Pathways to Farming 4 Plant growth, Seeds & compost Emma Maxwell

Over view Recap Questions Plant Growth & Environmental conditions Types of seed & Seed purchasing Potting mixes Succession

Re-cap Plant Families Crop calculator

Plant needs Light Water Air Nutrients Substrate Correct temperature

Light Plant adaptions to light Pumpkins native to north america

Water Too much Too little No soil oxygen Anaerobic Toxic build up of ethanol in roots Root die back Leaf wilt Stomata shut down Reduced respiration Ultimate death

Air Good air flow reduces humidity leading to fungal diseases Too much Wind can reduce growth by 20-25%

Nutrients Major nutrient N, P, K Secondary Ca, Mg, S Minor nutrients Magnesium for chlorophyll Sulphur- An essential component of amino acids and hormones as well as plant oils.

History of potting compost Seed sowing 2:1:1 2 parts loam 1 part peat/ peat substitute 1 part coarse sand Fertilisers (Chalk & Phosphate) Potting mix 7:3:2 Fertilisers (hoof and horn meal, superphosphate, sulphate of potash) Head gardeners Standardising mixes John Innes Soil less composts Peat alternatives Advantages of soil based compost Trace elements Water holding

Substrate The material on or from which an organism lives, grows, or obtains its nourishment Organic Potting mixes Coir Bracken Wood chip fine bark wood fibre Green compost Hop waste Soil Hydroponics Rockwool/stonewool Perlite/Vermiculite Expanded clay pellets Sand Gravel Sawdust Coconut fiber Oasis cubes

Creating the correct temperature

Science & termonology

Photosynthesis sunlight 6C02 + 6H20 C6H1206 + 602 Chlorophyll

Respiration The intake of oxygen and the release of carbon dioxide glucose + oxygen → carbon dioxide + water (+ energy released) C6H12O6 + 6O2 → 6CO2 + 6H2O

Transpiration The process by which moisture is carried through plants from roots to aerial parts of the plant where it evaporates.

Plant Nutrients Major Minor Iron Nitrogen (N) Manganese Phosphorus (P) (Trace elements) Iron Manganese Copper Zinc Boron molybdenum Nitrogen (N) Phosphorus (P) Potassium (K) Magnesium (Mg) Calcium (Ca) Sulphur (S)

Plant growth regulators

Auxin Auxin is a plant hormone responsible for controlling the direction of growth of root tips and stem tips in response to different stimuli including light and gravity.

Auxin Made at the tips of stems and roots. Moved in solution to older parts of the stem and root where it changes the elasticity of the cells. More elastic cells absorb more water and grow longer, causing bending in the stem or root.

Apical dominance Apical bud produces an auxin (IAA) Inhibits growth of the lateral buds further down on the stem towards the axillary bud.

This can happen naturally, due to grazing mammals Pruning The selective removal of parts of a plant, such as branches, buds, or roots. This can happen naturally, due to grazing mammals

Roots Anchors Storage organs Absorption

Storage organs Bulb – Corm – Tubers – Rhizome – Root of many concentric coats or layers Corm – Reduced, compact underground stem Tubers – Swollen stem or root Rhizome – Horizontally growing shoots

Root structure

N fixing nodules

Growing media Peat free, organic, coir, wool, bracken Lets take a look