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Kombiok J.M.,Savanna Agricultural Research Institute
Tropical Agriculture | Year: 2013

The mean seed yield of sesame (Sesamum orientale L.) grown in Ghana by broadcasting the seeds is low. A field experiment to determine the effect of different plant populations and planting distances on the seed yield of sesame was conducted at Nyankpala in the northern Savanna zone of Ghana in 2009 and 2010. The treatments including row planting populations of 333,000/ha, 332,000/ha, 222,000/ha, 166,000/ha and broadcasting at the rate of 300,000 seeds/ha were laid out in randomized complete block design (RCBD) and replicated four times with SJ2 as the test crop variety. The most appropriate plant populations and planting distances that significantly (p< 0.05) increased seed yield/ha were 60 x 5 cm (333,000 plants/ha) and 60 x 10 cm spacing (332,000 plants/ha). Although plant population by broadcasting method was similar to the above; the seed yield was significantly (p<0.05) lower because the method of planting resulted in over-crowding which might have enhanced interplant competition for resources such as nutrients. Plant spacing (60 x 15 and 60 x 20 cm) that gave lower plant densities produced significantly (p<0.05) higher branches and pod number/plant but these could not be translated into higher seed yields/unit area as these compensatory factors were not enough to raise yields/unit area. Pod length, seeds/pod and plant height at harvest were not affected by plant population in the study. Farmers in the northern savanna zone of Ghana should therefore be sensitized and encouraged to adopt the 60 x 5 cm spacing at 1 plant/stand (333,000 plants/ha) or 60 x 10 cm spacing at 2 plants/stand for high sesame yields. The broadcasting method should be discouraged since it results in low seed yields and makes weed control, fertilizer application and harvesting more difficult © 2013 Trop. Agric. (Trinidad). Source

Amagloh F.K.,University for Development Studies | Amagloh F.C.,Savanna Agricultural Research Institute | Coad J.,Massey University
International Food Research Journal | Year: 2016

The in vitro starch digestibility (IVSD) method ("as-is" or modification) was used to assess the digestibility of two sweetpotato-based complementary food (CF), denoted orange-fleshed ComFa and cream-fleshed ComFa, and two cereal-based CF: Cerelac (wheat-based commercial infant cereal) and Weanimix (maize-soybean-groundnut blend). Using the IVSD method ("asis"), the sweetpotato formulations with high maltose (averaging 22.24 g/100 g) and low starch, about 15.15 g/100 g, had far lower digestibility values of 6.29 g/100 g, a quarter of that for Weanimix, which contained maltose and starch at levels of 2.72 g/100 g and 48.38 g/100 g, respectively. Further, the IVSD method employed "as-is" estimated the digestibility of Cerelac to be 11.53 g/100 g, about half the value for Weanimix. Conversely, for the modified method, the sweetpotato-based formulations had estimated digestibility value about 3 times higher than Weanimix (63.91 g/100 g), and 1.5 times higher than Cerelac (117.76 g/100 g). The IVSD method ("as-is") gives false negative results when used to estimate the digestibility of CF that contain significant amount of endogenous maltose. Therefore, its application to predict the suitability of CF warrants further validation. © 2008 IFRJ. Source

Rodenburg J.,Africa Rice Center | Zwart S.J.,Africa Rice Center | Kiepe P.,Africa Rice Center | Narteh L.T.,Food and Agriculture Organization of the United Nations FAO | And 2 more authors.
Agricultural Systems | Year: 2014

