Staple Root Research Articles

Consumer preference in buying snack and beverage products made from sweet potato (Ipomoea batatas (L.) Lam.) and cassava (Manihot esculenta Crantz) in Southern Cebu, Philippines

Sweet potato and cassava are staple root crops in the Philippines and other tropical and subtropical regions. These crops, like other root crops, are considered survival crops. Processing these root crops into different snacks is another way to enhance their commercial value. However, consumer acceptability and preference must be considered to ensure the marketability of new food products developed. This study aimed to assess the consumer’s preference for sweet potato and cassava-based snack and beverage products and developed a strategy to effectively market the products, in Southern Cebu. A 5-point Likert scale survey instrument was used to determine the consumers’ preference (n = 210) in buying root crops derivative products. Results showed that the most preferred products are sweet potato chips (47.02±0.02%), sweet potato juice (45.75±0.02%), and cassava chips (37.20±0.03%). In addition, flavor is the most desired quality and the first thing the consumers consider. Aside from the flavor, consumers also preferred snack and beverage products that are cheap. Based on the stepwise regression, the increasing influence of price, in both sweet potato and cassava snack products, showed a negative effect, with a coefficient (β) -0.155 (CI: -0.015, -0.005) and -0.095 (CI: -0.012, -0.001) respectively. In contrast, increasing the influence of the product quality was found to have an enhancing effect on consumers’ buying preference for sweet potato beverage products, with a coefficient (β) 0.091 (CI: 0.002, 0.080). Therefore, strategies must be centered on these attributes to effectively market the snack and beverage products developed from sweet potato and cassava.

Evaluation of improved taro (Colocasia esculenta(L.) Schott) genotypes on growth and yield performance in North-Bench woreda of Bench-Sheko zone, South-Western Ethiopia

Taro is the world's fourth most important root crop in terms of production by weight, behind cassava, potato, and sweet potato, and the second most significant staple root crop in terms of consumption, after sweet potato. However, a shortage of well-adapted cultivars is one of the production problems that contribute to low yields and small planted areas across the country. As a result, genotypes with high production potential and adaptability for local environmental circumstances must be evaluated. During the 2018 and 2019 main cropping seasons, field experiments were done in the North-Bench woreda in the Bench-Sheko zone, south-western Ethiopia, to improve taro production and productivity by evaluating and selecting high yielding taro cultivars. Three improved and one local taro variety were used in the trial, which was laid out in a randomized complete block design (RCBD) with three replications at the North bench location. The data were collected and analyzed by using SAS 9.2 Version statistical software. The study's findings revealed that variety had a significant (P < 0.01) impact on all of the variables considered. Accordingly, combined analysis over years indicated that the highest leaf number per plant (7.76), plant diameter (40.82cm), corm diameter (8.28cm), cormel number per plant (6.10), and total yield (22.34 t/ha) were observed for Boloso-1 variety. The highest value of the number of suckers per plant was also observed for the Boloso-1 variety in both years (8.2 in 2018 and 6.2 in the 2019 growing season). However, combined analysis over years indicated the highest corm length in local variety (12.15cm) followed by Boloso-1 variety (10.34cm). Therefore, based on the overall results of this study, the Boloso-1 variety performed best and was more adapted to the area as compared to other varieties. This variety should be popularized and disseminated to users to boost the production and productivity of taro in the testing location and similar agro-ecologies of the region.

Farmers' knowledge, attitudes and practices towards management of cassava pests and diseases in forest transition and Guinea savannah agro-ecological zones of Ghana.

