Effect of timing of propiconazole application on foliar disease and yield of irrigated spring wheat in Saskatchewan from 1990 to 1992

Abstract

Applications of propiconazole on spring wheat at various growth stages at Outlook, Saskatchewan showed that the optimal time to spray was between the extension of the flag leaf growth stage to the medium milk growth stage (G.S. 41–75). The maximum yield increase was about 10% on the soft white spring wheat, Fielder, compared to a 3% yield increase on the hard red spring wheat, Katepwa. The disease levels on penultimate leaves was reduced by spray applications between stem elongation and medium milk growth stages (G.S. 31–75). Most of the foliar disease was caused by Septoria spp. with S. nodorum being the most prevalent pathogen; Pyrenophora tritici-repentis was also present. Key words: Propiconazole, septoria leaf blotch, tan spot