53
silicate and magnesium) composed of 25%Ca, 6.0%Mg and
11% SiO2 which is estimated at a relative total neutralizing
power (TNP) of 85%.
The Agro-silicon was applied under tree canopy projections
Dnd sXSerficiDOOy incorSorDted into the soiO
During the trial, diseases, pest and natural enemies were
monitored with the particular diseases under inspection
being YegetDtiYe PDOIorPDtion ÁorDO PDOIorPDtion Dnd
anthracnose while the plant pest monitored was Thrips.
The nutritional characteristics of soil and plants (leaves
and fruits) and the vegetation, production and fruit quality
characteristics were also under evaluation, with an analysis
of their variance according to the various levels of Silicon
being applied used to study these characteristics, as well
as regression levels.
Results and discussion
The trial results showed that overall
disease incidence levels were below
5%, regardless of the silicon quantities
fertilized to each of three three ‘Palmer’
mango trees, meaning that under normal
circumstances they would not require any
chemical control.
A low incidence of Thrips (less than 0.1%
in the inflorescence) was also recorded as
well as the presence of natural predators,
which reached its peak during the month
of May, a time in which Mango trees are
at full bloom.
A factor that became increasingly
apparent as the trials progresses was
that thecombination of healthy nutrition
and precise micro-sprinkler irrigation,
alongside the relatively low rainfall and
humidity in this semiarid region may have
combined to contribute to the low pest
and disease incidence.
Ageneral trend of increasing pH, calcium
and magnesium levels in the soil around
the trees were recorded as the quantity
of Agro-silicon increased, indicating a
corrective effect on soil acidity in the soil
chemical characteristics at depths of 0-20
palmer mango
While silicon
may take an
active role in
plant defense
responses, it
may have a
more effective
passive role
in improving
tolerance of
stresses such
as drought
Table One: Physicio-chemical characteristics of “Palm-
er” Mango Fruit as found in the Minor Gerais region
of Brazil
Maturity
Stage
Soluble
Solids
(°Brix)
Firm-
ness (N)
Acidity
%
pH
Green 6.33 39.67 0.67 3.48
Ripe 15.10 2.53 0.13 4.53
Average 10.72 21.10 0.40 4.01
CV(%) 8.21 15.05 27.91 4.14