Sampling techniques for isolating trunk disease fungi from a Nelson vineyard

Abstract

A trial was conducted of two different sampling techniques (destructive and a non destructive) undertaken at three different times to ascertain the fungal population associated with trunks of grapevines A Nelson vineyard was surveyed in October 2007 using a coring method on 5 vines and 105 vines were subsequently sampled in July and October 2008 using a crosssection sampling method Botryosphaeria Cylindrocarpon Eutypa and Phomopsis were isolated on all occasions regardless of method The detection of other fungi varied with sampling technique and time taken Differences in isolations between methods and timings of sample collection reflect the heterogeneous distribution of the fungi within the trunks of old vines The core sampling technique was sufficient to determine fungi associated with symptomatic and asymptomatic vines The more destructive technique where crosssection samples were taken gave similar results but required more resources If isolations are to be collected from vines then the method timing and sample size need to be considered and standardised