Woody Plant Growth-11

WOODY PLANT GROWTH

Reference Text: Arboriculture: Integrated Management of Landscape Trees, Shrubs and Vines. Harris, Clark, & Matheny. 2004. Fourth edition, Prentice Hall. p. 580.

Objectives

1. Be able to define and identify plant tissues and types of roots and shoots.

2. Be able to explain and summarize relationships and interactions between tissues, roots, shoots, and plant growth.

3. Be able to identify and analyze factors that can affect plant growth.

BASICS OF PLANT ANATOMY AND GROWTH

Plant Meristems

1. Meristems -- plant tissue that is actively

2. Types of meristems

a. -- tips of roots and shoots

b. -- vascular cambium and cork cambium

Stem Anatomy

1. Xylem --

2. -- carries sugars and growth substances downward

3. Vascular cambium -- forms (inside) and (outside)

4. Epidermis -- 2

5. Cortex --

6. ( ) – lateral meristem that forms

7. Periderm -- ( ) protective tissue

Leaf Arrangement/Phyllotaxy

1. Opposite - two leaves at each

2. Alternate - leaves borne in a spiral

3. Whorled -

Alternate Leaf Arrangement

1. Expressed as a fraction (e.g., 1/3, 1/4, 3/8).

2. Numerator - number of times around the stem for two

3. Denominator - number of buds

Branch Types

1. Normal - typical growth of plant.

2. - short branches with close nodes. Examples -

3. Epicormic shoot –

4. - upright, vigorous branches formed above ground or graft union.

5. Suckers -

Bud Types

1. Dormant buds - grow after

2. buds - more than 1 year old but grows only a little each year to

3. Adventitious buds -

Control of Shoot Growth

1. Apical dominance - bud at apex prevents

a. Caused by

b. Control often effective for

2. Apical control - bud at apex

a. Caused by plant growth regulators

b. Responsible for growth habit.

Plant Growth Habits

1. Excurrent habit - 4

a. shaped plant results.

b. Apical dominance may be weak but

2. Decurrent habit - rounded shape and lacks

a. Lateral branches grow

b. Apical control is usually

Root Tissues

1. Xylem - same function as in the stem.

2. Phloem - same function as in the stem.

3. Vascular cambium - same function as in the stem.

4. Pericycle - source of

a. Has meristematic potential, since

b. Roots arise in an

5. Endodermis - forms sheath around vascular tissues (called the )

a. Contains the strip.

b. Important for

6. Cortex - region between vascular system and epidermis. 5

7. Epidermis - surface layer of cells.

Root Functions

2. Absorb

3. Store

4. Produce certain

Types of Roots

1. - from seedlings.

2. Taproot - prominent root with

3. Lateral roots - grow horizontally.

a. Extend beyond

b. Distance below the surface

4. Sinker roots - grow from lateral roots. Also called

a. Located near

b. Absorb water during

5. - arise from main trunk and grow downward.

a. Provide plant

b. Can affect

6. Feeder roots -

a. Responsible for

b. Regenerate

c. Located in upper

Root Hairs

Root hairs - do NOT

a. Live several weeks to

b. Absorb most water

c. Grow up to long.

Types of Root Systems

1. Taproot system - one main root with

2. Fibrous root system - many lateral roots form

Root System Characteristics

1. Most roots are in 7

2. Most absorbing roots in

3. Lateral roots extend beyond

4. Soil conditions influence root system.

a. Good conditions -

b. Poor conditions -

Juvenile versus Adult Tissues in a Woody Plant

1. Juvenile tissue was produced when the plant was young.

2. Adult tissue was produced when the plant was older.

Summary

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