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Anthracnose caused by Elsinoë ampelina is one of the most important table grape diseases in humid regions in Brazil and Australia. The objective of this study was to characterize E. ampelina isolates from Brazil and Australia by means of phylogenetic analyses, morphological features and pathogenicity tests. Phylogenetic relationships among 35 isolates were determined based on a data set of internal transcribed spacer (ITS), histone H3 (HIS3) and elongation factor 1‐α (TEF) sequences. In phylogenetic tree analyses, using a combined ITS and TEF sequence alignment, all E. ampelina isolates were clustered together in a single well‐supported clade. In contrast to the absence of genetic variability within ITS and TEF sequences, HIS3 sequences showed 54 polymorphic sites. The haplotype network generated from HIS3 data set showed four distinct haplotypes. EA1 was the predominant haplotype including 29 isolates from both countries. High genetic variability was observed in two Brazilian isolates, haplotype EA4, which may have lost the intron region during species evolution. Colony colours differed between Brazilian and Australian isolates, but showed similar wrinkled colony texture, absence of spores, sparse‐to‐absent white aerial mycelium and slow growth (0.049–0.060 mm/day). Brazilian isolates produced conidia of 5.65 × 2.65 μm, larger than conidia from Australian isolates, which measured 5.14 × 2.30 μm. In pathogenicity tests, all nine Australian isolates inoculated were pathogenic on detached canes and potted vines of table grape.

Botryosphaeria dieback, caused by species of Botryosphaeriaceae, is an important grapevine trunk disease in Australia. Inocula produced by the pathogens are primarily dispersed by rain splash and wind and infect pruning wounds leading to cankers, dieback, and eventually death of vines. The objective of this study was to develop molecular tools to detect and quantify Botryosphaeriaceae inocula from the environment. These tools are essential for investigating spore dispersal patterns of Botryosphaeriaceae pathogens in Australian vineyards. DNA extraction protocols were evaluated and one modified protocol was found suitable for extracting Botryosphaeriaceae DNA from artificially and naturally inoculated Burkard volumetric spore sampler tapes. Multispecies primers and a hydrolysis probe for quantitative PCR (qPCR) were further developed to detect and quantify Botryosphaeriaceae inocula from environmental samples. Specificity tests showed that the multispecies primers were able to amplify the DNA of 10 Botryosphaeriaceae species (58 isolates) found in Australia while none of the 27 nontarget fungal species (90 isolates) tested were amplified. The qPCR assay was suitable for amplifying purified DNA, synthetic DNA fragments (gBlocks), and mixed DNA from spore trap tapes. The qPCR method developed in this study was shown to be rapid and sensitive in detecting Botryosphaeriaceae inocula from the environment using spore traps.

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Background and Aims: Eutypa dieback is an economically important disease of grapevines and a major threat to vineyard longevity throughout the world. Developing effective preventative strategies offers the best means of control. In this study, pruning wound protectants and various spray applications were evaluated for their ability to prevent infection by ascospores of Eutypa lata. Methods and Results: Fungicides and natural alternative treatments were applied by hand to grapevine pruning wounds in winter prior to inoculation with E. lata. In a series of greenhouse and field experiments, tebuconazole, pyraclostrobin, fluazinam, garlic extract and lactoferrin significantly reduced infection. A range of tractor-driven sprayers was used to apply tebuconazole to pruning wounds, and those which provided good coverage reduced infection by E. lata to a level similar to that when tebuconazole was applied with a paintbrush. Conclusion: Eutypa dieback can be controlled with several fungicides and natural treatments. Tractor-driven sprayers, which by design or modification can efficiently deliver maximum possible coverage at high output rates, can be used for application of pruning wound treatments. Significance of the Study: Results of this study contributed to registration of fungicides for use as pruning wound treatments to control E. lata in Australia. Demonstrating the ability of tractor-driven sprayers to apply treatments effectively has led to greater industry adoption of dormant treatments and may decrease the future impact of Eutypa dieback.