Department of Crop Science

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    Reorienting research investments toward under-researched crops for sustainable food systems
    (Food and Energy Security, 2024) Munialo, S.; Siddique, K.H.M.; Amissah, J.N.; et al.
    The dominance of a few staple crops (maize, rice, and wheat) in most agricultural systems hampers the application of interventions to improve food security and nu trition. Research and development attention has focused on improving the pro duction and utilization of these crops, leaving other crops under-researched and underutilized. Subsequently, there have been high malnutrition rates due to poor diet diversity, yet there are “opportunity crops” that remain under researched. The opportunity crops can unlock solutions to food insecurity, malnutrition, a lack of biodiversity, and indeed poor climate adaptation. The study explored diversifica tion in agricultural systems to analyze whether reorientation of research invest ment to include under-researched crops can increase nutrient gain and enhance dietary diversity. Research outputs benchmarked as the number of publications from three leading African universities, Nairobi, Pretoria, and Ghana, were related to crop diversity and nutrition of crops in five clusters: cereals, vegetables, leg umes, roots and tubers, and nuts. The findings show that maize was the predomi nantly researched crop across the three institutions. Low research outputs were observed for pearl millet, finger millet, and yam across the three institutions: ama ranth and nightshade (Pretoria), sweet potatoes (Pretoria and Ghana), Marama bean (Nairobi), and soya bean (Nairobi and Ghana). There was nutrient gain across all five clusters, particularly from under-researched indigenous crops such as finger millet, amaranth, nightshade, yam, sweet potatoes, Marama bean, and soybean. Nutrient gain was contributed more by cereals and root and tuber crops from Pretoria, vegetables and nuts (Ghana), as well as legumes (Nairobi). The find ings demonstrate that incorporating research on the least researched crops with successful integration of other research and development initiatives (policy and dissemination) can increase nutrition and improve dietary diversity. The nutrient gain will positively affect food security and nutrition, contributing to the achieve ment of Africa Agenda 2063, the United Nation's Sustainable Development Goals,and reducing food imports. The findings can inform research investment and decision across different institutions within the African continent. Research in vestment targeting crops such as finger millet, amaranthus, sweet potatoes, soya beans, and cashew nuts is needed considering the nutritional contribution, cli mate change adaptability, market potential, and biodiversity contribution. Further analysis should explore production, socio-economic (marketability and income generation), and environmental gains (adaptive ability to climate change) for spe cific crops. The development of frameworks to guide the analysis of the nature and scope of factors affecting the contribution of these crops to food security and nutri tion, as well as research on specific crops considering geographic distribution and institutional involvement, is also needed.
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    Evaluation of Preplant Seed Protectants for the Management of Root-Knot Nematode of Okra in Ghana
    (International Journal of Agronomy, 2024) Baah, P.; . Nyaku, S.T.; Agamah, B.; Tongoona, P.B.
    Root-knot nematode (Meloidogyne incognita) poses a signifcant threat to okra production, resulting in substantial yield losses. Te objectives of this study were to assess the impact of biological seed protectants on the growth and establishment of okra plants and nematode population reduction in soil. Okra seeds were coated with 40% sesame oil, 50% neem oil, 100% citrus oil, velum at 3.8 ml/7l of water, and a control (sterilized distilled water) at diferent time intervals of 30 min, 60 min, 90 min, and 120 min to determine the germination percentages and vigor. Te experimental setup was laid out in a completely randomized design (CRD), with three replications, utilizing a Jacobson table for the germination test. Te laboratory results demonstrated signifcant diferences (P < 0.05) in germination percentage and vigor index across the diferent time intervals. Neem oil, citrus oil, and velum exhibited higher germination percentages and vigor indices at all time intervals. Notably, 30-minute time interval proved to be efcient with 100% citrus oil producing 80.33% germination and 965 vigor index and 50% neem oil producing 75% germination and 994 vigor index. Field evaluations revealed citrus at 100% concentrations as seed coating (T5) and neem at 50% concentrations as seed coating (T3), with the highest nematode reductions (90.1% and 90.4%) and least reproductive factors (RFs) of 0.05 and 0.04, respectively, at the Atomic farms. Te study has revealed that treating okra seeds with 100% citrus oil and 50% neem oil has the efcacy of reducing nematode reproduction in soil, while enhancing germination and seedling vigor, together with an improvement in growth and yield. Sesame oil has a negative infuence on seed germination and vigor and is therefore not recommended as a preplant protectant
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    Response of pepper (Capsicum annuum L.) to preemergence application of Oxadiargyl and pendimethalin
    (Journal of Agriculture and Food Research, 2023) Nketiah, V.; Ofosu–Anim, J.; Cornelius, E.W.; Kotey, D.A.; Tetteh, R.
