Sensitivity of <i>Botrytis cinerea</i> to fungicides used in New Zealand wine grape spray programmes

  • R.M. Beresford The New Zealand Institute for Plant & Food Research Ltd, Mt Albert Research Centre, Private Bag 92169, Auckland 1142, New Zealand
  • P.J. Wright The New Zealand Institute for Plant & Food Research Limited, Pukekohe Research Centre, Cronin Road, RD1 Pukekohe, New Zealand
  • C.L. Middleditch The New Zealand Institute for Plant & Food Research Ltd, Mt Albert Research Centre, Private Bag 92169, Auckland 1142, New Zealand
  • M. Vergara The New Zealand Institute for Plant & Food Research Ltd, Mt Albert Research Centre, Private Bag 92169, Auckland 1142, New Zealand
  • L. Hasna The New Zealand Institute for Plant & Food Research Ltd, Mt Albert Research Centre, Private Bag 92169, Auckland 1142, New Zealand
  • P.N. Wood The New Zealand Institute for Plant & Food Research Ltd, Hawke’s Bay Research Centre, Private Bag 1401, Havelock North, Hastings 4157, New Zealand
  • R.H. Agnew The New Zealand Institute for Plant & Food Research Ltd, Marlborough Wine Research Centre, PO Box 845, Blenheim 7240, New Zealand
Keywords: Botrytis bunch rot, fungicide resistance management, cross-resistance

Abstract

Fungicide resistance development in Botrytis cinerea threatens the efficacy of anilinopyrimidine (AP) fungicides, which have been used for botrytis bunch rot control in New Zealand vineyards for about 20 years. A 2016 survey of 33 vineyards in Gisborne, Hawke's Bay and Marlborough showed that the majority of 670 isolates tested in agar-based assays were sensitive to the AP cyprodinil (EC50 < 1 mg/litre), although 18% showed low-resistance (EC50 1-10 mg/litre) and 10% showed medium-resistance (EC50 >10 mg/litre). There was high cross-resistance to the APs cyprodinil and pyrimethanil. The survey also established baseline sensitivity to the succinate dehydrogenase inhibitor (SDHI) fungicide boscalid and >90% of isolates were sensitive (EC50 < 5 mg/litre). There was a low degree of cross-resistance between the SDHIs boscalid and fluopyram. There was also high sensitivity to fludioxonil (0.009 to 0.018 mg/litre) and to fenhexamid (0.49 to 0.76 mg/litre).

Published
2017-07-26
How to Cite
Beresford, R., Wright, P., Middleditch, C., Vergara, M., Hasna, L., Wood, P., & Agnew, R. (2017). Sensitivity of <i>Botrytis cinerea</i&gt; to fungicides used in New Zealand wine grape spray programmes. New Zealand Plant Protection, 70, 285-294. https://doi.org/10.30843/nzpp.2017.70.62
Section
Vol 70 Kiwifruit & Grape Pathology 2017