This report details the outcomes of a 24-month project investigating parsnip canker.
This project carried out surveys to investigate both the cause and extent of parsnip canker in Victoria, Western Australia and Tasmania.
Parsnip canker can cause crop losses up to 80 %. Parsnip is a long-term crop, harvested after 5–7 months.Parsnip isa difficult crop to grow and there are few major growers in Australia.
Victoria produces over 80 % of the total parsnip production in Australia. Surveys of parsnip canker at harvest in 2006 and 2007 showed that canker levels peaked between September and November, on crops sown in February to March.
The peak average losses due to canker for this period were 45% for 2006 and 23% for 2007.
This represents a potential loss of A$3 million for the parsnip industry over the two years.
Several fungi were isolated from cankers and there was strong evidence that the debilitating disease is caused by more than one organism.
The fungi isolated included Itersonilia perplexans, the main cause of this disease overseas, and fungi such as Cylindrocarpon spp., Fusarium spp., Mycocentrospora acerina, Pythium spp. and Rhizoctonia spp.
Observations in the field, as well as laboratory studies, indicated that superficial damage to the roots predisposed parsnips to fungal attack and canker.
Symptoms of parsnip canker are large black lesions on mature parsnip roots, mostly on the shoulder or crown that can spread to other sections of the root and in extreme cases, cover the entire root, making the product unusable.
Information resulting from this research was presented in conference posters, at Steering Committee meetings and field days.
The researchers acknowledge the financial support for this project from Horticulture Australia Limited (HAL), AUSVEG, the Federal Government and the Department of Primary Industries.
The authors thank participating growers Peter, Darren and Paul Schreurs; Russell Lamattina, Joe Kelly, and Silvio and Glenn Favero for supplying field sites and advice.
We also thank Mark Milligan and Karl Riedel for their helpful discussions.
The input of past and current State IDO’s is gratefully acknowledged, including Alison Anderson (NSW), David Ellement (Western Australia), Craig Feutrill (South Australia), Craig Murdoch (Victoria) and Stephen Welsh (Tasmania).