PLANT PROTECTION 1 – Pests, Diseases and Weeds

PLANT PROTECTION 1 – Pests, Diseases and Weeds
Management (IPM)
Are you a commercial grower or home gardener?
1.Obtain/prepare a plan that fits your situation.
2.Crop region. Recognize variations.
3.Identification of pest must be confirmed. Consult
a diagnostic service if necessary (page xiv).
4.Monitor pest and/or damage and record results as
recommended.
Orchards without MD need pheromone traps
and/or spray warning services (if available)
which indicate when conditions favour
infestation. Also check infestation at thinning
time, if present review program.
Orchards with MD. It is recommended that
growers use a consultant or suitably trained staff to
carry out monitoring as MD interferes with trap
catches. Efforts are being made to find more
effective attractants for monitoring.
Monitoring may be required after harvest through to
leaf fall.
5.Threshold. How much damage can you accept?
Have any thresholds been established? If so, what are
they, eg economic, aesthetic, environmental? Do you
need to calculate your own threshold?
6.Action. Decisions about some methods of control,
eg mating disruption (MD), need to be made long
before monitoring has indicated a need for an
insecticide application. Seek expert advice if unsure.
Orchards without MD or warning service,
should apply insecticides when moth activity is
first observed (usually within 14 days of petal fall,
October onwards) or if 10% of shoots are infested.
If a warning service based on trap catches is
available, intervals between applications could be
extended beyond the usual 3 weeks. Observe
withholding periods.
Orchards with MD may require spraying.
7. Evaluation. Review IPM program to see how
well it worked, eg after harvest through to leaf fall .
Control methods
Infestations should be controlled in both bearing
and young non-bearing trees as the framework of
developing trees may be seriously damaged. Also
moths may spread to adjoining mature trees.
Cultural methods. Avoid heavy pruning,
fertilizing, irrigation which promote lush growth.
Sanitation.
Damage to individual home garden trees may be
reduced by pruning off and destroying infested
tips (about 20 cm) starting in spring. This
reduces the number of 1 st generation moths.
Destroy all fallen and infested fruit on the tree
every few days (page 91, codling moth).
Remove loose or rough bark under which larvae
may pupate from the tree.
Biological control.
Natural controls. Wasps parasitize larvae and
pupae and may reduce numbers considerably.
For purchase. Mating disruption (MD).
– Pheromone lures are available for monitoring.
– Pheromones, eg Isomate OFM Rosso-S,
Isomate C/OFM TT and Disrupt-OFM , are used
commercially to control oriental fruit moth. The
pheromone is contained in a thin flexible polythene
tube with an aluminum wire for stiffness. It looks
rather like a garbage bag tie. The large quantities of
female pheromone released by the dispensers confuse
male moths, preventing them from locating and
mating with females. Dispensers are twisted around
the laterals of trees in spring, when leaf buds are
emerging from dormancy in spring. They must be
replaced with new dispensers 3 months later. All trees
in an orchard must be treated, for near perfect control
it is also necessary to treat trees adjacent to the
orchard (See Table 10 below and page 44).
– MD for OFM control has been successful over large
areas with low populations and where alternative
hosts are not present. MD can be augmented with
pesticides if populations are high. Alternate hosts
should be treated with MD to prevent migration of
mated female moths.
Resistant varieties. Fruit damage is said not
to be so common in low-chill cultivars.
Physical & mechanical methods.
Hessian or cardboard bands around trunks can be
used in a manner similar to that for codling moth.
Insecticides.
Determine the need for spray applications by
monitoring and refer to predictive models which
use temperature and other factors to predict
favourable conditions. The aim is to kill moths
as they alight on treated surfaces and caterpillars
as they crawl on the surface of the plant.
The use of pesticides to control oriental fruit
moth may reduce natural enemies of twospotted
mites increasing damage by this pest and special
attention to its control may be necessary.
Table 10. Oriental fruit moth – Some insecticides and bio-controls.
What to use?
MATING DISRUPTION (MD)
Pheromones, eg
Isomate OFM Rosso –S Pheromone Insect Confusion
agent
Isomate OFM Rosso Pheromone Insect Confusion
Agent
Isomate C/OFM TT Pheromone Insect Confusion
Agent
Disrupt-OFM Mating Disruption Agent
TRAP CATCHES NOT AVAILABLE
Group 1A, eg carbaryl (not on food-producing plants in home gardens)
Group 1B, eg Lebaycid (fenthion); Malathion (maldison)
Group 4A, eg Calypso (thiacloprid); Sumarai (clothianidin)
Group 5, eg Entrust Naturalyte Insect control (spinosad)
Group 22A, eg Avator (indoxacarb)
Group 28, eg Altacor (chlorantraniliprole)
TRAP CATCHES FROM PHEROMONE LURES
Available for monitoring only
When and how to apply?
Mating disruption of OFM has been successful where
populations of OFM are low over large areas and
alternate hosts not present. When traps indicate, apply
dispensers at the recommended number per hectare,
height and distribution in trees. Suitability depends on
size and layout of blocks. May be necessary to
supplement MD with an effective insecticide.
Follow label instructions.
Apply when moth activity is indicated
from monitoring and at recommended intervals
thereafter.
These sprays may affect predators of twopotted mite
and lightbrown apple moth.
Intervals between spraying will be longer and will
depend on trap catches.
Insects and allied pests - Lepidoptera (butterflies, moths) 95