Use of survival analysis and space-time point pattern analysis to study the epidemiology of papaya yellow crinkle in Australia

Use of survival analysis and space-time point pattern analysis to study the epidemiology of papaya yellow crinkle in Australia

Title
Publication TypeJournal Article
Year of Publication2005
AuthorsEsker, PD, Gibb, KS, Dixon, PM, Nutter, Jr, FW
JournalPhytopathology: international journal of the American phytopathological society
Volume95
IssueSuppl. 6
PaginationS128 - S128
Date Published01/01/05
ISSN0031-949X
Abstract

The epidemiology of papaya yellow crinkle in Australia was studied by testing hypotheses regarding the influence of tomato big bud (TBB) and sweet potato little leaf V4 (SPLL-V4) phytoplasma strains, papaya plant age, and seasonal (wet/dry) effects on post-incubation time-to-death (TDD) in papaya with survival analysis. Survival analyses were applied to 36-consecutive monthly incidence assessments in a papaya plantation in the Northern Territory, Australia. These methods included Kaplan-Meier estimates of survival functions, accelerated failure time models, and Cox proportional hazards. No differences in TDD between TBB and SPLL-V4 infected papaya were observed. Moreover, neither plant age or seasonal effects influenced TDD. Post-incubation TDD ranged from 4 to 5.5 months. We also used spacetime point pattern analysis to study spatial and temporal dependence for both TBB and SPLL-V4. This approach simultaneously tests the interaction between space and time to quantify space-time windows with increased disease risk. Based on spatial analysis only, SPLL-V4 infected papaya was aggregated upwards of 30 m (10-15 plants along or across rows), whereas TBB-infected papaya was randomly dispersed. However, based on space-time analysis small-scale aggregation of infected plants (< 10 m spatially and < 5 months temporally) for TBB-infected papaya was observed.

URLhttp://espace.cdu.edu.au/view/cdu:7104

Publications

RIEL Headlines

Pages

Jump to NRBL themeJump to CMEM themeJump to FEM themeJump to SMWC themeJump to TRF themeJump to RIEL home

Innovative Research University

© 2011-2013 Charles Darwin University
Research Institute for the Environment and Livelihoods
Privacy Policy
CRICOS Provider No. 00300K | RTO Provider No. 0373

Phone (+61) 8 8946 6413
Email riel@cdu.edu.au