Cert III Horticulture key terms

Items worn to reduce injury or exposure risk, such as gloves, eye protection, hearing protection, boots, and high-visibility clothing. Employers provide it where hazards cannot be controlled by other means, and workers must use it correctly.

A document supplied with a hazardous chemical that lists its hazards, safe handling, first aid, spill response, and storage requirements. It must be readily accessible to workers who use or store the product.

A ranked approach to managing risk, from most to least effective: eliminate the hazard, substitute it, use engineering controls, apply administrative controls, then rely on protective equipment. It guides decisions about how to make horticultural tasks safer.

The process of identifying hazards in a task or site, judging how likely and how severe any harm could be, and deciding what controls are needed. It is recorded and reviewed when conditions or work practices change.

A procedure for isolating energy sources such as electricity, fuel, hydraulics, or stored pressure before maintenance, using locks and warning tags so equipment cannot start unexpectedly. Only the person who applied the lock removes it.

The two-part naming system for living organisms, giving each a genus name and a species epithet, usually in Latin and italicised, with the genus capitalised. It provides one internationally recognised name per species.

A plant variety selected and maintained by humans for particular characteristics, whose name follows the species name in single quotes and is not italicised. Cultivars are propagated to retain those chosen traits.

A taxonomic rank grouping related genera, with a name usually ending in -aceae. Knowing a plant's family helps predict flower structure, pest susceptibility, and compatible grafting partners.

The water-conducting tissue that carries water and dissolved minerals upward from roots to shoots through dead, lignified cells. Damage to xylem interrupts supply to leaves and causes wilting.

The living tissue that transports sugars and other organic compounds from leaves to growing and storage tissues. Because phloem sits just under the bark, girdling the stem starves roots.

The loss of water vapour from plant surfaces, mainly through leaf pores, which pulls water up through the plant and cools the leaves. It drives much of a plant's water demand on hot, windy days.

Small adjustable pores, mostly on leaf undersides, that open to admit carbon dioxide for photosynthesis and close to limit water loss. Guard cells control their opening in response to light, water status, and temperature.

The process by which green plants use light energy to convert carbon dioxide and water into sugars, releasing oxygen. It supplies the carbohydrates that fuel growth, flowering, and fruit production.

The relative proportions of sand, silt, and clay particles in a soil, which together determine how it holds water and nutrients and how easily it drains and can be worked. It is assessed by feel and by settling tests.

The arrangement of soil particles into aggregates or peds, creating pore spaces for air, water, and roots. Good structure improves drainage, aeration, and resistance to erosion and can be damaged by compaction.

A soil's ability to hold positively charged nutrient ions on clay and organic matter surfaces and release them to roots. Higher capacity means greater nutrient retention and less leaching.

A measure of soil acidity or alkalinity on a scale from 0 to 14, which strongly affects nutrient availability and plant choice. Most horticultural plants grow best between about pH 5.5 and 7.0.

A layer of organic or inorganic material spread over the soil surface to suppress weeds, conserve moisture, moderate temperature, and protect structure. It should be kept clear of stems and trunks to avoid rot.

Producing new plants from non-seed plant parts such as cuttings, divisions, or layers, so offspring are genetically identical to the parent. It is used to preserve cultivar traits and shorten time to flowering.

Preparing and inserting a severed piece of stem, leaf, or root into a rooting medium so it forms roots and becomes a new plant. Success depends on node position, moisture, temperature, and hygiene.

Joining a scion from one plant onto the rootstock of another so the tissues unite and grow as one plant. It is used to combine a desirable top with a root system offering vigour, size control, or disease resistance.

A disease of seedlings and cuttings in which soil-borne organisms rot the stem at or below the surface, causing collapse and death. Clean containers, fresh media, and good airflow reduce its incidence.

Treating potting mix, tools, or containers with heat, steam, or approved chemicals to kill pathogens and weed seed. It is a key hygiene step in nursery production and propagation areas.

Routine practices that prevent pest and disease entry and spread in a growing area, including cleaning benches, controlling weeds, disinfecting tools, and removing infected plants promptly. It is cheaper than treating established problems.

A shallow saucer-shaped depression formed in the soil around a newly planted tree or shrub to direct water to the root ball. It is removed or reshaped once the plant is established.

The mass of roots and the growing medium that comes out of a container or is lifted with a bare-root or field-grown plant. Keeping it intact and moist is critical during transplanting.

Temporary wilting, leaf drop, or slow growth after a plant is moved, caused by disturbed roots and an imbalance between water uptake and loss. It is reduced by careful lifting, adequate watering, and shading.

Removing or damaging a ring of bark and phloem around a stem, which stops sugars moving to the roots and can kill the plant. It also describes roots that encircle and strangle a trunk.

A deliberate cut made to remove, shorten, or shape growth, positioned so the wound seals and the remaining tissue can respond. Correct angle and position near a bud or branch collar reduce decay risk.

The slightly swollen ring of tissue where a branch joins its parent stem, containing the cells that seal the wound. Cuts made just outside the collar heal faster than flush cuts.

A layer of dead and living stems, roots, and organic matter between the green turf canopy and the soil surface. Excessive thatch blocks water and air movement and increases disease and pest problems.

The height at which a mower cuts the grass, affecting root depth, density, weed competition, and drought tolerance. Removing too much leaf at once stresses the turf, so no more than about one third should be taken.

Mechanical removal of thatch and surface organic matter from turf using vertical blades, to improve air, water, and nutrient penetration. It is best done when the grass is actively growing so it can recover.

A grass chosen for a lawn or sports surface based on climate, wear tolerance, shade tolerance, and maintenance budget. Warm-season and cool-season types differ in growth pattern and seasonal performance.

A decision-making approach that combines monitoring, cultural, physical, biological, and chemical controls, using pesticides only when thresholds are reached. It reduces reliance on chemicals and the risk of resistance.

The pest population level at which the cost of control is justified by the damage avoided. Monitoring to compare pest numbers with the threshold prevents unnecessary spraying.

Using living organisms such as predators, parasitoids, or pathogens to reduce pest populations. It works best when habitat is protected and broad-spectrum chemicals are avoided.

The minimum time that must pass between applying a pesticide and harvesting or grazing the treated crop, or re-entering the area. It is stated on the label and must be observed.

The downward movement of water through soil carrying dissolved nutrients and chemicals beyond the root zone. Over-irrigation and low cation exchange capacity increase nutrient loss and off-site pollution.

Deciding when and how much to water by matching application to plant demand, soil type, and weather, often using timers, tensiometers, or evapotranspiration data. Good scheduling saves water and reduces disease and leaching.

Yellowing of normally green leaf tissue caused by loss of chlorophyll, often from nutrient deficiency, poor drainage, or root damage. The pattern of yellowing helps identify the cause.

A small petrol engine in which oil is mixed with fuel to lubricate moving parts, commonly used in chainsaws and brushcutters. It requires the correct oil ratio and regular air filter and spark plug checks.