Certificate In Horticulture (Horticultural Technology)

How To Be More Successful in Horticulture?

Modules

Note that each module in the Certificate In Horticulture (Horticultural Technology) is a short course in its own right, and may be studied separately.

1. Introduction to plants
The purpose of this study area is to explain the binomial system of plant classification and demonstrate identification of plant species through the ability of using botanical descriptions for leaf shapes and flowers.

Objectives

• Describe the relevant identifying physical features of flowering ornamental plants.
• Demonstrate how to use prescribed reference books and other resources to gain relevant information.
• Dissect, draw and label two different flowers.
• Collect and identify the shapes of different leaves.
• Demonstrate how to identify between family, genus, species, variety and cultivar.

2. Plant culture
The purpose of this study area is to demonstrate the ability to care for plants so as to maintain optimum growth and health while considering pruning, planting, and irrigation.

Objectives

• Describe how to prune different plants.
• Demonstrate how to cut wood correctly, on the correct angle and section of the stem.
• Describe how to plant a plant.
• Demonstrate an awareness of different irrigation equipment, sprinklers, pumps and turf systems available by listing their comparative advantages and disadvantages.
• Demonstrate competence in selecting an appropriate irrigation system for a garden, explaining why that system would be preferred.
• Define water pressure and flow rate and how to calculate each.
• Explain the need for regular maintenance of garden tools and equipment.
• List factors that should be considered when comparing types of machinery for use in garden maintenance.

3. Soils and plant nutrition
The purpose of this study area is to provide students with the skills and knowledge to identify, work with, and improve the soil condition and potting mixes, and to evaluate fertilisers for use in landscape jobs to maximize plant growth.

Objectives

• Describe the soil types commonly found in plant culture in terms of texture, structure and water-holding and nutrient holding capacity.
• Describe methods of improving soil structure, infiltration rate, water holding capacity, drainage and  aeration.   
• List the elements essential for plant growth.
• Diagnose the major nutrient deficiencies that occur in ornamental plants and prescribe treatment  practices.
• Describe soil pH and its importance in plant nutrition.
• Describe the process by which salting occurs and how to minimise its effect.
• Conduct simple inexpensive tests on three different potting mixes and report accordingly.
• Describe suitable soil mixes for container growing of five different types of plants.
• List a range of both natural and artificial fertilizers.
• Describe fertilizer programs to be used in five different situations with ornamental plants.

4. Introductory Propagation
The purpose of this study area is to improve the student's understanding of propagation techniques with particular emphasis on cuttings and seeds. Other industry techniques such as grafting and budding are also explained.

Objectives

• Demonstrate propagation of six (6) different plants by cuttings and three from seed.
• Construct a simple inexpensive cold frame.
• Mix and use a propagation media suited to propagating both seed and cuttings.
• Describe the method and time of year used to propagate different plant varieties.
• Describe and demonstrate the steps in preparing and executing a variety of grafts and one budding technique.
• Explain the reasons why budding or grafting are sometimes preferred propagation methods.

5. Identification and use of plants
The purpose of this study area is to improve the student's range of plant knowledge and the plant use in landscaping and the ornamental garden, and the appreciation of the different optimum and preferred growing conditions for different plants.

Objectives

• Select plants appropriate for growing in different climates.
• Select plants appropriate to use for shade, windbreaks, as a feature, and for various aesthetic effects.
• Categorise priorities which effect selection of plants for an ornamental garden.
• Explain the differences in the way plants perform in different microclimates within the same area.
• List and analyze the situations where plants are used.

6. Pests, Diseases and Weeds
The purpose of this study area is develop the student’s ability to identify, describe and control a variety of pests, diseases and weeds in ornamental situation, and to describe safety procedures when using agricultural chemicals.

