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Journal and Journal Articles: Recent submissions
Now showing items 2181-2200 of 5277
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Legume rotation in the moist tropical savanna: managing soil nitrogen dynamics and cereal yields in farmers' fields
(1998)The contribution of root and leaf litter to soil nitrogen dynamics, nitrogen uptake and balance was evaluated under cereal–legume rotations in a tropical moist savanna soil. Two legumes, soyabean (Glycine max) and stylo (Stylosanthes hamata), and maize (Zea mays) as a control were grown in four farmers' fields of different native fertility in 1993. At the end of the season, soyabean grain and stover were harvested and stylo biomass was removed for fodder. At the beginning of the 1994 season levels ... -
Physical, chemical and water absorption properties of improved, openpollinated maize cultivars
(1999)The physical quality characteristics of test weight, 1000-kernel weight, percent floaters, Stenvert Hardness Index, kernel size (dimensions), water absorption index of grain and starch and chemical properties (protein, fat, ash, crude fiber, total sugars, starch, amylose, and amylopectin) were determined on twenty-five improved, tropical, open-pollinated maize cultivars. -
Evaluation of methods for measuring microbial biomass C and N and relationship between microbial biomass with soil organic matter particle size classes in West African soils
(1999)The fumigation–incubation (FI) and the fumigation–extraction (FE) ninhydrin methods for quantifying the microbial biomass pool were tested and the relationships between microbial biomass characteristics and soil organic matter fractions (separated following particle size) investigated for a range of soils representative for the West-African moist savanna zone (13 soils). Three soils from the humid forest zone were also included. Microbial C values calculated using the CO2-C production of the ... -
Productivity and residual effects of legumes in ricebased cropping systems in a warmtemperate environment II. Residual effects on rice
(1999)Field experiments were conducted over the period 1994–1996 to investigate the residual effect on rice of a wide range of temperate legume species, grown during the preceding winter season in a warm-temperate environment in Nepal. The incorporation of large quantities of above- and below-ground legume biomass (roots and foliage) resulted in substantial residual effects on the subsequent upland rice crop. The effects on rice yield in terms of percent increase over the control were more pronounced ... -
Effect of drought and plant density on radiation interception, radiation use efficiency and patitioning of dry matter to seeds in cowpea
The effects of drought and plant density on fractional interception (f), radiation-use efficiency (RUE) and dry matter accumulation and partitioning to seeds in cowpea (Vigna unguiculata) need to be quantified in order to calibrate cowpea simulation models for West Africa. Accordingly, a short duration cultivar of cowpea, IT84S-2246-4, was grown at a range of plant densities in well-watered and drought conditions in 1990–91 at two contrasting locations in Nigeria, Ibadan (7°N) and Kano (12°N). ... -
Epidemiology of Stenocarpella macrospora (Earle) Sutton on maize in the midaltitude zone of Nigeria
(1999)Disease progress of Stenocarpella macrospora (Earle) Sutton (syn. Diplodia macrospora Earle) was monitored on selected maize breeding lines over two seasons at three locations. Tagged plants were assessed at 10 day intervals for foliar lesions on a 1–9 scale and for ear rot on a 1–5 scale. The level of disease at a farm in Jos (West Africa Milk Company farm) was significantly greater than those at the other two locations (UTC Tenti and Saminaka), which had reduced or zero debris from the previous ... -
Survey on incidence and severity of Stenocarpella macrospora (Earle) leaf blight of maize in the midaltitude zone of Nigeria
(1999)Surveys were conducted on the incidence and severity of Stenocarpella macrospora (Earle) Sutton (= Diplodia macrospora Earle) on maize in the mid-altitude zone of Nigeria in 1995 and 1996. The results indicated a possible link between disease severity and plant density. Fewer symptoms were observed at altitudes below 700m. There was no significant correlation between cropping system and incidence or severity. -
Yield loss in East African highland banana (Musa spp., AAAEA group) caused by the banana weevil, Cosmopolites sordidus Germar
(1998)Yield loss in highland banana caused by the banana weevil, Cosmopolites sordidus, was studied in field trials in Uganda. Weevils were released at the base of banana mats 9 months after planting. Weevil populations, corm damage, plant growth and yield were assessed over four crop cycles. The effect of damage was greater on bunch weight than on plant growth and rate of development. Yield loss increased with crop cycle and ranged from 5% in the first cycle to 44% in the fourth cycle. The cumulative ... -
