Part 1 of my presentation on Olive Pruning

1. I have been using this presentation as basic scheme in many occasions and for
different audiences. The aim is not to create perfect pruners – pruning cannot be
learned only indoor and require practicing – but to explain my vision of this
practice and its financial and technical consequences.
This presentation was part of a course to be accomplished outdoor in the grove.
1

2. Before starting with the slide show, it is useful to list all the reasons for pruning
and the expected consequences of non pruning. Any kind of reason can find its
place in the list. This done, the different points can be sorted into groups.
Possible categories are:
plant health,
production,
management,
g ,
aesthetic,
etc…..
This section include the observation of an abandoned tree (at blooming or fruit
setting).
2

3. Pruning requires highly skilled laborers and is therefore a very expensive
practice.
This figure of course bears a high degree of approximation if applied to the
general situation since each farm has its harvesting systems, each year its
different yield, each environment a different productive potential, etc.
Regardless to numbers and percentages, pruning is expensive and good
economic reasons for it must be found.
These figures presented at the Third International Symposium on Olive Growing.
Chania, Greece- September 1997 are based on data from:
G. Fontanazza e R. Romiti. “Analisi tecnica ed economica della introduzione delle
innovazioni proposte dallo studio I.S.E.A. 1986” in “L’olivicoltura intensiva
nell’Italia centrale”; Istituto per lo Sviluppo Economico dell’Appennino centro-
settentrionale, 1995: 71-110.
3

4. Olivae, the IOOC magazine, published on the June 2002 issue a very interesting trial
carried out in Spain by J Morales Bernardino and comparing 4 different pruning
J.
schedules.
•One plot of trees is pruned every other year,
•a second plot was pruned only once every three years,
•a third plot, once every four years,
•a reference blank plot was not pruned at all, during the trial.
The plants were monitored along ten years.
A first conclusion from these figures (looking at the average in bold at the end of the
table) is that pruned trees bore less than un-pruned ones.
Namely:
non pruned at all plot turned out to be the most productive and produced more olive than
p
pruned every 4,
y
pruned every 4 produced more olive than pruned every 3,
pruned every 3 produced more olive than pruned every 2,
pruned every 2 were the less productive.
Should we deduce that pruning decreases the yield per tree? And it is also an expensive
practice!
The Spanish research presented more results.
4

5. In most cases we are more interested in oil rather than in olives.
The figures resulting from the trial (table up) shows that best result is achieved by
pruning every four years.
A light pruning is therefore beneficial to oil content in olives.
Further, the canopy of non-pruned trees is quite bigger than for the pruned ones (middle
table).
This
Thi means th t
that:
a) un-pruned trees produce more because they have developed bigger canopies,
b) the volume-unit is more productive in pruned than in un-pruned canopy (left of
bottom table),
c) the oil content in olive increases if plant are pruned and this partially compensates
the loss due to the canopy reduction (right of bottom table).
Most relevant of all: this means that pruning does not induce the single plant to
produce more (not olive nor oil)!
In numbers:
Oil kg /m3 x m3/tree = Oil kg/tree
Un-pruned:
p 0,09 x 136,23 = 1226,23
, , ,
Pruned every other year: 0,13 x 92,81 = 1206,53
5

6. This photo was shot in 2003 of a Nocellara del Belice which has not been pruned
from 1991. Mind that this is not an abandoned plant. It undergoes all the
management practices but the pruning.
Although no exact figure is available, I was told that this plant produces every
year, although Nocellara del Belice is considered an alternate bearing cv.
Further its canopy is not a messy green mass. On the contrary, a sort of light-
intercepting architecture can be recognised in the canopy.
Campo Carboy is a research and demonstration farm of the Ente Sviluppo
Agricoltura of the Regione Siciliana (Menfi – Castelvetrano – TP - Sicily).
6

7. This is how the inside was!
The Pseudomonas cancers are not so many if we consider that none of them has
been removed in the last 12 years, further when I visited the tree they were not
actively developing. The new shoots were quite healthy (not less than the other
pruned trees in the nearby).
There is an enormous number of dried braches inside the canopy but none of
them is dead. All these old and dry looking shoots reached the external part of
the canopy bearing green and lively leaves. Quite impressing: I could not find any
totally dead shoot.
7

8. This is the canopy of an neglected and aged tree. Although the front of the
canopy was probably damaged it is possible to recognize the same logic in the
architecture:
A base crown all around the tree (in the damaged part new branches are
developing),
another intermediate crown made of medium height branches and
a core top.
It was a very old tree (unpruned trees do not die) and it was at full blooming
(unpruning do not affect their productive potential).
8

9. Let’s review all the reasons for pruning listed at the beginning of the slide show
and compare them with the preliminary results.
9

10. The harvest is the practice most benefiting of a proper pruning, but also the foliar
spraying, the soil tillage and finally also the pruning itself (in the following years)
are more easy in properly pruned plants.
The main point is that the plants themselves do not need any pruning. Wild plants
happily survive and bear fruit.
Pruning is nothing more than a management need. Having stated that, all pruning
decisions must match with specific farming systems and aims.
f f
10

11. 11