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1.
Summary The objective of this study was to evaluate the distribution of cotton (Gossypium hirsutum cv GSA 71) root system under four depths of trickle irrigation emitter. Cotton was grown on an Amarillo fine sandy loam (fine loamy, mixed thermic Aridic Paleustalf) at Lubbock, Texas. Trickle irrigation was applied at the surface (0), 0.15, 0.3, or 0.45 m depths in amounts calculated using daily pan evaporation, crop coefficient, and crop development stage. Effects of depth of trickle irrigation were evaluated by measuring the cotton root-length density in 0.15 m increments to the 0.90 m depth at distances of 0, 0.25, and 0.5 m perpendicular to the cotton rows. The root-length distributions were not significantly (0.05%) different in the top 0.15 m when the surface irrigated treatment was compared with the 0.45 m irrigation depth treatment. Root-length densities for the 0.15 and 0.3 m treatments were not significantly different from one another nor were they different from treatments within the evaluated zones (0 to 0.3 m or 0.15 to 0.45 m). Root-length density within the 0.3 to 0.6 m zone, was not significantly different for the 0.45 m treatment compared with the surface irrigation treatment. Root-length density in the 0.6 to 0.9 m zone was not significantly different for any treatment. Emitter depth of trickle irrigation did not significantly influence the depth or distribution of cotton-root development. 相似文献
2.
D. M. Phiri B. Coulman H. A. Steppler C. S. Kamara F. Kwesiga 《Agroforestry Systems》1993,24(3):271-276
The effect of feeding maize (Zea mays L.) husk and leucaena (Leucaena leucocephala) as a mixture or separately on the voluntary intake of maize husk was studied over a 40-day period. Ten male goats with an average weight of 15 kg were used. The maize husk intake and total dry matter intake for the two feeding methods was about the same. Thus, total dry matter intake was not affected (P<0.05) by the feeding method. There was also no significant difference (P<0.05) between the two feeding methods in the digestibility values. The data were considered to indicate that there were no significant differences in the intake of maize husk when fed in a mixture with leucaena or when offered separately but at the same time. 相似文献
3.
Kamara BI Brandt EV Ferreira D Joubert E 《Journal of agricultural and food chemistry》2003,51(13):3874-3879
The fermented leaves and stems of Cyclopia intermedia are used to brew Honeybush tea, a herbal tea indigenous to South Africa. The plant is also used to manufacture a sweet herbal infusion used for restorative properties such as soothing coughs and alleviating bronchial complaints including tuberculosis, pneumonia, and catarrh. It is claimed to have a low tannin content and no caffeine and contains various antioxidants. Continued investigations into the phenolic content of the leaves and stems of C. intermedia yielded tyrosol and a methoxy analogue, 2-[4-[O-alpha-apiofuranosyl-(1' '-->6')-beta-d-glucopyranosyloxy]phenyl]ethanol, 4-[O-alpha-apiofuranosyl-(1' '-->2')-beta-d-glucopyranosyloxy]benzaldehyde, five glycosylated flavonols, two isoflavones, four flavanones, two isoflavones, and two flavones. Structure elucidation was done by NMR, CD, and MS methods. Because flavonoids are presumed to contribute significantly toward the scavenging effects of active oxygen species, our results indicate that the tentative claimed health-promoting properties may be attributed to the presence of these and other phenolics in C. intermedia. 相似文献
4.
Seroprevalence of leptospiral antibodies among dairy cattle kept in communal corrals in periurban areas of Bamako, Mali, West Africa 总被引：1，自引：0，他引：1
Mamadou Niang Loren A. Will Mamadou Kane Alpha A. Diallo Manzoor Hussain 《Preventive veterinary medicine》1994,18(4):259-265
Sera obtained from dairy cattle in communal corral herds located near the city of Bamako in Mali, West Africa were sceeened using the microscopic agglutination test against 26 serovars representing 15 serogroups of Leptospira interrogans. Forty five percent (44.8%; 288/642) were positive to one or more serovars. This seroprevalence rate likely reflects infection since vaccination against leptospiral infection has not been practiced i Mali. The rate was higher among females. The most common titers were against antigens of serovars cynopteri (14.7%), hardjo (13.3%), pomona (9.2%), nona (8.1%), kambale (6.5%), grippotypyosa (6.4%), hebdomadis (6.2%), and pyrogenes (5.2%). 相似文献
5.