Decomposition of four Leucaena and Senna prunings in alley cropping systems under subhumid tropical conditions: the process and its modifiers
(1997)A litterbag experiment with Leucaena leucocephala and Senna siamea residues collected during four different pruning activities was carried out in no-tree-control and alley cropping plots. Decomposition was followed for 112 days after the respective pruning dates. Other factors studied were “amount of residue” confined in the litterbags and “plot management” (cropped or bare plots). The leaf litter of the same species, collected during the different prunings had different qualities. Older Leucaena ... -
Serial analysis of gene expression (SAGE) of hostplant resistance to the cassava mosaic disease (CMD)
(2004)Cassava mosaic disease (CMD) is a viral disease of the important tropical staple crop cassava (Manihot esculenta) and preferred management involves use of host–plant resistance. The best available resistance is controlled by a single dominant gene. Serial analysis of gene expression (SAGE) was used to analyze the gene expression pattern in a bulk of 40 each of CMD resistant and susceptible genotypes drawn from a gene mapping progeny. Messenger RNA used for the SAGE analysis came from plants that ... -
Policy and competitiveness of agroforestrybased technologies for maize production in Cameroon: an application of policy analysis matrix
(1998)Questions have been raised about the ecological consequences and economic sustainability of exclusive reliance on chemical fertilizers for the rapidly expanding maize production across sub-Saharan Africa. Alternative agroforestry-based natural resource management technologies have been developed for farmers. This paper applies the policy analysis matrix (PAM) to analyze the social profitability of agroforestry-based technologies for maize production in the highland savanna zone of Cameroon, and ... -
Banana die-back virus- a new virus infecting banana in Nigeria
(1998)Two viruses naturally infect Musa in Nigeria: banana streak badnavirus (BSV) and cucumber mosaic cucumovirus (CMV). During a recent field survey at Ibadan (Nigeria), some severely stunted banana plants (cv. Valery) were found that tested negative for CMV, banana bunchy-top virus, and BSV. The plants had symptoms of leaf crinkling, leaf necrosis, and cigar-leaf die-back. Subsequent suckers from the same mats were progressively more stunted. A 28- to 30-nm isometric virus was purified, and used for ... -
Soil organic matter dynamics after addition of nitrogen15labeled leucaena and dactyladenia residues
(1998)Quantification of the movement of residue N through various biologically meaningful soil organic matter (SOM) fractions is essential in low-input tropical cropping systems for the development of management practices aimed at optimizing N-use efficiency. The flow of N derived from 15N-labeled leucaena [Leucaena leucocephala (Lam.) de Wit] and dactyladenia [Dactyladenia barteri (Hook f ex Oliv.) Engl.] leaf residues was followed through the SOM of different particle-size fractions during 858 d. A ... -
Isolation of insecticidal lectinenriched extracts from African yam bean (Sphenostylis stenocarpa) and other legume species
(1999)Insecticidal lectins were isolated from 20 resistant Vigna and non‐Vigna legumes and tested againstn 3 pests of cowpea namely: Maruca vitrata, Callosobruchus maculatus and Clavigralla tomentosicollis. Crude lectins were separated from seeds using sodium chloride extraction, ammonium sulfate fractionation, and dialysis. SDS‐PAGE indicated the molecular size of ca. 30 kDa for the most intense (and presumably active) band. Haemagglutination assays using trypsin‐treated rabbit erythrocytes suggested ... -
Estimating the productivity impacts of technology adoption in the presence of misclassification
(2018-04-16)This article examines the impact that misreporting adoption status has on the identification and estimation of causal effects on productivity. In particular, by comparing measurement error-ridden self-reported adoption data with measurement-error-free DNA-fingerprinted adoption data, we investigate the extent to which such errors bias the causal effects of adoption on productivity. Taking DNA-fingerprinted adoption data as a benchmark, we find 25% “false negatives” and 10% “false positives” in ... -
Efficacy of chemical and flourescent protein markers in studying plant colonization by endophytic nonpathogenic Fusarium oxysporum isolates
(2009)In studying plant colonization by inoculated Fusarium oxysporum endophytes, it is important to be able to distinguish inoculated isolates from saprophytic strains. In the current study, F. oxysporum isolates were transformed with the green (GFP) and red fluorescent protein (DsRed) genes, and benomyl- and chlorate-resistant mutant isolates were also developed. The benomyl- and chlorate-resistant mutants, and the fluorescently labelled transformants, were able to grow on potato dextrose agar amended ...
