Conference Documents: Recent submissions

Now showing items 161-180 of 597

    • Response of some tropical nitrogenfixing woody legumes to drought and inoculation with mycorrhiza 

      Awotoye, O.O.; Atayese, M.O.; Osonubi, O.; Mulongoy, K.; Okali, D.U.U. (1992)
      This paper reports on a study of the influence ofdrought and inoculation with mycorrhiza on dry-matter production, nutrient uptake and water relations of Acacia auriculiformis, Albizia lebheck. Gliricidia sepium and Leucaena leucocephala in a sterile soil. Inoculation with L. leucocephala roots containing vesicular-arbuscular mycorrhizal (VAM) fungi (Glomus and Acaulospora spp.) resulted in infection of 25-68% in regularly watered plants. Drought stress reduced infection by 8-49%. In general, VAM ...

    • Fitting soilimproving legumes into inland valley ricebased cropping systems in West Africa 

      Carsky, R.J.; Ajayi, E.O. (1992)
      Because of their favourable hydrology, the small inland valleys of West Africa offer the possibility of sustainable increases in food crop production. A key component in any sustainable cropping system is the maintenance or restoration of soil fertility. This paper explores avenues for introducing biological nitrogen fixation management into existing cropping systems. A description of one system has allowed the identification of possible niches for leguminous species. Various activities are being ...

    • Effect of fertilizatin and Rhizobium inoculation on the growth of Leucaena and Gliricidia on an Alfisol in southwestern Nigeria 

      Cobbina, J.; Mulongoy, K.; Atta-Krah, A.N. (1992)
      The aim of the research reported here was to compare the early growth and nodulation of Leucaena leucocephala and Gliricidia sepium, grown in pots containing soils of differing fertility obtained from alley farms. The plants' response to nitrogen and phosphorus fertilizers and to inoculation with rhizobia was also assessed. The application of the fertilizers, separately or combined, in the low-fertility soil increased plant height and shoot dry-matter and nitrogen yield at 84 days after planting. ...

    • Early growth and symbiotic properties of three woody legumes grown on a sandy soil in southwestern Nigeria 

      Mulongoy, K.; Owoaje, B.T. (1992)
      The early growth and symbiotic properties ofthree woody legumes, Cassia siamea, Gliricidia sepium and Leucaena leucocephala, were monitored on a farmer's field and in the screenhouse using the same soil. L. leucocephala and G.. septum nodulated freely and were heavily infected by native vesicular-arbuscular mycorrhizal fungi. Six months after planting, G. sepium had the highest dry-matter production, percentage of mycorrhizal infection, nodule number, dry weight and nitrogenase activity per plant ...

    • Biological nitrogen fixation in trees in agroecosystems: twenty years of biological nitrogen fixation research in Africa. 

      Danso, S.K.A. (1992)
      With the low input of fertilizers into African farming systems, it is necessary to harness biological nitrogen fixation to its fullest extent. The greatest potential, at least in the short term, lies in nitrogen fixation in grain and pasture legumes and in nitrogen-fixing trees. To maximise nitrogen fixation in these plants and under various cropping systems requires intensified research. Inoculation techniques and inoculum production in Africa are not yet advanced, and this is unlikely to change ...

    • Potential role of transgenic approaches in the control of cowpea insect pests 

      Machuka, J. (2002)
      Crops' incompatibility makes conventional breeding approaches untenable in transferring available insect resistance From wild Vigna sp. into cowpea. The alternative recourse is to isolate and transfer alien resistance genes using genetic transformation. This has the added advantage of using useful genes from distantly related organisms to control cowpea pests. Artificial diet bioassays carried out on the Maruca pod borer, pod sucking bugs, and cowpea weevils indicate that these insects can be ...

    • Insecticidal activities of the African yam bean seed lectin on the development of the cowpea beetle and the pod sucking bug 

      Okeola, O.G.; Machuka, J.; Fasidi, I.O. (2002)
      The cowpea beetle, Callosobruchus maculatus, and pod-sucking bug, Clavigralla tomentosicollis, are two of the major insect pests of cowpea in Africa. A lectin was purified from the seeds of the African yam bean (AYB), Sphenostylis stenocarpa, by affinity chromatography on Galactosc-Sepharose 4B. The purified AYB lectin (AYBL) was tested on the two insect pests of cowpea. When C. maculatus larvae were fed on artificial cowpea seed containing 0.2, 2, and 5% (w/w) of dietary lectin, larval mortality ...

    • Regeneration and genetic transformation in cowpea 

      Machuka, J.; Adesoye, A.; Obembe, O.O. (2002)
      Over the last three decades, sporadic efforts have been made to develop regeneration and transformation systems in cowpea ( Vigna unguiculata L. Walp). This paper reviews the progress made to date, including highlights of culture media and explants used for regeneration and chimeric gene constructs employed in transformations. Progress has been slow, mainly due to limited resources, since very few laboratories have been involved. There is an urgent need for more focused and consistent efforts to ...

    • Breeding cowpea varieties for resistance to Striga gesnerioides and Alectra vogelii 

      Singh, B.B. (2002)
      Two parasitic flowering plants, Striga gesnerioides (Wild.) Vatke and Alectra vogelii (Benth.), cause substantial yield reduction in cowpea in the dry savannas of sub-Saharan Africa. Alectra is more prevalent in the northern Guinea savanna and southern Sudan savanna of West Africa, as well as in East and southern Africa whereas Striga is mostly found in West and Central Africa. However, both are fast spreading beyond these limits. Collaborative studies with national and regional programs have ...

