Kaolin can be used against the olive fly: this naturally-derived product has a near-zero environmental impact.

Dear farmer friends, over the last few years the use of low environmental impact products has grown considerably. And as for fighting the olive fly, we have some very interesting products available.

One of these is kaolin.

Sprayed onto vegetation, it forms a think milky white layer of mineral particles that offers protection against overheating and burns caused by the sun.

The benefits of this method are numerous, since the correct dose:
- reflects sunlight offering a very high level of protection,
- reduces ultraviolet and infrared radiation (reducing burns by up to 70%)
- improves the quality of the radiation necessary for photosynthesis,
- lowers the temperature of the plant, given that the white coating increases the reflection of the solar radiation,
- does not interfere with gaseous exchanges
- protects and reinforces the cuticle of the leaves,
- reduces the wetting period and the evapotranspiration of the surface of the plant,
- it does not create problems during harvesting as it does not require waiting periods and simply washing the fruit with water eliminates all traces of the product
- it forms a thin protective film that creates a kind of barrier for certain parasites such as the fruit fly

Especially, it has proven effective against the olive fruit fly (Bactrocera Oleae) whose chemoreceptors perceive a foreign substance and therefore prevent the insect from laying eggs in environments which are perceived as unfavourable.

Remember one thing: for kaolin to be efficient against the olive fruit fly and other parasites, you need to take care when preparing the product and distributing it.

The product needs to be highly micronized (particles of around 2 μm) in order to avoid abrasions and then mixed with doses of around 3 – 5 kg per 100 litres of water and sprayed with a nozzle or mist blower: the quantity to be dispensed essentially depends on the foliage density per hectare.

It can be sprayed with pesticides (which must be added after the kaolin has dissolved in water), but it is preferable not to use it with cupric products which could reduce its screening effect.

Distribution must be uniform across the plants as it is vital to create a kind of “film” that is evenly distributed without gaps. Spraying should occur on sunny days or after summer pruning. When the whitish colouring begins to fade, you can repeat treatment.

Beware of the weather forecast!

Precipitation may lead to the product dissolving. Kaolin should be distributed before the eggs are laid and treatment should normally repeated every month until the olives are harvested.