Epidemic Spread of the Rust Fungus Puccinia lagenophorae and its Impact on the Competitive Ability of Senecio vulgaris in Celeriac During Early Development
Titel:
Epidemic Spread of the Rust Fungus Puccinia lagenophorae and its Impact on the Competitive Ability of Senecio vulgaris in Celeriac During Early Development
Auteur:
Rieger, Heinz Muller-Scharer Stephanie
Verschenen in:
Biocontrol science and technology
Paginering:
Jaargang 8 (1998) nr. 1 pagina's 59-72
Jaar:
1998-03-01
Inhoud:
The 'system management approach' of biological weed control was applied in a small-scale field experiment with celeriac (root celery), intersown with an inbred line of the annual weed Senecio vulgaris L. The naturalized rust fungus Puccinia lagenophorae Cooke (Basidiomycetes: Uredinales), a common and widespread pathogen of S. vulgaris in Europe, was introduced into parts of the plots, and its impact on the competitive balance between the crop and weed in the presence and absence of an additional herbicide treatment was studied. Competition by S. vulgaris (at a realized density of only 50 plants/m2) during the first 10 weeks of growth was substantial, reducing the fresh weight of the celeriac bulbs by 28%. The epidemic spread of the rust fungus was relatively fast, and the time to infection was similar to that in full-area applications. Inoculation with the rust fungus strongly reduced crop losses due to competition with S. vulgaris . The fresh weight of the celeriac bulbs in plots with both S. vulgaris and the fungus was not statistically diVerent from the celeriac yield in plots without S. vulgaris . This eVect was mainly the result of the reduced biomass of S. vulgaris , and not reduced survival. Infected plants may, therefore, still contribute to soil cover and may help to suppress later germinating weed species. Older plant stages were found to be infected earlier than younger stages. No significant interactions were observed between the eVects of the fungal infection and a low-dose application of the herbicide chlorbromuron on weed performance. Basic studies necessary to develop the system management approach further are discussed.
Tijdschrift beschrijving