Volume 24, Issue 4, November 2018, Pages 1834–1848
Messi Lin Marcellin1, Manga Essouma François2, Voula Audrey Valteri3, Essouma Marie-Josephe Endali4, and B.A.D. Begoude5
1 Institute of Agricultural Research for Development, Regional Biocontrol and Applied Microbiology Laboratory, PO Box. 2067, Yaoundé, Cameroon
2 University of Yaounde I, Cameroon
3 Institute of Agricultural Research for Development Central Entomology Laboratory, PO Box. 2067, Yaoundé, Cameroon
4 Institute of Agricultural Research for Development, Regional Biocontrol and Applied Microbiology Laboratory, PO Box. 2067, Yaoundé, Cameroon
5 Institute of Agricultural Research for Development, Regional Biocontrol and Applied Microbiology Laboratory, PO Box. 2067, Yaoundé, Cameroon
Original language: English
Copyright © 2018 ISSR Journals. This is an open access article distributed under the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.
In Cameroon, mycoparasitic strains of T. asperellum used in biocontrol of cocoa black pod disease have shown inconsistencies in their effectiveness. One possibility to optimize their performances is within the frames of the integrated management programme involving a combination of chemical and biological control methods. However, implementation of such an approach strongly relies on the compatibility between the biocontrol agents and the conventional synthetic fungicides. This study aimed to assess in vitro the compatibility between two antagonistic strains of T. asperellum (PR11 and PR12) and six fungicides (Ridomil, Penncozeb, Beauchamp, Nordox, Golden Blue and Kocide) approved and regularly used to control P. megakarya. These strains were cultured on PDA media supplemented with five different concentration levels (0, 0.01, 0.1, 10 and 100 % of the recommended field dose) of the above-cited fungicides. Effects on conidial germination, vegetative growth and conidial production were measured to evaluate the compatibility between the tested fungicides and the T. asperellum strains. Results showed an almost complete inhibition of conidial germination for the highest concentrations for all the fungicides. Vegetative growth and conidiogenesis were also significantly affected by the recommended field dose for all tested fungicides. The physiological parameter index used to classify compatibility showed that all tested fungicides are incompatible with both strains of T. asperellum at recommended field doses. According to the results reported in this study, the synthetic fungicides used to reduce the incidence of cocoa black pod disease have negative effects on both antagonistic T. asperellum strains PR11 and PR12. This suggests that their use in conjunction with T. asperellum as part of a disease control scheme would only be possible at sub-optimal concentrations.
Author Keywords: fungicide, biocontrol agent, compatibility, cocoa, Phytophthora megakarya.
Messi Lin Marcellin1, Manga Essouma François2, Voula Audrey Valteri3, Essouma Marie-Josephe Endali4, and B.A.D. Begoude5
1 Institute of Agricultural Research for Development, Regional Biocontrol and Applied Microbiology Laboratory, PO Box. 2067, Yaoundé, Cameroon
2 University of Yaounde I, Cameroon
3 Institute of Agricultural Research for Development Central Entomology Laboratory, PO Box. 2067, Yaoundé, Cameroon
4 Institute of Agricultural Research for Development, Regional Biocontrol and Applied Microbiology Laboratory, PO Box. 2067, Yaoundé, Cameroon
5 Institute of Agricultural Research for Development, Regional Biocontrol and Applied Microbiology Laboratory, PO Box. 2067, Yaoundé, Cameroon
Original language: English
Copyright © 2018 ISSR Journals. This is an open access article distributed under the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.
Abstract
In Cameroon, mycoparasitic strains of T. asperellum used in biocontrol of cocoa black pod disease have shown inconsistencies in their effectiveness. One possibility to optimize their performances is within the frames of the integrated management programme involving a combination of chemical and biological control methods. However, implementation of such an approach strongly relies on the compatibility between the biocontrol agents and the conventional synthetic fungicides. This study aimed to assess in vitro the compatibility between two antagonistic strains of T. asperellum (PR11 and PR12) and six fungicides (Ridomil, Penncozeb, Beauchamp, Nordox, Golden Blue and Kocide) approved and regularly used to control P. megakarya. These strains were cultured on PDA media supplemented with five different concentration levels (0, 0.01, 0.1, 10 and 100 % of the recommended field dose) of the above-cited fungicides. Effects on conidial germination, vegetative growth and conidial production were measured to evaluate the compatibility between the tested fungicides and the T. asperellum strains. Results showed an almost complete inhibition of conidial germination for the highest concentrations for all the fungicides. Vegetative growth and conidiogenesis were also significantly affected by the recommended field dose for all tested fungicides. The physiological parameter index used to classify compatibility showed that all tested fungicides are incompatible with both strains of T. asperellum at recommended field doses. According to the results reported in this study, the synthetic fungicides used to reduce the incidence of cocoa black pod disease have negative effects on both antagonistic T. asperellum strains PR11 and PR12. This suggests that their use in conjunction with T. asperellum as part of a disease control scheme would only be possible at sub-optimal concentrations.
Author Keywords: fungicide, biocontrol agent, compatibility, cocoa, Phytophthora megakarya.
How to Cite this Article
Messi Lin Marcellin, Manga Essouma François, Voula Audrey Valteri, Essouma Marie-Josephe Endali, and B.A.D. Begoude, “In vitro study of the compatibility of six fungicides with two strains of Trichoderma asperellum, biocontrol agents used against cacao black pod disease in Cameroon,” International Journal of Innovation and Applied Studies, vol. 24, no. 4, pp. 1834–1848, November 2018.
