Faculty of Natural Resources Management and Agriculture

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Poor maize productivity in Zimbabwe: Can collusion in pricing by seed houses be the cause?
(Cogent OA, part of Taylor & Francis Group, 2019-11-04) Tibugari, Handsen; Chikasha, Tinei; Manyeruke, Ngonidzaishe; Mathema, Ndabanye; Musara, Joseph P.; Dlamini, Dumisa; Mapuranga, Rangarirai; Mapanje, Olga; Banda, Annabel; Parwada, Cosmas
High cost of hybrid seed can affect food self-sufficiency. A study was conducted to investigate the structure, conduct and performance of the hybrid maize seed industry in Zimbabwe to determine whether the level of competition in the industry caused high and unstable prices. Primary data on the quantity of hybrid maize produced and/or marketed, pricing strategies and hybrid maize seed prices for the period 2011 to 2015 was collected using questionnaires administered to marketing managers of 10 seed houses involved in hybrid maize seed production and marketing in Zimbabwe as well as key stakeholders. The questionnaires were also used as interview guides for key informant interviews with production managers of respective seed houses. Secondary data were obtained from annual reports and technical bulletins of respective companies. The analysis involved respondent triangulation as well as triangulating the data from responses with secondary data in order to increase the convergent validity of the data. Descriptive statistics, ANOVA and trend analysis were used for data analysis. Results indicated that the hybrid maize seed industry in Zimbabwe is highly concentrated meaning that there is low competition. The study established that there may be tacit collusion in the pricing of hybrid maize seed in the form of dominant firm price leadership. The study showed that prices have not been stable for the period 2011 to 2015. It is recommended that the government should enact policies that; prohibit abuse of a dominant position, prohibit mergers which create or strengthen a dominant position and prohibit state aid that creates monopolies.
Characterisation of upland cotton grown in Zimbabwe using agronomical and morphological markers for Verticillium wilt tolerance
(Cogent OA, part of Taylor & Francis Group, 2020-05-25) Chapepa, Blessing; Mapuranga, Rangarirai; Manjeru, Pepukayi
Accurate morphological characterisation of plants is used for selecting the best performing varieties. The morphological markers can be visualised without molecular techniques making it the easiest way of identifying variation within varieties. Characterisation of Verticillium wilt tolerant lines in cotton variety is important in understanding the underlying genetic control of Verticillium wilt tolerance. Five local varieties with varying tolerance to the disease and different yield potentials were crossed in a half diallel mating design in 2013. The ten crosses and five parental lines that were produced by the mating system were subjected to Verticillium wilt by artificial inoculation in 2013/14. These cotton lines were characterised using agronomic and morphological markers to identify Verticillium wilt resistance. Screening for Verticillium wilt resistance was done to identify morphological and agronomical markers which were used to group similar lines through cluster analysis. Three parental lines were identified with good morphological and agronomical performance that could be used in Verticillium wilt resistance breeding. These were CRI-MS-1, SZ9314 and BC853 which produced superior offspring in the diallel mating system. Furthermore, qualitative morphological traits and the agronomical traits were used as markers for selection of Verticillium wilt resistance cotton germplasm.
The impact of plant density and spatial arrangement on light interception on cotton crop and seed cotton yield: an overview
(BMC., 2020-07-27) Chapepa, Blessing; Mudada, Nhamo; Mapuranga, Rangarirai
Light attenuation within a row of crops such as cotton is influenced by canopy architecture, which is defined by size, shape and orientation of shoot components. Level of light interception causes an array of morpho-anatomical, physiological and biochemical changes. Physiological determinants of growth include light interception, light use efficiency, dry matter accumulation, duration of growth and dry matter partitioning. Maximum light utilization in cotton production can be attained by adopting cultural practices that yields optimum plant populations as they affect canopy arrangement by modifying the plant canopy components. This paper highlights the extent to which spatial arrangement and density affect light interception in cotton crops. The cotton crop branches tend to grow into the inter-row space to avoid shade. The modification of canopy components suggests a shade avoidance and competition for light. Maximum leaf area index is obtained especially at flowering stage with higher populations which depicts better yields in cotton production.
