caa a22 4500 467929777 CHVBK 20180406152940.0 cr unu---uuuuu 170328e20060801xx s 000 0 eng 10.1007/s10658-006-9024-5 doi (NATIONALLICENCE)springer-10.1007/s10658-006-9024-5 Plant extracts containing caffeic acid and rosmarinic acid inhibit zoospore germination of Phytophthora spp. pathogenic to Theobroma cacao [Elektronische Daten] [Timothy Widmer, Nathalie Laurent] The three most important species of Phytophthora worldwide causing black pod disease of cacao are P. palmivora, P. megakarya, and P. capsici. Chemicals are effective in controlling this disease but more natural methods would be preferred. One alternative is to use natural plant extracts. Rosemary and lavender leaf extracts were found to be effective in reducing germination of P. capsici, P. megakarya, and P. palmivora zoospores when supplemented to agar plates at different dilutions. The extracts displayed the biggest impact on P. megakarya zoospores where it completely inhibited germination at a 25% dilution of the prepared extract. When applied to cacao leaf disks, rosemary extract reduced necrosis caused by P. megakarya zoospores. In a bioassay, pears first treated with lavender extract showed no symptoms of P. megakarya infection compared with the non-treated controls. Based upon HPLC analyses, the active compound in these extracts was determined to be caffeic acid, rosmarinic acid or some simple derivative thereof. When added to agar plates, synthetic caffeic acid and rosmarinic acid completely inhibited germination of P. capsici, P. megakarya, and P. palmivora zoospores at concentrations of 3 and 6gl−1, respectively. In addition, sage and rice bran extracts, which both contain caffeic acid, were also effective in reducing zoospore germination. In contrast, inhibition of Botrytis cinerea or Trichoderma asperellum conidia germination did not occur, displaying some level of specificity. These extracts could provide an economically safe method for reducing damage caused by black pod disease on cacao until resistant varieties are developed and released. Springer Science+Business Media, B.V., 2006 cacao nationallicence cinnamic acid nationallicence lavender nationallicence natural products nationallicence rosemary nationallicence sage nationallicence Widmer Timothy European Biological Control Laboratory, USDA/ARS, Campus International de Baillarguet, CS 90013 Montferrier sur Lez, 34988, St. Gely du Fesc, France aut Laurent Nathalie European Biological Control Laboratory, USDA/ARS, Campus International de Baillarguet, CS 90013 Montferrier sur Lez, 34988, St. Gely du Fesc, France aut European Journal of Plant Pathology Kluwer Academic Publishers 115/4(2006-08-01), 377-388 0929-1873 115:4<377 2006 115 10658 https://doi.org/10.1007/s10658-006-9024-5 text/html Onlinezugriff via DOI 1 research-article jats NATIONALLICENCE 856 40 https://doi.org/10.1007/s10658-006-9024-5 text/html Onlinezugriff via DOI NATIONALLICENCE 700 1- Widmer Timothy European Biological Control Laboratory, USDA/ARS, Campus International de Baillarguet, CS 90013 Montferrier sur Lez, 34988, St. Gely du Fesc, France aut NATIONALLICENCE 700 1- Laurent Nathalie European Biological Control Laboratory, USDA/ARS, Campus International de Baillarguet, CS 90013 Montferrier sur Lez, 34988, St. Gely du Fesc, France aut NATIONALLICENCE 773 0- European Journal of Plant Pathology Kluwer Academic Publishers 115/4(2006-08-01), 377-388 0929-1873 115:4<377 2006 115 10658 Metadata rights reserved Springer special CC-BY-NC licence nationallicence BK010053 XK010053 XK010000 NATIONALLICENCE NATIONALLICENCE NL-springer