Abstract
Pod rot causes up to 30 % losses in world cocoa production. In order to predict the risk evolution of disease, it is important to take into consideration the developmental stage of fruits. In fact, it has been shown that the risk of attack by pod rot depends amongst others on the developmental stage of fruits. We proposed here to estimate the susceptibility at different stages. Susceptibility of fruit to disease was investigated at three fruit developmental stages (cherelle, young pod and adult pod); disease severity was assessed in laboratory conditions, on detached, artificially inoculated fruits, while disease incidence was assessed in the field, under natural inoculum pressure. In both assessment fruits at the cherelle stage were the most susceptible whereas the young and adult fruits were equally susceptible. The vertical position of the fruits on the tree did not influence their susceptibility. Estimates of the fruit susceptibility and of the infectious potential were derived from the severity and incidence measurements, using a model assuming that the number of spores on a fruit follows a Poisson distribution with the mean, the density of spores per fruit as the parameter. The estimated parameter values allowed the evaluation of the probability of attack of a fruit by the disease, which could be implemented in a disease warning system.
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References
Acebo-Guerrero, Y., Hernandez-Rodriguez, A., Heydrich-Pérez, M., El Jaziri, M., & Hernandez-Lauzardo, A. N. (2012). Management of black pod rot in cocoa (Theobroma cocoa L.): a review. Fruits, 67, 41–48.
Akrofi, A. Y., Appiarh, A. A., & Opokua, I. Y. (2003). Management of Phytophthora pod rot disease on cocoa farms in Ghana. Crop Protection, 22, 469–477.
Ando, K., Hammar, S., & Grumet, R. (2009). Age-related resistance of diverse cucurbit fruit to infection by Phytophthoracapsici. Journal of the American Society for Horticultural Science, 134, 176–182.
Berry, D. (1999). Lutte chimique raisonnée et techniques culturales. In D. Mariau (Ed.), Les maladies des cultures pérennes et tropicales (pp. 282–294). Montpellier: Cirad.
Chillet, M., Hubert, O., & Bellaire, L. D. (2007). Relationship between physiological age, ripening and susceptibility of banana to wound anthracnose. Crop Protection, 26, 1078–1082.
Cox, D. R. (1972). Regression models and life tables. Journal of the Royal Statistical Society, B, 34, 187–220.
Dacunha-Castelle, D., & Duflo, M. (1992). Probabilités et Statistiques: problèmes à temps fixe. Paris: Masson.
Deberdt, P., Mfegue, C. V., Tondje, P. R., Bon, M. C., Ducamp, M., & Hurard, C. (2007). Impact of environmental factors, chemical fungicide and biological control on cocoa pod production dynamics and black pod disease (Phytophthoramegakarya) in Cameroon. Biological Control, 44, 149–159.
Ducamp, M., Nyasse, S., Grivet, L., Thévenin, J. M., Blaha, G., Despréaux, D., & Cilas, C. (2004). Genetic diversity of cocoa tree Phytophthora pathogens. In C. Cilas & D. Despréaux (Eds.), Improvement of cocoa tree resistance to Phytophthora disease (pp. 45–75). Montpellier: CIRAD.
Efomban, M. I. B., Biyesse, D., Nyasse, S., & Eskes, A. B. (2011). Selection for resistance to Phytophthora pod rot of cocoa (Theobroma cocoa L.) in Cameroon: repeatability and reliability of screening tests and field observations. Crop Protection, 30, 105–110.
Efron, B., & Tibshirani, R. J. (1993). An introduction to the bootstrap. London: Chapman and Hall.
Kaplan, E. L., & Meier, P. (1958). Nonparametric estimation from incomplete observations. Journal of the American Statistical Association, 53, 451–481.
Martijn ten Hoopen, G., Deberdt, P., Mbenoun, M., & Cilas, C. (2012). Modelling cacao pod growth: implications for disease control. Annals of Applied Biology, 160, 260–272.
Monfort, A. (1971). Cours de statistique mathématique. Paris: Economica.
