Plant Propagation Plant Propagation The process of increasing

Plant Propagation

Plant Propagation • The process of increasing the numbers of a species, maintaining a species, or preserving the vigor of a plant.

Successful Plant Propagation • Knowledge of technical skills – The art of plant propagation • Knowledge of plant biology – Morphology, anatomy, physiology, etc. • Knowledge of plants – Selected method related to conditions and techniques to propagate an individual plant

Plant Propagation • Sexual Propagation – Recombination of genetic materials to form uniquely genetic individual • Asexual Propagation – Use of vegetative organs to create plantlets genetically identical to parent plant

Sexual Propagation

Propagation by Seed • Biology – Pollination – Anatomy – Germination • Applied – – – Purchasing Starting Transplanting Collecting Storing

Pollination • Pollination: transfer of pollen from anther (male part) to stigma (female part) in a flower. – Exchange of genetic material

Monocots vs. Dicots

Pollination • Self pollination: – Transfer on same flower – From different flowers on the same plant o – From flowers on different plants of the same cultivar – Examples: Beans, peas, lettuce, eggplant, peppers, and tomatoes

Pollination • Cross pollination: – Transfer of pollen on plants of different cultivars of the same species – Examples: Onions, cucumbers, corn, pumpkins, squash, broccoli, beets, carrots, cabbage, cauliflower, melons, radishes, spinach, Swiss chard and turnips

Pollination • Fertilization – the union of a male reproductive cell and a female reproductive cell that is capable of developing into an new individual

Anatomy • Embryo: miniature plant in arrested development • Endosperm (Cotyledons): built-in food storage • Seed Coat: hard out covering for protection, prevents water from entering and initiating germination before proper time.

Anatomy

Seed Coat Endosperm Embryo

Germination • The process of seed growth and development

Germination • Dormancy – Viable seed that will not germinate when in proper environment – Due to internal or external cause

Germination • Quiescent – Ripened seed, ready to germinate, waiting for the proper environmental conditions for germinations – Allows seed to survive over periods of time

Germination • Scarification – Physically altering the seed coat to allow moisture penetration – Natural scarification processes: passing seed through GI tract of animals, weathering of coat – Artificial scarification processes: hot water bath, sandpaper, etc. – Breaks seed coat allowing moisture to enter!

Germination • Stratification – Exposing a seed to moisture and specific temperatures (cold) in order to encourage germination – Degrades chemical inhibitors causing dormancy

Germination • Factors affecting germination – Water (moisture) – Light (or dark) – Oxygen – Heat

Germination • Water (moisture) – Penetrates seed coat---Imbibition – Endosperm swells- seed coat splits – Dissolves nutrients to initiate germination

Germination • Light (or dark) – Can stimulate or inhibit germination – Check seed package for planting instructions

Germination • Oxygen – Required for respiration – Facilitated with light, well aerated soil mix

Germination • Heat – Optimum range for germination – Many seeds have wide range – Check catalog or seed package for instructions – Drives metabolic process

Propagation by Seed • Biology – Pollination – Anatomy – Germination • Applied – – – Purchasing Starting Transplanting Collecting Storing

Purchasing Seed • Choose superior cultivars • High quality seed – Disease resistant cultivars when available • Garden centers • Mail order – Obtain by mid-February

Purchasing Seed • Germination rates – Expected percentage of seed to germinate – Generally, 65 -80% will germinate – 60 -75% will grow into useful seedlings – May affect density of planting

Starting • Indoors – Small seeds – Long season plants • Supplies needed – Grow lights – Clean containers (with drainage) – Sterile seed starting medium – Location with proper ventilation and temperature

Starting • Growing media – Loose, uniform, fine texture – Mixes labeled for seed starting – Pasteurized (sterile) – May be low in fertility

Starting • Containers – Any container will do – Disinfested – Good drainage – Adequate root space

Starting • Containers – Compressed peat pellets – Peat pots – Paper pots – Plastic cell packs – Flats

Starting • Sowing – Account for seed germination in timing factor and growing time – 2 weeks to germinate, 6 weeks to transplant date 8 weeks for full development time. – Sow in mid-March or April depending on plant species and growing conditions

Starting • Fill container to within ¼ inch of the top of the rim with moistened seed-starting medium

Starting • Large seeds directly in pots or cell packs – Squash, cucumber, watermelon – 2 per pot – Use pencil or dibble to make hole for seeds – Cover with media related to seed size

Starting • Small seeds scatter on surface of large cell packs or other containers for later transplant – Sprinkle more potting media over seeds or sphagnum moss (sphagnum moss helps prevent damping off) – Mix small seeds with sugar or extremely fine sand to help with equal distribution

Starting • Watering – Water from below in tray before seeds germinate and when seedlings are very small – Allow drying between waterings • Helps prevent damping-off – Standing water in flats leads to disease problems – Don’t allow seedlings to wilt – Cell damage can occur that is permanent

Starting • Moisture – Plastic covers are useful to trap moisture – Retains moisture – Remove to promote hardening of tissues

Starting • Supplemental lighting – 3” – 4” from light source – Cool white and warm white fluorescent lights – Move lights as plants grow or move plants – 14 – 16 hours a day • Timers are inexpensive and very useful – High intensity and quality light less leggy plants

Starting • Temperature – Nights 60 – 68 F and 75 F • Good rule of thumb-day temperatures 10 degrees warm than night. – Cool season crops cooler day/night temps • 55 degrees night – 65 degrees day – Warm season crops higher day/night temps • 65 degrees night – 75 degrees day – Heating mats

Starting • Fertilization – After germination – Go ½ rate, avoid burn – Two week intervals

Starting • Transplanting – Move to larger container when first set of true leaves form – Lift seedlings from containers with small flat tool – Tease apart tangled plants/roots – Handle by true leaves