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Characterizaton of the spatiotemporal attributes of sclerotinia flower blight epidemics in a perennial pyrethrum pathosystem
journal contribution
posted on 2023-05-17, 04:17 authored by Pethybridge, SJ, Hay, FS, Gent, DHSclerotinia flower blight, caused by Sclerotinia sclerotiorum, causes substantial losses in Australian pyrethrum fields. The spatiotemporal characteristics of epidemics were characterized in five fields over 3 years. Log likelihood tests indicated that the â-binomial distribution fit better than the binomial distribution for 92% of the data sets. The index of dispersion, D, was significantly greater than 1 in 97% of the data sets. The estimated parameters of the slope and intercept terms of the binary power law were 1.631 (standard error [SE] = 0.059) and 0.678 (SE = 0.099), indicating a high degree of aggregation at the individual sampling unit scale. In 69% of the data sets, the magnitude of the first-order autocorrelation coefficient , was significantly greater than 0. In 11 of the 12 epidemics, the monomolecular model provided the best fit, indicative of monocyclic processes. A significant spatial association between apothecia and incidence of Sclerotinia flower blight within the lag of one sampling unit was also quantified. This study suggests that S. sclerotiorum apothecia emergence was closely synchronized with flower development, and epidemics were dominated by localized sources of ascosporic inoculums. This research provides the basis for improved management strategies for Sclerotinia flower blight in pyrethrum
Funding
Australian Research Council
Botanical Resources Australia Pty Ltd
History
Publication title
Plant DiseaseVolume
94Issue
11Pagination
1305-1313ISSN
0191-2917Department/School
Tasmanian Institute of Agriculture (TIA)Publisher
Amer Phytopathological SocPlace of publication
3340 Pilot Knob Road, St Paul, USA, Mn, 55121Rights statement
Copyright 2010 The American Phytopathological SocietyRepository Status
- Restricted