Category Archives: sorghum

Insect pest management in sorghum – a refresher

Sorghum is most sus­cep­ti­ble to crop loss from insect pests dur­ing flow­er­ing and grain fill, and this arti­cle deals most­ly with these species (sorghum midge, heli­cov­er­pa and Ruther­glen bug). How­ev­er, some years there may be pest infes­ta­tions in veg­e­ta­tive sorghum. Veg­e­ta­tive sorghum Dur­ing the veg­e­ta­tive stages you may see a few army­worm or heli­cov­er­pa lar­vae caus­ing shot-holes in the leaves,… Read more »

Making decisions about Rutherglen bug in maturing sorghum crops

Ruther­glen bug (RGB) num­bers are per­sist­ing in many sorghum crops as they start to reach phys­i­o­log­i­cal matu­ri­ty. Queens­land Depart­ment of Agri­cul­ture and Fish­eries (DAF) research has shown no evi­dence of yield loss as a result of direct feed­ing on grain once it reach­es phys­i­o­log­i­cal matu­ri­ty (black lay­er). How­ev­er, because most crops this year have stag­gered head emer­gence, there are a… Read more »

Thrip damage to early summer crops

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Emerg­ing and veg­e­ta­tive sum­mer crops in close prox­im­i­ty to unhar­vest­ed win­ter crop are at risk of thrip dam­age, but the dam­age is large­ly cos­met­ic and rarely war­rants treat­ing. Thrips breed up in win­ter cere­als, and par­tic­u­lar­ly after rain, will move out of the win­ter crops in huge num­bers. Most of you will be famil­iar with the joys of thrips bit­ing… Read more »

Monitoring for establishment pests prior to sowing.

Where there is a his­to­ry of soil insect dam­age result­ing in poor crop estab­lish­ment a pre-sow­ing inspec­tion of the affect­ed fields is war­rant­ed to deter­mine the like­ly risk to the upcom­ing sum­mer crop. Grain baits are an effec­tive way of mon­i­tor­ing for soil-dwelling insect pests of sum­mer crops, and is prefer­able to sam­pling with a shov­el, which is both time… Read more »

Locusts and grasshoppers active across western regions and central Queensland

Locusts and grasshop­pers are active across large areas of west­ern Queens­land and NSW and cen­tral Queens­land. Reports of the Aus­tralian Plague Locust, Migra­to­ry Locusts,  Yel­low winged locust and spur-throat­ed locust have been received from areas around St George to the Cen­tral High­lands dur­ing Jan­u­ary and ear­ly Feb­ru­ary. It has been sev­er­al years since we have seen such high locust and grasshop­per… Read more »

Armyworms defoliating sorghum, millet and corn on the Downs

On the Dar­ling Downs there have been a num­ber of reports of com­mon army­worm caus­ing sig­nif­i­cant defo­li­a­tion in sorghum, corn and mil­let. Jim­bour grow­er John Alexan­der treat­ed a severe­ly defo­li­at­ed sorghum crop two weeks ago. Mil­let and corn crops in the same area have also been affect­ed. Although patchy, the out­breaks have the poten­tial to cause sig­nif­i­cant yield loss if… Read more »

Helicoverpa and midge management in sorghum

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As crops come into head and start to fill grain, sorghum midge and heli­cov­er­pa will start to infest crops. Mak­ing a deci­sion about when con­trol is war­rant­ed is made some­what eas­i­er with the avail­abil­i­ty of eco­nom­ic thresh­old cal­cu­la­tors now avail­able on the Beat­sheet Blog (; or use the ready reck­on­ers in this arti­cle. MANAGEMENT OF SORGHUM MIDGE How to count… Read more »

Management of Rutherglen bug in seedling crops, sorghum and sunflower — updated

Since ear­ly Novem­ber, large num­bers of Ruther­glen bug (RGB) have been migrat­ing into crop­ping regions from north­ern NSW through to Cen­tral Queens­land. Whilst the exact ori­gin of the bugs is unknown, it is like­ly that they are being car­ried on storm fronts from inland regions where they have bred up over win­ter and spring on native host plants that are… Read more »

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.

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 key issues rel­e­vant to deal­ing… Read more »