Background: Cassava is a major staple root crop in Ghana, which serves as a food security and an income generating crop for farming families. In spite of its importance, the crop is plagued with biotic factors such as pests and diseases, resulting in yield and income reductions. Methods: Farmers' knowledge, attitudes and practices towards cassava pest and disease management were investigated. A mixed research questionnaire was used to collect both qualitative and quantitative data from 94 cassava farm households across two major cassava growing agro-ecologies. Results: Using descriptive statistics, parametric and non-parametric analysis, our study revealed that farmers' knowledge on cassava pests was high but low for diseases. Whiteflies ( Bemisia tabaci Gennadius), grasshoppers ( Zonocerus variegatus), aphids ( Aphis gossypii Glover), mealybugs ( Phenacoccus manihoti), termites ( Isoptera), and grasscutters ( Thryonomys swinderianus) were perceived as the most common damaging pests. Farmers' descriptions showed that disease pathogens attacked foliar tissues, stem and root tissues and caused leaf dropping and die back. Cassava mosaic disease and root rot were the most common diseases; however, disease descriptions suggested the incidence of viral, bacterial and fungal diseases. Some of the farmers observed mixed symptoms on their farms. The results also showed that only 25.5% cultivated improved varieties. Management actions applied included field sanitation practices and pesticide application. The effectiveness level of the control actions was rated moderately effective. Conclusions: The analysis showed heterogeneity in personal and farm level characteristics of respondents across the two agro-ecologies, but agro-ecologies were independent of the management practices employed. There is a need to improve farmers' access to improved disease-free planting materials through efficient dissemination pathways and increase farmers' knowledge on cassava pests, diseases and integrated management through publfic awareness creation and capacity building by extension agents and research institutions. Continued government investment is needed to achieve sustainable outcomes.

Comprehensive genotyping of a Brazilian cassava (Manihot esculenta Crantz) germplasm bank: insights into diversification and domestication

Key messageBrazilian cassava diversity was characterized through population genetics and clustering approaches, highlighting contrasted genetic groups and spatial genetic differentiation.Cassava (Manihot esculenta Crantz) is a major staple root crop of the tropics, originating from the Amazonian region. In this study, 3354 cassava landraces and modern breeding lines from the Embrapa Cassava Germplasm Bank (CGB) were characterized. All individuals were subjected to genotyping-by-sequencing (GBS), identifying 27,045 single-nucleotide polymorphisms (SNPs). Identity-by-state and population structure analyses revealed a unique set of 1536 individuals and 10 distinct genetic groups with heterogeneous linkage disequilibrium (LD). On this basis, a density of 1300–4700 SNP markers were selected for large-effect quantitative trait loci (QTL) detection. Identified genetic groups were further characterized for population genetics parameters including minor allele frequency (MAF), observed heterozygosity ({H}_{o}), effective population size estimate widehat{{(N}_{e}}) and polymorphism information content (PIC). Selection footprints and introgressions of M. glaziovii were detected. Spatial population structure analysis revealed five ancestral populations related to distinct Brazilian ecoregions. Estimation of historical relationships among identified populations suggests an early population split from Amazonian to Atlantic forest and Caatinga ecoregions and active gene flows. This study provides a thorough genetic characterization of ex situ germplasm resources from cassava’s center of origin, South America, with results shedding light on Brazilian cassava characteristics and its biogeographical landscape. These findings support and facilitate the use of genetic resources in modern breeding programs including implementation of association mapping and genomic selection strategies.

Farmers’ knowledge, attitudes and practices towards management of cassava pests and diseases in forest transition and Guinea savannah agro-ecological zones of Ghana

Background: Cassava is a major staple root crop in Ghana, which serves as a food security and an income generating crop for farming families. In spite of its importance, the crop is plagued with biotic factors such as pests and diseases, resulting in yield and income reductions. Methods: Farmers’ knowledge, attitudes and practices towards cassava pest and disease management were investigated. A mixed research questionnaire was used to collect both qualitative and quantitative data from 94 cassava farm households across two major cassava growing agro-ecologies. Results: Using descriptive statistics, parametric and non-parametric analysis, our study revealed that farmers’ knowledge on cassava pests was high but low for diseases. Whiteflies ( Bemisia tabaci Gennadius), grasshoppers ( Zonocerus variegatus), aphids ( Aphis gossypii Glover), mealybugs ( Phenacoccus manihoti), termites ( Isoptera), and grasscutters ( Thryonomys swinderianus) were perceived as the most common damaging pests. Farmers’ descriptions showed that disease pathogens attacked foliar tissues, stem and root tissues and caused leaf dropping and die back. Cassava mosaic disease and root rot were the most common diseases; however, disease descriptions suggested the incidence of viral, bacterial and fungal diseases. Some of the farmers observed mixed symptoms on their farms. The results also showed that only 25.5% cultivated improved varieties. Management actions applied included field sanitation practices and pesticide application. The effectiveness level of the control actions was rated moderately effective. Conclusions: The analysis showed heterogeneity in personal and farm level characteristics of respondents across the two agro-ecologies, but agro-ecologies were independent of the management practices employed. There is a need to improve farmers’ access to improved disease-free planting materials through efficient dissemination pathways and increase farmers’ knowledge on cassava pests, diseases and integrated management through publfic awareness creation and capacity building by extension agents and research institutions. Continued government investment is needed to achieve sustainable outcomes.

