Category Archives: Sorghum

Thresholds and changing sorghum crop value

By admin | Published: December 16, 2008
Growers and consultants need to revise the thresholds used for important insect pests of grain sorghum such as corn earworm and sorghum midge in light of lower prices currently being offered. With new crop grain sorghum prices below $200 per tonne, the break even cost of control means that higher pest numbers (density) are needed [...]
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Bring on NPV against grubs on grain sorghum

By admin | Published: November 26, 2008
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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Will Rutherglen bug damage sorghum post grain fill?

By admin | Published: January 16, 2008
As many of the early sorghum crops reach physiological maturity, and approach harvest, questions are being asked as to whether it is necessary to control large populations of nymphs in these crops. More specifically, whether these RGB will cause any damage to the maturing grain between physiological maturity and harvest. Photo: Dave Murray (BigBug) out [...]
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Watch out for midge this season

By admin | Published: January 9, 2008
Adam Hardy Senior Entomologist, Queensland Department of Primary Industries and Fisheries, Toowoomba. Photo: Adam Hardy (right) and Bernie Franzmann inspecting midge rating trials. Over the last decade sorghum midge have not caused many headaches for sorghum growers. However, staggered sorghum plantings mean that sorghum midge are likely to be found building up in numbers in later planted sorghum [...]
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Rutherglen Bug in sorghum

By admin | Published: December 21, 2007
Rutherglen bug infestations of grain sorghumThis season we are seeing large infestations of Rutherglen bug (Nysius vinitor) (RGB) in sorghum crops from Central Queensland to the Downs, and further south. The large infestations are most likely a result of storm activity and the growth of weed hosts on which they breed up. RGB are very [...]
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Getting the most from NPV sprays on grain sorghum

By admin | Published: December 14, 2007
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 than normal. [...]
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Friendly fighter conquers foe

By admin | Published: November 30, 2007
Microplitis demolitor is just one of many friendly fighters that battle to contain numbers of one of our most important pests, the corn earworm, Helicoverpa armigera. Corn earworm on grain sorghum is making its presence felt and many crops are being sprayed with Helicoverpa nucleopolyhedrovirus (NPV) to control above-threshold infestations of caterpillars. The current high value of [...]
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Corn earworm chews into sorghum profits

By admin | Published: November 16, 2007
Sorghum growers across the Darling Downs can expect to see an influx of the corn earworm, Helicoverpa armigera, in their flowering sorghum crops over the next few weeks. Growers are well equipped to deal with the problem in an environmentally friendly way. Moths are active and wanting to lay eggs on susceptible crops, and sorghum crops [...]
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No concern for tell-tale holes

By admin | Published: November 2, 2007
Corn earworm larvae on vegetative sorghum crops produce characteristic holes in the leaves after feeding in the throat of the plant. These tell-tale signs are of no great concern as this type of feeding will not affect crop yield. Caption: BEB alias Austin McLennan showing a characteristic holey sorghum leaf. The recent presence of high numbers [...]
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