Tanja Gotlin Čuljak

The occurrence and distribution of potato cyst nematodes in Croatia

Potato cyst nematodes (PCN) Globodera rostochiensis (Wollenweber, 1923) Behrens, 1975 and Globodera pallida (Stone, 1973) Behrens, 1975 are the most troublesome pests of potatoes worldwide. Since 1968 there have been no investigations of the presence of PCN in ware potato lands in Croatia although these pests were recognised as an A1 plant-health quarantine species. After the first discovery of G. rostochiensis in the locality of Belica (Medjimurska County) in 2001, intensive monitoring of the distribution of PCN in Croatia started. In 2001 G. rostochiensis was detected in 55% of soil samples taken in ware potato lands. In 2002 G. rostochiensis was detected in 4.1% of soil samples and in 0.08% of soil samples in mixed populations with G. pallida. The pathotype Ro1 was found in all tested populations and Ro1 and Pa 2/3 were detected in populations from localities Vidovec, Ivanovec and Sivice. In 2003 G. rostochiensis was detected in 1.03% of soil samples, and also in 12.8% of soil samples collected in 2004. In 2003 cysts of G. rostochiensis were detected in several seed potato fields. These results indicate the urgent need for the application of further control measures to determine the presence and distribution of PCN in ware and seed potato lands in Croatia, in order to prevent the spread of PCN to non-infested areas. Integrated management strategies, neglected until 2001, have now been implemented and will prevent the build-up of infestation and replace the previous practices of monoculture, the use of short rotations and growing susceptible cultivars.

First Report of the Golden Potato Cyst Nematode, Globodera rostochiensis, in Bosnia and Herzegovina

The golden potato cyst nematode, Globodera rostochiensis (Wollenweber, 1923) Behrens, 1975, is the most problematic pest of potato (Solanum tuberosum L. subsp. tuberosum) worldwide and it is recognized as an A1 plant health quarantine species. In Bosnia and Herzegovina, there have been no surveys for the presence of potato cyst nematodes (PCN) in ware potato lands, although they have been documented in the nearby countries of Serbia and Croatia (3). To determine the presence and distribution of PCN and to prevent further spread or increase of PCN populations, a survey in ware potato land was undertaken in 2008, 2009, and 2010. Soil samples consisting of 100 cores of 4 to 5 ml of soil were taken in a grid pattern throughout the plots. Samples of approximately 500 g were processed in the laboratory. The samples were air dried and cysts were extracted using a Spearss flotation method (4) from a 100-ml subsample. Species identification was based on morphometrical characters (2) and real-time PCR where the ribosomal internal transcribed spacer (ITS5, PITSr3) region was amplified and detected by the Sequence Dection Software v1.3 (Applied Biosystems, Carlsbad, CA) (1). In 2008, soil sampling was conducted in five locations and PCN were not detected in any of 10 soil samples taken. In June 2009, 17 soil samples were collected from seven locations. Two viable cysts of G. rostochiensis were detected in one soil sample from Tihaljina (Zaside; E 6447659.560, N 4797392.101, altitude 130 m). A total of 110 soil samples were collected from 90 locations in May and June 2010. Five viable cysts of G. rostochiensis were detected in one soil sample taken from Čapljina (Opličići - Turajlovina; E 6485169, N 4775964, altitude 222 m). On the basis of the survey results, G. rostochiensis is not widely spread but the cysts are detectable, indicating that the infestation is relatively recent and that there is a threat of further spread of this quarantine species. Consequently, producers need to grow resistant potato cultivars and implement additional control measures to keep the nematode populations below damaging levels. References: (1) J. Bacic et al. Russ. J. Nematol. 16:1, 61, 2008. (2) C. C. Fleming and T. O. Powers. Potato Cyst Nematodes: Biology, Distribution and Control. R. J. Marks and B. B. Brodie, eds.CAB International, Wallingford, 1998. (3) D. Grubišic et al. J. Pest Sci. 80:21, 2007. (4) J. F. Spears. Agr. Handb. No. 353. U.S. Dep. Agric., 1968.

Attractiveness of the wheat cultivars to the aphids

Attractiveness of different wheat cultivars to aphids assessed in investigation are presented in article.