Control of speckled leaf blotch of wheat with fungicides

Abstract

Two field trials were conducted in autumnsown wheat cv Domino which is highly susceptible to speckled leaf blotch in Central and South Canterbury Eighteen fungicide treatments were applied at two growth stages (tillering and ear emergence) at the manufacturers recommended rates Severity of speckled leaf blotch and other diseases was assessed on several occasions Speckled leaf blotch was severe in the South Canterbury trial but only low levels of the disease were recorded in the central Canterbury trial Most fungicides reduced disease severity and increased yield especially in the South Canterbury trial where disease pressure was highest and yield increases greater than 30 were recorded The second fungicide application appeared to provide most of the increase in yield The increases in thousand grain weights following fungicide applications contributed approximately onethird of the total yield increases in the South Canterbury trial and half in the Central Canterbury trial

Fungicide timing for the control of septoria tritici blotch of wheat

“…According to Godwin et al (1999), mixtures of azoxystrobin with a strong eradicant product such as epoxiconazole can result in improved control of STB. However, results from the present work were similar to other experiments carried out in New Zealand, where superior control of STB has been achieved using azoxystrobin alone, compared with other protectant and eradicant fungicides (Cromey et al 2000;I.C. Harvey & B. McCloy, unpubl.…”