The winter climatic conditions, characterised by mild temperatures in the months of January and February, favoured the survival and development of the fungus Spilocea oleagina in leaf tissues, responsible for the disease Peacock eye, capable of persisting and proliferating in a temperature range between 7 and 10°C, contributing to an invisible spread of the disease, which can generate the illusion of apparently healthy hair, but which is nevertheless compromised by the progression of the pathology.
Diagnosis and symptoms
The checks carried out revealed a significant defoliation phenomenon, attributable to fungal infections. 
This disease is often underestimated due to the difficulty in identifying the symptoms early, but can lead to a progressive weakening of the plant. The infections responsible for leaf fall could date back to the months of November and December. presence of latent infections, without visible symptoms, can be diagnosed by immersing the leaves in a 5% solution of sodium hydroxide (caustic soda) or potassium hydroxide (caustic potash) at 26-28°C for 10-12 hours. Under these conditions, infected leaves develop rounded blackened areas, making the presence of the disease evident.
Defense strategies
With the expected increase in temperatures, it becomes the adoption of targeted defense strategies is crucial, in particular, the execution of phytosanitary treatments after pruning which play a strategic role, as the cut wounds can constitute entry points for new infections. Therefore, a disinfectant intervention is recommended immediately after pruning, in order to reduce the risk of further contamination.
Among the available products, copper-based formulations, in particular the oxychlorides, are confirmed to be among the most effective which have a double effect:
1. protective/preventive action on healthy leaves, preventing new infections.
2. defoliating action on already infected leaves, accelerating its fall. This effect is due to the phytotoxicity of copper towards the compromised tissues, thus promoting the regrowth of new leaves on a canopy without sources of inoculum.
Watch the weather
Fallen leaves, being already infected, are unlikely to constitute a source of direct reinfection, but to ensure maximum effectiveness of the treatment it is essential operate in favorable weather conditions, avoiding humid or windy days that could compromise adhesion and uniform distribution.
The use of Dodine based products, a molecule with a high capacity for penetrating leaf tissues and capable of eliminating the pathogen while preventing new infections, must take into account the environmental thermal conditions. In fact, its effectiveness can be reduced by low temperatures or climatic situations that have not yet reached stability.
AIPO Director
Interregional Association
Olive producers
