Skip to main content

Cocoa-based media for culturing Phytophthora palmivora (Butl.) Butl., causal agent of black pod disease of cocoa

Abstract

Green cocoa pod husk agar (GCPA), ripe cocoa pod husk agar (RCPA), green cocoabean agar (GCBA), ripe cocoa bean agar (RCBA), green cocoa mucilage agar (GCMA)and ripe cocoa mucilage agar (RCMA) were prepared and assessd for their clarity andfor potential to support mycelial growth and sporulation of P. palmivora. Oatmeal agar (OMA), potato-dextrose agar (PDA), vegetable 8 juice agar (V8JA) and pineapple crown agar (PCA) were included for comparison. The highest radial growth rates of 8.3 and 7.2 mm/day were recorded, respectively, on OMA and GCPA but these were not significantly different (P ≤ 0 05) from each other. The two media also supported good aerial mycelial growth but were not clear. Radial mycelial growth rates of 6.5, 7.0 and 6.6 mm/day were obtained on GCMA, RCPA and V8JA, respectively, and these rates were also not significantly different from each other. Of the three media, only the GCMA was clear and supported the best aerial mycelial growth. In comparison, the RCMA supported a significantly lower radial growth (4.6 mm/day) of P. palmivora than the three media. Growth rates were least on RCBA, PCA and PDA but sporulation was poorest on PDA, PCA and V8JA. GCMA was found to be the best medium based on all the growth parameters and media characteristics. GCMA has been used effectively to isolate/detect P. palmivora from infected cocoa pod tissues. Apart from differences in radial growth rate, both the GCMA and RCMA were similar in all other respects and are recommended for culturing P. palmivora.

This is a preview of subscription content, access via your institution.

References

  1. Blencove JW, Wharton AL. Black pod disease in Ghana: Incidence of disease in relation to levels of productivity. Report of the 6th Commonwealth Mycological Conf., London, 1961: 139–147.

  2. Dakwa JT. A serious outbreak of black pod disease in a marginal area of Ghana. Proc. 10th Int. Cocoa Res. Conf., Santo Domingo, 1987: 447–541.

  3. Dakwa JT. Nationwide black pod survey. Report Cocoa Res., Inst., Ghana, 1984: 263.

  4. Erwin DC, Ribeiro OK. Growth media and methods, pp 84–95. In: Phytophthora Diseases Worldwide. St. Paul (USA): American Phytopath. Soc., 1996: 562 pp.

    Google Scholar 

  5. Englander L, Turbitt W. Increased chlamydospore production by Phytophthora cinnamomi using sterols and near-ultra violet light. Phytopathology 1979; 813–817.

  6. Luterbacher MC. The identification, epidemiology and control of Phytophthora megakarya on cocoa in West Africa. [Thesis]. London England: Univ. of London, 1994: 369 pp.

    Google Scholar 

  7. Stamps JW, Waterhouse GM, Hall GS. Revised tabular key to the species Phytophthora. Kew (England): Mycological papers No. 162, 2nd Ed. CAB Int. Mycol. Inst., 1990; 28 pp. 147

  8. Wood GAR. From harvest to store. pp 445-508. In: Cocoa 4th ed. London (England): GAR Wood and LA Lass (ed). Longman Scientific & Tech., 1985; 620 pp.

  9. Tuite J. Plant Pathological Methods, Fungi and Bacteria. Minneapolis (USA): Burges Pub. Co. 1969; 239 pp.

    Google Scholar 

  10. Johnston A, Booth C. Plant Pathologist's Pocketbook. 2nd ed. Aberystwyth (Wales): The Cambrian News Ltd. 1983; 439 pp.

    Google Scholar 

Download references

Author information

Authors and Affiliations

Authors

Rights and permissions

Reprints and Permissions

About this article

Cite this article

Awuah, R., Frimpong, M. Cocoa-based media for culturing Phytophthora palmivora (Butl.) Butl., causal agent of black pod disease of cocoa. Mycopathologia 155, 143–147 (2002). https://doi.org/10.1023/A:1020415109308

Download citation

  • Issue Date:

  • DOI: https://doi.org/10.1023/A:1020415109308

  • black pod
  • cocoa mucilage agar
  • culture media
  • Phytophthora palmivora