    Two field experiments were conducted in two agro-ecological zones of Ghana (Forest and Coastal Savannah) to assess the efficacy of preemergence herbicides Oxadiargyl and Pendimethalin on weed incidence, growth and yield of pepper. The experiment was factorial arranged in a randomized complete block design. The treatments were Oxadiargyl at 0.4, 0.5, 0.6 L/ha, Pendimethalin at 1.5, 2.0, 2.5 L/ha and hand weeding at intervals of 3, 6 and 9 weeks as control. Data was collected on weed type and abundance, number of days to weed emergence, type of re-emerging weeds and percentage weed cover. Data on plant height, number of branches per plant, yield and yield components of pepper plants were also collected. Results indicated that application of Pendimethalin led to a significantly (p < 0.05) longer number of days to weed emergence as compared to the application of Oxadiargyl which also delayed weed emergence significantly longer than hand weeding. Plant height was not affected by weed control method. The yield of pepper plants was significantly higher in plots where Pendime thalin (2.0 L/ha) was applied. Generally, the yield components of pepper plants have been positively affected by weed control treatments. However, application of Pendimethalin at 2.0 L/ha resulted in better weed control
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    Influence of β-Ionone in the Phytotoxicity of the Rhizome of Iris pallida Lam
    (Plants, 2024) Sothearith, Y.; Appiah, K.S.; Sophea, C.; et al.
    Iris pallida Lam., also known as Sweetie Iris, is a perennial ornamental and medicinal plant that produces a wide range of secondary metabolites. The Sweetie Iris was recently reported to have high allelopathic properties with the potential to be explored in sustainable weed management. This study aimed to identify and evaluate the contributions of compounds involved in the inhibitory effects of the rhizome of Sweetie Iris. High-performance liquid chromatography (HPLC) analysis was used to determine the content of β-ionone in the rhizome of Sweetie Iris. The phytotoxicity of β-ionone was evaluated on lettuce (Lactuca sativa L.) and other test plants. The content of β-ionone The crude extract of Sweetie Iris rhizome was found to be 20.0 mg g1 by HPLC analysis. The phytotoxicity bioassay showed that β-ionone had strong inhibitory activity on the growth of lettuce (Lactuca sativa L.) and the other test plants, including Taraxacum officinale, Stellaria media, Eleusine indica, Amaranthus hybridus, Vicia villosa, and Brassica napus. At a concentration of 23.0 µg mL−1, , β-ionone inhibited the growth of all test plant species treated. Therefore, β-ionone is an active compound among the other allelopathic substances contained in the rhizome of Sweetie Iris.
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    Mechanisms and modelling approaches for excessive rainfall stress on cereals: Waterlogging, submergence, lodging, pests and diseases
    (Agricultural and Forest Meteorology, 2024) Kim, Y-UK.; Webber, H.; Adiku, S.G.K.
