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Exercise 4
Exercise: Use of mist chamber for propagation and hardening of plants. Materials required: Mist chamber, cuttings, secateurs, hormone solution and sand Procedure: Plate 4.1 Cuttings of Olive and Kiwifruit in mist chamber i) Timer ii) Electronic leaf iii) Thermostat and timer IV) Screen balance and photoelectric cell.
I). Timer: Two types of timers are used in a mist unit one turn on in the morning and off at night and second operates during day hours to produce an intermittent mist, usually 60 seconds ‘On’ and 90 seconds ‘Off’. Hardening of plants in mist chamber:ii) Electronic leaf: A plastic with two terminals is placed under the mist along with cuttings, the alternate drying and wetting of the terminal breaks off the current, which in turn controls the solenoid value. iii) Thermostat: Controls the temperature of mist. iv) Screen balance: It consists of a stainless steel screen attached to a lever with mercury switch. When mist is on water is controlled on the screen and when weight is more, it trips the mercury switch. v) Photoelectric cell: It is based on the relationship between light intensity and transpiration rate. Plate 4.2 Hardening of plants in mist chamber i) There should be regular supply of water ii) The pH of water should be in the range of 5.5 to 6.5, avoid hard and alkaline water, as it blocks the nozzles. iii) Rooting media should have good aeration iv) Keep mist chamber free from the growth of blue green algae. |
Last modified: Thursday, 20 September 2012, 4:53 AM