Horticultural News January - February issue

use clean water for post-harvest
john Mbaria talks to Ellen Merk (above)
Sales Engineer, Hatenboer-Water b.v
De s c r i b e
c o m m o n
i m p u r i t i e s
in water and
their effects
on fresh produce
Water is the basis of all life. We
all need water to live and grow.
So does your crop. The quality of
water can really make a difference.
Depending on what water
source you are using, you will meet
different kind of water quality
issues.
When starting from rain water
(harvested from the roof of your
36
greenhouse for instance), you
will have (chemically speaking) a
very good quality water. However
you should take into account,
that biology – all kind of micro
organisms - can grow in your basin
or silo and create biofilms. Biofilms
are the perfect surrounding for
more micro organisms (bacteria,
viruses, fungi) to grow in.
Or you might be using surface
water from a river or a lake. Water
from the lake could have a good
water composition; however the
quality will fluctuate, depending
on all kind of influences. For
H O R T I C U LT U R A L N E W S I j a n u a r y - F E B r u a r y 2 0 1 2
instance rainfall can strongly
influence the quality. Water could
contain a lot of fine particles of clay
or dust. During drought periods,
meanwhile the water quality can
be very different again. Salinity of
the water can vary in time. also
temperature and other seasonal
changes can affect the water
quality. Surface water is therefore
a water source not always as
trustful with respect to availability
and quality.
What are the effects of
utilizing unclean water in post
harvest stage? Please state the
specific difficulties that could
arise or which normally arise
whenever flowers or other fresh
produce are washed, or stored
in unclean water
unclean water can affect flowers
in every stage. From the post
harvest stage to the water that the
consumer uses in the vase.
The effects of the above
mentioned micro organisms and
pollution on the flowers can be
of all kind. a flower, like every
living creature, needs good water
of a stable quality to remain in
an optimum condition. When
water is polluted by biology,
diseases have a breeding ground
for development, causing lower
quality and unconstant quality
flowers.
The post harvest stage is
important. The flower is freshly cut
and needs optimum and stable
circumstances.
your treatment product such
as flower food and care have a
proven enhanced effect on the
vase life of flowers in combination
with clean water.
How important is it to ensure
the water used up in the post
harvest stage is purified?
The flower is cut from its
roots but still needs to be fed.
Without good water it would not
survive. Moreover the grower
wants to supply a stable quality
product to the market. Therefore
it is important that the water is
of a stable and constant quality.
Surface water (from a lake or river)
can vary in quality through the
season. after heavy rainfall the
water will be very different from
water in drought periods. all kind
of seasonal influences play an
important role. Temperature is of
course an important influence as
well.
a very interesting effect of
starting with clean water is: the
water can be re-used! re-use of
water = saving water = saving
costs!
Is it true that you can increase
the shelf life of horticultural
products by using purified
water during the post-harvest
stage?
yes, this is very much true! The
consumers satisfaction depends
on the quality of the flowers.
Through the whole flower chain
there are several influencing
factors like time and temperature.
Post harvest circumstances are the
first step in the chain. By giving the
flower clean water of a stable and
constant quality, your flower food
products will have more effect. This
will lead to an increased vase life.
The fact remains that the next steps
in the chain must be dealt with care
as well to have a healty and long
lasting product at the consumer.