Godfree Chigeza Steve Boahen Melaku Gedil Eric Agoyi Hapson Mushoriwa Nicholas Denwar Therese Gondwe Abush Tesfaye Alpha Kamara Oladeji Emmanuel Alamu David Chikoye 《Plant Breeding》2019,138(4):455-464
Formal public sector soybean breeding in Africa spans over four decades, and it was initiated by the International Institute of Tropical Agricultural (IITA). As the demand of soybean continues to outstrip production, strategic projects such the Tropical Legume (TL) were initiated, in which the main goal was to enhance the productivity of soybean in the farmers’ fields in Sub‐Saharan Africa. One of the strategies to enhance the productivity of soybean in the farmers’ fields is through developing and deploying improved soybean varieties in the target countries. Through the TL I and TL II projects, a number of varieties were released in the target countries, Kenya, Nigeria, Malawi and Mozambique by employing participatory variety selection (PVS). This review provides highlights of the achievements made by IITA breeding programme and insights of what needs to be done to enhance yield improvement for soybean in Africa using demand‐driven breeding approaches. 相似文献
6.
Alpha Bocar Baldé Eric ScopelFrançois Affholder Marc Corbeels Fernando Antonio Macena Da SilvaJosé Humberto Valadares Xavier Jacques Wery 《Field Crops Research》2011,124(2):240-251
In the context of conservation agriculture on small scale farms of the Brazilian Cerrado, we hypothesized that planting a cover crop in relay with a commercial crop improves the efficiency of use of available natural resources, increasing biomass for use as fodder without reducing the grain yield of the main crop. The objective of this study was to measure the performance of two intercropped systems in terms of total above-ground biomass production and maize (Zea mays) grain yield: pigeon pea (Cajanus cajan) and Brachiaria (Brachiaria ruziziensis) sown as cover crops in established maize under a no-tillage management. The cover crops were sown at two different dates and a comparison was made with the three crops sown as a sole crop at the early sowing date. The experiment was conducted during the 2007-2008 and 2008-2009 growing seasons. Maize grain yield was not reduced by the presence of the relay cover crops in comparison with maize as the sole crop, even when the cover crop was sown soon after maize emergence. In contrast, the production of above-ground biomass by the cover crop was significantly lower when grown with maize than it was when grown as a sole crop. In the intercropped systems, when sown early, the cover crop produced higher total biomass than when sown late. Total above-ground biomass production of maize intercropped with a cover crop was much higher than that of any of the crops sown alone: the total biomass (average of the two growing seasons) produced by maize and pigeon pea was more than double that of maize grown alone. The land equivalent ratio (LER) of maize grain yield and biomass production was higher than one whatever the intercropped system used. It was particularly high when maize was intercropped with early sown pigeon pea; grain yield LER and biomass LER reaching, respectively, 1.72 and 1.73 in 2007-2008 and 2.02 and 2.03 in 2008-2009. These high LER values provide evidence for the complementary and the high efficiency of use of available resources by the intercropped plants and thus the advantage of such systems to produce both maize grain and cover crop forage under the conditions of our study. 相似文献
7.
L. O. Omoigui A. Y. Kamara G. I. Alunyo L. L. Bello M. Oluoch M. P. Timko O. Boukar 《Genetic Resources and Crop Evolution》2017,64(5):901-911
The parasitic weed, Striga gesnerioides, is a major threat to cowpea productivity throughout the savannas of West and Central Africa. The identification of sources of S. gesnerioides resistance and their incorporation into breeding programs would be a beneficial strategy to combat the devastation caused by the parasite in cowpea fields. In this study we examined one hundred and ninety-four (194) accessions, four commercial varieties and two controls collected from a mini core collection of cowpea held at the International Institute of Tropical Agriculture genebank for resistance to S. gesnerioides race 3 (SG3), the most prevalent race in Nigeria, using phenotypic screening and molecular marker analysis. Our studies identified two cowpea accessions, Tvu-1272 and Tvu-16514, that are resistant to S. gesnerioides SG3. Resistance in these lines is associated with the molecular marker SSR1, known to segregate with the gene conferring resistance to SG3 in the cultivar B301. Phenotypically, resistance in Tvu-1272 and Tvu-16514 is expressed as a hypersensitive response at the site of infection on the roots. Allelism tests indicated that the gene that conferring SG3 resistance in Tvu-1272 is independent of that conferring resistance in B301. Tvu-1272 and Tvu-16514 will provide additional new sources of resistance to Striga and races prevalent in Nigeria. 相似文献
8.
