Restriction Fragment Length Polymorphisms (RFLPs) were used to study the genetic diversity within and between accessions of 'wild' and cultivated B. rapa. Two of the wild accessions were likely to be escapes from cultivation because of their geographical origins (Argentina and California). The nature of the other three wild accessions (from Turkey, Algeria and Sicily) was not known. Principal components analysis placed the Argentinian, Californian and Turkish accessions within a cluster which ...

Striga hermonthica is an important cause of yield loss in sorghum in the semi‐arid zone of Africa. Two trials were conducted in northern Cameroon to evaluate the effect of herbicides for two cropping seasons on densities of emerged Striga in treatment years and on densities of Striga seed and plants in subsequent years. Herbicide application using 2,4‐D, triclopyr, paraquat, and bromoxynil and urea solution (20%) was compared with hand‐weeding of Striga and an unweeded control. Reduction of emerged ...

In an area of Nigeria where downy mildew of maize is present, histological assessment of maize seed revealed the presence of mycelium and oospores of Peronosclerospora sorghi in the kernels. Seed transmission of downy mildew of maize was demonstrated when grain purchased at local markets gave mean seedling infection rates of 12•3% (untreated days of emergence, after storage seeds) and 10•0% (in metalaxyl‐treated seeds) within 7 days. When untreated seeds taken from nubbin ears of systemically in ...

The relative contribution of ploidy status and genome composition to the variability of root traits in Musa was studied in 18 genotypes (from 5 genomic groups and 3 ploidy levels) at Onne, Nigeria. There was a significant effect of ploidy level on the different characteristics, except for root dry weight and cord root length of the mat. Generally, with increasing ploidy level the magnitude of plant characteristics tended to increase. The effect of genotype was significant for all assessed traits, ...

The impact of land use (unfertilized continuous maize cropping, unfertilized and fertilized alley cropping with maize, Gliricidia sepium tree fallow, natural fallow) on the soil organic matter (SOM) status and general soil fertility characteristics were investigated for a series of soils representative for the West African moist savanna zone. Three soils from the humid forest zone were also included. In an associated pot experiment, relationships between maize N and P uptake and SOM and general ...

Virus diseases cause substantial yield reduction in cowpea ( Vigna unguiculata (L.) Walp) production in West and Central Africa. Improved cowpea cultivars have been developed and distributed to various national programs but these cultivars were tested only against local virus isolates. To identify resistance applicable to a wider cowpea distribution, fourteen cowpea lines were analyzed under glasshouse conditions for susceptibility to infection by three isolates of Blackeye cowpea mosaic virus ...

We examine variation in mutation dynamics across a single genome (Zea mays ssp. mays) in relation to regional and flanking base composition using a data set of 10,472 SNPs generated by resequencing 1776 transcribed regions. We report several relationships between flanking base composition and mutation pattern. The A + T content of the two sites immediately flanking the mutation site is correlated with rate, transition bias, and GC → AT pressure. We also observe a significant CpG effect, or increase ...

The private sector has been involved in the production and marketing of production inputs such as seeds (Premier, A1heri, UAC), fertilizers (Dangote, Golden), implements John Holt, Saulawa Machinery), agrochemicals (CAPL Rhone Total, etc.) in the state. This sector is also involved in the purchase of farm produce for industrial (flour. food, beverages, etc.) processing and supports commodity research and extension. A greater involvement of the private sector in the manufacture of prototype ...

Understanding how novel microbes enter into the human population is perhaps the fundamental goal of the study of emerging infectious diseases (EID). The frequency at which microbes will emerge is determined by the diversity of microbes present in the environment, the level of contact between a potential host and this microbial diversity and the susceptibility of the novel host to infection. While a range of microbial media exist, including soils, plants and animals, the greatest emergence risks ...

Sorghum ergot, initially restricted to Asia and Africa, was recently found in the Americas and Australia. Three species causing the disease have been reported: Claviceps sorghi in India, C. sorghicola in Japan, and C. africana in all ergot-positive countries. The objective of our study was to study the intraspecific variation in C. africana isolates in the Americas, Africa, India, and Australia. We confirmed C. africana, C. sorghi, and C. sorghicola as different species using differences in ...