Journal of Plant Pathology (2017) 99, 423-427

L. Ferretti, B. Corsi, L. Luongo, C. Dal Cortivo and A. Belisario (2017)
A survey of Cherry leaf roll virus in intensively managed grafted English (Persian) walnut trees in Italy
Journal of Plant Pathology 99 (2), 423-427
Abstract: Blackline disease, caused by Cherry leaf roll virus (CLRV), is considered a serious threat limiting English walnut (Juglans regia) production in Italy and worldwide if walnut species other than J. regia, e.g. 'Paradox' hybrid (J. regia × J. hindsii), French hybrid (J. regia × J. major or J. regia × J. nigra) or northern California black walnut (J. hindsii), are used as the rootstock. The virus transmissibility by pollen as well as latent infections can result in the spread of CLRV-contaminated propagative material, which is a major means of the virus dispersal by human activities. In 2014 and 2015, to ascertain the presence and the distribution of blackline symptoms in commercial orchards and to provide a description of the symptomatology, visual inspections and double antibody sandwich enzyme-linked immunosorbent assay (DAS-ELISA) analyses were carried out on 1,684 walnut trees in four different intensively managed grafted English walnut orchards in northeast Italy (Veneto region). Trees with clear blackline symptoms at the scion-rootstock junction, often associated with general decline of the plant, were found only in one commercial orchard in northeast Italy on trees older than ten years of cvs. 'Tulare' and 'Chandler', grafted onto 'Paradox' rootstock. To our knowledge, this is the first report of CLRV (blackline) decline and death in a commercial walnut orchard in Italy.
(The abstract is excluded from the Creative Commons licence and has been copied with permission by the publisher.)
Link to article at publishers website

Research topic(s) for pests/diseases/weeds:
surveys/sampling/distribution

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Pest and/or beneficial records:

Beneficial	Pest/Disease/Weed	Crop/Product	Country	Quarant.
	Nepovirus avii	Walnut/butternut (Juglans)	Italy