TWEAKING the management of Malt barley for enhanced productivity can be done through the management of grain protein with nitrogen application according to Department of Primary Industries and Regional Development (DPIRD) senior research officer Blakely Paynter.
Mr Paynter told the audience at the GRDC Grains Research Update in Perth recently how grain protein could be lifted without applying more nitrogen but through better timing.
Research conducted in 2018 looked at the influence of nitrogen timing on grain yield and grain protein.
The research was conducted with Planet and Spartacus, which differed in their pathways to yield formation.
Previous research from 2012 to 2016 had shown that delaying nitrogen fertiliser applications from seeding to stem elongation could increase grain protein without sacrificing grain yield.
“If we got a significant amount of our nitrogen on at the Z31 stage (first node detectable) of stem elongation we could boost the protein with no yield loss,” he said.
“It’s all relative to a split treatment, so if I put 60 units of nitrogen and the applications were 20 units at seeding, 20 at mid tiller and 20 at stem elongation.
“By putting all 60 units of nitrogen up front with seeding I was 0.5 per cent lower in protein across 22 trials and if I put it all on at stem elongation I was 0.5pc higher on protein, than splitting the nitrogen evenly over those three times.”
Effectively there was no difference in yield across the trial but the difference was protein.
In terms of screenings, Mr Paynter observed that if farmers put it all upfront they had the lowest protein but the plumpest grain and if they put it all on at stem elongation, they actually had the highest protein, but there would be an increase in screenings.
Mr Paynter’s 2018 study further explores the benefits and risks of a delayed nitrogen strategy, including how late is too late for Malt barley.
Other research looked at how and when they can continue to divide and apply nitrogen to get the best crop yield, protein and screenings.
“If we didn’t put nitrogen on or limited our nitrogen we had a 30- 40pc yield decrease compared to where we put nitrogen on with the sites highly reactive to nitrogen,” Mr Paynter said.
“Shifting nitrogen from mid tiller to the Z31-Z49 stage increased grain protein and increased screenings but with no effect on yield.”
Mr Paynter said applying some at the flag leaf could provide a protein boost but it wasn’t as consistent.
“A summary from this is that applying the bulk of the nitrogen at Z31 can be enhanced by adding some of that nitrogen to the flag leaf stage,” he said.
“Shifting some of the nitrogen you are putting on early to the Z31 stage where the crop can use it can provide a protein boost in barley but you may have a screening risk.”
Mr Paynter emphasised that rates are something growers need to get right in the operation and timing will only provide the protein boost.
“Timing isn’t about maximising yield but it’s about getting the better grain quality through nitrogen application,” he said.
“Shifting nitrogen allocated for seeding or mid tiller to the period from Z31 to Z49 can boost grain protein without sacrificing grain yield, hectolitre weight or grain brightness but can increase screenings.”
Mr Paynter said Banks and Planet varieties were good options for getting the right protein window for Malt barley but neither were perfect for getting yield.
He also discussed the introduction of FlowerPower, a statistical model to predict the date of awn emergence (Z49) for barley in WA environments.
The data was developed from hill plot data between 2007 and 2018 and was validated against phenology scores from national variety trial sites in 2016-2018.
It was tested in 75 locations and 23 different varieties and predicted the optimum sowing window for Malt barley was between April 10 to July 10, assuming a wet sowing.
The software model provides a probability of stress events such as cold after and heat before flower date.