Propagation Environments and Atmospheric Factors

Study Notes

Nursery structures modify atmospheric conditions, such as temperature, light, and humidity, to optimize plant growth.
Photosynthesis converts light energy into chemical energy in plants, using chlorophyll. Photosynthesis produces sugars from carbon dioxide and water, releasing oxygen as a byproduct.
Transpiration is the loss of water vapor through stomata (pores on leaves) when carbon dioxide is taken in.
Growers should manage atmospheric factors that limit photosynthesis, to maximize plant growth.
Managing factors limiting plant growth is key to successful nursery management. The best possible environment should be designed.

Limiting atmospheric factors include light, temperature, humidity, carbon dioxide, and organisms.
Outdoors, the climate affects these factors.
Propagation structures (greenhouses, for example) modify these environmental factors.
Organisms, like insects, can be excluded from a nursery using proper design.
Beneficial microbes can be encouraged.

Growing medium (substrate/potting soil) supports plant development.
It should provide a suitable rooting environment, storage of air for the roots, water absorption and retention, and nutrients for plant roots.
Various components, such as peat, coir pith, wood fibers, bark, and composted organic matter, are used to create growing media.
The specific needs of different plant species dictate the best growing medium mix.
Availability and sustainable development considerations affect the materials used in the horticulture industry.

Propagation environments are described as minimally controlled, semi-controlled, and fully controlled.
Minimally controlled environments include open growing compounds with an irrigation system and a fence.
Semi-controlled environments include various growing structures, ranging from cold frames to shade houses.
Fully controlled environments, such as growth chambers and greenhouses, control most environmental variables, allowing year-round production.

Horticultural techniques modify the propagation environment.
Container type, volume, spacing, and other factors can alter plant size, quality, and type of crop.
Good water supply and proper fertilizer use are essential for plant growth.
Controlling light and temperature is important for plant growth, especially in greenhouses.

Growing media, or substrates, are materials used for plant growth.
They support proper plant development, providing essential elements.
A suitable growing medium maintains physical stability, stores air, absorbs and retains water, and supplies nutrients.
A wide range of media constituents are used, including peat, coir pith, wood fibers, and bark.
Growing media are often formulated with additives like fertilizers, lime, and biological ones to optimize physical, chemical and biological properties for plant growth.
Plant species have specific needs regarding water and nutrients, thus requiring various growing media mixes.

Composting is an excellent alternative to traditional growing mediums.
Using native soils, or incorporating them into a growing medium, must be done carefully.
Compost improves growing medium properties, including water retention, aeration, porosity, and fertility.
Composting involves decomposing organic matter, modifying environmental conditions and managing variables like moisture, temperature, and carbon to nitrogen ratio (C:N).

Container choice is crucial for nursery success.
Factors like volume, height, diameter, shape, and material influence plant growth, cost, and operation in a nursery.
Container sizes should be appropriate for the plant species, its volume, height and diameter.
Container type, dimensions, filling, and harvesting methods affect operations in the nursery.
Suitable container materials improve plant growth, minimize operational costs, and maintain quality.

Spacing between plants influences light, water, nutrient availability, and plant growth.
Spacing is specific to species, and plant type dictates spacing for optimum results in a nursery environment.
Proper spacing is crucial for plant health and growth.
Using the correct container type for plant species, is an important factor to ensure the best outcome.

Various container types are available, each with advantages and disadvantages (one-time-use, single, exchangeable cell, block, and others).
Selecting the appropriate container type is essential for successful plant growth and nursery operations.