A TRIAL is underway to test the effect of gibberellic acid on increasing head emergence in hay crops.
As part of the National Hay Agronomy project, the Department of Primary Industries and Regional Development (DPIRD) is evaluating the use of gibberellic acid at either stem elongation, flag leaf emergence or both to promote panicle emergence from the boot.
DPIRD research scientist Georgie Troup said in lower rainfall areas or when crops were sown late, particularly when the crop experiences a dry spring, it could be difficult for the panicle to emerge fully from the boot.
"When this happens the plant can continue to progress through its growth stages, which, when it progresses beyond flowering, has a detrimental effect on hay quality," Ms Troup said.
"Growers are then left with a difficult decision - to cut hay while the panicle remains partially in the boot, which in turn creates uneven curing, or to wait until the panicle emerges, and have reduced hay quality, either way the grower ends up in a difficult situation.
"Gibberellic acid is already used in grass-dominant pastures to stimulate growth for high intensity grazing, so our trials will investigate whether it is also a potential tool for use in oaten hay crops."
The trial was sown on May 8 at DPIRD's Wongan Hills research facility, with three replicates of each variety, sown in 10 metre plots.
Ms Troup said both the stem elongation and flag leaf applications of gibberellic acid have been applied.
"The visual effect of the application is apparent, and it will be interesting to see if this difference carries through to hay cutting," she said.
"It looks like it is going to yield well at Wongan Hills, I am estimating that the site could yield five to six tonnes pers hectare.
"The season appears to be closing off quite rapidly, and like all hay growers, I too would like a rainfall event in the next week to let the site reach its potential."
This is the first season that DPIRD has investigated gibberellic acid as a plant hormone for the export oaten hay industry.
