PLANT PROTECTION 1 – Pests, Diseases and Weeds

PLANT PROTECTION 1 – Pests, Diseases and Weeds
Fungus (pl. fungi) A simple plant with a mycelium
as a body, possesses no chlorophyll and reproduces
by spores; in a separate kingdom of their own.
Gall. A swelling, more or less spherical, of
unorganized plant cells occurring on any part of the
plant, as a result of infection by fungi, other disease
organisms or infestation by insects.
Genetic engineering (GE) Various experimental
techniques that manipulate the genes of an organism,
eg transfer of genes for drought resistance from wild
plants to crop plants.
GPUTS Garden Plants Under The Spotlight.
Grasshopper An insect belonging to the Order
Orthoptera (crickets, grasshoppers, locusts).
GRDC (Grain Research & Development Corporation).
Greenhouse effect A process by which
carbon dioxide (CO 2) and other gases such as
chloro-fluorocarbons (CFCs), methane and
nitrous oxide in the atmosphere, prevent some of
the heat radiation produced by the action of the
sun's energy on earth from returning to space.
Greening Floral parts are green, usually caused by a
phytoplasma disease (tomato big bud, virescence).
‘Grubs’ Thick-bodied larvae of beetles and weevils
(Coleoptera), butterflies and moths (Lepidoptera).
Gumming, gummosis An obvious secretion of
gum which may be caused by bacterial or fungal
diseases, insect pests or other agents.
HACCP. Hazard Analysis Critical Control Point.
Haustorium (pl. haustoria) A simple or branched
projection of fungal hyphae or cells into host cells
which act as food-absorbing organs.
Herbicide A substance active against weeds or
unwanted vegetation.
Heteroecious Requiring 2 different kinds of hosts
to complete its life cycle, eg some rust fungi.
Honeydew An excretion of some Hemipterous
insects (aphids, lerp insects, mealybugs, scales,
whiteflies), with a high carbohydrate, sugar and
nitrogen content attractive to ants. Black sooty mould
fungi grow on it.
Hormone herbicide Belonging to the phenoxy
aliphatic acid group of herbicides, eg 2,4-D, MCPA,
active against broadleaved weeds. Act in a similar
manner to the natural plant hormone auxin. Benzoic
acids, eg dicamba, act in a similar way.
Host A plant on, or in which, a pest or parasite lives.
Host range Plants attacked by a pest or disease.
Hydathodes Small pores at the margins of leaves
that release small droplets of plant fluid when turgor
pressure is high.
Humectant A soil humectant is a compound that
attracts and/or retains moisture in the soil.
Hydroponics Growing plants in aerated water
containing all the essential nutrients.
Hygiene The practice of keeping a greenhouse or
planting area clean by removal of weeds and plant
debris, sterilization of growing media and pots, and
disinfection procedures. See Sanitation.
Hyperparasite A parasite parasitic on another
parasite.
Hyphae Single branches of a fungal mycelium.
Immune. Ability of a plant to remain completely
free from attack by specified diseases and pests.
Imperfect Fungi A fungus that is not known to
produce sexual spores.
Indexing The transmission of a virus from a
diseased to a healthy plant (a variety on which
symptoms can be easily seen) by budding, grafting.
Indigenous Plants found naturally in a particular
area.
Infection Establishment of a parasite within a host.
Infestation When pests arrive and multiply to a
large number causing plant damage. It can also refer
to established pest populations.
Insect Arthropod with 3 body segments, 3 pairs of
legs on thorax,1pair antennae,with or withoutwings.
Insect growth regulator (IGR) Specific insecticides
such as growth hormones that disrupt the normal
development of insects.
Insecticide Any agent active against insects and
mites, includes pheromones, lures, baits, repellents,
biological pesticides.
Insects & allied pests Insects and related animals,
eg springtails, mites, spiders, slaters and millipedes,
belonging to the Phylum Arthropoda.
Instar One stage of growth between moults from
egg to adult.
Integrated pest management (IPM) Systematic
management of pests with consideration for the
environment. Part of managing crops as a whole,
includes Integrated Disease Management (IDM) and
Integrated Weed Management (IWM).
ISO International Standards Organization.
Invasive A pest or plant which colonizes and persists
in an ecosystem in which it did not occur before.
Knockdown spray. 1. An insecticide spray used
against flying insects that acts quickly causing
sprayed insects to fall. 2. A contact herbicide that is
rapid in action.
Lacewing. A predaceous insect belonging to the
Order Neuroptera (antlions, aphidlions, lacewings).
Larva (pl. larvae) The growing worm-like stage of
insects with a complete metamorphosis, eg
butterflies, moths, flies, beetles, sawflies.
Latent infection A virus that infects but does not
induce symptoms in its host.
Leaf blister Raised surface of a leaf caused by many
agents, eg blister mites, peach leaf curl (fungal disease).
Leaf curl Distortion and malformation of leaves and
shoots caused by insects, eg aphids, peach leaf curl
(fungal disease), herbicide injury, other agents.
Leafhopper An insect belonging to the Order
Hemiptera (bugs; hoppers; aphids, lerps, scales,
mealybugs, whiteflies).
Leaf insect An insect belonging to the Order
Phasmatodea (stick insects, leaf insects, phasmatids).
Leafmining Damage caused by the larvae of insects
feeding internally between the lower and upper leaf
surfaces, including moths (Lepidoptera), eg wattle
leafminer; sawflies (Hymenoptera), eg leafblister
sawfly); flies (Diptera), eg cineraria leafminer;
sometimes beetles (Coleoptera), eg lantana leafminer.
Leaf rolling Any obvious rolling of leaves, may be
caused by a range of agents, eg insects, mites, cold
weather, lack of water.
Leaf scorch Dead areas of various shapes on
leaves, which may be caused by heat, lack of water or
other agents, eg insects, fungal and bacterial diseases.
Leaf spot A self-limiting lesion on a leaf, commonly
caused by fungal diseases but also caused by virus
and virus-like diseases, bacterial diseases, insects
feeding and by a range of non-parasitic problems, eg
senescence or contact herbicide injury.
Lenticel A opening on the stem of woody plants,
tubers, etc, that allows for the exchange of gases
between the plant and the atmosphere.
Lerp An insect belonging to the Order Hemiptera
(bugs; hoppers; aphids, lerps, scales, mealybugs,
whiteflies).
Lesion A local spot of diseased tissue on a leaf,
fruit, trunk or other plant part.
Lichen A symbiotic relationship of a fungus and an
alga in which the two components are interwoven to
form what appears to be a single individual.
Life cycle The stages in the growth and development
of an organism that occur between the appearance and
the re-appearance of the same stage, eg spore, egg.
Line pattern Lines of light coloured tissue on
normal coloured leaves caused by some virus diseases.
Locust An insect belonging to the Order Orthoptera
(crickets, grasshoppers, locusts).
Looper A caterpillar that loops its body as it moves.
Lure A chemical that attracts a pest to a trap, bait or
to a lethal deposit of pesticide.
Glossary & Acronyms 477