Basic Horticulture

Adding things I'm learning about horticulture as I self-study at a snail's pace :)

What are plants with their own specialized transport system for moving water and nutrients called?

Vascular plants

Functions of the roots (3)

1. Anchoring
   2. Abosrbing water + dissolved minerals
   3. Storing food reserves

Taproot system

A single, thick primary root that grows deep into the soil + great for drought resistance. e.g. carrot, oak.

Fibrous root system

A dense network of thin, shallow roots = good for preventing soil erosion. e.g. grasses, daisies

Root hairs

Microscopic extensions near root tips, most absorption happens in the hairs

Shoot system

This includes the stems, leaves, flowers and fruits

Two types of buds (underdeveloped shoots)

1. Terminal buds
   2. Lateral buds

What are plants that make their own food called?

Autotrophs

Equation for photosynthesis

Carbon dioxide + water + energy from light = glucose+ oxygen

Describe plant respiration

The plant uses oxygen to break down the glucose stored from photosynthesis to release energy (ATP) used for growth and cell repair.

How does a heatwave impact photosynthesis?

During a heatwave, the plant stomata stay tightly closed to prevent water loss. However, it also stops carbon dioxide from entering which in turn stops photosynthesis from taking place.

What is soil solution?

Minerals and nutrients in the soil dissolve into the thin film of water surrounding soil particles.

Why must cation exchange take place for the plant to absorb nutrients?

Soil particles typically have a negative electrical charge, while many nutrients (calcium, magnesium, potassium) have a positive electical charge.

Explain osmosis

The root cells have a higher concentration of sugars and salts than the surrounding water, so it naturally rushes in. The plant does not have to expend energy for this to happen.

Explain active transport

The concentration of nutritents inside the root is usually higher than in the soil, so the plant must expend energy to absorb the nutrients

What are the top three essential elements for most plants?

Nitrogen, phosphorus, potassium

Role and deficiency of nitrogen.

Role = core component of chlorophyll. Needed for leaf and stem growth.
Deficiency = chlorosis, old leaves turn pale yellow

Role and deficiency of phosphorus

Role = critical for energy transfer plus root and flower development.
Deficiency = leaves turn dark purple/green and roots are stunted.

Role and deficiency of potassium

Role = overall health and disease resistance, regulating stomata.
Deficiency = edges of leaves look scorched or burnt.

What happens when a plant gets overwatered?

The air pockets in the soil get filled with water so no oxygen enters the plant. This means that respiration is unable to take place and no ATP is created for active transport.

Name 4 common methods of cloning

A. Cuttings
B. Division (divide root ball)
C. Layering (bend stem to ground)
D. Grafting

Lightly describe the propagation method: Grafting

Take the scion (young shoot/branch/bud) of one plant (commonly fruit trees/roses) and fuse it to the rootstock of another. The vascular systems will weave together as one plant.

What are auxins?

A type of phytohormone (plant hormone) that regulate plant growth and development.

What is phototropism?

The growth of an organism in response to a light stimulus

How does auxin control phototropism?

It prefers the dark, so it always moves to the shaded side of the plant, causing the cells on that side to elongate and bend towards the light source.

Where is auxin primarily produced?

In the terminal bud.

What is apical dominance?

This is how the main central stem of the plant is dominant over the other sides. Auxin travelling down from the terminal bud tells the lateral buds to stay mostly dormant.

What is pinching or heading?

A method used by horticulturalists to create a bushier, fuller plant. They cut off the terminal bud, causing the lateral buds to activate.