Moral, J., Bouhmidi, K., & Trapero, A. (2008). Influence of fruit maturity, cultivar susceptibility, and inoculation method on infection of olive fruit by Colletotrichum acutatum. Plant Disease, 92, 1421–1426.
Ndoumbe-Nkeng, M. (2002). Incidence des facteurs agro-écologiques sur l’épidémiologie de la pourriture brune des fruits du cacaoyer au Cameroun: contribution à la mise en place d’un modèle d’avertissement agricole. Paris, France: INA-PG, PhD thesis.
Ndoumbe-Nkeng, M., Cilas, C., Nyemb, E., Nyasse, S., Bieysse, D., Flori, A., & Sache, I. (2004). Impact of removing disease pods on cocoa black pod caused by Phythopththoramegakarya and on cocoa production in Cameroon. Crop Protection, 23, 415–424.
Ndoumbe-Nkeng, M., Efoumbagn, M. I. B., Nyasse, S., Nyemb, E., Sache, I., & Cilas, C. (2009). Relationships between cocoa Phythophthorapod rot disease and climatic variables in Cameroon. Canadian Journal of Plant Pathology, 31, 309–320.
Nyasse, S., Grivet, L., Risterucci, A. M., Blaha, G., Berry, D., Lanaud, C., & Despréaux, D. (1999). Diversity of Phytophthora megakarya in Central and West Africa revealed by isozyme and RAPD markers. Mycological Research, 103, 1225–1234.
Opoku, I. Y., Akrofi, A. Y., & Appiah, A. A. (2007). Assessment of sanitation and fungicide application directed at cocoa tree trunks for the control of Phytophthora black pod infections in pods growing in the canopy. European Journal of Plant Pathology, 117, 167–175.
Peter, M., & Gill, W. (2007). Efficient calculation of p-values in linear-statistic permutation significance tests. Journal of Statistical Computation and Simulation, 77, 55–61.
R Development Core Team. (2008). R: a language and environment for statistical computing. Vienna: R Foundation for Statistical Computing.
Soberanis, W., Rios, R., Arévalo, E., Zuniga, L., Cabezas, O., & Krauss, U. (1999). Increased frequency of phytosanitary pod removal in cacao (Theobroma cacao) increases yield economically in eastern Peru. Crop Protection, 18, 677–685.
Sonwa, D. J., Coulibaly, O., Weise, S. F., Adesina, A. A., & Janssens, M. J. J. (2008). Management of cocoa: constraints during acquisition and application of pesticides in the humid forest zones of southern Cameroon. Crop Protection, 27, 1159–1164.
Soubeyrand, S., Sache, I., Lannou, C., & Chadœuf, J. (2007). A frailty model to assess plant disease spread from individual count data. Journal of Data Science, 5, 67–83.
Xu, X. M., & Robinson, J. D. (2010). Effect of fruit maturity and wetness on the infection of apple fruit by Neonectriagalligena. Plant Pathology, 59, 542–547.
Xu, X. M., Robinson, J. D., & Berrie, A. M. (2009). Infection of blackcurrant flowers and fruits by Botrytis cinerea in relation to weahter conditions and fruit age. Crop Protection, 28, 407–413.
Acknowledgments
IRAD (Institute of Agricultural Research for Development, Cameroon), INRA (National Institute of Agricultural Research, France), ENSP (National Polytechnic Institute, Cameroon) and SCAC (Service for Cooperation and Cultural Action, French Embassy in Cameroon) are acknowledged for the support provided. Sincere thanks are expressed to the staff of the Plant Pathology Laboratory of IRAD who carried out the field and laboratory trials, as well as to Mr. Awah N. Richard who critically reviewed the manuscript.
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Soh, P.T., Ndoumbè-Nkeng, M., Sache, I. et al. Development stage-dependent susceptibility of cocoa fruit to pod rot caused by Phytophthora megakarya . Eur J Plant Pathol 135, 363–370 (2013). https://doi.org/10.1007/s10658-012-0092-4
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DOI: https://doi.org/10.1007/s10658-012-0092-4