New guidelines show delayed fungicide and nitrogen fertiliser applications can boost crop profitability

The recommendations have emerged from targeted HRZ research funded by the Grains Research and Development Corporation (GRDC).

Nick Poole, Foundation for Arable Research (FAR), New Zealand co-ordinates FARs GRDC-funded research program in Australia, focusing on canopy management in cereals.

Mr Poole says delaying input decisions from seeding to stem elongation (Growth Stage 30-39) boosts profits because there is a more “complete picture” available on both nutritional requirements and the need for disease control.

"A foliar fungicide used at GS33-39 to control diseases such as rusts and mildew has greater economic benefit than the best upfront seed treatments or in-furrow fungicides applied alone,” Mr Poole said.

"The cause is insufficient active ingredient reaching the top three leaves of the canopy from the at-seeding treatments, a finding that was common to both barley and wheat crops.”

Mr Poole said to get the most from changing strategies HRZ growers and advisors need to be equipped with the knowledge of cereal plant growth stages at stem elongation, in particular the pseudo stem erect – first node stage (GS30 - 31) to flag leaf emergence stage of development in wheat (GS39) or first awn development in barley (GS49).

"Under high disease pressure in barley, two sprays timed at GS30-31 followed by GS49 where the first awns are emerging on the main stem should be considered over single timings or at-seeding applications.”

Mr Poole said growers should consider a disease management strategy particularly for high-yielding, disease-susceptible wheat and barley crops in southern regions of Victoria,South Australia, Western Australia and Tasmania or crops that are irrigated.

"This is particularly important if nitrogen applications are likely to exceed 60 kilograms N per hectare as nitrogen levels above this rate have been associated with greatly increased disease pressure,” he said.

The new practice also offers environmental benefits including using less fertiliser overall and lower greenhouse gas production from more efficient nitrogen use.

GRDC has invested heavily in HRZ research over the last six years to equip growers with the knowledge and practices needed to increase grain production.

Key GRDC-funded HRZ research issues include:
• the types of crops likely to maximise yield
• canopy management approaches to protecting the crop
• management of crops in raised and non-raised bed situations
• water, nutrient and chemical movement
• soil constraints to achieving potential yield

For more information, visit www.grdc.com.au.