Invasive Species Compendium

Detailed coverage of invasive species threatening livelihoods and the environment worldwide

Abstract

Control of spot blotch in barley by fungicide applications timed according to weather factors.

Abstract

In field trials at Elora and Ailsa Craig, Ontario, barley cv. Fergus was sprayed with Bayleton (triadimefon) at growth stage 8. Triadimefon applied at doses of 140 or 250 g a.i./ha markedly suppressed the progress of spot blotch (Bipolaris sorokiniana) and delayed leaf senescence. 3 or 4 triadimefon sprays applied after periods of leaf surface wetness at more than or equal to 18 deg C of more than or equal to 14 h, more than or equal to 15 h or more than or equal to 18 h controlled spot blotch adequately and about as effectively as 6-14 sprays applied after shorter wet periods or on a weekly or twice-weekly schedule. Yields and 1000-grain wt. among plots sprayed according to various fungicide-timing programmes were similar, but were respectively 15-29% and 8-14% greater than in non-sprayed control plots. The yield differences were not statistically significant.<new para>ADDITIONAL ABSTRACT:<new para>In field trials against Bipolaris sorokiniana [Cochliobolus sativus] 3-4 leaf sprays with triadimefon (bayleton) at 140 or 250 g a.i./ha, applied after periods of leaf surface wetness at more than or equal to 18 deg C of more than or equal to 14 h, more than or equal to 15 h or more than or equal to 18 h, considerably checked disease development and delayed leaf senescence. Such sprays were as effective as 6-14 sprays applied after shorter wet periods or on a weekly or twice-weekly schedule. Yields and 1000-kernel weights were higher than in unsprayed plots. Seed infection was 18-67% with the various fungicide programmes as against 85-99% in unsprayed plots.