Today grain sorghum is a major player of dryland cropping in north-east Australia, comprising 400,000-700,000 hectares annually.
Production in 2022-23 was 2.6 million tonnes whereas 40 years ago sorghum was a minor crop compared to today and yielded far lower.
Rob McCarron, Gunnedah-based territory manager with Pacific Seeds, has been in the sorghum industry for 42 years and has recently written and published The History of Grain Sorghum in Australia.
It details the dramatic productivity upgrades and highlights further ones in the pipeline.
Mr McCarron was awarded the prestigious Brownhill Cup in 2018 and has been involved in much of this research and development and provides an excellent unbiased history of the industry.
The first varieties grown in Australia were USA open pollinated ones, not broadly adapted, had small grain, unreliable yields, longer maturity and were prone to lodging.
Varieties such as Caprock, Martin, Wheatland and Alpha were mainstream until hybrids emerged in the 1960s.
Initially there were eight seed companies servicing Australian.
Early hybrids were longer maturity and had mixed yield results. Varieties like E57 were initially popular.
Better results occurred after the development of quicker maturing hybrids like Goldrush, Prize, Nugget, DK 38 and Pride.
Mr McCarron notes that hybrid releases led to a rapid sorghum expansion in NSW and Queensland.
Agronomy upgrades have played a big part of sorghum's success.
Soil moisture was often not efficiently stored, a part result of fallowing with tynes or discs.
Country often was first ploughed and sown within a few weeks.
Once hybrids became the norm, more attention was paid to agronomic aspects like conserving soil moisture and lowering seeding rates to 1.5-3 kilograms per hectare (rates of up to 11 kg/ha had been the norm).
Fertilizers to improve nutrition and herbicides for weed control became standard.
Mr McCarron reports that a big step forward was the uptake of zero tillage in the early 1980s.
This change, involving Glyphosate along with better hybrids lifted yields dramatically.
Glyphosate has a further role being used for spraying sorghum crops out, allowing an earlier and more even harvest whilst also providing a useful management tool to help avoid weather damage and downgrades.
Farmers replacing their planting equipment with precision planters was another major step forward.
Changing from combine/airseeders into planters with depth control, seed singulation and placement improved establishment and yield.
With the upgrade in farming practises, breeders refocussed to take advantage of improved stored moisture and more precise establishment with hybrids slightly longer in maturity.
A major breakthrough in the early 1980s was incorporation of midge resistance.
The first resistant hybrids had drawbacks like longer maturity, small grain and lodging issues. Breeders overcame these.
Major insecticide savings have been achieved since the release of these hybrids, coupled with an increase in production.
In the late 1990s, the introduction of insecticides on planting seed protected it from insect pests such as wireworms which causes issues with establishment.
Mr McCarron highlights some successful sorghum breeders.
Neil Muller bred hybrid MR Buster which became the industry standard for 32 years, after its release in 1991.
It combined consistent high yields coupled with midge resistance, good grain size and good standability.
Buster has been overtaken by hybrids like Resolute and Halifax which combines traits like stay green, pre and post flowering stress tolerance and limited tillering - which helps in a tight finish. These are slightly longer in maturity.
More recent releases include herbicide tolerant sorghums like Sentinel IG, having IMI tolerance (igrowth® technology) which provides more grass/weed control options. Other herbicide tolerant varieties are in the breeding programs.
Current research includes better heat and drought tolerance. Sorghum grain has far more uses today than stockfeed.
It is used for ethanol, alcohol and breakfast cereals like gluten free Weet Bix. Sorghum is proving a good break crop for cotton.
Seed companies are aiming for higher yields for dryland a well as for full irrigation. Other initiatives include sorghums for the western areas and earlier plantings.
Copies of the Rob McCarron sorghum history paper can be obtained from Pacific Seeds website pacificseeds.com.au
Next week: Climate history still important for crop and pasture decision strategies.
- Bob Freebairn is an agricultural consultant based at Coonabarabran. Email robert.freebairn@bigpond.com or contact 0428 752 149.
