The DAF plant pathology team has recently identified powdery mildew and downy mildew from soybean crops growing in the Mackay region. Powdery mildew in soybean is caused by the fungus Erysiphe diffusa. This air-borne pathogen thrives in cool, humid weather. Infected plants develop symptoms initially on older leaves in the lower canopy. Whitish grey powdery patches develop on the upper… Read more »
Detections of Russian wheat aphid Diuraphis noxia (RWA) in New South Wales appeared later than usual this year. RWA was detected in Tambar Springs in northern New South Wales (NSW) in August 2023, followed by detections in the Liverpool Plains, Trangie and Moree Plains. More than 60 cereal and grass samples were collected in northern NSW between April and July… Read more »
Powdery mildew has been detected in several mungbean crops growing in southern Queensland within the last couple of weeks. Powdery mildew in mungbean is caused by the fungal species, Podosphaera xanthii and Erysiphe vignae. Two fungicide options are currently under permit to manage the disease, including tebuconazole products (PER13979 – download the permit from the APVMA portal for more details… Read more »
There have been several recent reports of fungal diseases in winter and spring crops in the northern grains region. Cereal rusts Rust has been detected in cereal crops growing in central and southern Queensland this winter/spring. Monitor crops closely, keeping an eye out for pustules on stems and leaves, and submit rust samples for pathotype testing to the University of… Read more »
Spring has sprung, and as is typical following a wetter winter, insects are abundant in crops. There are native armyworms in winter cereals from Central Queensland to northern NSW. Aphids are abundant in winter cereals, canola and faba beans. Key drivers of pest abundance in wetter seasons are the increased availability of plant hosts over winter and into spring and… Read more »
The DAF pathology team has recently received reports of ergot in sorghum panicles growing near Toowoomba in southern Queensland. Sorghum ergot is caused by the fungus Claviceps africana. The disease can result in poor seed set, lower grain quality, and can cause harvesting issues due to the sticky honeydew on sorghum panicles. Infected grain will be replaced by fungal sclerotes… Read more »
After an initial report in Sydney, faba bean aphid (FBA – Megoura crassicauda) was confirmed in September 2017 in faba beans in Tamworth and Breeza. Very few commercial faba bean crops were sown during the drought in 2018 and 2019, however seasonal conditions then improved and FBA was found in July 2020 in faba bean trials in Grafton. This infestation… Read more »
It was expected that many southern Queensland regions would be too cold for fall armyworm (FAW) (Spodoptera frugiperda) to survive. However larval populations were found in the South Burnett and Lockyer Valleys, and small numbers of moths were also detected in pheromone traps on the Darling Downs this winter. Caterpillars and moths in the South Burnett In July, larvae were… Read more »
Beet webworm (Spoladea recurvalis) moths are being seen in huge numbers in mungbean crops at present. The moths are brown with white bands across the wings, and rest with their wings swept back. Those familiar with bean podborer (Maruca vitrata) will see the similarities between the two moths – both small brown moths that move readily when disturbed. At rest,… Read more »
A plague of a native geometrid moths (Antictenia punctunculus – no common name) has visited southern Queensland, with huge numbers of moths reported. The species belongs to the twig looper family (Family Geometridae) and occurs in Queensland, New South Wales and the ACT. The moths have a 35-40 mm wingspan and distinctive colour pattern. The adults are a greyish brown… Read more »