Plant Protection Science, 2001 (vol. 37), issue 1

Distribution of Apple stem grooving virus in apple trees in the Czech RepublicOriginal Paper

Jaroslav Polák, Jiřina Zieglerová

Plant Protect. Sci., 2001, 37(1):1-4 | DOI: 10.17221/8360-PPS  

From 1997 to 2000 the distribution of Apple stem grooving virus (ASGV) in selected intensive apple orchards was investigated at six sites in the Czech Republic. Detection of ASGV was by ELISA. The virus was found to be commonly distributed; it was detected in over 50 % of the tested trees. Some cultivars were infected up to 100 %, while several were found to be virus-free. A high incidence of infected trees appeared in both older (20 years) and younger (7 to 8 years) orchards. This emphasizes the necessity to initiate the certification of the health condition of nursery material according to the system recommended by the EPPO.

Importance of the fungus Cytospora rubescens Fr. in relation to dieback of Sorbus aucuparia L.Original Paper

Gabriela Juhásová, Helena Ivanová

Plant Protect. Sci., 2001, 37(1):5-9 | DOI: 10.17221/8361-PPS  

During 1997-1999 the health condition of Sorbus aucuparia L. in the urban environment of the town Nitra was evaluated in relation to the type of usage or location of the trees, and occurrence, spread and harmfulness of the parasitic fungus Cytospora rubescens Fr. The developmental stages of the fungus in field and laboratory conditions, the virulence and growth rates of the mycelium isolated from trees of different usage or location was determined. The degree of damage by C. rubescens to S. aucuparia in Nitra was determined. No direct relation between degree of damage and the content of nine elements in the fungus...

Wheat leaf rust races/pathotypes in the Czech Republic in 1999-2000Original Paper

Pavel Bartoš, Alena Hanzalová, Eva Stuchlíková

Plant Protect. Sci., 2001, 37(1):10-16 | DOI: 10.17221/8362-PPS  

In 1999-2000 virulence of the wheat leaf rust population was studied on Thatcher near isogenic lines (NILs) with Lr1, Lr2a, Lr2b, Lr2c, Lr3, Lr9, Lr10 (only in 2000), Lr11, Lr15, Lr17, Lr19, Lr21, Lr23, Lr24, Lr26 and Lr28. On these NILs 11 pathotypes were determined in 1999, and 18 in 2000. All rust samples were avirulent on Lr9, Lr19, Lr24 and Lr28. There was a relatively low frequency of virulence on Lr1, Lr2a and Lr2b. Most rust samples were...

Seasonal dynamics and entomophthoralean infection of the pea aphid, Acyrthosiphon pisum HarrisOriginal Paper

Ľudovít Cagáň, Marek Barta

Plant Protect. Sci., 2001, 37(1):17-24 | DOI: 10.17221/8363-PPS  

The seasonal dynamics of the pea aphid, Acyrthosiphon pisum Harris, and entomopathogenic fungi from the order Entomophthorales attacking the aphid were analysed in alfalfa and field pea crops during the growing seasons of 1998 and 1999 at Nitra-Malanta. In both years, pea aphid populations on pea showed a pattern with one peak, culminated at flowering and pod formation. The infestation level on alfalfa was low in both years. Entomopathogenic fungi attacking the pea aphid were identified as Erynia neoaphidis Remaudičre and Hennebert and Conidiobolus obscurus (Hall and Dunn) Remaudičre and Keller. Both pathogens infected...

Fusarium species, their taxonomy, variability and significance in plant pathology - a reviewReview

Michaela Zemánková, Aleš Lebeda

Plant Protect. Sci., 2001, 37(1):25-42 | DOI: 10.17221/8364-PPS  

Fusarium Link (1809) is an anamorph genus with worldwide distribution and a remarkable degree of biodiversity. Its species are common in soil and have been found on a very wide range of vascular plants. Some specialized species are parasitic on other fungi and or insects. In the system of fungi the genus Fusarium is classified in the class Hyphomycetes which belongs to the Deuteromycotina. Teleomorphs have been placed in the genera Nectria and Gibberella, order Hypocreales (Ascomycetes). The taxonomy of the genus Fusarium is not settled and the number of species and sections varies....