Parsnip Yellow Fleck Virus

The parsnip yellow fleck virus (PYFV) anthriscus strain was found in many of last season's (1998, UK) carrot crops. Symptoms on the young plant include stunting, yellowing or reddening of the foliage, wilting and in extreme cases all of the plant's foliage may die with a creamy brown stain or rot apparent when the crown of the carrot is cut. Affected plants are randomly scattered throughout the field and this is one of the distinguishing features between this virus complex and the carrot motley dwarf virus complex, which is characteristically seen in patches within the field.

In order for PYFV to be transmitted a 'helper virus' (Anthriscus yellows) is required.

'This virus is obtained when the aphids feed on indigenous Umbelliferae species such as cow parsley. The aphid loses the Anthriscus yellows virus when it feeds on the first plant so the aphid can only transmit the complex to the first plant that it feeds on and subsequent spread from plant to plant within the field is impossible. This therefore differentiates this complex from carrot motley dwarf.

Carrot roots affected by parsley yellow fleck virus may assume a cigar shape, show die back symptoms on the primary root tip or some secondary root tips and the crown when cut may reveal a brown, sometimes circular, necrotic patch or patches. These plants have later developed symptoms characteristic of crown rot.