PLANT PROTECTION 1 – Pests, Diseases and Weeds

PLANT PROTECTION 1 – Pests, Diseases and Weeds
SANITATION
LEGISLATION
WHAT IS
SANITATION?
CROP DEBRIS,
LITTER
LEGISLATIVE REQUIREMENTS include:
Sanitation measures are often part of an overall management program and
be compulsory in some situations, eg
– Codling moth
– Mediterranean and Queensland fruit flies
Method of disposal may also be prescribed by legislation, eg
– Mediterranean and Queensland fruit flies
– Citrus gall wasp
Sanitation is aimed at eliminating or reducing the amount of infested material in a
garden, nursery, orchard, glasshouse or other situation, preventing spread of pests to
other healthy plants or produce.
FRUIT, PLANTS
Infested fruit on the tree and all fallen fruit (healthy and infested) must
be removed and destroyed at regular intervals as prescribed by legislation, eg
codling moth, fruit fly.
Promptly remove and destroy all plant debris. Some insects
‘overwinter’ on crop debris and litter surrounding host plants, eg
– Mealybugs can survive on crop debris.
– Cabbage white butterfly as pupae attached to the food-plant debris.
Destroy old crops by ploughing in as soon as harvest is complete. As the
plants breakdown so do the most of the organisms that were attacking it. The
ploughed-in plant material must be fully broken down before the new crop is
planted or pests will move onto the new crop.
DESTRUCTION OF
HOST PLANTS
Cineraria leafminer
may n
weed
hosts, eg sowthistle
PRUNING
HYGIENE
IT MAY BE NECESSARY TO DESTROY HOST PLANTS
Roguing is the removal and destruction of infested plants in a crop that could
spread infestation to healthy plants within the crop, eg
– Insect populations that develop on a few plants can provide a source of
infestation for the whole crop.
– Indoor and glasshouse plants may be so badly infested with mealybugs
that chemical and other methods of control are likely to be ineffective. Their
destruction would be a necessary part of a control program.
Many plant pests ‘overwinter’ on weed hosts, alternate hosts, volunteer
seedlings and crops and are a source of infestation for commercial plantings as
they dry off. Destruction of these hosts before they seed is essential for control,
exceptions might be where these hosts support predators. Weed hosts of some
plant pests include:
Cape weed
Sowthistle, other Asteraceae
Weeds, other herbaceous plants
Grass, herbage
Unwanted and unharvested fruit trees
- Brown vegetable weevil
- Cineraria leafminer
- Twospotted mite
- Rutherglen bug
- Codling moth, fruit fly
SEVERELY INFESTED PORTIONS OF PLANTS
Pruning of severely infested parts of plants and destroying them is frequently an
effective way of coping with some pests, eg
– Callistemon tip borer
– Oriental fruit moth
– Scale infestation on ferns
WHERE APPROPRIATE (depends on the crop)
Clean and disinfect benches and floors regularly in glasshouses.
Clean equipment before moving it to clean areas.
Thoroughly clean containers and packing equipment prior to re-use.
Clean and sterilize secateurs, pruning tools and harvest utensils.
Restrict movement by vehicles and people (insects adhere to clothes).
Handle pest-free plants before handling infested plants. Wash hands.
Insects and allied pests - Integrated pest management 41