by Domenico Bucca
AgriBioClay Technical Consultant
The 2025 season is revealing how difficult it is to control the olive fruit fly, especially in central Italy. Regional bulletins confirm this: in Tuscany, the report AgroAmbiente Tuscany for the week of September 1-7 reports ideal conditions for the reproduction of the insect, with infestations between 6% and 30% on olives in veraison. Also in Abruzzo, the bulletin of Phytosanitary Service – Agroambiente Abruzzo The August 21st forecast highlights unstable weather conditions and widespread rain, ideal for population recovery. Umbria also confirms this trend: Assoprol Umbria, in its August phytosanitary bulletin no. 9, highlights a significant increase in fly flights throughout the region. An average active infestation of 2,9% is recorded, which remains below the intervention threshold (5–7%) for now, but in some locations, such as Assisi, it exceeds 16%. These data confirm growing pressure, but it can still be managed with targeted and timely interventions.
The role of kaolin
Faced with this scenario, many olive growers have only now begun treatments, risking delays. There is much confusion about kaolin and clarifying its role is essential to correctly orient practices in the field.
Often the kaolin is presented as “solution” against the fly, but in its natural form it is a rock dust, anclay.
Kaolin comes back, when placed on the market as is, among the invigorating, which, being different from pesticides, can be used alongside them rather than replacing them and must be placed on the market without any phytopharmaceutical indications.
It can be effective only if included in a preventive strategy, based on early applications, homogeneous coverage, continuous monitoring and operational timeliness.
A case study
The three-year project currently underway is based precisely on these foundations. Nocciano (Abruzzo), realized by Gianni Santilli e Camillo Calore.
We often collect information and data directly from our customers, which represent our most valuable source of knowledge. In particular, we carefully observe the work of those olive growers who choose a meticulous approach and trust our recommendations for product use. In the company, we strongly believe in mutual listening and the possibility of achieve goals together, transforming the field experience into a shared heritage.
Here, the protocol organically grown products uses kaolin and propolis – a resinous substance with antibacterial properties – to sustainably protect olives. So far, the treated plants have shown greater resistance to heat and drought, and the first observations on the variety tender listen indicate an active damage contained around 5%, compared to 70% in previous years.
The season is coming to an end and there is still time to harvest olives for oil. However, from the monitoring of September 1st, a particularly significant result emerges on the tender Ascolana variety, already ready for harvesting as a table olive: 95% of the drupes are healthy.
A fact that confirms the validity of the preventive strategy adoptedGianni Santilli and Camillo Calore's goal remains to organically bring the olives to the perfect level of ripeness, thus obtaining a high-quality oil. If fly pressure increases, they may decide to bring forward the harvest, adopting the solution best suited to safeguarding the quality of the oil.
The data collected so far are promising and confirm some fundamental principles: Kaolin only works if used before the attack, propolis improves its effectiveness but without monitoring and timeliness the damage can increase quickly.
The real challenge will be to see if this strategy will hold up until the harvest, allowing us to obtain a high quality organic oil, despite the strong pressure of the olive fly in this complex season.
The project is still ongoing and the next weeks They will be crucial to understanding whether the strategy will be effective in maintaining protection until the oil is harvested. We will continue to closely monitor Gianni and Camillo's experience, sharing updates and data collected.
