The control of tan spot of wheat (caused by <i>Pyrenophora triticirepentis</i> a possible emerging disease in New Zealand


  • I.C. Harvey
  • R.A. Craigie
  • B.L. McCloy



Pyrenophora triticirepentis the cause of tan spot of wheat was first recorded in New Zealand in 1979 but only on wheat seed However this pathogen has recently been recorded as causing possible yield losses in isolated crops A small plot trial set up in a central Canterbury crop of cv Saracen tested several fungicides alone or in mixtures Control was not entirely effective since tan spot infection was well established when the first applications were made at GS33 (third node detectible) Nevertheless two triazoles (propiconazole and prothioconazole) and three SDHI fungicides (isopyrazam bixafen plus prothioconazole and fluxapyroxad plus epoxiconazole) all gave similar levels of control either when applied alone or in mixtures Two triazoles (epoxiconazole and difenoconazole) were less effective alone while addition of strobilurin (pyraclostrobin) to mixtures gave little extra control Several treatments showed significant increases in green leaf retention and final grain yield The life cycle of the pathogen dictates that management of the overwintering inoculum in stubble is a probable essential step in control of the disease




How to Cite

Harvey, I., Craigie, R. and McCloy, B. 2015. The control of tan spot of wheat (caused by &lt;i&gt;Pyrenophora triticirepentis&lt;/i&gt; a possible emerging disease in New Zealand. New Zealand Plant Protection. 68, (Jan. 2015), 428–433. DOI: