PLANT PROTECTION 1 – Pests, Diseases and Weeds

PLANT PROTECTION 1 – Pests, Diseases and Weeds
NON-SYSTEMIC & SYSTEMIC INSECTICIDES
Contact & translocated insecticides – Movement in plants
NON-SYSTEMIC
INSECTICIDES
Contact
NON-SYSTEMIC INSECTICIDES ARE NOT. ABSORBED BY THE PLANT.
They are only effective at the site of application. Contact sprays are only
effective on insects, eg scales and mealyugs that are actively moving over the
plant. Adult scales and mealybugs that have developed their waxy covering are
difficult to kill with contact pesticides.
They are sometimes called ‘preventative’ as they are often applied before the
insect has actually been found but where it is expected.
Contact sprays may be devastating to beneficial insects.
NON-SYSTEMIC. – FOLAGE, eg
Dipel , various (Bacillus thuringiensis)
Malathion , various (maldison)
Mavrik , various (tau-fluvalinate)
Pyrethrum
Success , various (spinosad)
NON-SYSTEMIC. - SOIL, eg
Garlon , various (triclopyr)
Lorsban , various (chlorpyrifos)
Malathion , various (maldison)
SYSTEMIC
INSECTICIDES
Translocated
SYSTEMIC INSECTICIDES ARE. ABSORBED BY THE PLANT.
They are carried (translocated) through the sap stream to parts remote from the
site of application where they control sap-sucking pests, eg aphids, mites, which
are actively feeding. Once the pest has stopped feeding it is too late to control it.
They can be effective against some insects already inside the plant.
The whole plant surface need not be treated, eg systemic insecticides may be
applied as foliage, root and soil or as tree injection treatments.
New developing foliage may be protected from insect attack
Systemic insecticides are not necessarily evenly distributed within the plant. Know
how a particular product moves within the plant. Penetrants are insecticides that
just penetrate the cuticle, eg Lebaycid (fenthion) will kill fruit fly eggs laid
immediately under the skin of fruit.
May control a pest more slowly than contact non-systemic insecticides.
SYSTEMIC. - FOLIAGE, eg
SYSTEMIC. – APPLIED TO SOIL, eg
Taken up by LEAVES
Confidor , various (imidacloprid)
Folimat , various (omethoate)
Pirimor , various (pirimicarb)
Rogor , various (dimethoate)
Taken up by ROOTS
Gaucho , Merit , Premise , various (imidacloprid)
Nemacur , various (fenamiphos)
Temik (aldicarb)
Excessive residues
may still occur if withholding
periods are not
observed. Washing the
outside of fruit does
not remove internal
residues. If surface
residues disappear
quickly, they will result
in minimum risk to
non-target
organisms
Systemic insecticides applied to foliage do
not generally move downwards to the roots
Once applications of systemic pesticides
have been absorbed by the plant foliage they
cannot be washed off by rain or irrigation.
When applied to the soil, systemic pesticides
dissolve in soil water and are taken up by the
roots and translocated upwards to varying
degrees within the plant. The soil must be kept
moist for continued uptake. Some systemic
insecticides applied to roots and trunks are
translocated upwards into the foliage to control
foliage-feeding insects.
Insects and allied pests - Integrated pest management 51