Ghana Journal of Agricultural Science <p>The <em>Ghana Journal of Agricultural Science</em> is a national scientific journal which is published by the Council for Scientific and Industrial Research of Ghana to serve as an outlet for papers concerning West African agriculture and related disciplines.</p> Accra: Council for Scientific and Industrial Research, Ghana en-US Ghana Journal of Agricultural Science 0855-0042 <p>Copyright for articles published in this journal is retained by the journal.</p><p>This journal content is licensed under a <a class="subfoot" href="" rel="license">Creative Commons Attribution 4.0 International license</a>.</p> Plant-parasitic nematodes associated with sweet potato rhizosphere soil in the Semi- Deciduous Forest and Coastal Savannah Zones of Ghana <p>A survey was conducted in nine major sweet potato producing districts across the semi-deciduous forest and coastal savannah zones of Ghana to determine the prevalence of plant-parasitic nematodes parasitizing the crop. Soil samples were collected at 90-days after planting from the rhizosphere of sweet potato crop and analysed using Modified Baermann tray method from 100 farms across the study area. Seven plant-parasitic nematode genera were extracted from soil samples collected and morphologically identified under a microscope with four of them, namely <em>Meloidogyne, Pratylenchus, Rotylenchulus, </em>and <em>Helicotylenchus </em>being the most prevalent. <em>Scutellonema </em>sp. occurred in 89% while <em>Tylenchus </em>sp. occurred in 33% of the districts sampled. The ring nematode, <em>Criconemella </em>sp. was found in only two of the nine districts covered; Ketu North and Akatsi South which incidentally recorded 100% of the seven nematodes encountered in the survey. The abundant nematode was <em>Meloidogyne </em>sp. which represented 39% and <em>Criconemella, </em>the least (0.1%) of the total nematodes recovered in the survey. This study has shown that high diversity, incidence and density of economically important plant-parasitic nematodes are associated with sweet potato crop. Development of appropriate management strategies to mitigate the negative effects of plant-parasitic nematodes on sweet potato is recommended.</p> <p>&nbsp;</p> J. Adomako Y. Danso B. Sakyiamah F. Kankam K. Osei Copyright (c) 2020-12-24 2020-12-24 55 2 1 9 10.4314/gjas.v55i2.1 Time of introducing component crop influences productivity of intercropping system <p>Field experiment was conducted at National Horticultural Research Institute (NIHORT), Mbato Sub-station, Okigwe, Imo State, South-eastern Nigeria in the 2012 and 2013 cropping seasons to establish the most appropriate time to introduce component crops in cocoyam/cowpea mixture. Five different planting schemes (two and four weeks before, two and four weeks after and same day) and two cowpea genotypes (climbing <em>Akidienu </em>and erect IT97K-499-35) were used. The component crops were grown in monocultures to assess the productivity of the systems. The experimental design used was a completely randomized design with three replicates. Growth and yield of cocoyam and the cowpea genotypes increased significantly (P&lt;0.05) when either of the component crops was planted earlier than the other. Intercropping reduced significantly (<em>P</em>&lt;0.05) cocoyam yield by 0.7 − 74% in IT97K-499-35 and 22 − 80% in <em>Akidienu</em>. Sowing the cowpea genotypes the same day or before cocoyam resulted in over-yielding of cowpea, whereas sowing <em>Akidienu </em>and IT97K-499-35 after cocoyam caused pod yield reductions of 64% − 73% and 32% − 59% on average, respectively. Cocoyam planted two weeks before IT97K-499-35 produced more satisfactory yields of the intercrops than the other planting schedules with LER, LEC and ATER of 2.15, 1.03 and 1.57, respectively.