Massey Documents by Type

Permanent URI for this communityhttps://mro.massey.ac.nz/handle/10179/294

Browse

Subject: search.filters.subject.Sweet potatoes

Search Results

Now showing 1 - 5 of 5
  • Thumbnail Image
    Item
    The contribution of kumala to traditional food systems in two districts of Tanna Island, and its potential for increasing food security : a thesis presented in partial fulfilment of the requirements for the degree of Doctor of Philosophy in Horticulture and Ethnobotany at Massey University, Palmerston North, New Zealand
    (Massey University, 2024) Nasse, Amanda
    Sweetpotato (Ipomea batatas) is considered a versatile food crop owing to its robust adaptability to diverse soil conditions and environmental conditions. In Vanuatu sweetpotato is a significant food security crop that smallholder farmers cultivated within traditional cropping system. Within the national and local context, sweetpotato has played a significant role as recovery crop that supports the farmers and increasing urban population buffer against food scarcity during the aftermath of natural disasters. The research reported in this thesis examined and explored how kumala (sweetpotato) contributed to smallholder farmers livelihood and enhanced food and nutrition security. The aim of the study was to understand the significant role of kumala within the traditional food system and draws on smallholder farmers perspectives. Storian is the overarching cultural approach that underpinned the research process in this study, supported with the use of qualitative methods of collecting data these included, semi structure interviews, secondary data, and field observation. Subsequently the data collected through the interviews and storian were analysed using qualitative data analysis. The research study was carried out in Tanna Island, a society with stronghold of traditions and cultural activities that are interwoven in the livelihood of smallholder farmers influencing the farmers perception on the production of kumala. This research highlights kumala is a favoured food security and recovery crop featured as response to recovery program. Kumala has a role in the traditional food system which is enhanced by existing social and cultural ties. The study put forward a critical perspective on leveraging on short term resilient crops that emerge through strengthening and revitalize the role of kumala within the local food system can strengthen household resilience and enhance food security for smallholder farmers.
  • Thumbnail Image
    Item
    “Na mata ni Civa au a vakawaletaka” : an ethnobotanical study on kumala (Ipomoea batatas (L.) Lam) and its contribution to climate-smart agriculture in Ra, Fiji : a thesis presented in fulfilment of the requirements for the degree of Doctor of Philosophy in Horticulture, Massey University, School of Agriculture and Environment, Palmerston North, Aotearoa
    (Massey University, 2022) Leweniqila, Ilisoni Lasaqa Vuetinabouono
    Globally, sweetpotato (Ipomoea batatas (L.) Lam) or kumala is regarded as an essential, versatile, and under-utilised food security crop. In Fiji, kumala has a strong traditional base, and our ancestors valued this crop as a lifesaver to people during and after natural disasters to act as food security since both the tubers and leaves are consumed. This research weaves together two methodologies; the Fijian Vanua Research Framework (FVRF) which involves ethnobotany studies, and a western sciences (field trials) research element to support and reinstruct smallholder farmers on the value of kumala as a significant crop for subsistence and a source of livelihood for rural economic development in Fiji. The three research sites were Nabukadra (<20m asl ) located in the coastal land area, Bucalevu (>150m asl) in the high altitude inland, and Burenitu (80-100m asl) in the district of Nalawa which is situated at a lower altitude. The implementation of FVRF in this research paid specific attention to indigenous Fijian society aligning to future food security issues in an agricultural context. This research sought a solidarity approach for the rural areas in Fiji adopting their systems of knowledge and perception as the basis for inquiry extending the knowledge base of indigenous people and transforming their understanding of the social-cultural world like solesolevaki, which is our current cultural currency. The Dre’e metaphor was generated to discuss the findings from this research. The findings of this research discussed the cultural role of kumala production in the I-Taukei context under four components: values and beliefs, practices, skills, and knowledge. Indigenous Knowledge (IK) exists across all facets of the I-Taukei way of life, which includes health, belief system, and environmental survival. Given that each genotype or variety of kumala may respond differently to production factors, there was a need to evaluate available sweetpotato genotypes across geographic zones where it can be grown in Fiji. The application of agronomic field trials at different altitudes for this research provided a valuable recommendation that will assist farmers in decision-making for growing kumala at different altitudes in Ra. This will enhance food security and create economic opportunities. Furthermore, this extension of traditional and agronomic knowledge will support climate-smart agriculture (CSA) and help achieve food security in the province of Ra, Fiji Islands.
