Farmers may be able to reduce their herbicide spend if new spray technology that targets weeds and ensures herbicide is only applied where it is needed can be modified for Australian conditions.
At the BCG Main Field Day last week, agronomist Sam Trengove (Trengove Consulting) told farmers how German technology being trialed and ‘trained’ in Australia could open the way to variable rate (VR) herbicide application.
Mr Trengove has been working on a SA Grains Industry Trust Fund (SAGIT) project investigating the capabilities and limitations of herbicide-sensor (H-sensor) technology in Australian conditions.
“The H-sensor technology is an on-the-go weed mapping and application control system,” he said.
“It uses infra-red and near infra-red sensors to locate weeds on the basis of leaf shape, which could support site-specific weed management (SSWM).”
European developmental work with the new technology has been done in wheat, canola, corn and sugar beet and with weeds that can be quite different from those in Australia, so in addition to trialing it, Mr Trengove has been ‘training’ the technology to identify Australian weeds and Australian crops including grain legumes and barley.
“There are four components to SSWM which ideally we can achieve automatically,” Mr Trengove said.
“These include: weed identification (locate and identify); treatment decision (select the appropriate treatment to achieve control); application (apply an appropriate treatment, which could include increased crop competition through changing seeding rate); and documentation (record weed location and applied treatment).”
The H-sensor work builds on earlier research using green sensors such as Green Seeker and N Sensor that shows it is possible to accurately define weed patches in paddocks. Findings from this research were then used in work exploring agronomic or herbicide decisions that can be taken at particular crop and weed growth stages once a grower knows where they have patches of which weeds.
Mr Trengove said that while the H-sensor, developed by the German company Agri Con, has yet to be commercialised, his project was helping to provide validation of the system in crops such as lentils, chickpeas and canola, and with common problem weeds in Australian cropping systems.
“SSWM can allow the cost- effective treatment of small areas with high rates of expensive herbicides,” he said.
“The objective is to achieve the required level of weed control at no greater cost than the use of a blanket rate and ideally at less cost.
“Results have provided confidence that SSWM can allow the cost-effective treatment of small areas with high rates of expensive herbicides, rather than prioritising paddocks in order of weed burden and targeting herbicide application accordingly. Instead, each patch within each paddock can be targeted accordingly.”
An audio recording of Mr Trengove’s presentation will be available to BCG members on the BCG website. Contact Sam Trengove on 0428 262 057.