</p> M. O. Iwuagwu D. A. Okpara C. O. Muoneke Copyright (c) 2020-12-24 2020-12-24 55 2 10 25 10.4314/gjas.v55i2.2 Compatibility of Mancozeb 75 WP with some plant extracts in the integrated management of Cercospora leaf spot disease of okra (Abelmoschus esculentus (L.) Moench) <p>The use of synthetic mancozeb fungicide has not been effective in the control of okra leaf spot (<em>Pseudocercospora abelmoschi</em>) disease amidst critical issues of environmental concerns. Therefore, this study evaluated the compatibility of mancozeb 75 WP with some botanicals in the integrated management of the disease. Laboratory assay was a 3×4×2 factorial laid out in a completely randomized design with three replications, while the field experiment was a randomized complete block design with 14 treatments. Four extract concentrations, 15, 30, 45 and 50% w/v and 0.5 g/l Mancozeb 75 WP were evaluated. The application of <em>Syzygium aromaticum </em>extract at 50% w/v concentration had the highest mycelial growth reduction of 71.89% of the pathogen. The soil textural class was sandy loam and treatments effect on okra growth indices did not differ significantly (p&gt;0.05). The highest pod yield of 15.48 t/ha-1 was obtained in treatment inoculated with <em>P. abelmoschi. </em>but treated with a combination of <em>S. aromaticum </em>and Mancozeb. The same treatment had the lowest disease incidence of 4.01%, while combined application of <em>C. papaya, S. aromaticum </em>and Mancozeb recorded significantly (p&lt;0.05) lower disease severity among inoculated plants. Therefore, this combination is recommended as foliar spray on okra in place of Mancozeb.</p> V.O. Dania N. E. Sam Copyright (c) 2020-12-24 2020-12-24 55 2 26 38 10.4314/gjas.v55i2.3 Awareness and adoption levels of improved smoking oven among fish processors in Lagos Lagoon, Nigeria <p>This paper investigated awareness and adoption levels of improved smoking oven among fish processors in four fishing communities along Lagos Lagoon, Nigeria. Multi-stage sampling procedure was used to select 153 respondents who were engaged in fish smoking. Data collected using structured interview guides were subjected to descriptive and inferential analyses. Results revealed that majority of the respondents were young, married women with average fish smoking experience of 22.6 years. Majority (90.8%) of them were solely engaged in fish smoking while 9.2% combined fish smoking with other income-generating activities. All the processors used traditional smoking oven (drum, box and mud ovens). More than 66.0% of the fish processors were not aware of improved fish smoking equipment. Lack of awareness, inadequate access to the technologies, low relative advantage and lack of maintenance services and high cost of procurement were responsible for low adoption levels of improved smoking oven. Irregular visits of extension agents to the study area had negative impact on the adoption of improved traditional smoking ovens. Proper dissemination of innovations developed on improved fish processing equipment to the active fish processors in Lagos State using available communication channels is hereby advocated.</p> <p>&nbsp;</p> O. T. Alabi O. J. Olaoye F. O. A. George A. A. Adeola J. O. Alabi W. G. Ojebiyi Copyright (c) 2020-12-24 2020-12-24 55 2 39 58 10.4314/gjas.v55i2.4 Assessment of agro-ecological influence on the seed quality of groundnut (Arachis hypogaea) in The Gambia <p>A survey was conducted to assess the quality of groundnut seed produced and stored under ambient environment across various agro-ecologies of The Gambia, with a view to understanding regions with comparative advantage for its production and storage. Seed production activities of 60 seed growers in 26 communities were collected using structured questionnaires, interviews and observations. The Global Positioning System (GPS) coordinates of the communities were geo-referenced to identify the geographical positioning of the production sites. Samples of the groundnut pods were taken from the seed stores, threshed and subjected to seed quality analysis. Descriptive analysis was used to categorize the seed sources, hectarage cultivated, while seed quality data were subjected to analysis of variance of Nested Design. Means of significant factors were separated using Duncan Multiple Range Test (DMRT) at 5% significant level. The study showed that groundnut seed production is better concentrated in regions with optimum and sustainable rainfall that will reduce abiotic stress during seed development like the Lower River Region, West Coast Region and Central River Region. Fleur-11 variety was identified as one of the most promising varieties for groundnut cultivation in The Gambia and Tropical Africa.