Demographic and Biomass Production Consequences of Inundative Treatment of Cirsium arvense with Sclerotinia sclerotiorum
Titel:
Demographic and Biomass Production Consequences of Inundative Treatment of Cirsium arvense with Sclerotinia sclerotiorum
Auteur:
Bourdoot, G. W. Harvey, I. C. Hurrell, G. A. Saville, D. J.
Verschenen in:
Biocontrol science and technology
Paginering:
Jaargang 5 (1995) nr. 1 pagina's 11-26
Jaar:
1995-04-01
Inhoud:
The adventitious shoots in three populations of Cirsium arvense in sheep-grazed pastures were treated in October (spring) 1991 with a mycelium/wheat formulation of Sclerotinia sclerotiorum and the fates of mapped shoots were followed over the growing season. In untreated plots, deaths through natural causes were compensated for by births (emergence of new shoots above the soil) throughout the growing season, but, on plots treated with S. sclerotiorum, deaths from the induced disease exceeded births for 35 days following treatment, causing the shoot population to decline markedly. Disease-induced deaths occurred only among shoots present at the time of treatment; there was no evidence of transfer of the pathogen to shoots emerging after the treatment was applied. A life-table analysis showed that only 8% of the adventitious shoots emerging during the growing season survived to seeding on treated plots, compared with 28% on the untreated plots; most mortalities occurred in shoots at the vegetative stage of development. The dry mass of propagative roots in autumn was reduced to 35% of that on the untreated plots by the pathogen and the density of shoots emerging the following spring was reduced to a similar extent. The results of this study indicate that S. sclerotiorum has potential as a mycoherbicide for C. arvense in sheep-grazed pasture in New Zealand.