John Mulhare comments on the use of TERPAL in the video below and advises farmers to apply it earlier, rather than as the flag leaf begins to emerge.
He recommends applying the growth regulator a week to 10 days after the first fungicide application. This is also typically a week to 10 days before the T2 fungicide, preferably as a stand alone application.
TERPAL should be applied to spring barley at a rate of 0.5-0.7L/ha to strengthen straw and prevent brackling or lodging, GS32/37.