With an estimated surface area of 190. M. ha, inland valleys are common landscapes in Africa. Due to their general high agricultural production potential, based on relatively high and secure water availability and high soil fertility levels compared to the surrounding uplands, these landscapes could play a pivotal role in attaining the regional objectives of food security and poverty alleviation. Besides agricultural production, i.e. mainly rice-based systems including fish-, vegetable- fruit- and livestock production, inland valleys provide local communities with forest, forage, hunting and fishing resources and they are important as water buffer and biodiversity hot spots. Degradation of natural resources in these vulnerable ecosystems, caused by indiscriminate development for the sole purpose of agricultural production, should be avoided. We estimate that, following improved water and weed management, production derived from less than 10% of the total inland valley area could equal the total current demand for rice in Africa. A significant part of the inland valley area in Africa could hence be safeguarded for other purposes.The objective of this paper is to provide a methodology to facilitate fulfilment of the regional agricultural potential of inland valleys in sub-Saharan Africa (SSA) such that local rural livelihoods are benefited and regional objectives of reducing poverty and increasing food safety are met, while safeguarding other inland-valley ecosystem services of local and regional importance. High-potential inland valleys should be carefully selected and developed and highly productive and resource-efficient crop production methods should be applied. This paper describes a participatory, holistic and localized approach to seize the regional potential of inland valleys to contribute to food security and poverty alleviation in sub-Saharan Africa. We analyzed over a 100 papers, reference works and databases and synthesized this with insights obtained from nearly two decades of research carried out by the Africa Rice Center and partners. We conclude that sustainable rice production in inland valleys requires a step-wise approach including: (1) the selection of '. best-bet' inland valleys, either new or already used ones, based on spatial modelling and a detailed feasibility study, (2) a stakeholder-participatory land use planning within the inland valley based on multi-criteria decision making (MCDM) methods and using multi-stakeholder platforms (MSP), (3) participatory inland-valley development, and (4) identification of local production constraints combining model simulations and farmer participatory priority exercises to select and adapt appropriate practices and technologies following integrated management principles. © 2013 Elsevier Ltd. Source

Abukari I.A.,Savanna Agricultural Research Institute | Shankle M.W.,North Mississippi Research and Extension Center | Reddy K.R.,Mississippi State University
Scientia Horticulturae | Year: 2015

The herbicide S-metolachlor is used to control or suppress annual grasses, nutsedges and several broadleaf weeds in sweetpotato. However, a decline in storage root quality is suspected when an excessive rainfall occurs within 24h after application. A sunlit, controlled environment experiment was conducted to investigate sweetpotato response to five levels of S-metolachlor (0.00, 0.86, 1.72, 2.58 and 3.44kgha-1), and two levels of simulated rainfall (0 and 38mm at 51mmh-1) immediately after application. Sweetpotato slips were transplanted into white polyvinyl chloride pots filled with sandy loam soil. S-metolachlor treatments were applied to slips and a simulated rainfall treatment delivered immediately after transplanting and herbicide treatment. All pots were transferred to sunlit growth chambers that were maintained at 30/22°C, day/night temperatures and ambient carbon dioxide concentration (400μLL-1) for 60 days. An evapotranspiration-based irrigation system was used to supply water and nutrients. Plant biomass components and quality of storage roots were recorded 60 days after transplanting. There was no difference between rainfall treatments across S-metolachlor rates for vine lengths, leaf numbers and leaf area. These parameters, however, declined linearly and significantly with increase in S-metolachlor concentration. Total storage root weight declined linearly with increased S-metolachlor concentration; the decline was steeper with simulated rainfall. Yield of marketable storage roots declined by 18 and 31% in the absence of rainfall and 55 and 79% in the presence of rainfall with S-metolachlor at minimum (0.86kgha-1) and maximum (1.43kgha-1) recommended label rates, respectively, used to control weeds. Yield reduction was directly proportional to the rate of S-metolachlor applied in the absence or presence of rainfall; 77 and 123g fresh weight kg-1ha-1 S-metolachlor for no-rainfall and rainfall treatment, respectively. These results can be used to improve management decisions to optimize yield under field conditions as well as to mitigate risk of injury that could be associated with the use of S-metolachlor in sweetpotato production systems. © 2015 Elsevier B.V. Source

Siise A.,Savanna Agricultural Research Institute | Massawe F.J.,University of Nottingham Malaysia Campus
Genetic Resources and Crop Evolution | Year: 2013

Bambara groundnut an indigenous crop of African origin is drought tolerant and the third most important leguminous crop in Ghana and Sub-Saharan Africa. In order to assess the level of genetic diversity within a small collection of Ghanaian landraces, molecular analysis was performed using microsatellite markers alongside characterization of morphological features. Genetic distance based on Jaccard's similarity coefficient from the SSR marker analysis ranged from 0.48 to 0.9 among the landraces. 80 individual genotypes were clustered into 17 units with substantial levels of inter- and intra-landrace polymorphism. The analyses of variance from the morphological characterization for all quantitative traits were statistically significant (p < 0.05) except for terminal leaflet width. The first 4 principal components accounted for 41.97, 20.15, 13.39 and 9.81 % respectively of the morphological variations among the landraces. Qualitative traits however accounted for less of these variations. The results of the present study support the availability of high level of polymorphism within the collection of bambara groundnut analysed. This report is useful to crop improvement and germplasm conservation of bambara groundnut in Ghana. © 2012 Springer Science+Business Media Dordrecht. Source

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