Objectives

• Explain in general terms the principles of pest, disease and weed control and the ecological (biological) approach to such control.
• Explain the host‑pathogen‑environment concept.
• Describe a variety of pesticides for control of pests, diseases and weeds of ornamental plants in terms of their active constituents, application methods, timing and rates, and safety procedures.
• Photograph or prepare specimens, identify and recommend control practices for at least five insect ests of ornamental plants.
• Photograph, sketch or prepare samples, identify and recommend control practices for three non‑insect ornamental plant health problems (e.g. fungal, viral, bacterial).
• Describe the major ways in which diseases (fungal, viral, bacterial and nematode) affect turf, the life cycle features that cause them to become a serious problem to turf culture and the methods available for their control.
• Identify, describe and recommend treatment for three different weed problems.
• Collect, press, mount and identify a collection of ten different weeds, and recommend chemical and  non-chemical treatments which may be used to control each.
• List and compare the relative advantages and disadvantages of different weed control methods.

Elective Units

(50% of the Course -There are other options though apart from what is shown below)

Hydroponics I

There are ten lessons as follows:

There are eleven lessons as follows:

1.  How the Crop Plant Grows
2.  How to Run a Small Evaluation Trial
3.  Harvest and Post Harvest
4.  Tomatoes
5.  Capsicum
6.  Lettuce, Salad Greens and Foliage Herb Crops
7.  Cucurbits (Cucumber and Melons)
8.  Strawberries
9.  Roses
10. Carnations
11. Orchids

Plant Breeding

There are 7 lessons in this module as follows:

1.  The Scope and Nature of the Plant Breeding Industry
2.  Introduction to Genetics
3.  Gamete Production, Pollination and Fertilisation in Plants
4.  Mono Hybrid and Dihybrid Inheritance in Plants
5.  Systematic Botany and Floral Structures
6.  Practical Plant Breeding Techniques
7.  Current Developments in Plant Genetics
 

SELECTING MEDIA FOR AQUAPONIC PLANT CULTURE

There are many kinds of soil-less, organic mixes that can contain an assortment of ingredients. Most contain things like sphagnum moss or coconut fibre, perlite and vermiculite. This type of medium is frequently used for container gardening, wick systems and non-recovery drip systems. The fine particles can clog pumps and drip emitters so a filtration system would need to be used. Soil-less mixes usually have very good water retaining qualities, excellent wicking action, and are able to hold a good amount of air. This makes them an ideal growing medium for a variety of hydroponic and aquaponic systems.

The one thing which all hydroponic/aquaponic media must be is sterile or inert. In other words, they must be free of nutrients, chemicals, impurities, and preferably any sort of disease or other living organisms. For some plants which of necessity need to have certain microorganisms in their root environment (e.g. orchids, mushrooms), this inert quality is a distinct advantage. Apart from its inert quality, the other important characteristics of the medium which must be considered include:

a) Water-holding capacity
b) Air-holding capacity
c) Drainage  (this is different to air-holding capacity)
d) Nutrient-holding capacity

A medium which drains well is usually well aerated but can have a low water-holding and nutrient-holding capacity. These types of media need to be irrigated more often or perhaps even as a continuous flow. There is hence a relationship between the type of media you might choose for a system and the way in which the system is irrigated.

A medium which holds water and nutrients better should be irrigated less frequently (in summer as little as once every 7 days and in winter as little as once every 3 or 4 days).

Sand
Granitic or silica-type sands should be used. Calcareous sands are very alkaline and unsuited to plant growth. Beach sand is not suitable because of the high levels of salt in it. Some sand has a lot of dust or other fine material in it when purchased and needs to be washed out before it is used.

The best sand is the coarse granitic sand used by nurserymen for plant propagation and in fish aquariums. By itself sand will need frequent, if not constant flow of irrigation to prevent the plants drying out. It is often mixed with other water-retaining materials though to obtain a balanced medium. Although it provides a large surface area for bio-filters, it can be difficult to work with.

Expanded Clay
Also called LECA (light expanded clay aggregate), this material is made by blending and bloating clay in rotary kilns. The material looks a little like hard terracotta balls. It has a low air-filled porosity and a higher water-holding capacity.

Scoria
• This is organic rock and is supplied in various grades.
• It is highly porous providing excellent water retention properties.
• It is alkaline with a pH range of 7-10.
• High pH scoria is usually exposed to the weather to reduce the pH before horticultural use.
• Its coarse texture makes it unsuitable for seedlings.