    • Recent genetic studies in cowpea 

      Singh, B.B. (2002)
      A number of recent studies have added further information on the genetics of important traits in cowpea. These include inheritance of qualitative traits such as plant pigmentation; flower color; seed color; seed coat texture; resistance to rust, scab, smut, nematode, severe mosaic virus, Striga, Alectra, aphid, bruchid, heat; drought tolerance; and male sterility, and quantitative traits such as protein content, seed size, seed yield, and fodder quality. A few studies on linkage and mapping have ...

    • Development of drought resistant and water stress tolerant crops through traditional breeding 

      Ortiz, R.; Ekanayake, I.J.; Mahalakshmi, V.; Kamara, A.; Menkir, A.; Nigan, S.N.; Singh, B.B.; Saxena, N.P. (2002)

    • Improving cowpea cereals based cropping systems in the dry savannas of West Africa 

      Singh, B.B.; Ajeigbe, Hakeem A. (2002)
      Most of the farmers in the dry savannas of West Africa 'plant local varieties of cowpea, millet, sorghum, and groundnut in various intercropping systems with little or no purchased inputs. In this system, the cowpea and groundnut yields are low due to shading by cereals and lack of plant protection measures. The cereal yields are low mainly due to lack of fertilizer. Efforts are being made, therefore, to develop a combination of improved varieties and improved cropping systems for higher productivity ...

    • Recent progress in cowpea breeding 

      Singh, B.B.; Ehlers, J.D.; Sharma, B.; Freire Filho, F.R. (2002)
      Considerable progress has been made in breeding improved cowpea varieties in the last five years. The major breeding objectives were to develop high yielding cowpea varieties for sole cropping as well as intercropping with acceptable seed types and resistance to major diseases, insect pests, nematodes, and the parasitic plants Striga and Alectra and tolerance to heat and drought. Good progress was also made in breeding early maturing grain type, dual pupose, and fast growing fodder type cowpea ...

    • Advances in cowpea cropping systems research 

      Olufajo, O.O.; Singh, B.B. (2002)
      Cowpea (Vigna unguiculata) [L.] Walp.) is a major component of the traditional cropping systems in Africa, Asia, and Central and South America where it is widely grown in mixtures with other crops in various combinations. The productivity of cowpea in these mixtures is low, mainly due to low plant population, competition under intercropping, and lack of crop protection measures. Studies have shown that the productivity of cowpea in these systems could be enhanced through the use of improved ...

    • Recent advances in breeding maize for resistance to Striga hermonthica (Del.) Benth 

      Menkir, A.; Kling, J.G.; Badu-Apraku, B.; The, C.; Ibikunle, O. (2002)
      Striga represents the largest biological threat to cereal production in sub-Saharan Africa. Breeding for resistance to Striga has been the focal point of IITA to reduce the impact of this parasite on maize production. The early breeding work at IITA focused on search for tolerance to Striga. IITA has made a significant shift in emphasis towards selection of resistant maize genotypes that support a reduced number of Striga plants since the early 1990s. Population improvement and the inbred-hybrid ...

    • RUSEP: marketled agricultural technology transfer and commercialization in Abia State, Nigeria 

      Kormawa, P.M.; Ezedinma, C.I.; Makinde, K.; Adekunle, A.; Chianu, J. (2002)
      RUSEP is the latest attempt by the federal government of Nigeria to alleviate poverty through the transfer of market-driven agricultural technology to farmers and the commercialization of agriculture in selected states in Nigeria. Through this project, employment will be generated through enhanced agricultural enterprises. Abia state in the south East was chosen as one of the pilot states. The needs assessment study provides information on existing and available improved technologies and level of ...

    • A participatory appraisal of Imperata management strategies for sustainable land use in the subhumid savanna of Nigeria 

      Kormawa, P.; Ellis-Jones, J.; Ibana, S.; Chikoye, D.; Schultz, S.; Nielsen, O.K.; Douthwaite, Boru; Udensi, U. (2002)
      Increasing spread of Imperata in the sub-humid Savannah of Nigeria has had many neg- ative results threatening the sustainability of the natural resource base and livelihood of farmers. A community-based participatory approach (PA) was conducted to identify cur- rent and alternative technologies for controlling Imperata , which support sustainable land use. The PA involved Imperata infestation mapping, livelihood analysis, wealth ranking, crops and constraint prioritisation as well as farmers' ...

    • La pratique de la jachere en Afrique tropicale: ccomparee au Nigeria et au Cameroun 

      Nkamleu, G.B.; Kamajou, F.; Gockowski, J. (2000)
      In sub-Saharan Africa, intensification of agriculture and rational use of arable land are essential for long-term growth (Gros, 1979, Johnston, 1990, Oluf et al., 990). Extensive cultivation methods and the population explosion are pushing the limits of cultivated land every day; deforestation accelerates; the productive capacity of the land is reduced

    • Storage of pollens for longterm conservation of yam genetic resources 

      Ng, N.Q.; Daniel, I. (2000)

    • Cryopreservation of cassava and yam shoot tips by fast freezing 

      Ng, S.Y.C.; Ng, N.Q. (2000)