A Nigerian isolate of Yam mosaic virus (YMV), genus Potyvirus from Dioscorea rotundata leaves was used to mechanically inoculate Nicotiana benthamiana (propagation host) plants from which the virus was purified. A hybridoma cell line secreting a monoclonal antibody (Mab) against YMV was produced by fusion of FOX-NY myeloma cells with immune splenocytes from in vivo immunizations of a Balb/C mouse. The polyclonal antiserum to YMV and the Mab (YMV-M24) were used in developing a triple antibody ...

CD-ROM is an information technology with great potential for African Scientists and scholars. In this paper, the importance of CD-ROM as an information storage and retrieval technology in developing countries is highlighted.

Biological and chemical components of soil fertility were quantified under three different fallow types and related to soil quality of an Ultisol in southern Cameroon at the end of a 9-month fallow. Soil organic matter (SOM), soil exchangeable Ca2+, Mg2+ and K+ and available P concentrations, effective cation exchange capacity (ECEC) and, soil acidity in the 0–10 and 10–20 cm layers were evaluated under: natural regrowth mainly composed of Chromolaena odorata and the legume cover crops velvet bean ...

Greenhouse and field studies were conducted to determine the effect of earthworm casts on the production of maize and cowpea. In pot experiments with mixtures of soil and casts, shoot and root dry matter (OM) of maize and cowpea increased with increasing proportion of casts. Shoot OM of cowpea and root OM of maize increased significantly when worm casts were applied to the soil surface but not when the casts were mixed with the soil. Under field conditions, maize grain yield increased by 73%, 114%, ...

Mycotoxins are regulated in foods and feeds because of carcinogenic (aflatoxin), immunotoxic (deoxynivalenol), or environmental estrogenic (zearalenone) properties. In addition to having tumorigenic properties, many mycotoxins are antinutritional factors that cause unthrifty growth and immune suppression in young animals. In the developed world, human exposure, and particularly exposure of children, to dietary mycotoxins is virtually nonexistent because of regulatory standards. In developing ...

In the Republic of Benin, the scelionid egg parasitoid Telenomus isis (Polaszek) is one of the most important control factors of the noctuid maize stem borer Sesamia calamistis. In the present study, the role of various sources of contact kairomones (male or virgin or mated female moths) and of the moth's oviposition substrate (leaf sheath versus filter paper; host plant species) in host location and oviposition behavior of T. isis was investigated in Munger cells, open arenas, and/or Petri dish ...

This study aimed at an assessment of the potential of the egg parasitoid Telenomus isis (Polaszek) as a biological control agent of cereal stem borers. Therefore, the effects of temperature, host species, host age, and time of host deprivation on the development and the reproductive potential of T. isis were studied in the laboratory. By use of linear regression and a modified Logan model and with eggs of the noctuid Sesamia calamistis Hampson as hosts, the lower and upper thresholds for development ...

Cyanide a by-product from cyanogenic glucosides is toxic to humans and most living organisms due to its ability of binding to metals such as iron, zinc and copper functional groups of the ligands of most bio enzymes. The cyanide inhibits the reduction of oxygen in the respiratory electron transfer system, the inhibition of plastocyanin reduction in photosynthesis and catalase activity. The magnitude of cyanide metabolism varies greatly between different plant species. Although most plant species ...

The paper analyses innovation histories of two agro-mechanical and two seed-based technologies with high and low technological complexity, introduced into simple and complex farming systems in Asia. The main conclusion, which may be seen as a hypothesis for further testing, is that, as technology and system complexity increase so does the need for interaction between the originating R&D team and the key stakeholders (those who will directly gain and lose from the innovation) when the latter first ...

Studies were conducted in the laboratory to investigate the different components of the resistance of Vigna vexillata A. Richards, TVnu 72, and several cultivars of cultivated Vigna spp. to infestation and damage by the brown cowpea coreid, Clavigralla tomentosicollis Stäl. The main objective was to determine the different roles of the pod wall and seeds, and the relationship between seed size, number, and damage by this insect. Results showed that both the pod wall and seed clearly contribute ...