Coir

• Coir is derived from coconut fibres with a texture similar to sphagnum peat.
• It is often used as a peat substitute since peat is a non-renewable resource.
• It is easier to re-wet than peat and has a very high water retention capacity due to the abundant pore spaces between the fine and coarse fibres.
• It is high in the key nutrients of phosphorous and potassium and breaks down more slowly than peat since it is more resistant to the action of microbes.
• Is does not hold nutrients very well though.

Problems with Coir: sources of coir continue to be a big issue – some fibre (from some countries) tested to contain toxic (to plants) levels chlorides. Coconut coir has a higher potassium level, but also higher sodium and chlorine levels compared to sphagnum peat. Salt levels have thrown up some concerns with coir although it is suggested that this is readily leached from the root-zone. A reputable supplier will supply analysis of their product to show salt levels.

Grits

• Grits are composed of larger particles than sands.
• A variety of different grits are available.
• Pumice grits are highly absorbent but granite grits a free draining.
• Free draining grits can be added to mixes to improve drainage, open the soil structure, and add weight to pots.
• Finer grades are sometimes used to top germinating seeds.
• Grits can be used to anchor aquatic plants.

Gravels
Gravels are popular in aquaponics systems. They are a larger grade media than grits and are available in a variety of materials. It’s best to avoid limestone and sandstone gravels since these will increase the systems pH over time.

Vermiculite

• This is a mineral derived from mica.
• Horticultural vermiculite comes in several grades.
• It is a light material with a spongy texture enabling it to hold moisture and nutrients well but due to this high water retention property it is best mixed with other forms of growing media.
• It is often used in hydroponics.
• Finer grades are used in seed germination.
• It can be slightly acidic or alkaline but not enough to impede plant growth.
• It has an overall negative charge enabling it to attract and retain positively charged nutrients.

You should only use horticultural vermiculite in hydroponics/aquaponics. This is available in different grades:

• No1. – 5 to 8 mm in diameter
• No 2. – 3 to 4 mm in diameter (this is the standard grade)
• No3. – 1 to 2 mm in diameter
• No 4. – 0.75 to 1 mm in diameter (used only in seed germination)

Perlite

• This has a similar structure to vermiculite but is not as spongy and is more freely draining.
• It is derived from igneous rock.
• It can be used for propagation either alone or mixed with vermiculite.
• It is pH neutral, chemically inert and sterile.
• Algal growth is sometimes a problem due to its white colour.

Rockwool

• Rockwool is highly absorbent medium which can be used in soilless mixes.
• It is processed from spun molten rock and so is not biodegradable.
• It is easy to manipulate due to its rigidity.
• It is inert and so nutrients must be added if used alone and it does not hold nutrients.
• It has no pH buffering capacity.
• Due to its high water holding capacity deeper pieces will allow better drainage.
• Rockwool blocks can be used for striking cuttings and germinating seeds.

Note: the over-use of almost any environmental organic matter may compromise its sustainability.

Rockwool™ has been used extensively in the drip-type of hydroponic growing system. It is also used in aquaponics systems. Rock and sand are spun to create fibres which can then be pressed into various shapes and sizes from small starter cubes to large slabs, or used in its loose form.

Advantages of Rockwool

Rockwool has the ability to:

• Retain water – it holds a large amount of water which is an advantage during power outages or equipment failure.
• Hold air – it holds at least 18% air as long as it is not sitting directly in water. This helps to supply the plant’s root zone with adequate oxygen making over-watering unlikely.

It is also sterile and light, which reduces the possibility of disease and makes it easy to work with.

Disadvantages of Rockwool

• It is not environmentally friendly. Rockwool is hard to dispose of; if buried it will last indefinitely however it does not harm the environment
• Dust and fibres are a health risk. The fibres and dust from the Rockwool are a health risk when breathed into the lungs - a dust-mask should be used at all times when handling this material.

WHY THIS COURSE?

It allows you to keep your options wider than other certificates. You can still undertake substantial study in horticultural technologies; while also undertaking sufficient broader based horticultural studies to support a career path in landscape, nursery, turf or some other sector of the horticulture profession.