Evaluation of Breeding Substrates for Cocoa Pollinator, Forcipomyia spp. and Subsequent Implications for Yield in a Tropical Cocoa Production System

Michael Adjaloo, Ben Kwaku Branoh Banful, William Oduro

Department of Horticulture, Faculty of Agri- culture, College of Agriculture and Natural Resources, KNUST, Kumasi, Ghana.
Department of Wildlife and Range Management, Faculty of Renewable Natural Resources, College of Agriculture and Natural Resources, KNUST, Kumasi, Ghana.
Technology Consultancy Centre, College of Engineering, KNUST, Kumasi, Ghana.

DOI: 10.4236/ajps.2013.42027                

Abstract

A comparative study was carried out to determine the most suitable substrate for breeding of midges (Forcipomyia spp.) and the implications for pollination and yield in a typical cocoa production system in the forest ecological zone of Ghana. For the field experiment, the typically available substrates in cocoa farms which were used as the treatments under cocoa trees were: 1) rotten cocoa leaf litter; 2) rotten cocoa pod husks; and 3) rotten banana pseudostem. The untreated cocoa trees served as control. The experiment was set up in a randomized complete block design with three replications. For the laboratory experiment, the design was completely randomized design with four replications. The objective was to determine which substrate best supported breeding of the midges. The rotten banana pseudostem substrate recorded the highest population (7680) of Forcipomyia spp. after 56 days of observation. The cocoa pod husk and cocoa leaf litter recorded populations of 5226 and 1920, respectively. Similar observations were recorded in the level of pollination of the cocoa trees treated with rotten banana pseudostem (95.78%), cocoa pod husks (89.05%) and cocoa leaf litter (68.42%). Application of all substrates to the cocoa tree resulted in a 77% mean reduction in flower abortion as compared to the control. Fruit abortion, on the other hand, was significantly greater in trees treated with rotten banana pseudostem (73.7%) and rotten cocoa pod husks (71.3%) than in trees treated with rotten cocoa leaf litter (54.3%). Application of banana substrate explained 88% of the variation in cherelle production (fruit set) whereas cocoa pod husks and cocoa leaf litter accounted for 71% and 94%, respectively, of the variation in cherelle production. The study concluded that although cocoa leaf litter resulted in average increases in midges population and subsequently not too high levels of pollination, there was a significantly higher number of set fruits retained which implied high cocoa pod yields. Consequently, in accordance with the observed trend cocoa leaf litter should be considered as the most appropriate substrate for midges activity in cocoa for high yields.

Keywords

Breeding; Cocoa; Pollinator; Substrates; Yield

Conflicts of Interest

The authors declare no conflicts of interest.

