Aphid Environment & Risk Factors
Aphid populations are strongly influenced by plant growth, nutrition and environmental conditions.
Soft Growth And Nitrogen
Aphids thrive on soft, lush growth.
Risk increases when:
- Nitrogen levels are excessive
- Growth is rapid
- Plants are highly vegetative
- New flushes of growth occur
Temperature
Warm conditions generally increase aphid reproduction.
Most aphid species reproduce rapidly between 18–25°C.
Protected Crops
Protected environments favour aphid development because:
- Temperatures are stable
- Natural enemies may be absent
- Crops are available year-round
Weed Reservoirs
Many aphids survive on weeds surrounding production areas.
Practical Risk Indicators
- Rapid soft growth
- High nitrogen
- Warm weather
- Winged aphids detected
- Nearby weed hosts