“Rock powder” obtained from the physico-mechanical milling of quarry-extracted zeolite, of high purity and high clinoptilolite content (≥ 90%). The product is micronised to a level of fineness that prevents any clogging, thus protecting filters and atomiser nozzles. Zeolite DC coats leaves and fruit with a thin surface layer, particularly resistant to wash-off, which acts as a physical barrier against insect spread.