PEST MANAGEMENT DECISION GUIDE: GREEN AND YELLOW LIST
Fall armyworm on maize
- Avoid late or off-season planting.
- Plant tolerant maize varieties (e.g. with hard husk cover to prevent the pest from penetrating)
- Regularly weed to remove alternate hosts
- Plough after infested fields are harvested
- Ensure optimum use of fertilizer for strong maize plants able to compensate for damage done
- Avoid planting new crop near infested fields
- Do not move infested maize materials from one area to another; instead feed to livestock
- Start monitoring for the pest one week after germination, continue weekly or every second week
- Monitor 10 consecutive plants in 10 locations of the field.
- Look for creamy / grey egg masses covered in a felt-like layer of grey-pink scales on the underside of leaves
- Look for caterpillars having a dark head with a distinct pale, upside-down Y-shape on the front and 4 dark spots on the second-to-last body segment; do so in early morning or evening hours
- Check for large amounts of moist sawdust-like frass near the whorl and upper leaves
- Look for small shot or large ragged and elongated holes on the leaves and inside whorls of young plants
- At early whorl stage, take action if >20% of plants are damaged or infested with larvae. At late whorl stage, if small larvae can be found then consider taking control measures if >40% of whorls are damaged. At tassel and silk stage, do not spray anymore
- Handpick and destroy caterpillars (e.g.in hot water).
- Spray neem based product
- Insecticides are most effective on young larvae and before they enter the funnel and ears.
- Spray only according to needs identified by monitoring (including decision for a second application)
- Spray early morning or late afternoon when larvae are active.
- Minimise usage of WHO class II chemicals for own safety and protection of natural enemies which will help in pest control Always check label for details and wear appropriate PPE
Bacillus thuringiensis var aizawai
WHO Class III - (slightly hazardous). PHI 1 day, REI 1 day
Spinosad (e.g. Tracer at 4ml/20L). Repeat spraying after 14 days
WHO class III (slightly hazardous). PHI 1 day, REI 12 Hours. Toxic to honey bees; avoid spraying during flowering and near water ways
Chlorantraniliprole (e.g. Corragen)
WHO Class U (Unlikely to cause hazard under normal use). PHI 21 days
Indoxacarb (e.g. Avaunt 150 SL)
WHO class II (Moderately hazardous)
Alpha-cypermethrin (e.g. Bestox 100Ec at 60 ml/20L or Tata alpha 10EC at 6ml/20L of water)
WHO class II (moderately hazardous). REI is 24hours. PHI is 21 days.
CREATED/UPDATED: March 2017/December 2017
PRODUCED BY: Plantwise
©CAB International. Published under a CC-BY-SA 4.0 licence.