Sorghum midge-testing scheme joins NVT
The Sorghum midge is a small but destructive pest affecting grain sorghum across northern Australia. Photo: Qld DPI
THE GRAINS Research and Development Corporation has secured the future of the sorghum midge resistance rating program, which provides independent, crucial decision-making information to growers. This program, led by the Queensland Department of Primary Industries (QDPI), is now officially part of the National Variety Trials (NVT), ensuring its place as the only source of independent sorghum-midge ratings.
Since the 1990s, QDPI has been working with industry stakeholders, including the GRDC, to develop and refine a protocol to assess midge resistance in sorghum hybrids and assign official ratings to commercial lines. After years of collaboration with NVT, its official adoption into the world’s largest independent grain crop variety evaluation initiative removes any funding uncertainty.
GRDC manager NVT – North Laurie Fitzgerald said including this data in the NVT is a logical step as it is a trusted source for growers and agronomists selecting hybrids.
"The testing regime ensures quality assurance through independently assessed, precise and consistently applied ratings," Mr Fitzgerald said. "It is the only independent and industry-accepted program, so growers should always ask for NVT midge-resistance results."
QDPI principal experimentalist Tracey Shatte said the scheme complements NVT’s multi-site hybrid testing and centralized data reporting.
"We encourage growers, agronomists, and industry stakeholders to stay informed about developments in sorghum midge resistance and use NVT results to guide planting decisions," Ms Shatte said.
Sorghum midge, or Stenodiplosis sorghicola, is a small but destructive pest affecting grain sorghum across northern Australia. It can cause severe crop losses and often necessitates multiple insecticide applications. "Sorghum midge lays eggs in crop heads during flowering, and in hybrids lacking resistance, infestations can be devastating," Ms Shatte explained.
"DPI began breeding for midge resistance in the 1970s, with the release of the first midge-resistant commercial hybrid in the mid-1980s. Today, resistance is present in all current commercial hybrids, though levels vary. This demonstrates that our work is having a significant and lasting impact."
Seed companies submit pre-commercial hybrids to the midge-testing rating scheme, where DPI assesses their resistance levels. The resulting rating helps seed companies decide whether a hybrid should move to commercialization and provides growers with insight into expected field performance.
"Midge resistance ratings give growers greater confidence when planning sowing and making spray decisions. Knowing a hybrid’s resistance level can help determine whether spraying is economically worthwhile, reducing unnecessary chemical use and input costs," Mr Fitzgerald added.
The integration into NVT ensures midge resistance testing continues under a nationally recognized framework, delivering reliable results to support hybrid selection. Established by GRDC in 2005, NVT has evolved into the largest coordinated variety trial network in the world. Each year, more than 640 trials are conducted across over 300 locations nationwide, encompassing 10 different crop species, and contributing to a database that includes more than 1.5 million plot points.
