Insects other than helicoverpa are rarely a problem in chickpeas. Chickpeas secrete an organic acid (malic acid) from hairs on their leaves, stems and pods, which makes the crop unattractive to insects. Seedling pests, such as mites and cutworm, can attack chickpeas, but are seldom an economic problem.
Insect pest risk
|High risk||Moderate risk||Low risk|
||Weed free paddocks.|
|Minor pests||If paddock comes out of pasture – higher risk of soil insects||Retained cereal stubble helps to reduce aphid colonisation in wide rowed crops|
|Blue oat mite||Damaging||Present|
|Present||Present in crop but generally not damaging
|Damaging||Crop susceptible to damage and loss.|
Seedlings are most vulnerable to damage:
- before they develop three to four ‘true’ leaves
- during periods of moisture stress (too wet, too dry)
- when other factors such as low soil temperature or soil compaction limit plant growth.
Two species of helicoverpa attack chickpeas. Species composition is influenced by the time of year. In temperate regions (southern Queensland) the majority of the H. armigera population over-winter from mid-March onwards and emerge during September/October. H. punctigera is usually the dominant species through September, but seasonal variation can lead to H. armigera dominant early infestations in some years, particularly in northern districts. In Central Queensland, winter infestations in chickpeas are predominantly H. armigera.
The Helicoverpa Diapause Induction and Emergence Tool uses day length and temperature data to predict the level of diapause induction and the emergence of moths from overwintering pupae.
Key IPM strategies for Helicoverpa
- Tolerate early damage. Chickpeas can compensate for early damage by setting new buds and pods to replace those damaged by pests. Excessive early damage can delay harvest.
- Use biopesticides in vegetative chickpeas prior to flowering to preserve beneficials
- Control of helicoverpa at flowering does not result in a significant increase in yield or quality when compared to delaying control until pod-set (expanded pods).
- Aim for one well-timed spray
- Chickpea can tolerate moderate to high numbers of helicoverpa larvae (10-20 larvae/m2) through late vegetative and early flowering stages. Loss of yield and quality only occurs from pod set to maturity and this is the most critical stage for crop protection.
- Use the Beatsheet blog calculator that can be used to identify potential yield loss and provide an appropriate suggestion for action.
Factors that influence the decision, timing and product choice
- Age structure of the larval population – in relation to time to desiccation or harvest
- Proportion of H. armigera and H. punctigera
- Spray conditions and drift risk
- Insecticide options, resistance levels for Helicoverpa and recent spray results in local area.
- Residual of the products
Where both native budworm and corn earworm occur (north of Dubbo) be aware that insecticide resistance in corn earworm can affect the efficacy of SPs and OPs in mixed populations.
- Avoid prolonged use and over-reliance on any one chemical group for helicoverpa control
- Avoid use of pyrethroids on H. armigera populations wherever possible