These are the recommendations of Ivano
Gioffreda, the best olive grower in Salento, whose results I have directly
experienced on olive trees affected by CoDiRO (Olive Quick Decline Syndrome)
The rebirth
of Salento's olive trees. The serene after the storm
For the
past three years, ‘thanks’ to the dry and torrid summer temperatures, a gradual
improvement has been noticeable among the olive trees in the Salento region,
which were affected by CODIRO (rapid olive tree desiccation complex). After
years of fighting and combating desiccation, even the most sceptical have had
to admit to a vegetative recovery, so much so that, after years of lean years,
the mills in the 2024-25 oil campaign have many hundreds of thousands of
quintals of olives. An excellent figure is that of the Cooperativa Agricola
Olearia Sannicolese, a reality that includes more than 1,500 members from the
municipalities of the Salento Ionian arc, which to date has milled around
19,000 quintals of olives, 40% of which are of the Cellina di Nardò and
Ogliarola Salentina variety.
Unfortunately,
the institutions do not accept the reality of the facts and continue undaunted
to finance the destruction of our beautiful landscape through uprooting.
Despite this, many farmers and olive growers, encouraged by the vegetative
recovery of the olive trees, are asking how to intervene to consolidate it.
The first
step is correct pruning.
Before
pruning, sharpen the cutting tools well and disinfect the blades each time you
move from one plant to another.
1) Suckers
and suckers take energy away from the plant, so they must be removed, except in
cases where they are needed to replace a main or secondary branch.
2) Remove
all dry branches, even the smallest ones, (see photo) and leave as much green
as possible.
3) Respect
the physiology of the plant, and absolutely avoid pruning, always preserving
the apical parts of the branches (lymph pulls). Pruning blocks the normal flow
of sap.
4) Make
cuts with extreme precision, just above the collar line to facilitate the
healing of cutting wounds. Do not leave spurs etc, (as in the photo) these
become the gateway for all fungal pathogens.
5) After
pruning, disinfect (spray) the entire plant, trunks, branches and crown, with
self-produced Bordeaux mixture.
How to
prepare Bordeaux mixture:
Doses per
100 litres of water: 1 kg slaked lime (lime paste, the kind commonly used in
construction, packaged in plastic bags) and 1 kg copper sulphate pentahydrate.
Dissolve
the two minerals separately and then pour into the container with the water.
Shake well
during use.
It is
advisable to brush cut wounds larger than approx. 5 cm in diameter with
Bordeaux mixture (as thick as necessary).
6)
Treatment of trunk and branches with lime putty and 4% iron sulphate.
Fill the
container with 100 litres of water, take some water from the container with 2
separate buckets and separately dissolve 4 kg of iron sulphate in one bucket
and 1 kg of slaked lime in the other bucket.
CAUTION: do
not mix iron sulphate and lime together, otherwise the mixture will coagulate
and no longer be usable.
Once
dissolved, pour everything into the bucket with water using a fine-mesh sieve
and stir continuously.
ATTENTION:
THIS TREATMENT IS ONLY FOR THE WOODY PART OF THE TREE, DO NOT SPRAY DIRECTLY ON
THE CROWN!
Use the
coarsest nozzle for spraying and continue to mix the preparation in the drum
without stopping while doing so.
The two
minerals act; the lime as a disinfectant, the iron sulphate nourishes and
regenerates the bark.
Treatment
to be carried out in winter.
7) In
spring, I recommend spraying the entire plant, trunks, branches and foliage
with potassium bicarbonate, at a dose of 700 g per 100 litres of water. To be
repeated when climatic conditions of high humidity persist.
Potassium
salt increases the pH of the leaves towards basic and creates a hostile
environment, a barrier to fungal pathogens, causing them to die of dehydration.
In addition, potassium salt increases the plant's natural defences.
8) Soil
care and fertilisation. I recommend not ploughing, encourage grassing to
increase the biodiversity of wild grasses. Grass, contrary to what we have been
led to believe, enriches the soil with micro and macro organisms which, in
turn, by feeding on the grass roots, increase the organic substance in the
soil. It also increases the porosity of the soil, favouring the infiltration of
rainwater into the ground, avoiding water stagnation, which is harmful to olive
trees.
TO AVOID:
9) Avoid
chemical fertilisation, nitrates, urea, ammonium sulphate etc., damage soil and
groundwater, nitrogen promotes the proliferation of fungal pathogens through
raw sap.
10)
Irrigate only if necessary. Moisture promotes the proliferation of fungal
pathogens.
11) Do not
plough near the trunk to avoid injuring the roots. Every wound is a gateway for
pathogens.
Ivano Gioffreda
info mail: ivanogioffreda@gmail.com