Field efficacy of pyraclostrobin against populations of Pyrenophora teres containing the F129L mutation in the cytochrome b gene

Abstract

Resistance of plant pathogenic fungi towards QoI fungicides is mainly caused by two mutations in the cytochrome b gene, the F129L and G143A. In Pyrenophora teres, the causal agent of net blotch in barley, only the F129L mutation could be detected up to now. To investigate the practical impact of this mutation on the field efficacy of the QoI fungicide pyraclostrobin, field trials were performed on sites with different levels of F129L in populations of P. teres. Pyraclostrobin provided very good control of net blotch disease in fields with different frequency of the F129L in populations of P. teres in 2005 and 2006. The results suggest that the field performance of pyraclostrobin is not affected by the mutation F129L.