DRY periods during the growing season in WA's grainbelt in recent years have heightened grower interest in improved diagnosis and treatment of micronutrient deficiencies, to better inform decision making.
While decision support packages are common for macronutrients including nitrogen and phosphorus, there is still some uncertainty surrounding micronutrient decision making.
A two-year project with Grains Research and Development Corporation (GRDC) investment, led by the Liebe Group, aims to determine the requirements for and benefits of micronutrient foliar application in medium-to-low rainfall areas of WA's Northern Agricultural Region.
Liebe Group executive officer Rebecca McGregor said research into micronutrients had previously been conducted in the WA grainbelt, but much of this work had been in medium to high rainfall areas in southern and central cropping regions.
"Many growers believe crop-limiting micronutrient deficiencies are occurring in their paddocks and they want to know why this is happening and what strategies or practices are needed to address this," Ms McGregor said.
She said plant tissue testing remained a critical tool for diagnosing micronutrient deficiencies but was not widely used by growers and the project aimed to increase understanding of the benefits of utilising this decision support tool.
Ms McGregor said the project was collecting and analysing plant tissue data from the region in order to gain a greater understanding of the actual scale and impact of micronutrient deficiencies.
She said 100 wheat paddocks, comprising a total of 400 sites, had been sampled across the region in 2018, a year in which most farms in the area had received good growing season rainfall.
"Plant sampling, conducted at the mid tillering stage, showed 17pc of plant samples had Zn levels considered to be marginal, with only 5pc considered deficient and 6.75pc of samples had marginal Mn levels, with 2.25pc considered deficient," she said.
"No copper deficiencies were identified in the plant sample survey."
In 2019 the project will establish a demonstration site which will explore the affect of timing and rates of foliar micronutrients (Zn, Mn and Cu) on a wheat crop in the Latham region.