</p> J. A. Adetumbi M. Manga D. Jallow N. A. Akintoye T. Omodele Copyright (c) 2020-12-24 2020-12-24 55 2 59 69 10.4314/gjas.v55i2.5 The dynamics of agricultural extension delivery along the value chain: Assessment of agricultural extension activities of MMDAs in Ghana <p>This paper assessed agricultural extension delivery in 216 metropolitan, municipal and district assemblies (MMDAs) in Ghana. It examined the extent of balance and the nature of extension delivery with respect to input supplying, production, processing and marketing. A survey of Heads of the Department of Agriculture in 80 MMDAs randomly selected nationwide was conducted using structured questionnaires. The data were triangulated with in-depth interview sessions with farmers, regional extension officers and private extension providers. The study showed a production-oriented nature of extension delivery across the country with 90% of respondents claiming to have focused extension delivery in their localities on production. This had led to the rather inadequate attention directed at processing and value addition on account of limited capacity of agricultural extension agents. While extension on input supplying was observed to be a private sector-driven activity in the hands of input dealers, the study showed limited extension delivery on marketing as most farmers made their own marketing arrangements. This paper makes a strong case for an extension policy that ensures a reasonable balance and one that introduces competitiveness in value chain activities. The paper also calls for sustained institutional capacity building to give providers a more balanced extension delivery.</p> S.A. Manteaw B.Y. Folitse J.N. Anaglo S. Mahama N.A. Mingle Copyright (c) 2020-12-24 2020-12-24 55 2 70 85 10.4314/gjas.v55i2.6 Dry matter accumulation, distribution and fresh tuber yield of grafted accessions of Hausa potato <p>The Hausa potato is a minor tuber crop with nutritional and medicinal values. A lack of balance between the photosynthetic source potential and the sink capacity in terms of dry matter accumulation and distribution is believed to affect fresh tuber yield. This study was aimed to investigate the dry matter production, distribution and tuber yield of reciprocal grafts of some accessions of the Hausa potato. The grafts were made in all possible combinations and laid out using the completely randomized design in four replicates. Results showed that harvest index increased with time in most of the grafts. The proportion of dry matter partitioned to the tubers was generally lower than those of the leaves and stems in all the grafts. The highest rootstock-scion ratio of 0.97 was observed in the graft Bokkos 2 - Manchok 2 while the lowest (0.07) was observed in the self-graft of Bokkos 2. Fresh tuber yield was generally low, ranging from 0.03 t ha <sup>-1</sup> to 0.09 t ha<sup>-1</sup>. Apart from dry matter accumulation and distribution, the relationship between the source potential and sink capacity as well as the rate of translocation of assimilates from the photosynthetic source to the sink need to be investigated.</p> K.K. Nanbol O.A.T. Namo Copyright (c) 2020-12-24 2020-12-24 55 2 86 96 10.4314/gjas.v55i2.7 Carcass yield and intestinal morphology of male rabbits fed diets supplemented with turmeric (Curcuma Longa) powder <p>Thirty-two (7-8 weeks old) male rabbits that weighed between 700 and 800 g were used to determine the effect of inclusion of Turmeric powder on carcass yield and intestinal morphology of rabbits. The rabbits were randomly allotted to four diets containing varying levels of turmeric powder (0, 5, 10 and 15 g) in a complete randomized design. Data were collected on carcass yield, duodenum, jejunum, ileum, crypt depth, mucosal thickness and analyzed using ANOVA. Significant (p&lt;0.05) differences were obtained