Sylvester U. Ewansiha Alpha Y. Kamara Johnson E. Onyibe 《Archives of Agronomy and Soil Science》2013,59(5):597-608
A field trial was conducted during the rainy seasons of 2008 and 2009 at Samaru in northern Guinea savannah of Nigeria to determine the performance of semi-determinate and indeterminate cowpea cultivars intercropped with extra early, early and late maize cultivars. The trial was laid out in a randomized complete block design (RCBD) having treatments arranged as a split-plot factorial. Transmitted radiation was reduced by 49–63% due to shading by the maize plants. Similarly, intercropping cowpea with maize reduced intercepted radiation, fodder yield and grain yield of cowpea by 59–70%, 39–51% and 45–62%, respectively. Intercepted radiation and yields of intercropped cowpea were lower for late maize which maintained high leaf area over a longer period of time. This is supported by the higher plant height, higher leaf area index (LAI) and reduced transmitted radiation recorded in late maize compared with extra early and early maize. Extra early and early maize were less competitive with cowpea because of shorter period of association in addition to permitting higher radiation. Crop value of maize plus cowpea was higher than that of sole cowpea ($2616.8 vs. $1218.7 ha?1) because higher combined yield was achieved by a more efficient use of resources in the intercrop. Therefore, cowpea cultivar may be intercropped with extra early maize. 相似文献
9.
J. Nyemeck Binam T. Abdoulaye L. Olarinde A. Kamara A. Adekunle 《Journal Of Agricultural & Food Information》2013,14(2):177-198
This article provides an assessment of the potential impact of operationalizing agricultural innovation platforms (IPs) in the Sudan Savannah zone of Nigeria on adoption of improved maize/legume crop varieties, as measured by the potential outcome approach. The results show that, if the whole population in the intervention area were exposed to these varieties, the adoption rate could be increased to 69% instead of 49%. The study also shows that exposure, as well as adoption, is influenced by numerous social and institutional factors and suggests that the operationalization of IPs could help boost the adoption rate to around 51%. 相似文献
10.
Susan G. Njeri Dan Makumbi Marilyn L. Warburton Alpha Diallo MacDonald B. Jumbo George Chemining’wa 《Euphytica》2017,213(11):261
Maize (Zea mays L.) is an important source of carbohydrates and protein in the diet in sub-Saharan Africa. The objectives of this study were to (i) estimate general (GCA) and specific combining abilities (SCA) of 13 new quality protein maize (QPM) lines in a diallel under stress and non-stress conditions, (ii) compare observed and predicted performance of QPM hybrids, (iii) characterize genetic diversity among the 13 QPM lines using single nucleotide polymorphism (SNP) markers and assess the relationship between genetic distance and hybrid performance, and (iv) assess diversity and population structure in 116 new QPM inbred lines as compared to eight older tropical QPM lines and 15 non-QPM lines. The GCA and SCA effects were significant for most traits under optimal conditions, indicating that both additive and non-additive genetic effects were important for inheritance of the traits. Additive genetic effects appeared to govern inheritance of most traits under optimal conditions and across environments. Non-additive genetic effects were more important for inheritance of grain yield but additive effects controlled most agronomic traits under drought stress conditions. Inbred lines CKL08056, CKL07292, and CKL07001 had desirable GCA effects for grain yield across drought stress and non-stress conditions. Prediction efficiency for grain yield was highest under optimal conditions. The classification of 139 inbred lines with 95 SNPs generated six clusters, four of which contained 10 or fewer lines, and 16 lines of mixed co-ancestry. There was good agreement between Neighbor Joining dendrogram and Structure classification. The QPM lines used in the diallel were nearly uniformly spread throughout the dendrogram. There was no relationship between genetic distance and grain yield in either the optimal or stressed environments in this study. The genetic diversity in mid-altitude maize germplasm is ample, and the addition of the QPM germplasm did not increase it measurably. 相似文献