    As the intensity and frequency of extreme weather events are projected to increase under climate change, assessing their impact on cropping systems and exploring feasible adaptation options is increasingly critical. Process-based crop models (PBCMs), which are widely used in climate change impact assessments, have improved in simulating the impacts of major extreme weather events such as heatwaves and droughts but still fail to reproduce low crop yields under wet conditions. Here, we provide an overview of yield-loss mechanisms of excessive rainfall in cereals (i.e., waterlogging, submergence, lodging, pests and diseases) and associated modelling approaches with the aim of guiding PBCM improvements. Some PBCMs simulate waterlogging and ponding environments, but few capture aeration stresses on crop growth. Lodging is often neglected by PBCMs; however, some stand-alone mechanistic lodging models exist, which can potentially be incorporated into PBCMs. Some frameworks link process-based epidemic and crop models with consideration of different damage mech anisms. However, the lack of data to calibrate and evaluate these model functions limit the use of such frame works. In order to generate data for model improvement and close knowledge gaps, targeted experiments on damage mechanisms of waterlogging, submergence, pests and diseases are required. However, consideration of all damage mechanisms in PBCM may result in excessively complex models with a large number of parameters, increasing model uncertainty. Modular frameworks could assist in selecting necessary mechanisms and lead to appropriate model structures and complexity that fit a specific research question. Lastly, there are potential synergies between PBCMs, statistical models, and remotely sensed data that could improve the prediction ac curacy and understanding of current PBCMs’ shortcoming
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    Sustainable P-enriched biochar-compost production: harnessing the prospects of maize stover and groundnut husk in Ghana’s Guinea Savanna
    (Frontier in Environment Science, 2023) Fianko, D.A.; Nartey, E.K.; Abekoe, M.K.; et al.
    Farmers in resource-poor areas of the Guinea Savanna zone of Ghana often face declining soil fertility due to the continuous removal of nutrient-rich harvested produce from their fields. This study focuses on the Lawra Municipality in the Guinea Savanna zone of Ghana, where low soil fertility, specifically, limits phosphorus (P) bioavailability and hinders crop production. The objective of this research is to formulate P-enhanced biochar-compost from maize stover (MS) and groundnut husk, which abound in the area, to close the nutrient loop. MS was co-composted with groundnut husk biochar at varying rates of 0, 10, 20, 30, and 40% by volume. To facilitate decomposition using the windrow system, the composting heaps were inoculated with decomposing cow dung, and the moisture content was kept at 60% throughout the monitoring period. The addition of biochar shortened the lag phase of composting. However, rates above 20% resulted in reduced degradation of MS. Biochar incorporation enriched the available phosphorus content in the final compost from 286.7 mg kg−1 in the non-biochar-compost to 320, 370, 546, and 840.0 mg kg−1 in the 10, 20, 30, and 40% biochar-compost, respectively
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    The use of Beauveria bassiana for the control of the larger grain borer, Prostephanus truncatus, in stored maize: Semi-field trials in Ghana
    (Fungal Biology xxx, 2023) Luke, B.; Acheampong, M.A.; Rangel, D.E.N.; et al.
    Laboratory research in Ghana demonstrated the effectiveness of an isolate of Beauveria bassiana (IMI 389521) from the United Kingdom against the larger grain borer Prostephanus truncatus (Horn) (Cole optera: Bostrichidae), a major pest of stored maize. The minimum effective concentration, following artificial infestation trials on maize, was between 109 and 1010 cfu/kg maize. Before moving out to village level control, a major requirement was to determine if the product could effect control in artificially infested maize held under real environmental conditions in several locations in Ghana. Therefore, this study investigated the efficacy of formulated conidia of B. bassiana, IMI 389521, at two concentrations (1 109 and 3.16 109 cfu/kg maize) to control P. truncatus on stored maize kernels under semi-field conditions in Ghana. Maize (‘Obatanpa’ cultivar) kernels were treated with the formulated B. bassiana product and stored in polypropylene woven bags in cribs in Southern Ghana. After 24 h, one hundred adults of P. truncatus were placed into each bag containing the treated maize. Mortality and the percent of weight loss of kernels were assessed every two weeks for three months. The semi-field trials revealed the possibility of successfully controlling adult P. truncatus on maize kernels treated with B. bassiana at 3.16 109 cfu/kg maize. However, due to the minimal protection of kernels after four weeks, re-treating maize kernels after this period is recommended to ensure maximum protection during prolonged storage.
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    Exploring genetic variability, heritability, and trait correlations in gari and eba quality from diverse cassava varieties in Nigeria
    (Journal of The Science of Food and Agriculture published by John Wiley & Sons Ltd on behalf of Society of Chemical Industry, 2023) Aghogho, C.I.; Kayondo, S.I.; Offei, S.K.
