Category Archives: NPV

Helicoverpa and NPV in Sorghum – Current Issues

As the earlier plantings of sorghum progress through flowering, moderate to high Helicoverpa pressure means that many crops have caterpillar numbers over threshold.  Nucleopolyhedrovirus (NPV) is one of the main insecticides used to control Helicoverpa larvae in sorghum, however prevailing conditions play an important role in the speed and level of control achieved with NPV. [...]
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Early Season Helicoverpa issues and the use of NPV to control larvae

Helicoverpa populations have started with a bang this season.  One or more larvae per plant are common in pre-flowering sorghum, corn and cotton. However, early flowering sorghum crops are carrying up to 10 larvae per head.  Corn and sorghum (monocot crops) host only Helicoverpa armigera, not H. punctigera – which has implications for control.  Some [...]
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Chemigation for corn earworm control

Control of corn earworm, Helicoverpa armigera, in maize has generally not been practised because of the high cost associated with repeated insecticide application required during silking. In most years it is a case of forsaking the top of every cob to larval damage However, in some years, very high pest activity results in more severe [...]
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Bring on NPV against grubs on grain sorghum

Every year caterpillars of the corn earworm (helicoverpa), Helicoverpa armigera, cause losses to sorghum crops. Regular inspection during flowering is important to detect caterpillar infestations and properly time control measures. Pre-flowering heads of grain sorghum are very attractive to egg-laying moths of the corn earworm. On any individual head, most eggs are laid prior to [...]
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Getting the most from NPV sprays on grain sorghum

Some issues have recently been raised on the Darling Downs regarding the use of Helicoverpa nucleopolyhedrovirus (NPV) against corn earworm on grain sorghum. These issues involve the delay in time to kill and the level of control not necessarily meeting growers’ expectations. Seasonal conditions The last couple of weeks on the Downs have been cooler [...]
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