Evaluation of Released Taro ( &lt;i&gt;Colocasia esculenta(L.) Schott&lt;/i&gt;) Genotypes on Growth and Yield Performance in Bench-Sheko Zone SWE

Taro is globally the second most important staple root crop after sweet potato in terms of consumption and is ranked fourth root crop after cassava, potato, and sweet potato in terms of its production by weight. But lack of well adapted varieties are one of a production problems that account for low yield, and small area cropped to the nation. Thus it is essential to evaluate such genotypes, which have high yield potential and are suitable to local environmental conditions. Therefore, field experiment were conducted at Semen-Bench of Bench-sheko zone during 2018 and 2019 main cropping seasons with the objective of improving the production and productivity of taro at Bench-Sheko Zone through evaluation and selection of high yielding taro varieties. The study comprised of three improved and one local taro varieties laid out in RCBD with three replications at semen bench location. The growth and yield data were collected and analyzed by using SAS Version 9.2 statistical software. The result of the study revealed that all of the parameters considered were significantly (P<0.01) affected by varieties at semen bench location. Accordingly, at Semen-Bench combined analysis over years indicated that highest leaf number per plant, plant diameter, corm diameter, root number per plant and root yield were observed for Boloso-1 variety. Highest value of number of suckers per plant was also observed for Boloso-1 variety in both years at semen root length was Highest for local variety for in both growing seasons and in combined analysis over years for Semen Bench. This result also showed a yield difference across locations where highest value recorded at Semen Bench(22.34t/ha) locations for Boloso-1 variety. Based on the mean total root yield of locations and different yield evaluation methods, high yielding variety was identified. Accordingly, boloso-1 variety performed best at semen bench location. Therefore, this variety can play a vital role in food self-sufficiency and food security of southern region and it should be widely distributed to farmers of the testing locations and similar areas of the region.

Stacking disease resistance and mineral biofortification in cassava varieties to enhance yields and consumer health.

SummaryDelivering the benefits of agricultural biotechnology to smallholder farmers requires that resources be directed towards staple food crops. To achieve effect at scale, beneficial traits must be integrated into multiple, elite farmer‐preferred varieties with relevance across geographical regions. The staple root crop cassava (Manihot esculenta) is consumed for dietary calories by more than 800 million people, but its tuberous roots provide insufficient iron and zinc to meet nutritional needs. In Africa, cassava yields are furthermore limited by the virus diseases, cassava mosaic disease (CMD) and cassava brown streak disease (CBSD). In this study, we strove to develop cassava displaying high‐level resistance to CBSD and CMD to attain food and economic security for cassava farmers, along with biofortified levels of iron and zinc to enhance consumer health. RNAi‐mediated technology was used to achieve resistance to CBSD in two East African and one Nigerian farmer‐preferred cultivars that harboured resistance to CMD. The Nigerian cvs. TMS 95/0505 and TMS 91/02324 were modified with T‐DNA imparting resistance to CBSD, along with AtIRT1 (major iron transporter) and AtFER1 (ferritin) transgenes to achieve nutritionally significant levels of iron and zinc in cassava storage roots (145 and 40 µg/g dry weight, respectively). The inherent resistance to CMD was maintained in all four disease resistant and mineral enhanced cassava cultivars described here, demonstrating that this technique could be deployed across multiple farmer‐preferred varieties to benefit the food and nutritional security of consumers in Africa.

