Micro-propagation of meristemes is nowadays a proven technology, however
the most critical phase is the day of extraction, when the plantlets are taken out from the
ideal micro-climate of the sterile propagation flask, to be rooted in substrate and to grow
to a deliverable plant. To support the fragile plantlets during this transitions phase a
fogging plant is of utmost importance to reduce the dropouts to a low enough level.
Mr. DI Leonhard, one of the managers at VitroPlant extended the specifications
for plantlet hardening one step further than usual. Following the first step of hardening
and rooting the humidity of the propagation table should be re-adjusted without moving the
table to another location to complete the hardening phase - i.e. final rooting and hardening
chambers - at the lower level the meristemes upper level hardening chambers where
the plantlets are acclimatisized to non-sterile surroundings
To fulfil these specifications with a total of some 24
table being in use at any point in time we have configured the system as follows :
The system consists of two independent high-pressure aggregates.
Each of them feed two pressure lines to the row of tables on both sides of the hardening
house. Each of the tables contains only one nozzle-line - set with nozzles type K1-150 -
has however two feeder lines with manual valves.
A humidity-feeler - representing all tables on one side
of the house - is positioned in one of the tents covering the tables and
set to the desired (high) value for phase 1. A second feeler detects the humidity for phase
2 (usually at a lower humidity value) in a hardening tent. If necessary the feelers can be placed
in each of the tents having connection cables long enough. The other side of
the house is configured similarly.
To illustrate the method - assumes tables 1, 2, 6, 9 and 12 in the
left row receive fresh plantlets from the in-vitro-cultures. They receive a humidity of some
95% relative. The feeler is placed in the tent of table 6, which represents tables 1, 2,
9 and 12. Pump 1 with feeder line 1 serves these tables according to the controls.
The manual valves of feeder line 1 are opened to the a.m. tables; the valves to feeder line
2 remain closed.
Details of installation: each of the lower table-levels is
connected to both feeder lines. Switching from one to the other feeder line is done
manually by opening one valve and closing the other.
The tables 3, 4, 5, 10 and 11 contain larger plantlets; their
feeler is placed in table 5 and thereby represents all other connected tables. The feeder
lines are serviced by pump 2 with line 2, therefore the valves are open for line 2, line
1 remains closed. The rest of the tables (7 and 8) are currently not in use, being empty.
Both valves to the feeder lines remain closed.
The system was installed in 1988 and has been running
with fullest satisfaction since then
Information from DI Leonhard, Tel. +43 - 2243 –