3.1 Flashcards
Objective of using specialist equipment
Optimise rooting/germination potential to achieve a strong and uniform stock.
Advantages of seeds and provisions necessary for the growth of plants from seeds.
Right temperature, light levels and specified day length.
Correct growing medium.
Oxygen.
Correct amount of water/humidity.
Freedom from pests, poisons and diseases.
Heated propagation
Heated propagating frame.
Closed, heated propagating case located over heating pipes.
Lined with moist peat/peat free growing media.
Pots, seed trays and cuttings can be plunged into growing media for propagation.
Inside temp around 25oC.
High humidity.
Subdued light levels.
Disadvantages of heated propagating case.
Fungi thrive in warm, humid conditions.
Examples of plants suitable for heated propagating case.
Seeds of Begonia semperflorens Cultorum group.
Leaf cuttings Saintpaulia ionantha.
Stem cuttings of Fuchsia magellanica.
Mist propagation
Reasons for use
Thin film of water produced keeps foliage turgid.
Water loss from foliage and cut surface and base is reduced.
Moisture is provide but air is not excluded.
Green foliage continues to photosynthesise, creating sugars needed for wound healing tissue and root development.
Mist units
Maintenance
Check for draughts.
Ensure nozzles are working and provide good coverage.
Retain hygiene.
Check mist sprays are working with sufficient frequency.
Check temperature and even up to the requirement.
Problems with mist units.
Lime scale can build up on plants, particularly those that take a long time to root. Nitric acid may be used to overcome this proble.
Chemicals in mains water maybe detrimental.
Cuttings kept for long periods in closed frames tend to rot off due to high humidity. - controlled by hot water or electrically heated bed with controlled, intermittent misting operated by electronic leaf.
Examples of plants propagated under mist.
Hydrangea serrata ‘Bluebird’
Kerria japonica
Philadelphus ‘Avalanche’
Parts of mist unit
Water supply with float valve. Filter Electricity supply. Control box. Pump. Pressure valve & gauge set between 2 to 4 bars. Solenoid valve. ‘Electronics Leaf’ - to regulate amount of moisture in unit. Thermostat. Warming cables.
Misting unit
Rooting media
Free draining.
Eg. 4 parts coarse perlite/sand to one part peat/peat substitute.
Plants can be rooted directly into growing media or put into pot.
Plants will need to be weaned off.
Misting unit construction
Rigid base unit 150 to 200mm deep. Drainage hole in base. 50mm gravel on base then warming cables. Rooting medium on top. Often ‘polythene’ tent on top, shading may be necessary in summer.
Fog units
Reasons for use.
Provide continuous fog, plant material is surrounded by a totally damp environment, foliage cannot surfer water stress.
Fog unit.
Diasadvantages.
Requires attention to detail and monitoring to ensure sequence of fog emission is regular.
Costly - requires very clean water, high air pressure, modest water pressure and light/ temperature/draw ugh to control.
Examples of plants propagated under fog:
Bougainvillea’Brilliance’
Camellia x williamsii
Centrum elegant
Principal of fogging system.
Medium pressure water sprayed through small spray at nozzle.
This spay is then blasted by massive blast of air that G3P breaks water particles up to form ‘fog’ particles suspended in air.
Cold frame.
Purpose
Hardening off stock plants.
Rooting of hardwood cuttings eg. Cornus and other woody species.
Offer protection from adverse weather conditions and extreme temperatures.
Cold frame construction
Timber or metal frame.
Glass, polythene or poly carbonate sides and top.
Hinged or removable, sloping roof.
Very free draining growing medium to prevent waterlogging and fungal rot
No artificial heating, can become too hot in summer, shading maybe necessary.
Ventilation is provided by opening top (lights) - best to be kept ventilated every day.
Plants propagated under plastic covers.
Evergreen shrubs from hardwood stem cuttings under double polythene.
Cotinus coggygria ‘Pink Champagne’
Kolkwitzia amabilis
Nepeta grandiflora ‘Bramdean’
Low Polythene Tunnels
Water tends to condense on the polythene, this keeps the leaves wet and therefore not stressed.
Problem with low polythene tunnels.
Humidity is high which can lead to fungal infection.
Good hygiene is important.
Fungicides May be used especially if there are signs of botrytis.
Polythene covering plants should be reduced by mid April to avoid over heating, high temperatures, too rapid a growth and very high humidity leading to disease.
Hot pipe callusing.
Reasons for use
Method of graft aftercare designed to ensure that heat is directed to the graft union only, to optimise healing of the grafted union.
Can improve rate of callusing.
Encourages more rapid healing rather than overall growth which would not be beneficial.
Stick and extending scion are exposed to cooler temps (remain dormant).
Hot pipe callusing.
How plants are positioned.
Potted grafts are placed into slits made in polystyrene covering of central heated pipe.
Care should be taken to ensure only graft is applied to heat.
Plants suitable for hot pipe callusing technique.
Fagus sylvatica Malus domestica Abies alba(Silver Fir)
