Hostname: page-component-586b7cd67f-l7hp2 Total loading time: 0 Render date: 2024-12-05T02:15:11.591Z Has data issue: false hasContentIssue false

Weeds and natural enemy regulation of insect pests in upland rice; a case study from West Africa

Published online by Cambridge University Press:  09 March 2007

J.V.K. Afun
Affiliation:
Crops Research Institute, PO Box 3785, Kumasi, Ghana
D.E. Johnson
Affiliation:
Natural Resources Institute, University of Greenwich, Central Avenue, Chatham Maritime, Kent, ME4 4TB, UK
A. Russell-Smith*
Affiliation:
Natural Resources Institute, University of Greenwich, Central Avenue, Chatham Maritime, Kent, ME4 4TB, UK
*
* Fax: 01634 880066 E-mail: [email protected]

Abstract

Effects of five weed management regimes on abundance of weeds, insect pests, generalist predators and on pest damage and rice yield were investigated in upland rice in Côte d‘Ivoire over two years. In both years there was a highly significant negative correlation between weed biomass and grain yield across all treatments. Only two pest insect groups, Nephotettix spp. (Cicadellidae) and seed sucking Heteroptera, were consistently more abundant in unweeded plots and had a consistent significant positive correlation between abundance and weed biomass across all seven treatments. These polyphagous groups may have been more dependent on resources provided by weeds than the other pests studied. However, pest damage was not affected by presence or absence of weeds, suggesting that populations were below a damage threshold. Ants were the most abundant predators in the rice canopy and were most abundant in unweeded treatments. Abundance of both ants and spiders was significantly positively correlated with weed biomass across treatments. Abundance of reduviid bugs was positively correlated with weed biomass only in 1995. Any benefits due to presence of weeds in the crop were completely outweighed by loss of crop yield due to weed competition. However, if crop losses due to weeds were sufficiently reduced, it is possible that significant losses due to insect pests might emerge.

Type
Research Article
Copyright
Copyright © Cambridge University Press 1999

Access options

Get access to the full version of this content by using one of the access options below. (Log in options will check for institutional or personal access. Content may require purchase if you do not have access.)

References

Afun, J.V.K. (1997) The role of weeds in the natural control of insect pests in upland rice in Cote d'Ivoire, West Africa. 226 pp. PhD thesis, University of London.Google Scholar
Alghali, A.M. (1979) Studies on the relative susceptibility of rice varieties to Diopsis thoracica West (Diptera: Diopsidae) PhD thesis. University of Ibadan, Nigeria.Google Scholar
Altieri, M.A. (1995) Agroecology: the science of sustainable agriculture. 2nd edn, 433 pp. Boulder, Colorado, Westview Press.Google Scholar
Alteiri, M.A. & Gliessman, S.R. (1983) Effects of plant diversity on the density and herbivory of the flea beetle,Phyllotreta crucifera Goeze, in California collard (Brassica oleracea) cropping systems. Crop Protection 2, 497501.Google Scholar
Altieri, M.A. & Whitcomb, W.H. (1980) Manipulation of insect populations through seasonal disturbance of weed communities. Protection Ecology 1, 185202.Google Scholar
Altieri, M.A., Van Schoonhaven, A. & Doll, J. (1977) The ecological role of weeds in insect pest management systems: a review illustrated by bean (Phaseolus vulgaris) cropping systems. PANS 23, 195205.Google Scholar
Altieri, M.A., Wilson, R.C. & Schmidt, L.C. (1985) The effects of living mulches and weed cover on the dynamics of foliage and soil arthropod communities in three crop systems. Crop Protection 4, 201213.CrossRefGoogle Scholar
Andow, D.A. (1988) Management of weeds for insect manipulation in agroecosystems. pp. 265301in: Altieri, M.A. & Liebman, M. (Eds)Weed management in agroecosystems: ecological approaches. USA, CRC Press.Google Scholar
de Rouw, A. (1991) Influence de raccourcissement de la jachère sur l'enherbement et la conduite des systèmes de culture en zone forestière. pp. 257266in: Floret, C. & Serpantié, G. (Eds). La jachère en Afrique de l Ouest. Paris, ORSTOM.Google Scholar
Ezueh, M.I. & Amusan, L.O. (1988) Cowpea insect damage as influenced by the presence of weeds. Agriculture, Ecosystems and Environment 21, 255263.CrossRefGoogle Scholar
Heong, K.L., Aquino, G.B. & Barrion, A.T. (1991) Arthropod community structure of rice ecosystems in the Philippines. Bulletin of Entomological Research 81, 407416.Google Scholar
Lor, S.L. (1978) Ecologie des populations d'arthropodes des rizières irriguées de la region de Bouaké (Côte d'Ivoire), en considerant particulièrement Scirpophaga melanoclista Meyrick (Lepidoptera: Pyralidae) et les araignées. 150 pp. Thèse de Doctorat, Université de Paris VI.Google Scholar
Mack, T.P., Walker, R.H. & Wehtje, G. (1987) Impact of sicklepod control on several insect pests and their arthropod natural enemies in Florunner peanuts. Crop Protection 6, 185190.CrossRefGoogle Scholar
Ofuya, T.I. (1989) Effect of weeds on pre-flowering insect infestation and seed yield of cowpea (Vigna unguiculata) in a rainforest area of Nigeria. Experimental Agriculture 25, 343347.CrossRefGoogle Scholar
Ofuya, T.I. (1989) Effect of weed removal regimes on post-flowering insect damage and grain yield of cowpea, Vigna unguiculata (L.) Walp. in a rain forest area of Nigeria. Tropical Agriculture (Trinidad) 66, 142144.Google Scholar
Schoenly, K., Cohen, J.E., Hoeng, K.L., Litsinger, J.A., Aquino, G.B., Barrion, A.T. & Arida, G. (1996) Food web dynamics of irrigated rice fields at five elevations in Luzon, Philippines. Bulletin of Entomological Research 86, 451466.CrossRefGoogle Scholar
Settle, W.H., Ariawan, H., Astuti, E.T., Cahyana, W., Hakim, A.L., Hindayana, D., Lestari, A.S. & Pajarningsih, (1996) Managing tropical rice pests through conservation of generalist natural enemies and alternative prey. Ecology 77, 19751988.CrossRefGoogle Scholar
Southwood, T.R.E. (1966) Ecological methods. 391 pp. London, Methuen.Google Scholar
Topping, C.J. & Sunderland, K.D. (1994) Methods of quantifying spider density and migration in cereal crops. Bulletin of the British Arachnological Society 9, 209213.Google Scholar
Way, M.J. & Heong, K.L. (1994) The role of biodiversity in the dynamics and management of insect pests of tropical irrigated rice – a review. Bulletin of Entomological Research 84, 567587.CrossRefGoogle Scholar