    BACKGROUND: Gari (especially in Nigeria) is an important West African food product made from cassava. It is an affordable, precooked, dry, easy to prepare and store food product. Eba is a stiff dough produced by reconstituting gari in hot water. Gari and eba quality is an important driver of varietal acceptance by farmers, processors, and consumers. RESULTS: This study characterized the genetic variability, heritability, and correlations among quality-related traits of fresh roots, gari, and eba. Thirty-three diverse genotypes, including landraces and released and advanced breeding genotypes, were used in this study. In total, 40 traits categorized into fresh root quality, colour, functional, and texture properties trait groups were assessed. We observed broad phenotypic variability among the genotypes used in this study. Dry matter content had a positive (P < 0.05) correlation with gari%, bulk density and a negative correlation with eba hardness and gumminess. Broadsense heritability across all environments varied considerably among the different trait groups: 62% to 79% for fresh root quality, 0% to 96% for colour, 0% to 79% for functional and 0% to 57% for texture properties. CONCLUSIONS: The stable broad-sense heritability found for gari%, gari and eba colour, bulk density, swelling index, and hardness measured using instrumental texture profile analysis coupled with sufficient variability in the population indicate good potential for genetic improvement of these traits through recurrent selection. Also, it is possible to genetically improve gari%, bulk density, and swelling power by simultaneously improving the dry matter content of fresh roots.
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    Plant Growth Inhibitory Activity of Hibiscus sabdariffa Calyx and the Phytotoxicity of Hydroxycitric Acid Lactone
    (2023) Tugba, G.I.O.; Appiah, K.S.; Akalin, E.; Yoshiharu, F.
    Weeds pose major constraints in crop production. The use of allelochemicals and allelopathic species can provide an effective alternative for sustainable weed management. In a previous study that evaluated the allelopathic activity of wild and cultivated plants in Turkey, Hibiscus sabdariffa demonstrated the strongest inhibitory potential. This study aimed to estimate the phytotoxic influence of the H. sabdariffa water crude extracts on Lactuca sativa L. in a bioassay experiment. High-performance liquid chromatography (HPLC) analysis was used to identify two major compounds, hydroxycitric acid lactone and hydroxy citric acid, and their plant growth inhibitory activities were evaluated by bioassays. Hydroxycitric acid lactone had a stronger growth inhibitory activity on L. sativa L. and was estimated as a major allelochemical in H. sabdariffa calyx. The high concentration (16.7% of the dry weight of the calyx) and strong inhibitory effect (EC50, 73.7 ppm) of the hydroxycitric acid lactone could demonstrate the growth inhibitory activity of the H. sabdariffa calyx extract. This study showed that hydroxycitric acid lactone, a major compound in the calyx of Hibiscus sabdariffa, is a plant growth inhibitor.
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    Conidial mass production of entomopathogenic fungi and tolerance of their mass-produced conidia to UV-B radiation and heat
    (Fungal Biology, 2023) Rangel, D.E.N,; Acheampong, M.A.; Bignayan, H.G.; et al.
    We investigated conidial mass production of eight isolates of six entomopathogenic fungi (EPF), Apha nocladium album (ARSEF 1329), Beauveria bassiana (ARSEF 252 and 3462), Lecanicillium aphanocladii (ARSEF 6433), Metarhizium anisopliae sensu lato (ARSEF 2341), Metarhizium pingshaense (ARSEF 1545), and Simplicillium lanosoniveum (ARSEF 6430 and 6651) on white or brown rice at four moisture condi tions (75e100%). The tolerance of mass-produced conidia of the eight fungal isolates to UV-B radiation and heat (45 C) were also evaluated. For each moisture content compared, a 20-g sample of rice in a polypropylene bag was inoculated with each fungal isolate in three replicates and incubated at 28 ± 1 C for 14 days. Conidia were then harvested by washing the substrate, and conidial concentrations deter mined by haemocytometer counts. Conidial suspensions were inoculated on PDAY with 0.002% benomyl in Petri plates and exposed to 978 mW m 2 of Quaite-weighted UV-B for 2 h. Additionally, conidial suspensions were exposed to 45 C for 3 h, and aliquots inoculated on PDAY with benomyl. The plates were incubated at 28 ± 1 C, and germination was assessed at 400 magnification after 48 h. Conidial production was generally higher on white rice than on brown rice for all fungal species, except for L. aphanocladii ARSEF 6433, regardless of moisture combinations. The 100% moisture condition provided higher conidial production for B. bassiana (ARSEF 252 and ARSEF 3462) and M. anisopliae (ARSEF 2341) isolates, while the addition of 10% peanut oil enhanced conidial yield for S. lanosoniveum isolate ARSEF 6430. B. bassiana ARSEF 3462 on white rice with 100% water yielded the highest conidial production (approximately 1.3 1010 conidia g 1 of substrate). Conidia produced on white rice with the different moisture conditions did not differ in tolerance to UV-B radiation or heat. However, high tolerance to UV B radiation and heat was observed for B. bassiana, M. anisopliae, and A. album isolates. Heat-treated conidia of S. lanosoniveum and L. aphanocladii did not germinate.
