Helicoverpa management in chickpea – a refresher

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A comprehensive overview of Helicoverpa management in chickpea can be found in the DPI&F brochure Helicoverpa management in chickpea (2007).
Key management decisions
The following is an excerpt from the Helicoverpa management in chickpea brochure, and deals specificially with determining whether an infestation of helicoverpa warrants control – based on the economics of potential yield loss vs cost of control.

If control is warranted, which product?
There is a range of products registered for helicoverpa control in chickpea. However, the use of synthetic pyrethroids is really only an option in regions where H. punctigera dominates, or where the population is predominantly made up of larvae smaller than 5 mm in length. The use of SPs against a predominantly H. armigera population is likely to deliver a poor result in terms of control.
NPV (VivusMax) and Bt (e.g. Dipel) are two options which are effective against both species of Helicoverpa. They are most efficacious when deployed to control populations of small larvae (less than 7 mm in length), and lower pressure infestations.
Thiodicarb (Larvin) is another option, particularly where efficacy of this product in the local area is known to be high. Methomyl (Marlin®) could be considered whare large larvae are present close to harvest as it has a 1 day withholding period
Spinosad (Tracer II ™) and indoxacarb (Steward ™) are both effective against both H. armigera and H. punctigera. Remember that Steward has a cut-off for use in chickpea (15 September in CQ, 15 October in warm areas, 30 October in cool areas).
One strategy for the management of mixed age populations of helicoverpa is to use Steward™ first, if prior to cut-off, and then one of the other products if the crop needs to be sprayed again.