Seed transmission of Itersonilia pastinacae in parsnip and its elimination by a steam-air treatment

Abstract

The fungus Itersonilia pastinacae Channon, which causes parsnip canker, was found to persist both on the surface of parsnip seed and also in the trash associated with the seed. The fungus on the seed coat could be inactivated by chemical surface sterilization. However, to inactivate it from the trash, it was necessary to treat the seed sample with a steam-air mixture at a temperature of 45.5�C for 30 minutes.

The Survival in Soil of Itersonilia Pastinacae Channon, the Cause of Parsnip Canker

“…Infected parsnip roots obviously are an important source of carry over, in addition to infected seed (Smith 1966), unless the roots decompose rapidly and thereby expose the fungus to the lytic action of soil microorganisms. When infected roots were mutilated and placed in the soil, the survival time of the fungus was reduced to the same length as that of cultures of the organism added to soil on pieces of fibre glass.…”

“…The seedlings were grown from seed treated with an air-stream mixture at 45·5°C for 30 min to eliminate seed-borne infection with I. pastinacae (Smith 1966). Mter 21 days the roots were removed and replaced by a second batch of roots of simHar size.…”