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    Combined effects of shade and drought on physiology, growth, and yield of mature cocoa trees
    (Science of the Total Environment, 2023) Mensah, E.O.; Ræbild, A.; Asare, R.; et al.
    Climate models predict decreasing precipitation and increasing air temperature, causing concern for the future of cocoa in the major producing regions worldwide. It has been suggested that shade could alleviate stress by reducing radiation intensity and conserving soil moisture, but few on-farm cocoa studies are testing this hy pothesis. Here, for 33 months, we subjected twelve-year cocoa plants in Ghana to three levels of rainwater suppression (full rainwater, 1/3 rainwater suppression and 2/3 rainwater suppression) under full sun or 40 % uniform shade in a split plot design, monitoring soil moisture, physiological parameters, growth, and yield. Volumetric soil moisture (ϴw) contents in the treatments ranged between 0.20 and 0.45 m3 m− 3 and increased under shade. Rainwater suppression decreased leaf water potentials (ѱw), reaching − 1.5 MPa in full sun con ditions indicating severe drought. Stomatal conductance (gs) was decreased under the full sun but was not affected by rainwater suppression, illustrating the limited control of water loss in cocoa plants. Although pre dawn chlorophyll fluorescence (Fv/Fm) indicated photoinhibition, rates of photosynthesis (Pn) were highest in full sun. On the other hand, litter fall was highest in the full sun and under water stress, while diameter growth and carbon accumulation increased in the shade but was negatively affected by rainwater suppression. Abortion of fruits and damage to pods were high under shade, but dry bean yield was higher compared to under the full sun. The absence of interactions between shade treatments and rainwater suppression suggests that shade may improve the performance of cocoa, but not sufficiently to counteract the negative effects of water stress under field conditions.
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    Plant Growth Inhibitory Activity of Hibiscus sabdariffa Calyx and the Phytotoxicity of Hydroxycitric Acid Lactone
    (Agronomy, 2023) Ozkan, T.G.I.; Appiah, K.S.; Akalin, E.; Fujii, Y.
    Weeds pose major constraints in crop production. The use of allelochemicals and allelopathic species can provide an effective alternative for sustainable weed management. In a previous study that evaluated the allelopathic activity of wild and cultivated plants in Turkey, Hibiscus sabdariffa demonstrated the strongest inhibitory potential. This study aimed to estimate the phytotoxic influence of the H. sabdariffa water crude extracts on Lactuca sativa L. in a bioassay experiment. High-performance liquid chromatography (HPLC) analysis was used to identify two major compounds, hydroxycitric acid lactone and hydroxy citric acid, and their plant growth inhibitory activities were evaluated by bioassays. Hydroxycitric acid lactone had a stronger growth inhibitory activity on L. sativa L. and was estimated as a major allelochemical in H. sabdariffa calyx. The high concentration (16.7% of the dry weight of the calyx) and strong inhibitory effect (EC50, 73.7 ppm) of the hydroxycitric acid lactone could demonstrate the growth inhibitory activity of the H. sabdariffa calyx extract. This study showed that hydroxycitric acid lactone, a major compound in the calyx of Hibiscus sabdariffa, is a plant growth inhibitor.
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    Food safety in the horticultural sector in Ghana: challenges, risk factors and interventions
    (Frontier in Sustainable Food Systems, 2023) Essilfie, G.L.; Lamptey, S.; Baddoo, R.N.N.; et al.
