Use of survival analysis to determine the postincubation time-to-death of papaya due to yellow crinkle disease in Australia

P Esker, Karen Gibb, Anna Padovan, P Dixon, F Nutter

    Research output: Contribution to journalArticleResearchpeer-review

    Abstract

    The current management recommendation for papaya (Carica papaya) plants exhibiting symptoms of yellow crinkle disease in Australia is the practice of ratooning infected plants. Ratooning involves removing the main stem of diseased papaya plants and allowing a lateral stem (supposedly pathogen-free) to develop and replace the diseased stem. Using nonparametric and parametric methods of survival analysis, we tested different hypotheses regarding plant factors that may influence the postincubation period survival time of phytoplasma-infected papaya. The factors included plant age, the season (wet versus dry) when papaya plants first became symptomatic, and the two predominant phytoplasma strains causing papaya yellow crinkle: tomato big bud (TBB) or sweet potato little leaf strain V4 (SPLL-V4). Median survival time was estimated to be from 4 to 5 months. Therefore, we estimated that the infectious period (incubation period plus the period from postincubation to time-to-death period) of infected papaya ranges from 6 to 9 months. Using parametric accelerated failure modeling and nonparametric Cox proportional hazard modeling, no significant improvement from a null model (no covariates) was found when analyzing plant age, the season a plant was observed to be symptomatic, or phytoplasma strain. However, the season in which a papaya plant became symptomatic differed between the two phytoplasma strains, indicating that the TBB and SPLL-V4 strains may have different modes of insect acquisition and transmission. Because of the long infectious period and the rate of plant-to-plant spread, we question the use of ratooning as the primary management tactic for managing papaya yellow crinkle. � 2006 The American Phytopathological Society.
    Original languageEnglish
    Pages (from-to)102-107
    Number of pages6
    JournalPlant Disease
    Volume90
    Issue number1
    Publication statusPublished - 2006

    Fingerprint

    papayas
    death
    Phytoplasma
    ratooning
    Carica papaya
    plant age
    sweet potatoes
    stems
    buds
    tomatoes
    signs and symptoms (plants)
    leaves
    wet season
    insects
    pathogens

    Cite this

    @article{eafd2731f88746ffa74838a45d6fa472,
    title = "Use of survival analysis to determine the postincubation time-to-death of papaya due to yellow crinkle disease in Australia",
    abstract = "The current management recommendation for papaya (Carica papaya) plants exhibiting symptoms of yellow crinkle disease in Australia is the practice of ratooning infected plants. Ratooning involves removing the main stem of diseased papaya plants and allowing a lateral stem (supposedly pathogen-free) to develop and replace the diseased stem. Using nonparametric and parametric methods of survival analysis, we tested different hypotheses regarding plant factors that may influence the postincubation period survival time of phytoplasma-infected papaya. The factors included plant age, the season (wet versus dry) when papaya plants first became symptomatic, and the two predominant phytoplasma strains causing papaya yellow crinkle: tomato big bud (TBB) or sweet potato little leaf strain V4 (SPLL-V4). Median survival time was estimated to be from 4 to 5 months. Therefore, we estimated that the infectious period (incubation period plus the period from postincubation to time-to-death period) of infected papaya ranges from 6 to 9 months. Using parametric accelerated failure modeling and nonparametric Cox proportional hazard modeling, no significant improvement from a null model (no covariates) was found when analyzing plant age, the season a plant was observed to be symptomatic, or phytoplasma strain. However, the season in which a papaya plant became symptomatic differed between the two phytoplasma strains, indicating that the TBB and SPLL-V4 strains may have different modes of insect acquisition and transmission. Because of the long infectious period and the rate of plant-to-plant spread, we question the use of ratooning as the primary management tactic for managing papaya yellow crinkle. � 2006 The American Phytopathological Society.",
    keywords = "Diseases, Plant cell culture, Plants (botany), Kaplan-Meier survival functions, Phytoplasma strains, Ratooning, Fruits, Cells, Plants, Candidatus Phytoplasma, Carica papaya, Insecta, Ipomoea batatas, Lycopersicon esculentum",
    author = "P Esker and Karen Gibb and Anna Padovan and P Dixon and F Nutter",
    year = "2006",
    language = "English",
    volume = "90",
    pages = "102--107",
    journal = "Plant Disease",
    issn = "0191-2917",
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    }

    Use of survival analysis to determine the postincubation time-to-death of papaya due to yellow crinkle disease in Australia. / Esker, P; Gibb, Karen; Padovan, Anna; Dixon, P; Nutter, F.

