Quiz 7: Protected Culture for Vegetable Production

Purpose of Cold Frames

Harden seedlings; production of low-growing Cole crops

Characteristics of Cold Frames

Temporary Structure

Unheated

Designed for maximum light harvest

Designed to use passive cooling

Purpose of Hot Beds

Harden seedlings; production of low-growing Cole crops

Characteristics of Hot Beds

Temporary Structure

Heated

Designed for maximum harvest of light energy

Designed to use passive cooling

Purpose of High Tunnels

Protect plants from suboptimal temperatures

Description of High Tunnels

Hoop structures placed over plant rows; remain in place until conditions improve

Characteristics of High Tunnels

Film Plastic

PVC ribs to support structure

Varying thickness

Ventilation

Quonset Greenhouse

Most economical and common design

May be short or tall-sided

Facilitates film coverings

Even-Span Greenhouse

Roof pitches are equal

Side wall height from 8-25ft

Covered with ridged plastic

Greenhouse Cultural Systems (3)

Organic

Hydroponics

Aquaponics

Protected Structures for Organic Production

Uses soil and compost as substrates

Grow plants in ground or containers

May be heated (or not)

What is hydroponics?

culture of plants in a nutrient rich liquid medium with or without an inert support substrate

Why use hydroponics? (advantages 5)

Conserve water/nutrients

Reduced insect/disease problems

Reduced labor

Improves plant yield

Plant environment easily controlled

Bag Culture Description

Plants grown directly in bags that contain an inert substrate

Advantages for Bag Systems

Provides proper nutrition

Inexpensive

No soil to pasteurize

Nutrition can be monitored continuously

Conserves water and nutrients

Disadvantages for Bag Systems

Difficult to maintain consistent moisture level among all bags

Best for shallow-rooted crops

Bag System Harvest Procedures

Workers harvest tomatoes from plant and place in cart

Loaded carts moved down aisle until all fruit are harvested

Cart is transported to dumping stations located in floor.

Fruit travel down water way to packaging station

Packaged fruits placed on pallets for shipment

Nutrient Film Technique

Plants grown in plastic troughs through which a thin film of nutrient solution is passed

Nutrient Film Technique Advantages

Closed system

Efficient

No soil/inert substrate necessary

Nutrition continuously monitored

Nutrient Film Technique Disadvantages

Best for short-term crops

Expensive to set up

Mainly for shallow-rooted crops

Verti-Gro System

Plants grown in polystyrene containers that can be stacked vertically

Verti-Gro System Advantages

Used for wide variety of crops

Space used efficiently

Can be automated or run manually

Conserves water and nutrients

Inexpensive to construct

Verti-Gro System Disadvantages

Difficult to control moisture levels among all containers

Weight of plants