PLANT PROTECTION 1 – Pests, Diseases and Weeds

PLANT PROTECTION 1 – Pests, Diseases and Weeds
Pest management See Integrated Pest Management.
Phasmatid An insect belonging to the Order
Phasmatodea (stick insects, leaf insects).
Pheromone A substance emitted by an animal that
influences the behaviour of other animals of the same
species, may be synthetically produced for insect traps.
Phloem Tissues which transport nutrients from
leaves which produce them to other plant parts.
Phylum A division of the plant and animal Kingdom.
Physical control Use of certain physical properties
of the environment, eg temperature, to control pests,
diseases and weeds.
Phytoplasma See Virus & virus-like organism.
Phytotoxity Toxicity of a pesticide or a pesticide
component to desired plants
Pigmentation Development of pigments other than
chlorophyll in leaves, flowers and fruit. Can occur as
a result of insect infestations, disease, weather
conditions or other agents.
Plant growth regulator A substance which
accelerates, retards or alters the natural development
of any vegetation.
Plant quarantine Legislative regulatory control
against introduction and dissemination of weeds and
pests and diseases of plants into new areas.
Plasmodiophoromycota A Phylum in the Fungi
which are obligate endoparasites of plants, eg club
root of brassicas (Plasmodiophora brassicae).
Poisoning A toxic reaction when touched or eaten.
Post-emergent herbicide A herbicide applied
after weeds have appeared through the soil.
Powdery mildew A fungus in the Phylum
Ascomycota which produces white, powdery spores
on mostly upper leaf surfaces, stems, flowers, fruit.
Praying mantid A predaceous insect belonging to
the Order Mantodea (mantids, praying mantids).
Predator An animal that attacks, kills and feeds on
other animals, eg assassin bugs.
Pre-emergent herbicide A herbicide applied
before the weeds have appeared through the soil.
Protectant A fungicide applied to a plant prior to
infection by a disease organism in order to prevent
infection of the host plant.
Protocol A negotiated formal procedure drawn up
and recorded.
Provenance(s) Populations of a species from
different regions, individual trees within regions, and
even different branches of one tree.
Pubcris The registered product database of the
Australian Pesticide & Veterinary Medicines
Authority (APVMA).
Pupa (pl. pupae) The stage during which an insect
with a complete metamorphosis transforms from the
larval to the adult stage.
Pustule A small blister-like elevation of epidermis
created as spores from underneath push outwards.
pv.. See Pathovar.
Quarantine. See Plant Quarantine.
Race. 1. A genetically and often geographically
distinct mating group within a species. 2. A group of
pathogens that infect a given set of plant varieties.
Relative humidity The amount of water vapour in
the air compared to the amount required for
saturation, stated as a percentage. If air contains only
half the amount of water vapour that it can hold when
saturated, relative humidity is 50%.
Repellent A compound that keeps insects, rodents,
birds or other pests away from plants, domestic
animals, buildings or other treated areas.
Resistance 1. The ability of a host plant to suppress
or retard the activities of one or more specified
disease organisms. 2. Populations of pests, diseases
or weeds that are unaffected by a certain dosage of
chemical used to control other populations of the
same organisms successfully.
Resistance mode of action groups (of a pesticide)
The classification of pesticides by Croplife Australia
which is displayed on commercial pesticide labels.
Rhizomorph A root-like strand of fungal hyphae,
used to spread for long distances through soil or along
or under bark of woody plants, eg Armillaria spp.
Ringspot Yellowish or chlorotic rings with green
tissue in the centre, caused by many virus & viruslike
diseases, eg peony ringspot virus.
Risk assessment The process of assessing whether a
pest, disease or weed is likely to become a major pest.
Rodenticide A agent active against rodents (vermin).
Roguing The removal of an infested or diseased
plant from an otherwise healthy crop to prevent
spread to neighbouring plants or through its seeds to
future generations. Weeds may also be rogued.
Rot A decay or decomposition of plant tissue which
can affect any plant part, eg roots, trunks, fruit, bulbs,
seed. It may be caused by bacteria or fungi, waterlogging
or by other agents.
Russet Development of brown, roughened areas on
the skin of fruit due to the formation of cork, caused
by mites, virus diseases, powdery mildew, frost, etc.
Rust A fungus in the Phylum Basidiomycota which
causes a disease characterized by orange brown spore
masses, eg chrysanthemum rust.
Salinity. A concentration of soluble salts in water
between soil particles sufficient to restrict plant growth.
Sanitation The elimination or reduction of pest and
disease organisms and weeds in a nursery,
glasshouse, storage facility or other horticultural
situation, to reduce spread to other healthy plants or
produce, especially at the beginning of a new season.
Saprophyte An organism using dead plant matter as
food.
Sawfly An insect belonging to the Order
Hymenoptera (ants, bees, wasps, sawflies).
Scab Localized lesion on plant parts, eg leaves, fruit,
corms, usually slightly raised, giving a scabby
appearance. It may be caused by bacterial or fungal
diseases, eg apple scab or by environmental agents,
eg oedema. See Oedema.
Scale An insect belonging to the Order Hemiptera
(bugs; hoppers; aphids, lerps, scales, mealybugs,
whiteflies).
Sclerotium (pl. sclerotia) A hard compact mass of
fungal threads, when dry dark on the outside, can
survive unfavourable conditions, eg Sclerotinia rot.
Scorch Dead, ‘burnt’ areas on leaves and fruit,
which may cover nearly the entire plant, irregular in
shape, or form patterns (other than spots). May be
caused by insects, disease, environmental conditions.
Secretions. Substances extracted from plant sap by
insects for their use or to be excreted as waste.
Seed banks Existing seed in soil.
Semio-chemical A chemical that modifies pest
behaviour.
Shothole Small spots on leaves which fall away to
leave small holes. Used to describe types of fungal
diseases, eg shothole of stone fruit; bacterial diseases,
eg bacterial canker of stone fruit. Insects, eg metallic
flea beetles, chew tiny irregular holes in leaves, which
enlarge to give the leaves a ‘shotholed’ appearance.
Sick soil syndrome Often referred to as ‘replant
disease’. Disease microorganisms are thought to build
up in soil during the life time of certain plants, eg
roses; when planting roses into old rose beds soil is
replaced.
Sign The presence of actual insects, fungi, snails or
other agents causing the problem. If signs are present
the problem can usually be readily identified.
Signal heading Indicates the hazard level of the
product, eg a pesticide.
Silk Produced by caterpillars of butterflies and
moths (Order Lepidoptera) from special glands in the
mouth, used for constructing cocoons, binding leaves
together or lowering themselves for dispersal.
Silvering Leaves become silvery in appearance
instead of the normal green colour, most commonly
caused by thrips rasping and sucking leaf surfaces,
but also caused by senescence and other agents.
Glossary & Acronyms 479