    The fruit and vegetable industry remains one of Ghana’s most promising agricultural sectors mainly because of heightened awareness of the health benefits associated with their consumption. However, food safety is of ultimate concern due to the association of foodborne hazards resulting in escalation of foodborne illness. This report is a review of key foodborne hazards in Ghana’s horticultural value chain. The study identified the risk factors and hazards that contaminate fruits and vegetables in addition to existing methods for mitigating health risks and reducing pathogen levels in the produce. The study revealed that enteric pathogens such as Escherichia coli and Salmonella spp. mainly contaminate produce through fresh manure and contaminated irrigation water used during the production of vegetables. Chemical hazards identified included pesticides (organochlorine pesticides) and heavy metals such as cadmium, arsenic, chromium, and lead. Physical hazards identified included twigs, roots, sand, and stones. Washing fruits and vegetables thoroughly with potable water and sanitizing with vinegar and Chlorine solutions were among the common practices stakeholders adopted to reduce microbial levels. Soil remediation was also reported as a common approach for reducing chemical contaminants in agricultural fields. The study, therefore, recommends establishing a traceability system as well as appropriate measures and standards for hygienic practices for fresh fruits and vegetables produced and sold on the local market in Ghana. Value chain actors should be sensitized regularly on measures and interventions that can be employed to significantly reduce the levels of foodborne hazards and associated risks.
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    The IV International Symposium on Fungal Stress and the XIII International Fungal Biology Conference
    (Fungal Biology, 2023) Alder-Rangel, A.; Bailao, A.M.; Acheampong, M.A.; et al.
    For the first time, the International Symposium on Fungal Stress was joined by the XIII International Fungal Biology Conference. The International Symposium on Fungal Stress (ISFUS), always held in Brazil, is now in its fourth edition, as an event of recognized quality in the international community of mycological research. The event held in S~ ao Jose dos Campos, SP, Brazil, in September 2022, featured 33 renowned speakers from 12 countries, including: Austria, Brazil, France, Germany, Ghana, Hungary, Mexico, Pakistan, Spain, Slovenia, USA, and UK. In addition to the scienti fic contribution of the event in bringing together national and international researchers and their work in a strategic area, it helps maintain and strengthen international cooperation for scientific development in Brazil
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    Grafting for sustainable management of Fusarium wilt disease in tomato production in Ghana
    (Journal of Agriculture and Food Research, 2023) Awu, J.E.; Nyaku, S.T.; Amissah, J.N.; Okorley, B.A.; Agyapong, P.J.A.; Doku, F.E.; Nkansah, G.O.
    Fusarium wilt disease limits tomato production, especially in Ghana. In managing the Fusarium wilt disease, two rootstocks (Solanum torvum and Solanum macrocarpon) were used in grafting experiments. Plant growth, yield, disease severity and incidence of both grafted plants, and non-grafted plants were evaluated in a pot experiment and also under a naturally infected open field condition at Berekum. During the early stage (14 days after inoculation) under artificial inoculation conditions, grafted plants exhibited higher photosynthetic rates (10.41 μmol− 2 s − 1 ) compared to the non-grafted plants (8.36 μmol− 2 s − 1 ). Under naturally infested field conditions, chlorophyll content and photosynthetic rate of non-grafted plants decreased. Solanum lycopersicum grafted onto S. macrocarpon and S. torvum were moderately susceptible (20%–40%) to Fusarium oxysporum. However, the non grafted plants were highly susceptible (50%–100%). Yield from the pot experiment for S. lycopersicum grafted onto S. macrocarpon was significantly higher (453.1 g/plant), compared to S. lycopersicum grafted onto S. torvum (350.3 g/plant) and the non-grafted plant (205 g/plant). However, in naturally infected field, the grafted plants increased in fruit yield compared to the non-grafted tomato plants. Solanum macrocarpon and S. torvum as rootstocks offered resistance against F. oxysporum and showed significantly lower disease progression, than the non-grafted plants (P < 0.05). This study revealed that grafting is an effective tool for the management of Fusarium wilt disease and for tomato growth and yield improvement.
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    Cowpea Cropping Systems, Traits Preference and Production Constraints in the Upper West Region of Ghana: Farmers’ Consultation and Implications for Breeding
    (CABI Agriculture and Bioscience, 2023) Karikari, B.; Akakpo, D.B.; et al.
