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SUMMARY OF GREENHOUSE PROJECT OUTCOMES
Construction phase
- There is a need for good planning.
- The greenhouse requires careful attention to the preparation
of levels, compaction and a need to clear surrounds before construction.
- Particular attention needs to be given to burying all pipes,
even those that may be needed in the future.
- Once underway the construction phase ran relatively smoothly.
This was possible because a reputable company was selected to
construct the greenhouse.
- A full description of the materials and design can be obtained
by contacting AES (ADVANCED ENVIRONMENTAL STRUCTURES).
Construction cost
The old greenhouse constructed in 2000 cost approximately $100/square
meter. The new generation greenhouse completed in 2003 cost approximately
$150/square meter. The additional cost was mainly due to the polycarbonate
roof and design.
This cost is exclusive of computers, electrical work, controls
and water treatment. Costs only cover the greenhouse.
Detailed costing of components can be obtained by contacting:
NETAFIM for control,
irrigation and fogging systems
GF McKAY ELECTRICS PTY LTD
for electrical work
ADAM AGRICULTURAL
SERVICES PTY LTD for plumbing
Activities since construction
Management
The main activity is monitoring and inspecting plants for insects
and diseases once per week and to check water/fertiliser every second
week and adjust the latter, if necessary. Leaf and water analysis
is undertaken every second week. The remainder of the monitoring
is undertaken by the computer. Staff will alert management when
something extreme happens.
Operations
- Preparation and planting (from 15 July 2002 to 1st December
2002) Maintenance and set up including fogging, greenhouse and
gullies
- Planting (started on the 1st December 2002)
- Since planting (up until 31 January 2003)
¤ Covering gullies with plastic
to keep moisture in, splitting, stringing up and clipping plants
and general maintenance.
¤ One spray for thrips was undertaken
during this period.
A field day will be conducted in March
Progress in production since planting
- The environment within the greenhouse and growing conditions
are superior compared to the greenhouse constructed in 2000. The
main reasons being:
¤ Air circulation to control
temperature and humidity
¤ Higher solar screening gives
a larger volume of air in the roof space of the greenhouse. With
this fogging becomes more effective.
¤ A temperature difference of
3-4 degrees Celsius can be easily maintained between outside and
inside.
- The combination of insect screens, aluminum shading, fogging
and larger venting windows at the top achieves an environment
that optimises plant growth.
- The polycarbonate roof presents different growing conditions.
Compared to the "plastic" roof on older greenhouses,
the material allows more light which has increased plant growth
and led to increase use of fertilization and water. It also required
changes in fogging regimes and aluminum screening adjustments.
- The computer system is working up to expectations especially
the data programming including data retrieval and responding to
sensors.
- The computer does what is required and has had no faults so
far.
- At this stage plant growth is much better than expected. The
plants are still young but well past the fruit setting stage.
Plant growth has been that quick that it has put the team behind
in the timing of labour. David had to cut fertiliser in the early
stages to slow growth so he had enough time to adjust his labour.
- At the current rate of plant growth it is expected that the
greenhouse will yield the equivalent amount of capsicums as the
greenhouse built in 2000 but in a shorter time i.e. 12 months
down to 8 months.
- Heating will be installed in winter.
Problems encountered so far
The transparency of the polycarbonate roof has increased the heat
load of the greenhouse. It is anticipated that the greenhouse may
require a roof screen during summer to alleviate this problem. Zaldeesh
is currently investigating appropriate technology for this purpose.
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