Even inert substrates such as stonewool are colonized by
rhizosphere microbes.
Studies have shown that inoculating hydroponic systems and
different plant species with these bacteria led to increased
root growth and enhanced formation of lateral roots and root
hairs, which may be at least partially attributed to bacterial
IAA. This results in an enhanced tolerance to plant stress and
improved ability to take up water and nutrients.
While a large number of proven beneficial bacteria exist,
fungi also contain some highly effective species that have
been proven in both soil and hydroponic systems. One of
the most significant of these is Trichoderma. Others are
arbuscular mycorrhizal fungi such as Gliocladium virens,
non pathogenic F. oxysporum, Paecilomyces lilacinus,
Penicillium chrysogenum, and a number of others identified
in studies as having an antagonistic effect on pathogenic
fungi. In many of these studies it has been discovered that
combinations of synergistic fungi species often have a
greater effect on disease control than when used singly.
50
Maximum Yield
Coconut fiber substrates are easily inoculated with beneficial fungi
and bacteria inoculant sources.
INOCULATION OF MICROBES
While naturally occurring, beneficial microbes do typically
self-inoculate into new hydroponic systems, however, this
can be a slow process and species diversity may be limited.
Well-established hydroponic systems, where microbial
life is not being continually killed with the use of sterilant,
biocide chemicals such as chlorine or hydrogen peroxide,
ultraviolet or ozone treatment, or other methods, tend to
have a greater diversity of beneficial microbial species
than newer systems. Microbes can be introduced through
several different methods. Commercial, packaged inoculant
products designed for hydroponics
are now widely available and since
these contain species known to be
beneficial, they are a good place
to start. Ideally, since different
microbial species carry out different
roles and have varying effects on
growth, disease control, and other
factors, using a product that has a
diverse mix of species as a general
first inoculant is a good idea.
Such inoculate products are often
designed to be added directly to the
nutrient solution, however, some are
in more widespread use as substrate
inoculant products incorporated
into the growing medium before
planting. If using inoculants such
as Trichoderma, it’s often easier to
establish beneficial microbes into a
new substrate as little competition
exists from microorganisms already
present. But if the substrate is rela-
tively inert, such as stonewool or
other synthetic growing mediums,
this is initially a difficult environ-
ment for microbial life to take hold.