorded — the field is blank rather than guessed.

Supplies: Kaolin clay, 5 L pressure sprayer, Gloves and mask

Days to harvest after spraying: 3

Best months: June, July, August, September

Cautions

The white residue washes off at harvest but looks dramatic in the meantime. Needs full coverage - a partly coated tree is an uncoated tree to a fly.

The thing people get wrong

Against olive fly this is the organic grower main defence and it works by camouflage, not poison, so nothing develops resistance. The catch is discipline: start before the first fly, not after you see stung fruit.