Worrying cadmium and lead levels in a commonly cultivated vegetable irrigated with river water in Zimbabwe
(Cogent OA, part of Taylor & Francis Group, 2020-08-10) Tibugari, Handsen; Mafere, Gerald; Dube, Sinikiwe; Chakavarika, Murawu; Mandumbu, Ronald; Musara, Joseph P.; Mapuranga, Rangarirai; Gumbo, Tapiwa; Banda, Annabel; Mathema, Ndabanye; Goche, Tatenda; Zvigumbu, Bernard M.; Mpofu, Nkosentsha
Vegetable cultivation using river water, which may be polluted with heavy metals, can cause health problems to consumers. A study to establish cadmium and lead levels in water from Msasa, Manyame; Mukuvisi and Nyatsime Rivers was conducted in 2019. A questionnaire survey involving 105 randomly selected urban vegetable growers was conducted to examine farmer knowledge of the potential of polluted water to contaminate produce through heavy metals. Water, soil and vegetable samples were also collected and analysed for heavy metal presence using atomic absorption spectrophotometry. Results showed that some farmers (62%) were aware that wastewater could contain heavy metals. The majority of farmers (67%) applied phosphate-based fertilisers, a potential source of cadmium. Tested at P < 0.05, the results showed that sampled water from the four sites failed to meet the Standards Association of Zimbabwe 5560 (1997) standards. Cadmium tissue concentration from wastewater from Msasa and Manyame rivers was 1.3 and 1.17 mg g−1 respectively, which were 59 and 65 times higher than 0.02 mg g−1 from the control. Water from Manyame and Nyatsime rivers contains levels of heavy metals which exceed the Environmental Management Agency (EMA) safety guidelines. Farmers need to be educated on health hazards from contaminated wastewater. Enforcing regulations on effluent disposal, licencing of vegetable vendors and labelling of vegetables with information on source of water used to irrigate the crop can help reduce exposure of unsuspecting vegetable consumers.
Heat Stress Triggers Differential Protein Accumulation in the Extracellular Matrix of Sorghum Cell Suspension Cultures
(MDPI, 2020-10-22) Ngcala, Mamosa G.; Goche, Tatenda; Brown, Adrian P.; Chivasa, Stephen; Ngara, Rudo
Plants reprogram gene expression as an adaptive response to survive high temperatures. While the identity and functions of intracellular heat stress-responsive proteins have been extensively studied, the heat response of proteins secreted to the extracellular matrix is unknown. Here, we used Sorghum bicolor, a species adapted for growth in hot climates, to investigate the extracellular heat-induced responses. When exposed to 40 ◦C for 72 h, heat-sensitive Arabidopsis cell suspension cultures died, while ICSB338 sorghum cell cultures survived by activation of a transcriptional response characterized by the induction of HSP70 and HSP90 genes. Quantitative proteomic analysis of proteins recovered from cell culture medium revealed specific heat stress-induced protein accumulation within the sorghum secretome. Of the 265 secreted proteins identified, 31 responded to heat (≥2-fold change), with 84% possessing a predicted signal peptide for targeting to the classical secretory pathway. The differentially accumulated proteins have putative functions in metabolism, detoxification, and protein modifications. A germin (SORBI_3003G427700) was highly heat-inducible at both protein and gene level. Overall, our study reveals new insights into sorghum responses to heat and provides a useful resource of extracellular proteins that could serve as targets for developing thermotolerant crops. Data are available via ProteomeXchange with identifier PXD021536.
An assessment of rodent-flea diversity and association in a semi-arid tropical ecosystem of south-western Zimbabwe
(Wiley, 2021-04-12) Banda, Annabel; Gandiwa, Edson; Muboko, Never; Muposhi, Victor K.
The present study assessed the rodent-flea diversity and their association in Nkayi and Umzingwane districts, south-western Zimbabwe. Although both districts occur in the same agriculture region IV zone, they, however, differ in plague disease occurrence with Nkayi district being a plague disease endemic area whilst Umzingwane district is reported as not (Munyenyiwa et al., 2019). The information generated from the study will potentially assist health personnel in surveillance and potential predictions for fu- ture possibilities of an outbreak or high-risk areas of plague disease. Further, the study results could potentially be used to develop ro- dents and flea control programmes.
