New Zealand: Source of tomato disease outbreak a mystery

The source of a plant disease that forced the destruction of a commercial tomato crop in the Tasman district may never be known, the Ministry for Primary Industries says. Plants in three glasshouses near Nelson were destroyed before Christmas, after testing identified potato spindle tuber viroid (PTSVd). Biosecurity New Zealand director of readiness and response John Walsh said the disease source has yet to be established and “there is a possibility that we may never be able to definitively identify how the viroid entered the glasshouses”. Testing was carried out on imported tomato seed samples used to grow the infected tomatoes. All tested negative. “We are currently focusing our investigations on sampling host material from the external environment close to the infected glasshouses, and further samples will be taken this week,” Walsh said. The infected plants were destroyed and the glasshouses cleaned and disinfected. The glasshouses are now being replanted with new, ...