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Methods of or the dissemination of food processing technologies: the soybean example in Nigeria
(1994)Protein deficiency is still a major problem in Nigeria and in Africa, particularly among the low-income groups. Cassava is the staple food for millions of people in Africa. Soybean could be fortified with cassava to reduce the alleviation of malnutrition problems caused by root crop based Nigerian/African diets. The IDRC Soybean Utilization Project, jointly implemented by IITA and national institutes in Nigeria, has been successful in developing several different uses for soybean in foods and ... -
Future strategy for Musa improvement
(1994)IITA has increased its knowledge about major constraints across agro-ecological zones and gene pools for Musa production in Africa. The authors review the following different aspects: adding more desirable attributes to breeding populations; integration of host-plant resistance, enhanced utilization, and improved cropping systems; networking; and training. -
Cassava plant protection in Africa
(1994)Manihot esculenta Cassava pest problems in Africa have changed dramatically over the last century. Rapidly expanding production and waves of exotic pests have created evolving cassava agroecosystems with changing production constraints. Cassava plant protection activities in Africa began with resistance breeding against African cassava mosaic virus. Cultural manipulations and biological control interventions were implemented later as devastating new pests invaded the continent. Sustainable plant ... -
The cyanogenic potential of cassava
(1994)Manihot esculenta Cyanogenesis, the ability to produce hydrogen cyanide (HCN), is common to over 2000 plant species. In cassava, two cyanogenic glucosides, linamarin and lotaustralin, are produced in the leaves and stored inside vacuoles. Linamarase, an enzyme capable of hydrolyzing the glucosides, is also produced by the plant, but is stored in the cell wall. The hydrolysis of the glucosides and the release of HCN only occurs when plant tissues are damaged, e.g. during processing. Once produced, ... -
The genetics of resistance to cocoyam root rot blight complex disease in Xanthosoma sagittifolium(L.)Schott
(1994)Six hybrid cocoyam clones from a uniform yield trial and a Local White accession from the germplasm collection were crossed in a diallel excluding reciprocals, in order to determine the inheritance pattern of resistance to cocoyam root rot blight complex (CRRBC) disease. The 21 progenies from this diallel crossing program were evaluated for CRRBC disease resistance in a randomized complete block design in 4 replications. The progenies showed varying levels of resistance to CRRBC disease. The diallel ... -
Processing of cassava leaves for human consumption
(1994)In almost all countries of the cassava belt in Africa, from Senegal to Mozambique, cassava leaves are consumed. In much of East Africa, all of Central Africa and parts of West Africa (e.g. Sierra Leone, Liberia), cassava leaves are a major component of the diet and constitute a very significant source of dietary protein, minerals and vitamins. The cyanogenic potential of cassava leaves is 5 to 20 times greater than that of roots. However the risk of intoxication associated with the consumption of ... -
Effect of maize variety and storage form on oviposition and development of the maize weevil, Sitophilus zeamais Motschulsky (Coleoptera: Curculionidae)
(1994)The effects of maize variety and storage form on development of the maize weevil, Sitophilus zeamais Motschulsky, were studied under artificial infestation at 25 ± 2 °C and 70 ± 5% r.h. in the laboratory. Three improved West African maize varieties, Abeleehi, EV8725-SR, Pop63-SR and the local variety, Volta Local, stored shelled and as cobs without husks (=unshelled) were used. Dissections of infested grain were used to monitor insect development at regular intervals. Maize variety and storage ... -
Development and performance of tetraploid hybrids of plantain (Musa spp., AAB group) with black sigatoka resistance
(1994)A strategy to control the black sigatoka disease of plantain (Musa spp, AAB group) in Africa, targeting the incorporation of durable host plant resistance, was initiated at the International Institute of Tropical Agriculture (IITA). The commonly accepted intractability of plantain to genetic improvement has been challenged by the identification of 37 different, seed-fertile plantain cultivars and by the production of 250 hybrids in four years of breeding. Twenty tetraploid hybrids have been selected ... -
Storage systems for maize ( Zea mays L.) in Nigeria from five agroecological zones