    In: Plant Disease, Vol. 90, No. 1, 2006, p. 102-107.

    Research output: Contribution to journalArticleResearchpeer-review

    TY - JOUR

    T1 - Use of survival analysis to determine the postincubation time-to-death of papaya due to yellow crinkle disease in Australia

    AU - Esker, P

    AU - Gibb, Karen

    AU - Padovan, Anna

    AU - Dixon, P

    AU - Nutter, F

    PY - 2006

    Y1 - 2006

    N2 - The current management recommendation for papaya (Carica papaya) plants exhibiting symptoms of yellow crinkle disease in Australia is the practice of ratooning infected plants. Ratooning involves removing the main stem of diseased papaya plants and allowing a lateral stem (supposedly pathogen-free) to develop and replace the diseased stem. Using nonparametric and parametric methods of survival analysis, we tested different hypotheses regarding plant factors that may influence the postincubation period survival time of phytoplasma-infected papaya. The factors included plant age, the season (wet versus dry) when papaya plants first became symptomatic, and the two predominant phytoplasma strains causing papaya yellow crinkle: tomato big bud (TBB) or sweet potato little leaf strain V4 (SPLL-V4). Median survival time was estimated to be from 4 to 5 months. Therefore, we estimated that the infectious period (incubation period plus the period from postincubation to time-to-death period) of infected papaya ranges from 6 to 9 months. Using parametric accelerated failure modeling and nonparametric Cox proportional hazard modeling, no significant improvement from a null model (no covariates) was found when analyzing plant age, the season a plant was observed to be symptomatic, or phytoplasma strain. However, the season in which a papaya plant became symptomatic differed between the two phytoplasma strains, indicating that the TBB and SPLL-V4 strains may have different modes of insect acquisition and transmission. Because of the long infectious period and the rate of plant-to-plant spread, we question the use of ratooning as the primary management tactic for managing papaya yellow crinkle. � 2006 The American Phytopathological Society.

    AB - The current management recommendation for papaya (Carica papaya) plants exhibiting symptoms of yellow crinkle disease in Australia is the practice of ratooning infected plants. Ratooning involves removing the main stem of diseased papaya plants and allowing a lateral stem (supposedly pathogen-free) to develop and replace the diseased stem. Using nonparametric and parametric methods of survival analysis, we tested different hypotheses regarding plant factors that may influence the postincubation period survival time of phytoplasma-infected papaya. The factors included plant age, the season (wet versus dry) when papaya plants first became symptomatic, and the two predominant phytoplasma strains causing papaya yellow crinkle: tomato big bud (TBB) or sweet potato little leaf strain V4 (SPLL-V4). Median survival time was estimated to be from 4 to 5 months. Therefore, we estimated that the infectious period (incubation period plus the period from postincubation to time-to-death period) of infected papaya ranges from 6 to 9 months. Using parametric accelerated failure modeling and nonparametric Cox proportional hazard modeling, no significant improvement from a null model (no covariates) was found when analyzing plant age, the season a plant was observed to be symptomatic, or phytoplasma strain. However, the season in which a papaya plant became symptomatic differed between the two phytoplasma strains, indicating that the TBB and SPLL-V4 strains may have different modes of insect acquisition and transmission. Because of the long infectious period and the rate of plant-to-plant spread, we question the use of ratooning as the primary management tactic for managing papaya yellow crinkle. � 2006 The American Phytopathological Society.

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    KW - Candidatus Phytoplasma

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    KW - Insecta

    KW - Ipomoea batatas

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    JO - Plant Disease

    JF - Plant Disease

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