Sorghum’s Whole-Plant Transcriptome and Proteome Responses to Drought Stress: A Review
(MDPI, 2021-07-17) Ngara, Rudo; Goche, Tatenda; Swanevelder, Dirk Z. H.; Chivasa, Stephen
Sorghum is a cereal crop with key agronomic traits of drought and heat stress tolerance, making it an ideal food and industrial commodity for hotter and more arid climates. These stress tolerances also present a useful scientific resource for studying the molecular basis for environmental resilience. Here we provide an extensive review of current transcriptome and proteome works conducted with laboratory, greenhouse, or field-grown sorghum plants exposed to drought, osmotic stress, or treated with the drought stress-regulatory phytohormone, abscisic acid. Large datasets from these studies reveal changes in gene/protein expression across diverse signaling and metabolic pathways. Together, the emerging patterns from these datasets reveal that the overall functional classes of stress-responsive genes/proteins within sorghum are similar to those observed in equivalent studies of other drought-sensitive model species. This highlights a monumental challenge of distinguishing key regulatory genes/proteins, with a primary role in sorghum adaptation to drought, from genes/proteins that change in expression because of stress. Finally, we discuss possible options for taking the research forward. Successful exploitation of sorghum research for implementation in other crops may be critical in establishing climate-resilient agriculture for future food security
Crop-livestock integration practices, knowledge, and attitudes among smallholder farmers: Hedging against climate change-induced shocks in semi-arid Zimbabwe
(De Gruyter, 2021-10-29) Musara, Joseph P.; Tibugari, Handsen; Moyo, Busani; Mutizira, Chinomukutu
Domestic and international crops and livestock trade remain fragile among Zimbabwean smallholder farmers. Commercial crop-livestock integration in climate change vulnerable areas is low and sparsely documented. Practice, knowledge, and attitude indicators influencing participation of smallholder farmers in crop-livestock integrated platforms as a hedge against climate changeinduced risks and uncertainties were assessed. A survey with 240 farmers in Insiza district, Matabeleland province, Zimbabwe was conducted. A modified knowledge, attitude, and perception framework was used to analyze data from six wards supported by World Vision through supplementary livelihood programs on crop-livestock integration. Conventional crop-livestock (63%), mixed cropslivestock (25%), and traditional grains-livestock (12%) options were dominant. There was a thin presence of stakeholders with a limited number of local buyers, contracting companies, and agro-dealers who participate on these platforms. Farmers have the knowledge, positive attitude, and motivated perceptions about the potential of traditional grains-livestock mechanisms to reduce climate change welfare compromising factors. Unbalanced policies, limited financing, and uncompetitive marketing channels limit the uptake of this option. Traditional grains-livestock alternatives should be supported in semi-arid environments to reduce food, income, and nutrition insecurity. Publicprivate partnerships should establish value addition systems to increase the market size of traditional grainslivestock products and enhance commercialization.
Prevalence of Yersinia pestis among rodents captured in a semi-arid tropical ecosystem of south-western Zimbabwe
(De Gruyter, 2022-01-03) Banda, Annabel; Gandiwa, Edson; Muboko, Never; Muposhi, Victor K.
This study assessed the prevalence of plague bacterium (Yersinia pestis) among rodents captured in Umzingwane and Nkayi districts, south-western Zimbabwe. A total of 44 rodents were captured on three consecutive days per trapping session in the study sites using a removal trapping method in April 2018. Captured rodents were euthanized, and blood samples were collected. The Giemsa stain method was used to detect plague bacteria. The trapping success was not significantly different (χ² = 1.50, df = 1, P = 0.221), 8.5% for the Nkayi district, while in the Umzingwane district, it was 8%. Overall, only one rodent species, i.e., Mastomys natalensis, tested positive for Y. pestis in the Umzingwane district, thus yielding a prevalence rate of 2.3% for the entire study area. This was the most important finding of a Y. pestis-positive rodent in a non-endemic wild area in the Umzingwane district. These results point to a low prevalence of Y. pestis in the study area and the importance of an active plague disease surveillance and monitoring system.
