This unit of competency describes the skills and knowledge required to diagnose tree diseases and develop a management program for their control. Diseases include pathogens, pests and other disorders of angiosperms, gymnosperms and woody monocotyledons.

The unit applies to individuals who work in arboriculture and analyse information and exercise judgement to complete a range of advanced skilled activities and demonstrate deep knowledge in a specific technical area. They have accountability for the work of others and analyse, design and communicate solutions to a range of complex problems.

No licensing, legislative or certification requirements apply to this unit at the time of publication.

An individual demonstrating competency must satisfy all of the elements and performance criteria in this unit.

There must be evidence that individual has identified and collated representative samples of at least 30 diseases of trees, including evidence of infection, into a referenced collection, including:

10 invertebrate pests, including insects and molluscs

10 pathogenic organisms

10 environmental and soil disorders.

Where biosecurity is a concern, the sample can be replaced by a high quality informative image.

There must also be evidence that the individual has:

identified the affected tree and determined its origin and seasonal growth stages

determined factors affecting tree health and growth, which must include:

current and past cultural practices

characteristics of growing environment

environmental and cultural factors that predispose trees to disease

assessed physical and chemical properties of the soil or growing media

identified trees with diseases

recognised natural defence systems for major disease types

determined disease groups according to disease classification

investigated trees for signs and symptoms of disease

recorded symptoms and signs of disease using accepted nomenclature

determined impact of disease type on tree parts and systems

determined the nature and severity of the disease

determined disease type

researched and identified tree diseases

prepared specimens of diseases for microscopic examination

collected, packaged and prepared specimens for dispatch for specialist diagnosis or laboratory testing according to biosecurity procedures

determined current health and vigour of the tree

assessed severity and extent of the disease

researched virulence of the disease on the specific host

determined phenology of the host and the disease

researched and considered the constraints for management options

considered influences of environmental conditions on host, disease and management options

documented prognosis according to workplace procedures

investigated and recommended management options

developed a disease management program

recorded and documented tree diseases and management programs in a report

monitored, reviewed and updated management plan.

An individual must be able to demonstrate the knowledge required to perform the tasks outlined in the elements and performance criteria of this unit. This includes knowledge of:

definition of disease and basic concepts of plant pathology, including:

plant pathogens, pests and disorders

macro organisms, microorganisms

disease classification guides

virulence, phenology, prognosis and disease severity and extent

economics and tree diseases

trees species; their growing environment and relationship to diseases, including:

taxonomic identification

tree anatomy, physiology, pathology

life cycle stages and characteristics of trees and their vulnerabilities

primary cellular and anatomical structures of trees

critical systems in trees and relationship to plant health, including physiological and biochemical

natural defence mechanisms and systems of trees

implications of growing season, climate and regional characteristics on tree species and disease development

cultural practices, including mulching, irrigation, pruning

impact of soil or media on tree health, including:

chemical and physical characteristics

test and test results indicating tree nutrient, and growth health issues

controlling soil and environmental problems

identification of signs and symptoms of tree health problems, including:

disease detection and identification methods

patterns of host–disease interaction for each major disease type

nomenclature of symptoms and signs of pathogens, pests and disorders

describing the nature and severity of disease infection, including:

chronic and acute

passive and aggressive

seasonal and ongoing

localised and unconfined

methods for managing pathogens, pests and disorders, including:

mechanical control practicalities

chemical use, toxicity and safety, compatibility and off-target considerations

managing the cultural factors, growing conditions and environment

managing soil fertility and amelioration

biological control and working with natural agents to control pathogens, pests and growing environment

importance and use of Integrated Pest Management strategies

biosecurity and basic principles of hygiene in arboricultural work

constraints to disease management, including:

timing and scheduling treatments

cost and budgetary constraints

perceived and real value of infected tree

tree diseases collection and diagnosis, including:

collecting, preserving, securing and storing specimens and examples of tree pathogens, pests and disorders

biosecurity risks and mitigation when collecting and storing specimens

preparation of specimens for diagnostics

microscopic and macroscopic examinations

microscope slide preparation

methods of providing a reasoned prognosis

horticultural function, cultural and performance requirements and characteristics of the trees or other woody plants

processes and principles of researching tree health problems, diagnoses and remedial treatment available

industry standards and terminology to describe disease attributes

recording and reporting tree disease prognosis and management strategies, including:

written documentation

oral presentations.

Assessment of the skills in this unit of competency must take place under the following conditions:

physical conditions:

an arboriculture work site with the diseased trees stipulated in the performance evidence

resources, equipment and materials:

computer with word processing software

digital imaging device

diagnostic tools, including sounding hammer, trowel, probe, cordless drill

soil testing equipment and materials

basic dissection microscope 10x – 100x

optical devices, including compound microscope, binoculars, hand lens

sampling equipment, secure storage containers, disinfectant

trees without diseases

trees with biotic diseases

trees with abiotic diseases

bio-secure samples of tree diseases

disinfection materials and equipment to minimise infections

specifications:

codes of practice relevant to tree diagnostics work.

Assessors of this unit must satisfy the requirements for assessors in applicable vocational education and training legislation, frameworks and/or standards. In particular, assessors must have:

arboriculture vocational competencies at least to the level being assessed

current arboriculture industry skills directly relevant to the unit of competency being assessed.

This section describes those language, literacy, numeracy and employment skills that are essential for performance in this unit of competency but are not explicit in the performance criteria.

Arboriculture (ARB)