August 30, 2004
From: ProMED-mail<promed@promedmail.org>
Source: European Plant Protection Organization (EPPO), Reporting Service, 2004 No. 6 [edited]

2004/088 Situation of several quarantine pests in Croatia in 2003

The NPPO of Croatia recently informed the EPPO Secretariat of the situation of the following quarantine pests in 2003:

_Globodera rostochiensis_ [Gr] (A2 quarantine list in Croatia, EPPO A2 list)

During the 2003 growing-season, visual inspections were carried out in potato fields and soil samples collected in 17 Croatian counties (204 locations). 3200 soil samples were analysed and _Globodera rostochiensis_ [Gr] was found in 33 samples originating from 4 counties: Zagrebacka (Pecno, 8 infested samples), Varazdinska (Nova Ves, 9 samples), Primorsko-goranska (Ravna Gora, 4 samples) and Medimurska (Gardinovec and Pribislavec, 12 samples). As the pest was found for the 1st time in Nova Ves and Ravna Gora, both morphological characters and
molecular testing were used to identify cysts in these newly infested areas. Pathotypes were identified by using bioassays. Ro1, Ro2 and Ro3 were found (Ro2 and Ro3 were found only at Ivanovec). The status of Gr in Croatia is declared as follows: Present in limited areas, under surveillance.

_Globodera pallida_ (A1 quarantine list in Croatia, EPPO A2 list)

_Globodera pallida_ [Gp] was found for the 1st time in Croatia during the 2003 growing season. Systematic surveys on potato cyst nematodes were performed and included: visual inspections of potato fields, collection of
soil samples (from 17 Croatian counties - 204 locations) and analysis of 3200 samples. 33 soil samples were found infested by potato cyst nematodes.

Cysts from 3 counties (Medimurska zupanija, Varazdinska zupanija, Primorsko-goranska zupanija) were analysed using bioassays to determine pathotypes present. Gp pathotypes Pa2 and Pa3 were detected. The 1st
determination of Gp was confirmed in soil samples collected from 3 locations, all situated in the northwestern part of Croatia [(Sivice and Ivanovec (county Medimurska zupanija) and Vidovec (Varazdinska zupanija)].

The status of Gp in Croatia is declared as follows: Present, 1st found in 2003, only in the northwest region.

[Gp (syn. White cyst nematode, Potato cyst nematode) and Gr (syn. Golden nematode, Potato cyst eelworm, Potato cyst nematode, Potato nematode, Potato root eelworm, and Potato root nematode) attack potato roots, causing very significant yield reduction (up to 70 percent) over time. Cysts can remain viable for up to 30 years in some instances, are worldwide in distribution and are considered one of the most difficult plant pests to manage.

Recommended management strategies include chemical control, resistant cultivars, crop rotation and cultural control, and soil solarization and biological antagonists. Pathotypes or races are defined as follows: Ro1, Ro2 etc are Gr pathotypes and Pa 1, Pa2 etc are Gp. The greatest range of pathotypes occurs in South America, where potatoes originated and where PCN evolved in conjunction with many other solanaceous plants.

Useful references: <http://www.fao.org/DOCREP/006/Y4011E/y4011e0p.htm>
<http://www.defra.gov.uk/planth/pestpics/qic2004/QIC65.pdf> <http://plpnemweb.ucdavis.edu/nemaplex/Taxadata/G053S2.HTM#Management>
- Mod.DH]