    Background Cowpea (Vigna unguiculata (L.) Walp) is used primarily as food for humans and feed for animals. It is also used for soil management within a cropping system. However, cowpea production is confronted with numerous challenges. As such farmers and consumers alike have certain preferences in terms of production and utilization. This present study investigated cowpea cropping systems, traits preference and production constraints among farmers in the Nandom, Lambusie and Lawra districts in the northern part of the Upper West Region of Ghana. A total of 306 farming households were sampled from the 3 chosen districts. Questionnaires and interviews were used for data collection. The IBM SPSS software, version 22, was employed to analyze the data using descriptive statistics, specifically frequencies, percentages and crosstabulations. Results The study’s results indicated that a majority (58.5%) of the cowpea farmers practice intercropping, whereas a minority (41.5%) practice sole cropping. The farmers intercropped cowpea with maize, millet, sorghum and yam. Farmers preferred cowpea varieties with the following traits: high yield, drought tolerance, early maturing, pest resistance, improve soil fertility, high price, high demand, better taste, less cooking time, storage quality, palatability and fast growing. Farmers indicated that susceptibility to storage pests, high pest incidence, late maturity, difficulty in harvesting, high input cost, small grain size, low yield, high disease incidence, poor colour, lack of improved variety, and drought are some constraints that hinder cowpea production. Conclusion Results indicate a need for behavioural change communication to assist cowpea farmers to adopt improved and appropriate cropping systems. Farmers should be involved in cowpea technology development in order to understand their preferences and constraints to enable subsequent adoption of such technologies. The results from this study call for an interdisciplinary committee to plan and breed cowpea varieties that meet the needs of the farmers.
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    Evaluation of Agronomic Performances and Fruit Quality of Improved Tomato (Solanum lycopersicum L.) lines under greenhouse conditions
    (Journal of Agriculture and Food Research, 2022) Asare-Addo, D.C.; Amissah, J.N.; Ofori, P.A.; Owusu-Nketia, S.; Opoku-Agyemang, F.; Nkansah, G.O.
    A B S T R A C T Although agriculture is the driving force of Ghana’s economy, accounting for one third of GDP and employing more than half of the workforce, Ghana is still far from achieving food security due to serious challenges facing the sector. If agriculture is to fulfill its promise of achieving food and nutrition security in Ghana by 2030, it must take drastic steps towards enhancing vegetable crop production. Greenhouse technology is fast gaining recognition in urban and peri-urban areas. Low tomato production in Ghana is a problem owing to the lack of improved and high-yielding varieties. Evaluation of improved lines of tomato under greenhouse condition which is a fast-growing technology in Ghana can help identify adaptable and promising lines for cultivation. This can lead to increased tomato production as well as meeting consumer demands. In this study, 12 improved lines and 2 local checks of tomato were evaluated under greenhouse conditions to determine their agronomic performances, and fruit quality traits using a Randomized Complete Block Design (RCBD) with three replications. The results indicate that Lines J138 and B24 recorded the highest yields (20.05 t/ha and 23.03 t/ha respectively) whiles the check varieties, Anna F1 and Nkansah HT gave yields of 18.77 t/ha and 16.96 t/ha, respectively. Lines B24, B25, J138, B45 and B46 also exhibited good fruit quality traits such as pH, pericarp thickness, fruit firmness and shelf life. These promising lines of tomato could be useful germplasm in tomato breeding programmes in Ghana and for cultivation under greenhouse conditions.
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    Influence of Mowing and Trampling on the Allelopathy and Weed Suppression Potential of Digitaria ciliaris and Cyperus microiria
    (Sustainability, 2022) Biramahire, B.; Appiah, K.S.; Tojo, S.; Fujii, Y.; Chosa, T.
