Development stage-dependent susceptibility of cocoa fruit to pod rot caused by Phytophthora megakarya. - Archive ouverte HAL Accéder directement au contenu
Article Dans Une Revue European Journal of Plant Pathology Année : 2013

Development stage-dependent susceptibility of cocoa fruit to pod rot caused by Phytophthora megakarya.

Résumé

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.

Dates et versions

hal-01190623 , version 1 (01-09-2015)

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Copyright (Tous droits réservés)

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Citer

P. Takam Soh, M. Ndoumbè-Nkeng, Ivan Sache, E.P. Ndong Nguema, H. Gwet, et al.. Development stage-dependent susceptibility of cocoa fruit to pod rot caused by Phytophthora megakarya.. European Journal of Plant Pathology, 2013, 135 (2), pp.363-370. ⟨10.1007/s10658-012-0092-4⟩. ⟨hal-01190623⟩
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