Local community awareness and practices on Yersinia pestis plague disease management in Nkayi and Umzingwane districts, south-western Zimbabwe
(Taylor and Francis Group [Commercial Publisher] Taylor and Francis [Imprint], 2022-03-03) Banda, Annabel; Gandiwa, Edson; Muboko, Never; Mutanga, Chiedza N.; Mashapa, Clayton
This study investigated the level of awareness and practices of local communities on Yersinia pestis plague disease in Nkayi and Umzingwane districts, south-western Zimbabwe. The research used a two-way case study where Umzingwane district was used as a quasi-control site and Nkayi district the treatment site. Purposive sampling was used to select four villages, i.e. two from Nkayi district (plague endemic area) and two from Umzingwane district (non-plague area). Data were collected through focus group discussions involving 35 respondents held between August 2017 and April 2018. The study respondents confirmed some awareness of zoonotic diseases albeit limited knowledge on specific rodent-borne diseases. Respondents from areas that had previous plague outbreaks (Nkayi district) were more knowledgeable of the disease compared to those from areas without previous known outbreaks (Umzingwane district). Several practises, e.g. use of traps, keeping domestic cats (Felis catus) and use of rodenticides to control rodents and educating people on plague disease, were highlighted from both study sites as local plague management strategies. Overall, the study results indicate that the awareness and practices employed by local people in the study area are generally influenced by local contextual factors and past experiences.
Ecological interactions, local people awareness and practices on rodent-borne diseases in Africa: A review
(Acta Tropica, Elsevier Science Direct, 2022-11-04) Banda, Annabel; Gandiwa, Edson; Muposhi, Victor K.; Muboko, Never
Several anthropogenic activities exposure humans to the risk of rodent-borne diseases. These activities are but not limited to logging, clearing land for crop cultivation, and consuming rodents. Rodents are a highly diverse mammalian group and harbor many zoonotic diseases. This review focuses on dominant rodent-flea species, rodent-borne zoonotic diseases and awareness and management practices against rodent-borne diseases in Africa. Relevant academic literature spanning from 1974 to 2021 was analysed. Dominant rodent species reported in Africa included:- Mastomys natalensis and Rattus rattus, while dominant flea species included Xenopsylla brasiliensis and Xenopsylla cheopis. Rodents were reported as hosts to a wide range of parasites which can be passed to humans. Rodents were also reported as hosts to some protozoans, trematodes, cestodes, nematodes, bacteria and viruses which are transmissible to humans. Some studies conducted in West Africa revealed good knowledge and practices on plague and Lassa fever diseases among respondents, whereas other studies reported poor practices on Lassa fever management. In part of Southern Africa, some studies reported poor knowledge and practices on plague disease. Further research on rodent-borne disease awareness and management strategies in African countries is desirable.
Effect of Cowpea Trap Crop on the Control of [Aphis gossypii (Glover)] in Zimbabwean Cotton
(Asian Journal of Research in Crop Science, 2023-05-11) Jimu, F.; Mapuranga, R.; Mubvekeri, W.; Ngara, B.; Kutywayo, D.
Cotton aphids are major cotton pests causing significant yield losses of more than 65% in Zimbabwe. Field experiments to investigate the effectiveness of cowpea as a trap crop in reducing aphid pressure on cotton were conducted over three seasons 2010/11 to 2013/14 at Cotton Research Institute (CRI) in Kadoma, and Umguza in Matebeleland North, in Zimbabwe. Incidence of aphid predators on sole cotton, cotton intercropped with cowpea trap crop and the trap crop itself were also assessed. The measurements were aphid scores, aphid predator counts in both sole cotton, intercropped cotton and cowpea trap crop. Seed cotton yield was measured. Aphid scores and predator counts were subjected to Analysis of Variance (ANOVA) using GenStat 14th Edition software. The square root transformation [x + 3/8] was used for scores or counts not normally distributed. At CRI Cowpea trap crop significantly controlled aphids in intercropped cotton better than chemical control using Acetamiprid 20 SP (P< 0.05). Coccinellid grubs (ladybird beetle larval) populations were highest in cowpea trap crop. At Umguza poor germination of cowpea resulted in highest Coccinellid adults (ladybird beetle adults) in intercropped cotton. Yield of intercropped cotton was comparable to yield from plots where Acetamiprid 20SP was used as a standard practice. Farmers can adopt this technology of aphid control in cotton using commercial cowpea variety CBC 3 as cotton aphid trap crop.
Efficacy of Spinosad 48SC on the Management of Cotton Bollworms Diparopsis castanea (Hubner) and Herlicoverpa amigera (Hampson) in Zimbabwe
(Asian Journal of Research in Crop Science, 2023-05-11) Jimu, F.; Mapuranga, R.; Mubvekeri, W.; Kutywayo, D.
