Question: olive tree with spotted leaves
good morning, I would like to know how to cure my olive tree which has dark spots
and numerous on the leaves. They told me they should be called peacock eye. I thank you in advance for the answer you want to give me and I offer you my best regards.
Answer: olive tree with spotted leaves
the peacock eye is a fungal disease affecting olive trees, very present on the Italian territory, although many new olive varieties are quite resistant to this type of pathology; the spots are clearly distinguishable from other types of pathology, such as powdery mildew or scab, as over time they differ in concentric circles: first we will have gray spots, with a black circumference on the outer perimeter; in summer, when the weather becomes hot and dry, yellow halos form outside. The common name of this pathology derives from the similarity between the spots on the leaves and the so-called "eyes" that can be admired on the tail of the male peacock.
So if you think it's peacock's eye, or if it has been suggested to you by someone who has seen the leaves of your olive tree, I think it is precisely this mushroom, given the unequivocal aspect of the symptoms.
In general, this type of pathology is worrying only when the olive tree is part of an olive grove, from which olives are obtained to obtain oil, or to sell them for other reasons; as this type of mushroom, although ruining many leaves and many fruits, hardly causes irreparable damage to the plant.
Surely the treatments against peacock eye work better as prevention, rather than as treatments to eradicate the disease, since once a leaf has been hit (or a fruit) it is very difficult to make the leaf return healthy; in general, products are used that will make the damaged leaves fall, stimulating the plant to produce new ones. These products are copper based, generally as copper oxychloride; this type of treatment is done in spring, at the beginning of the season, as prevention for the following months, or in autumn, as prevention for the following year. In your case I think it's too late for a copper-based treatment, try asking in the nursery if they have any product against fungal diseases that can be used even in late spring.
Certainly the spring of 2012 was decidedly inclement towards plants: low minimum temperatures and frequent rains, in fact stimulate the proliferation of fungal diseases, which therefore attack the plants with greater probability.
Other risk factors for the peacock eye are certainly the use of nitrogen fertilizers in excessive quantities; and also an incorrect pruning: the leaves that are well lit by the sunlight, and therefore dry quickly after the rain, tend to get sick with less probability; so remember to practice good pruning next year, which will air the hair well.