References

[1]	COCOBOD Report, 2012. http://www.cocobod.gh/news_details10.php
[2]	M. Asamoah and F. Baah, “Improving Research-Farmer Linkages: The Role of CRIG,” 4th International Seminar on Cocoa-Pests and Diseases (INCOPED), Accra, 19-21 October 2003.
[3]	C. Breisinger, X. Diao, S. Kolavalli and J. Thurlow, “The Role of Cocoa in Ghana’s Future Development,” Ghana Strategy Support Program (GSSP), Background Paper No. GSSP 0011, International Food Policy Research Institute, Accra, 2008.
[4]	J. Gockowski, “The Analysis of Policies, Productivity and Agricultural Transformation in the Cocoa-Producing Rural Economies of West Africa,” STCP Technical Report Executive Summary, International Institute of Tropical Agriculture, IITA-Ghana, Accra, 2007.
[5]	S. C. Harland, “Studies in Cacao. Part I. The Method of Pollination,” Annals of Applied Biology, Vol. 12, 1925, pp. 403-409.
[6]	M. M. Bos, I Steffan-Dewenter, T. Tscharntke, “Shade Tree Management Affects Fruit Abortion, Insect Pests and Pathogens of Cacao,” Agriculture, Ecosystems and Environment, Vol. 120, No. 2-4, 2007, pp. 201-205. doi:10.1016/j.agee.2006.09.004
[7]	A. F. Posnette, “The Pollination of Cacao in the Gold Coast,” Journal of Horticultural Science, Vol. 25, 1950, pp. 115-163
[8]	P. F. Entwistle, “Pests of Cocoa,” Longman, London. 1972.
[9]	T. Kaufman, “Ecology and Behaviour of Cocoa Pollinating Ceratopogonidae in Ghana, West Africa,” Environmental Entomology, Vol. 4, No. 2, 1975, pp. 347-351.
[10]	C. Cilas, “Study of Natural Cacao Pollination in Togo and Its Implication for Production,” Proceedings of the 10th International Cocoa Research Conference, Santo Domingo, 17-23 May 1987, pp. 283-286.
[11]	G. A. Ibrahim, “Effects of Insect Pollinators on Fruit Set of Cocoa Flowers,” Proceedings of the International Cocoa Research Conference, Santo Domingo, 17-23 May 1987, pp. 303-306.
[12]	A. M. Young, “The Chocolate Tree: A Natural History of Cacao,” Amazon and Co., 1994, p. 200.
[13]	A. M. Klein, B. E. Vaissiere, J. H. Cane, I. Steffan-Dewenter, S. A. Cunningham, C. Kremen and T. Tscharntke, “Importance of Pollinators in Changing Landscapes for World Crops,” Proceedings of the Royal Society of London, Vol. B274, 2007, pp. 303-313.
[14]	A. M. Klein, S. A. Cunningham, M. Bos and I. Steffan-Dewenter, “Advances in Pollination Ecology from Tropical Plantation Crops,” Ecology, Vol. 89, No. 4, 2008, pp. 935-943. doi:10.1890/07-0088.1
[15]	J. H. Groeneveld, T. Tscharntke, G. Moser and Y. Clough, “Experimental Evidence for Stronger Cacao Yield Limitation by Pollination than by Plant Resources,” Perspectives in Plant Ecology, Evolution and Systematics, Vol. 12, No. 3, 2010, pp. 183-191. doi:10.1016/j.ppees.2010.02.005
[16]	J. A. Winder and P. Silva, “Cacao Pollination: Microdiptera of Cacao Plantations and Some of Their Breeding Places,” Bulletin of Entomological Research, Vol. 61, No. 4, 1972, pp. 651-655. doi:10.1017/S0007485300047465
[17]	A. G. Stephenson, “Flower and Fruit Abortion: Proximate Causes and Ultimate Functions,” Annual Review of Ecology and Systematics, Vol. 12, 1981, pp 253-279. doi:10.1146/annurev.es.12.110181.001345
[18]	M. M. Bos, D. Veddeler, A. K. Bogdanski, A.-M. Klein, T. Tscharntke, I. Steffan-Dewenter and J. M. Tylianakis, “Caveats to Quantifying Ecosystem Services: Fruit Abortion Blurs Benefits from Crop Pollination,” Ecological Applications, Vol. 17, No. 6, 2007, pp. 1841-1849. doi:10.1890/06-1763.1
[19]	J. A. Winder, “Field Observations on Ceratopogonidae and Other Diptera: Nematocera Associated with Cocoa Flowers in Brazil,” Bulletin of Entomological Research, Vol. 67, No. 1, 1977, pp. 57-63. doi:10.1017/S0007485300010890
[20]	A. Ismail and A. G. Ibrahim, “The Potential for Ceratopogonid Midges as Insect Pollinators of Cocoa in Malaysia,” In: M. Y. Hussein and A. G. Ibrahim, Eds., Biological Control in the Tropics, Universiti Pertanian Malaysia, Serdang, 1986, pp. 471-484
[21]	A. H. Brew, “Cocoa Pod Husk as a Breeding Substrate for Forcipomyia Midges and Related Species Which Pollinate Cocoa in Ghana,” Cocoa Growers Bulletin, No. 40, 1988, pp. 40-42.
[22]	T. Kaufman, “Behavioral Biology of a Cocoa Pollinator, Forcipomyia inornatipennis (Diptera: Ceratopogonidae) in Ghana,” Journal of the Kansas Entomological Society, Vol. 47, No. 4, 1974, pp. 541-548.
[23]	A. H. Brew, “Forcipomyia Midge Species Breed in Rotten Organic Substrates,” Report of Cocoa Research Institute of Ghana1982/83-1984, 1987.