(1994)An international project to assess the extent of aflatoxin contamination of maize in West Africa has begun in Nigeria. A survey was conducted from October 1992 to July 1993 to identify maize storage systems used by farmers in five major agro-ecological zones in Nigeria and the problem associated with such systems. The zones were: humid forest, mid-altitude, southern Guinea savanna, northern Guinea savanna, and Sudan savanna. Five villages within each zone were selected and five farmers withineach ... -
Influence of a complex disease involving Praylenchus goodeyi and a nonpathogenic strain of Fusarium oxysporum on banana root health
(1994)Studies were undertaken to determine disease interactions involving P. goodeyi and a non-pathogenic strain of F. oxysporum, both responsible for root-rotting and subsequent toppling of 2 banana cultivars in Kenya. Thirty days after inoculation of young banana plants with P. goodeyi alone or in combination with F. oxysporum the higher density of P. goodeyi was found in necrotic primary roots of the cultivar Nakyetengu (AAA). In primary roots of the cultivar Sukali Ndizi (AB) high density of P. ... -
Intercrop yields of cassava and rice as influenced by cassava variety and population
(1994)The cassava variety and population, which when intercropped with rice leads to increased productivity of the system were identified. Two cassava varieties (Cocoa, a local variety; and 80/40, an improved one) were each planted at four populations (6 666, 10 000, 13 333, and 16 666) as sole crops or intercropped with the rice variety Rok 16. Variety 80/40 significantly out yielded Cocoa (17.2 and 4.1 t/ha, respectively). There was no significant difference in yield between sole and intercropped ... -
Effect of extracts from nine plant species found in Africa on the mycelial growth of Aspergillus flavus Link
(1994)Farmer survey conducted in 1991 and 1992 revealed that some farmer's combat storage moulds using locally available plants. Extracts and combination of extracts of nine different plant species that are used as traditional medicines and aromatic spices in Nigeria were tested for the effect in vitro on the growth of Aspergillus flavus. Aqueous extracts from the combination of dried fruits of xylopia aethiopica and dried seeds of piper guineense completely inhibited the growth of the fungus. Dried ... -
Cassava based foods: how safe are they?
(1994)Cassava production in Africa has increased by 12.5% between 1988 and 1990 with Nigeria becoming the largest cassava producer in the world. Almost all of the African cassava production is destined for human consumption. The consumption of cassava is sometimes associated with toxicity due to its cyanogenic potential (CNP). This paper presents the results of a preliminary survey of the CNP of cassava foods consumed in Kumasi, Ghana. The traditional processing of cassava in Africa and its potential ... -
Post transcriptional silencing of reporter transgenes in tobacco correlates whit DNA methylation
(1994)Endogenous plant genes or transgenes can be silenced on introduction of homologous gene sequences. Here we document a reporter gene-silencing event in Nicotiana tabacum that has a distinctive combination of features--i.e., (i) silencing occurs by a posttranscriptional process, (ii) silencing correlates with DNA methylation, and (iii) this de novo methylation is not restricted to cytosines located in the symmetrical motifs CG and CXG. -
Breeding for Striga hemonthica tolerant openpollinated maize varieties in Africa
(1994)A parasitic weed, Striga hermonthica (Del.) Benth., infects millions of hectares of arable land in sub-Saharan Africa, and it threatens production of cereal crops. The objectives of this study were to investigate inheritance in maize (Zea mays L.) inbred lines of tolerance and resistance to S. hermonthica, based on visible host plant symptoms and Striga emergence counts. A diallel cross involving 10 inbreds was tested under Striga infested fields at Mokwa, Nigeria, for 5 yr. Host plant response ... -
Determination of optimum sett size for white guinea yam (Dioscorea rotundata Poir.) seed yam production: trends in sprouting in the presprout nursery and field performance
(1994)Six weight-classes of white guinea yam (Dioscòrea rotundata Poir.) setts—2–5, 5.01–10, 10.01–20, 20.01–30, 30.01–40, and 40.01–50 g—were presprouted in fresh, moist sawdust in open-air, propagation beds. The 2–5 g and 5.01–10 g classes were described as microsetts. Three natural groups patterned along the various phases of the sigmoid curve, within which the classes did not perform differently were evident at 26 days after planting (DAP), for sets at the leafy-and leafless-shoots stage. The group ...