  • Thumbnail Image
    Item
    Extending the knowledge system and food value of kumala (lpomoea batatas or sweetpotato) in Vanuatu as a response to climate change : a thesis presented in partial fulfilment of the requirements for the degree of Master of Science in Horticultural Science at Massey University, Manawatū, New Zealand
    (Massey University, 2018) Setak, Patricia
    Loss of traditional knowledge in food production is a major problem occurring in many countries due to modernization and globalization. Additionally, further compelled by the impacts of climate change, this can have a devastating effect on the livelihood of people. As a result, farmers are therefore compelled to revive the use of traditional knowledge in food production especially its blended use with contemporary knowledge in adapting to and mitigating climate change impacts. The aim of this study is to identify the contribution of traditional knowledge of kumala (Ipomoea batatas) production in sustaining the livelihoods of people in Vanuatu. The target population of this study was kumala farmers in two villages: Lorevulko and Sara 1 in East Santo, Vanuatu where qualitative data using semi-structured interviews was obtained. A literature review was also undertaken on kumala production in other countries where kumala is commonly grown. The younger generations should be educated on traditional knowledge and skills, and efforts should be made to document traditional knowledge. Traditional knowledge is being used in the pre-production activities of kumala such as planting calendar, site selection, land clearing and soil preparation. Both knowledge systems are used in the production of kumala for example in kumala cultivar selection, division of labour, planting, crop maintenance, preparation and management of kumala during droughts and cyclones. In addition, both traditional and contemporary knowledge are used in post-production of kumala in different storage methods such as field, bag, basket, and food bed. Overall, the findings in this study confirm compelling evidence that traditional knowledge contributes towards the sustainable livelihood of the people in Lorevulko and Sara 1. It shows that there is an assimilation of knowledge systems and they create a cultural output that is unique to location and time, and provides a good example of cultural dynamics which never stand still and which respond to environmental and other pressures. Findings from this research will contribute immensely in improving food security at the household and national level in Vanuatu, and generate sustainable income for farmers and livelihoods for farmers. Researchers can also use the findings of this study as a basis to undertake further studies on traditional knowledge of kumala in Vanuatu. Moreover, the results will be useful for informing and influencing government policy and farming practices.
  • Thumbnail Image
    Item
    Exploring the opportunities in the sweetpotato value chain in diversifying the Nigerian economy : a thesis presented in partial fulfilment of the requirements for the degree of Master of AgriCommerce at Massey University, Palmerston North, New Zealand
    (Massey University, 2018) Adesina, Adebowale
    Nigeria is the second largest producer of sweetpotato in the world and the largest producer in Africa. However, the total average yields of sweetpotato in Nigeria is comparatively low (2.6 tons per hectare) when compared to the rest of Africa (9.6 tons per hectare) and the world (16 tons per hectare). Furthermore, Nigeria is not ranked among the top 150 global exporters of sweetpotato, and the unavailability of markets has been reported to as one of the primary constraints to sweetpotato production in Nigeria. The aim of this study is therefore to explore the opportunities in the sweetpotato value chain that can contribute to the development of the Nigerian economy. A structured questionnaire survey was used to obtain information from 115 farmers who were selected through non-probability convenience sampling. The findings from the structured questionnaire were complemented by an open-ended face-to-face interview. The analysis of the findings involved descriptive and inferential statistics. With the aid of the descriptive statistics, the contributing factors to the low yield of sweetpotato were identified along with the constraints to market access and market opportunities for sweetpotato nationally and internationally. The inferential analysis using the binary logistic model was used to determine the factors that had a significant influence on the yield of sweetpotato. The constraints identified that limit the production and yield of sweetpotato farmers included: inadequate market outlets to sell increased quantity of sweetpotato; high incidence of pest and diseases; scarcity of vines for planting; lack of knowledge on pest and disease management; lack of access to financial capital to buy farm inputs and carry out