growing plants vegetative propagation. propagation process of increasing the supply of a type of...
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Propagation Process of increasing the supply of a type of plant Can be done sexually (using seeds) - plants developed are non-identical Can also be done asexually - plants that develop are identical - can be done naturally – using natural structures (e.g.
bulbs) - or artificially – e.g cuttings
Natural propagation structures Bulbs - made of many leaf bases attached to a stem - swollen with stored food - side buds found in between the leaf bases - these develop into daughter bulbs - spring flowering bulbs can be re-planted in autumn - many bulbs (e.g. daffodil) make daughter bulbs naturally Tubers - swollen part of the stem or root – for food storage - each tuber can grow into a new plant if re-planted -e.g. potato plants form tubers on underground stems - ‘eyes’ form new shoots
- use food stored inside the tuber to help grow - tubers kept in a cool room (6 weeks) before re-planting - this is sprouting or chitting
Use of attached offspring Plantlet - tiny plant still attached to parent - often develop at the leaves - e.g. Mexican Hat plant, Piggy Back plant Runner - plantlets at end of ‘horizontal’ stems - e.g. spider plant, strawberry plant Offsets - plantlet that develops at the base of the
parent - these can be cut away from parent & re-
planted E.g mother-in-laws tongue
Artificial Propagation Increasing plant supply, using
non-natural methods Plant growth takes place at
growth points e.g root tips, buds Also at nodes – part of stem
where side branches grow If plant is wounded, it can re-
grow and replace missing parts Parts of plants can be cut off
and re-planted
Cuttings Piece of plant cut, and re-planted Roots grow from cut surface Cut end needs planting in moist soil or in
water Rooting powder can help root growth Cuttings can lose water through their leaves Water loss can be reduced by - trimming off lower leaves on cutting - placing cutting in a propagator/plastic bag
Heat during propagation Heating systems/propagators keep
constant temperatures Encourages cuttings to root Useful in colder months of the year,
BUT - too high a temperature will cause
water loss - too moist (humid) an atmosphere
helps spread disease - heating costs can be high A thermostat controlled system is
best