Teaching Organic Farming and Gardening

Propagation/Greenhouse Management

Unit 1.3 | 29
Instructor’s Demonstration 5 Outline

Demonstration 5: Greenhouse Irrigation

for the instructor

OVERVIEW

In this demonstration, students

will learn about the various tools

and techniques used to deliver

water to pre-emergent seeds and

seedlings in a given propagation

facility. Emphasis should be placed

on creating optimal soil moisture

conditions to facilitate healthy plant

growth through proper irrigation

frequencies and volumes of water

applied. You should also discuss the

advantages and disadvantages of the

systems and tools used.

PREPARATION AND MATERIALS

• All irrigation equipment commonly used in the propagation
  facility (e.g., hoses, watering cans, fixed spray nozzles,
  irrigation timers and solenoid control valves, mist systems,
  etc.)


• Recently sown seeds in flat and cell tray format


• Seedlings in flat and cell tray format

PREPARATION TIME

1 hour

DEMONSTRATION TIME

1 hour

DEMONSTRATION OUTLINE

A. Irrigating Seeds and Seedlings

1. Discuss and demonstrate irrigation techniques prior to
   seedling emergence with attention to the differences in
   wet-to-dry swing for large- and small-seeded crops


2. Discuss and demonstrate irrigation techniques used for
   post-seedling emergence and early seedling development


3. Discuss the typical changes in frequency and volume of
   water delivered during seedling development (i.e., from
   pre-germination—frequent, shallow applications—to
   lower frequency, greater volume of water supplied as
   seedlings mature)


4. Discuss and demonstrate any necessary adjustments
   needed based on germination, disease or pest problems,
   and/or plant growth observations


5. Emphasize the importance of paying extra attention
   to corners and edges of greenhouse; these are often
   overlooked