necessary farm activities; early spoilage of sweetpotato roots after harvest; lack of storage facilities to increase the shelf life of harvested sweetpotato; inadequate rainfall; grazing of cattle by herdsmen on sweetpotato farms; difficulty in getting farm labourers and inadequate access to farm machinery. The empirical results of the binary logistic regression indicated that farmers age, level of formal education, gender, cultivated land area, access to extension services access to market information and membership of a farmers group all had significant positive effect on the yield of sweetpotato farmers except farmers age which had a significant negative impact on the yield of farmers. Addressing the constraint to sweetpotato production and market access had the potential to increase farmers’ productivity, annual income and access to the high-value market, alleviate poverty and contribute to the economic development of Nigeria.
  • Thumbnail Image
    Item
    Effects of postharvest treatments on sweetpotato (Ipomoea batatas) storage quality : a thesis presented in partial fulfilment of the requirements for the degree of Doctor of Philosophy in Food Technology at Massey University, New Zealand
    (Massey University, 2015) Pankomera, Pilirani
    After harvest, sweetpotato (Ipomoea batatas) storage root quality is reduced due to weight loss, sprouting and rots. There are also hidden quality losses relating to loss of nutritional compounds. In order to maintain sweetpotato quality during storage, sweetpotatoes need to be stored at 13 - 15 °C and 80 - 90% RH. However, controlled temperature methods are difficult to achieve for subsistence farmers in less developed countries who have limited access to electric power. This work was undertaken to determine the potential postharvest techniques that would extend sweetpotato storage life without compromising phytochemical concentration. Postharvest treatments investigated in this work were hot water dipping (with or without coating) and ethylene (with or without 1-MCP) treatments. The work was undertaken using mainly ‘Owairaka Red’ and ‘Clone 1820’ sweetpotato cultivars. Following treatments, these sweetpotatoes were stored at 25 °C and 80 - 90% RH for 4 to 12 weeks. Hot water dipping (HWD) at 51 °C for 11 min delayed sprout growth by 2 weeks but increased weight loss. Coating (carnauba wax 5%) significantly reduced weight loss, but increased sprout growth in ‘Owairaka Red’. A combination of HWD and coating was effective in reducing both sprout growth and weight loss. ß-carotene content measured in ‘Clone 1820’ ranged from 17.3 to 25.6 mg/100 g dry weight. The concentration was not affected by HWD or coating, but declined by about 30% during 12 weeks storage. The calculated retinol activity equivalent (RAE) ranged from 363 to 537 RAE, per 100 g of edible portion of sweetpotato. Based on the recommended daily intake for vitamin A, a serve of 100 g would supply more than 25% of daily retinol requirement for all age groups, suggesting that even after storage ‘Clone 1820’ is a good source of vitamin A. In addition, no treatment adversely affected the phenolic acid and anthocyanin concentrations. Roots that were HWD showed a subtle increase in total phenolic content, phenolic acids and anthocyanin concentration when compared to control roots, but the effect was shortlived. Previous studies have demonstrated that ethylene is a potential sprout inhibitor, but causes darkening of flesh colour and the development of off-flavours after cooking. Ethylene-induced responses may be inhibited by 1-methylcyclopropene (1-MCP). 1- MCP and ethylene combined effects on sweetpotato physiological, flesh colour and phytochemical variables were assessed during storage. Ethylene treatment with or without 1-MCP inhibited sprout growth, increased root respiration rates by 2-fold, and caused root stem-end split leading to high weight loss and rots. Ethylene treatments also caused flesh darkening, and this was not prevented by a single 1- MCP (1 µL L-1) pre-storage treatment. When roots stored in continuous ethylene were subjected to multiple 1-MCP (1 µL L-1) treatments, the ethylene-induced root splitting and flesh darkening were delayed/reduced whilst maintaining minimal sprout growth. This implies that ethylene-induced negative responses in sweetpotato can be mitigated with on-going 1-MCP treatment. The sensory results showed that roots stored in air were highly preferred by consumers over roots stored in ethylene; nevertheless, acceptance means scores of all treatments were above five, indicating that ethylene-induced flesh darkening was not severe enough to cause consumer rejection. Based on these findings, it is proposed that a combination of HWD and coatings can be used to extend non-refrigerated storage life of sweetpotato with no major effect on phytochemical content. The results on ethylene are consistent with previous findings that ethylene suppresses sprout elongation. However, the associated negative effects outweigh the benefits of using ethylene as a sprout control. Future research therefore should focus on finding ways to get the benefit of ethylene for sprout reduction without incurring risk of root splitting.