[24]	J. B. Hall and M. D. Swaine, “Distribution and Ecology of Vascular Plants in Tropical Rain Forest. Forest Vegetation in Ghana. Geobotany 1,” Dr. W. Junk Publishers, The Hague, 1981.
[25]	A. M. Young, “Cocoa Pollination,” Cocoa Growers’ Bulletin, Vol. 37, 1986, pp. 5-23.
[26]	A. M. Young, “Effects of Shade over and Availability of Midge Breeding Sites on Pollinating Midge Populations and Fruit Set in Two Cocoa Farms,” Journal of Applied Ecology, Vol. 18, No. 1, 1982, pp. 149-155. doi:10.2307/2402485
[27]	W. S. Armbruster, “Multilevel Comparative Analysis of the Morphology, Function, and Evolution of Dalechampia Blossoms,” Ecology, Vol. 69, No. 6, 1988, pp. 1746-1761. doi:10.2307/1941153
[28]	K. M. Olsen, “Pollination Effectiveness and Pollinator Importance in a Population of Heterotheca subaxillaris (Asteraceae),” Oecologia, Vol. 109, 1997, p. 114.
[29]	J. N. Holland and D. L. DeAngelis, “Ecological and Evolutionary Conditions for Fruit Abortion to Regulate Pollinating Seed-Eaters and Increase Plant Reproduction,” Theoretical Population Biology, Vol. 61, No. 3, 2002, pp. 251-263. doi:10.1006/tpbi.2001.1571
[30]	O. D. Jennersten and H. Morse, “The Quality of Pollination by Diurnal and Nocturnal Insects Visiting Common Milkweed, Asclepias syriaca,” American Midland Naturalist, Vol. 125, No. 1, 1991, pp. 18-28. doi:10.2307/2426365
[31]	J. D. Thomson and B. A. Thomson, “Pollen Presentation and Viability Schedules in Animal-Pollinated Plants: Consequences for Reproductive Success,” In: R. Wyatt Ed., Ecology and Evolution of Plant Reproduction, Chapman and Hall, New York, 1992, pp. 1-24.
[32]	K. H. Hasenstein and M. S. Zavada, “Auxin Modification of the Incompatibility Response in Theobroma cacao,” Physiologia Plantarum, Vol. 112, No. 1, 2001, pp. 113-118. doi:10.1034/j.1399-3054.2001.1120115.x
[33]	A.-A. F. de Almeida and R. R. Valle, “Ecophysiology of the Cacao Tree,” Brazilian Journal of Plant Physiology, Vol. 19, No. 4, 2007.
[34]	F. A. Bazzaz, N. R. Chiariello, P. D. Coley and F. L. Pitelka, “Allocating Resources to Reproduction and Defense: New assessments of the Costs and Benefits of Allocation Patterns in Plants Are Relating Ecological Roles to Resource Use,” BioScience, Vol. 37, No. 1, 1987, pp 58-67. doi:10.2307/1310178
[35]	A. O. Brown and J. N. McNeil, “Fruit Production in Crandberry (Ericaceae: Vaccinium macro-carpon): A Bet-Hedging Strategy to Optimize Reproductive Effort,” American Journal of Botany, Vol. 93, No. 6, 2006, pp. 910-916. doi:10.3732/ajb.93.6.910
[36]	R. R. Valle, A. A. F. De Almeida and R. M. O. Leite “Energy Costs of Flowering, Fruiting and Cherelle Wilt in Cacao,” Tree Physiology, Vol. 6, No. 3, 1990, pp. 329-336. doi:10.1093/treephys/6.3.329
[37]	M. L. Stanton, J. K. Bereczky and H. D. Hasbrouck, “Pollination Thoroughness and Maternal Yield Regulation in Wild Radish, Raphanus raphanstrum (Brassicaceae),” Oecologia, Vol. 74, No. 1, 1987, pp. 68-76. doi:10.1007/BF00377347
[38]	K. Mijayi, S. Walny, D. Silva and P. D. T. Alvim, “Longevity of Leaves of a Tropical Tree, Theobroma cacao, Grown under Shading, in Relation to Position within the Canopy and Time of Emergence,” New Phytologist, Vol. 135, No. 3, 1997, pp. 445-454. doi:10.1046/j.1469-8137.1997.00667.x
[39]	P. de T. Alvim, “Cacao,” In: P. de T. Alvim and T. T. Kozlowsky, Eds., Eco-physiology of Tropical Crops, Academic Press, London, 1977, pp. 279-313.
[40]	K. Miyaji and H. Tagawa, “Longevity and Productivity of Leaves of a Cultivated Annual, Glycine max Merrill. I. Longevity of Leaves in Relation to Density and Sowing Time,” New Phytologist, Vol. 82, 1979, pp. 233-244.
[41]	K. Miyaji, W. S. Silva and P. T. Alvim, “Logevity and Productivity of Leaves of Theobroma cacao L. in Relation to Their Position within the Canopy under Different Shading,” Abstracts of the V International Congress of Ecology, Yokohama, 1990, p. 273.
[42]	P. G. Kevan and P. P. Truman, “The Economic Impacts of Pollinator Declines: An Approach to Assessing the Consequences,” Conservation Ecology, Vol. 5, No. 1, 2001, p. 8. http://www.consecol.org/vol5/iss1/art8/
[43]	J. E. Elizondo and G. A. Enriquez, “Evaluation of 12 Different Types of Musaceae as Breeding Sites for the Cacao Pollinating Insects (Forcipomyia spp.) in Shade and Full Sun at La Lola, Costa Rica,” Proceedings of the 10th International Cocoa Research Conference, Santo Domingo, 17-23 May 1987, pp. 297-302.
[44]	E. A. Frimpong, B. Gemmill-Herren, I. Gordon and P. K. Kwapong, “Dynamics of Insect Pollinators as Influenced by Cocoa Production Systems in Ghana,” Journal of Pollination Ecology, Vol. 5, No. 10, 2011, pp. 74-80.