Australasian Plant Pathology

, Volume 19, Issue 4, pp 127–129 | Cite as

The control of black pod, canker and seedling blight of cocoa, caused by Phytophthora palmivora, with potassium phosphonate

  • R. D. Anderson
  • D. I. Guest
Efficacy

Abstract

Trunk injected potassium phosphonate (8 or 16 g a.i. per tree every 6 months) controls black pod and stem canker of cocoa: Foliar sprays of potassium phosphonate (20 g a.i. per tree every 6 months) or Ridomil Plus 72WP (0.72 g a.i. per tree every 6 weeks during the wet season) do not control black pod. Trunk injection is less weather dependent than foliar sprays, and is a more effective application method for mature trees in the cocoa growing areas of Papua New Guinea. Single Ridomil Plus 72WP (0.8%) or potassium phosphonate (4%) sprays control artificially inoculated seedling blight more effectively than either a lower rate of potassium phosphonate (0.5%) spray or a soil drench of potassium phosphonate (1%).

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References

  1. Anderson R.D., Middleton R.M. and Guest D.I. (1989)— Development of a bioassay to test the effect of phosphorous acid on black pod of cocoa. Mycological Research 93: 110–112.CrossRefGoogle Scholar
  2. Jollands P. (1985)—Black pod control using knapsack pressure sprayers. Cocoa Board of Papua New Guinea, Technical Bulletin No. 4.Google Scholar
  3. McGregor A.J. (1982)—Evaluation of fungicides for control of black pod in Papua New Guinea. Proceedings of the International Conference of Plant Protection in the Tropics. Kuala Lumpur, March 1–4, pp. 1–8.Google Scholar
  4. McGregor A.J. (1984)—Control of Phytophthora seedling blight of cocoa. Papua New Guinea Journal of Agriculture, Forestry and Fisheries 33: 39–50.Google Scholar
  5. Prior C. and Sitapai E. (1980)—Resistance of clonal cocoa in Papua New Guinea to bark canker caused by Phytophthora palmivora (Butl.) Butl. Tropical Agriculture (Trinidad) 57: 167–169.Google Scholar

Copyright information

© Australasian Plant Pathology Society 1990

Authors and Affiliations

  • R. D. Anderson
    • 1
  • D. I. Guest
    • 2
  1. 1.Cocoa Black Pod Research Trust of Papua New GuineaMadangPapua New Guinea
  2. 2.School of BotanyUniversity of MelbourneParkville

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