    Abstract: A long-term, sustainable solution to weed infestation is extremely desirable because weeds have the potential to reduce crop productivity and the aesthetic appeal of the environment. In this study, the impacts of mowing and varying degrees of trampling pressure on the suppression of weeds, alongside wound-induced changes in the allelopathic potential, of the rhizosphere soil and the root exudates of southern crabgrass (Digitaria ciliaris) and Asian flatsedge (Cyperus microiria) were evaluated under both field and greenhouse conditions. The field study results showed that all trampling treatments induced the relative suppression of weed growth. Grass weeds showed higher resistance to trampling than broad-leaved weeds. However, laboratory bioassays showed that light trampling caused a significant increase in the growth-inhibitory effects of southern crabgrass rhizosphere soil on lettuce. Moreover, mowing (9.11% of control) and trampling (16.4% of control) resulted in a marginal increase in the growth-inhibitory effects of root exudates released from southern crabgrass. Furthermore, the growth-inhibitory activities of the Asian flatsedge rhizosphere soil were significantly reduced after heavy trampling pressure. Moreover, mowing and trampling resulted in marginal reductions in the growth-inhibitory activities of root exudates released from Asian flatsedge against lettuce (i.e., 18.7% and 28.5%, respectively). In general, mowing and varying degrees of trampling induced contrasting and integrated impacts on weed suppression as well as the allelopathic potential of both southern crabgrass and Asian flatsedge.
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    Identification of sources of resistance in cowpea lines to Macrophomina root rot disease in Northern Ghana
    (Heliyon, 2023) Lamini, S.; Kusi, F.; Cornelius, E.W.; Danquah, A.; Attamah, P.; Mukhtaru, Z.; Awuku, F.J.; Owusu, E.Y.; Acheampong, M.; Mensah, G.
    Macrophomina root rot disease (MRRD) caused by Macrophomina phaseolina is an emerging threat to the profitable cowpea production in northern Ghana. Recommended control methods including the use of fungicides are ineffective and expensive for resource poor farmers whilst biocontrol options are not commercially available. An integrated method based on host plant resistance is considered the cheapest and most effective method of managing the disease. This study sought to confirm and characterize previously identified MRRD isolates from Northern Ghana using molecular technology, and to identify cowpea with potential sources of resistance to the MRRD. A PCR assay of ten isolates of the cowpea root rot pathogen revealed all isolates belonged to the species M. phaseolina, whilst a nucleotide BLAST of eight isolates showed 98% similarity with the sequences of Macrophomina isolates from other host available in GenBank. A sick pot method evaluation of 49 cowpea lines found 10 lines resistant to MRRD on a 1–9 disease severity scale (disease score, less than 5). A selection of eight resistant lines (Suvita 2, Abagbaala, IT97K573-1-1, IT93K 503-1-1, Hewale, AV2 3224, Nhyira and T2T4), and a susceptible check (Songotra) were evaluated against 10 isolates of M. phaseolina using a sick pot method. All the genotypes except for the susceptible check were resistant to MRRD. Thus, these genotypes could be used in cowpea MRRD resistance breeding programs.
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    Limited effects of shade on physiological performances of cocoa (Theobroma cacao L.) under elevated temperature
    (Environmental and Experimental Botany, 2022) Mensah, E.O.; Asare, R.; Vaast, P.; Amoatey, C.A.; Markussen, B.; Owusu, K.; Asitoakor, B.K.; Asitoakor, A.
    Shade is one of the recommended management solutions to mitigate the effects of heat stress, which is a major challenge for cocoa production globally. Nevertheless, there are limited studies to verify this hypothesis. Here, we evaluate the effects of heat and shade on cocoa physiology using experimental plots with six-month old potted seedlings in a randomized complete block design. Infrared heaters were applied for one month to increase leaf temperatures by an average of 5–7 ºC (heat treatment) compared with no heat (unheated treatments), and shaded plants were placed under a shade net removing 60% of the light compared with no shade (sun treatments). Plants under heat treatments in sun and in shade showed severe reduction in photosynthesis. Measurements of chlo rophyll fluorescence and photosynthetic light response curves indicated that heat caused damages at photo system II and additionally resulted in lower rates of maximal photosynthesis. Temperature optima for photosynthesis were at 31–33 ºC with only small differences between treatments, and as light saturation was reached at low PAR levels of 325 – 380 µmol m− 2 s − 1 in shade and 427 – 521 µmol m− 2 s − 1 in sun, ambient rates of photosynthesis were comparable between sun and shade treatments. Heat treatments resulted in decreased concentrations of chlorophyll and changed pigment composition, reduced specific leaf areas, and plant biomass. While shade may benefit cocoa seedlings, our results indicate that the positive effects may not be sufficient to counteract the negative effects of increased temperatures on cocoa physiology.