on bled and eviscerated weights, forelimbs, hind limbs, neck, tail and loin. Highest (p&lt;0.05) duodenum crypt depth (111.50 μm) was obtained with buck fed diet containing 15 g turmeric inclusion while buck fed with diet containing 0 g turmeric had the least value of (67.67 μm). This was similar (p&gt;0.05) with values obtained for buck fed diets containing 5 g turmeric (73.83 μm) and those fed with 10 g turmeric inclusion (79.33 μm). There was significant difference (P&lt;0.05) of rabbit fed with diets with turmeric on jejunum villi height. There was significant difference (P&lt;0.05) in jejunum crypt depth and mucosal thickness. However, 10 g inclusion could be assumed as economic inclusion level for carcass yield and intestinal increase in rabbit production.</p> E.O. Okanlawon E.O. Okanlawon K.O. Bello O.S. Akinola O.O. Oluwatosin O.T. Irekhore R.O. Ademolue Copyright (c) 2020-12-24 2020-12-24 55 2 97 106 10.4314/gjas.v55i2.8 Effects of ensiling cassava peels on some fermentation characteristics and growth performance of sheep on-farm <p>This study determined the effect of drying or ensiling cassava peels on some conservation characteristics and growth performance of sheep. Fresh peels were either sun-dried to a DM of 904 g/kg or ensiled for 45 days for determination of some chemical and microbial characteristics, and growth performance of sheep. 45 Djallonké sheep were randomly assigned to three supplementary dietary treatments (Control and dried or ensiled) and fed for 70 days. Ensiling reduced the pH from 5.65 in the fresh peel to 4.15 compared to 6.15 in the dried peel. Crude protein (CP) increased from 45±0.44 g/kg DM in the fresh peel to 46±0.48 and 52±0.88 g/kg DM in the dried and ensiled peel, respectively. Reduction in neutral detergent fibre concentration was greater by ensiling than by drying. However, a greater (<em>P </em>= 0.001) reduction in HCN concentration was achieved by drying than by ensiling. Moulds were greater (<em>P </em>= 0.011) in the ensiled than dry peels. Average daily weight gain was higher (<em>P </em>= 0.031) for sheep offered the ensiled than the dried or Control diet. In conclusion, sun-drying was more effective at reducing HCN concentration whereas ensiling improved the CP content of cassava peels and growth performance of sheep.</p> R. Niayale W. Addah A.A. Ayantunde Copyright (c) 2020-12-24 2020-12-24 55 2 107 121 10.4314/gjas.v55i2.9 Evaluating the utilisation of Climate-Smart Agriculture (CSA) technologies and practices among smallholder farmers in The Lawra, Jirapa and Nandom districts of Ghana <p>Climate change is posing threat to agriculture in sub-Saharan Africa including Ghana. Climate-Smart Agriculture (CSA) is proposed to solve climate change impacts on agriculture. Smallholder farmers are adopting various strategies to be resilient to climate change effects. Empirical research is required to evaluate CSA utilisation in Ghana. Lawra, Jirapa and Nandom districts in the climate-risk areas of Guinea Savannah agro-ecological zone were chosen and Participatory Rapid Appraisal (PRA) tools were used. Farm budget analysis and market price methods were employed; key financial decision-making tools were net returns, profit margins and benefit-cost ratio. Soft systems content analysis, frequencies, means, ranking and data aggregation were employed to generate results. CSA use in the study districts was smallholder driven and male dominated. CSA was mainly used for staples including cereals and legumes and small ruminants under livestock. Crop-livestock integration and crop rotation were the common CSA practices with the highest costs (GH¢6,370.00) and highest revenues (GH¢9,460.00) respectively. Utilisation of CSA in the districts is beneficial and investments are profitable and financially viable. All actors and stakeholders must join forces to promote CSA in the districts. Rigorous promotional campaigns, capacity building and funding at all levels are crucial for CSA adoption in Ghana.</p> K.O. Sam V.A. Botchway N. Karbo G.O. Essegbey D. K. Nutsukpo R.B. Zougmoré Copyright (c) 2020-12-24 2020-12-24 55 2 122 144 10.4314/gjas.v55i2.10