Once the olive harvest is concluded or even after having completed part of it, it is It is important to disinfect the foliage and trunks of trees, because the tools used, such as olive harvesters, olive rakes or other mechanical devices, cause injuries to leaves, wounds and breakages to branches and ramifications, with the risk of contracting infections.
Could become Useful also remove the broken twigs, to prevent them from becoming too, remaining on the plant and drying out entry point for fungal or bacterial parasites, such as peacock's eye, copper cankers, plume, leprosy and olive scab. The practice of disinfection must be carried out scrupulously and will help keep the olive trees healthy, also useful because it is carried out over a period of time, the autumn, Where humidity and temperatures I am still favorable to the development and spread of pathogens fungal and bacterial.
The active ingredients suitable for this operation are: copper compounds, such as Bordeaux mixture or copper oxychloride.
In particular the alkaline Bordeaux mixture, made up of copper sulphate and hydrated lime, looks like the most appropriate.
Although obtained with an excess of lime, therefore less active, the alkaline Bordeaux mixture adheres well to plant surfaces, proving persistent and resistant to rain. If on the one hand precipitation tends to wash it away, on the other it guarantees that the copper ion, contained in the sulphate, is better dispersed on the plant parts and carries out its antimicrobial prevention activity, thus becoming an ideal product for autumn climates, fresh and with repeated rains.
When carrying out this phytosanitary intervention it is necessary to be careful water the plants well, so as to guarantee complete copper coverage which, among other things, by carrying out a phytotoxic action on already infected leaves, would favor their fall, thus decreasing the quantity of inoculum of fungal spores. It should not be forgotten that copper, in addition to its fungicidal and bactericidal effect, stimulates a thickening of the leaf cuticle, favoring the hardening of the epidermal tissues of the primary covering of the stem and leaves, which would become more resistant and more predisposed to low winter temperatures .
In recent years they have also entered the market fertilizers based on mixtures of copper and zinc sulphate or zinc complexed with citric acid or carboxylic acids, products capable of quickly correcting situations of deficiencies of these two microelements, but which may be able to prevent or stop the growth or action of pathogenic microorganisms.
Lo Zinc, in particular, has antimicrobial properties and acts even in a preventative way, is effective in hindering the metabolism of bacteria, in damaging their cell membranes and in interfering with their life cycle, actions that make it interesting against olive scab, caused by the bacterium Pseudomonas savastanoi.
Another product that could be used is the dodine, citrotropic fungicide, capable of penetrating plant tissues, has a preventive, curative and eradicating action, is able to effectively counteract the infection of the main fungal parasites of the olive tree, such as peacock eye, even if already in the infectious phase, and of defend the leaves from new attacks. Dodina also has an action to contain olive scab, on olive trees only two treatments a year are possible.
AIPO Director
Interregional Association
Olive producers