Bollworms management remains one of the major constraints to higher cotton productivity in Zimbabwe. Field trials to investigate the efficacy of Spinosad 48 SC on Diparopsis castanea (Hubner) and Herlicoverpa amigera (Hampson) were carried out for three seasons 2010/11 to 2013/14 at Cotton Research Institute, Kuwirirana, Umguza, and Chizvirizvi in Zimbabwe. A Randomised Complete Block Design with five treatments and four replications was used in this experiment. Three doses of Spinosad 48 SC 40ml/ha, 60ml/ha and 80ml/ha, were evaluated, along with Lambda cyhalothrin 5 EC at 200ml/ha as the standard treatment and the untreated control. Observations on bollworms eggs, larval counts and predator counts. The square root transformation of (x + 3/8) was used for data not following normal distribution. Data were analysed using Genstat 14th Edition. All the three doses of Spinosad 48 SC (40ml/ha, 60ml/ha and 80ml/ha) controlled Diparopsis castanea (Hubner) and Herlicoverpa amigera (Hampson) at CRI, Kuwirirana, Umguza and Chizvirizvi. The highest dose of Spinosad 48 SC of 80ml/ha resulted in the highest yield of seed cotton at CRI and Kuwirirana. All the three doses of Spinosad 48 SC killed predators in the same way as the standard insecticide. Spinosad 48 SC was recommended for registration on control of the two bollworms in Zimbabwe at 80ml/ha dose.
The effects of gibberellic acid and short-day treatments on growth and flowering of Chrysanthemum morifolium cv. Breeze cassus
(Horticultural Association of Kenya (HAK), 2023-10-21) Zanamwe, Pesanai; Tong, Rene
Chrysanthemum morifolium cv. Breeze cassus that is widely grown as a commercial pot plant in South Africa grow short and branch poorly under the usual photoperiodic conditions. It was hypothesised that understanding the effects of gibberellic acid(GA3), a plant hormone that promotes flowering and stem elongation in plants, may aid in improving its quality. To study this, the vegetative growth and flowering characteristics of Chrysanthemum morifolium cv. Breeze cassus plants treated with GA3 once, i.e., three weeks after transplanting, GA3twice, i.e., three and five weeks after transplanting, gibberellin biosynthesis inhibitor, daminozide, and short-day photo period were evaluated. Data was collected on plant height, number of branches per plant, time to flowering, flower buds per plant and flower size and subjected to analysis of variance. Plants treated with a short day photoperiod flowered early compared to the control. However, the plant height and flower buds per plant were significantly (p <0.05) reduced. The final plant height of short-day photoperiod and daminozide treated plants were not statistically (p > 0.05) different. Both GA3treatmentssignificantly(p < 0.05) increased plant height compared to the control, daminozide and short-day photoperiod treated plants. Plants treated with GA3 twice were significantly(p < 0.05) taller compared to plants treated with GA3 once. Treatment with GA3, either once or twice, had no effect on time to flowering, however, treating plants with GA3once,significantly increased flower buds and treating plants with GA3twice significantly increased flower diameter compared to the control. It was noted that treatment of Chrysanthemum morifolium cv. Breeze cassus with short-day photoperiod and GA3have different effects on plant growth and flowering. It was, therefore, concluded that, although GA3increasesplant height of Chrysanthemum morifolium cv. Breeze cassus, it may not replace short day photoperiod treatment where early flowering is desired.
User perceptions and acceptance of treated greywater reuse in low-income communities: a narrative review
(IWA Publishing, 2023-11-01) Madzaramba, Tendai Hardwork; Zanamwe, Pesanai
This research output established that a significant proportion of the global population lives in low-income communities mostly in the Global South. These communities face severe water scarcity and persistent sanitation challenges. It emerged that greywater reuse has the potential to improve the access to sufficient clean water in low-income communities. The study sought to ascertain user perceptions and acceptance of treated greywater reuse in low-income communities. To anchor this research, a comprehensive consultation of literature was done, and key sources of data were drawn from various secondary sources of data such as bibliographic databases. This was followed by the snowballing of obtained papers. The research employed a narrative review approach in methodology. The findings of this study indicate that people living in low-income communities have a positive perception regarding reusing treated greywater. Furthermore, it was established that the majority of persons living in low-income communities accept reuse for non-potable purposes including vegetable irrigation, laundry, toilet flushing, and car washing.

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