Food Security in COVID‐19: Insights from Indigenous Fijian Communities

Food Security in <scp>COVID</scp>‐19: Insights from Indigenous Fijian Communities

Farmers’ knowledge, attitudes and practices towards management of cassava pests and diseases in forest transition and Guinea savannah agro-ecological zones of Ghana

Background: Cassava is a major staple root crop in Ghana, which serves as a food security and an income generating crop for farming families. In spite of its importance, the crop is plagued with biotic factors such as pests and diseases, resulting in yield and income reductions. Methods: Farmers’ knowledge, attitudes and practices towards cassava pest and disease management were investigated. A mixed method research questionnaire was used to collect both qualitative and quantitative data from 94 cassava farm households across two major cassava growing agro-ecologies. Results: Using descriptive statistics, parametric and non-parametric analysis, our study revealed that farmers’ knowledge on cassava pests was high but low for diseases. Whiteflies (Bemisia tabaci Gennadius), grasshoppers (Zonocerus variegatus), aphids (Aphis gossypii Glover), mealybugs (Phenacoccus manihoti), termites (Isoptera), and grasscutters (Thryonomys swinderianus) were perceived as the most common damaging pests. Farmers’ descriptions showed that disease pathogens attacked foliar tissues, stem and root tissues and caused leaf dropping and die back. Cassava mosaic disease and root rot were the most common diseases; however, disease descriptions suggested the incidence of viral, bacterial and fungal diseases. Some of the farmers observed mixed infections on their farms. The results also showed that only 25.5% cultivated improved varieties. Management actions applied included field sanitation practices and pesticide application. The effectiveness level of the control actions was rated moderately effective. Conclusions: The analysis showed heterogeneity in personal and farm level characteristics of respondents across the two agro-ecologies, but agro-ecologies were independent of the management practices employed. There is a need to improve farmers’ access to improved disease-free planting materials through efficient dissemination pathways and increase farmers’ knowledge on cassava pests, diseases and integrated management through publfic awareness creation and capacity building by extension agents and research institutions. Continued government investment is needed to achieve sustainable outcomes.

Health values of cassava compared to wheat and yam in relation to diabetes and dyslipidaemia management

The objective of the study was to evaluate how diabetes and dyslipidaemia can be managed by increasing the consumption of root and tuber crops such as cassava and yam. Journal literatures based on research reports as well as institutional publications and databases on nutritional values of various foods were reviewed. Critical reviews were also performed to synthesize a comparison between the various foods, especially in terms of their fibre values. The critical review shows that guidelines devoted six pages to protein-energy malnutrition and another seven pages on micronutrients. However, there is no mention of the dietary fibre values of the staple root and tuber food crops. From the narrative review, previous report showed that carbohydrate or fibre and fat or fibre ratios are negligible in the raw products, but highest in wheat flour and higher in yam relative to cassava flour. A further comparative review in terms of proximate analysis of the foods elaborates that unprocessed wheat is high in crude protein, carbohydrate and fibre. Thus, the extent or nature of processing is a key factor. Whether wheat has better health value over root and tuber crops has neither being expatiated, nor cassava and yam acknowledged as having any medical value relative to wheat. Since fat is pro-obesity and pro-diabetic while fibre is anti-dyslipidaemic; the foods based on processed wheat flour may possess the least pharmacological values relative to the indigenous carbohydrate food crops. This report provides indication of medical nutrition therapy potentials of indigenous carbohydrate food crops in Delta state of Nigeria.

Climate change impacts on staple root and tuber crops production: implications for smallholder farmers' livelihoods in rural Ghana

Climate change impacts on staple root and tuber crops production: implications for smallholder farmers' livelihoods in rural Ghana

Climate change impacts on staple root and tuber crops production: implications for smallholder farmers' livelihoods in rural Ghana

This study investigated evidence of climate change impacts on cassava and yam production and its implications on smallholder farmers' livelihood in the Jaman South District of Ghana. Data were collected from 200 smallholder farmers using multi-stage purposive sampling technique. Rainfall and temperature data for the district corroborated the farmers' observation of climate change. In general, crop yield was reported to have decreased over the past two to three decades mainly due to unpredictability in sowing times linked to climate change, which has impacted the farmers livelihood because the crops are important staple food and primary income source. The limited capacity of farmers in adapting to erratic rainfall pattern is a major constraint to adaptation. Findings of the study contribute to a better understanding of autonomous adaptation practices by farmers and highlights a need for prioritising policies and programs for building climate change resilience among smallholder farmers in Ghana.

Farmer’s Perception of Cassava Mosaic Disease, Preferences and Constraints in Lupaula Province of Zambia

Cassava is the principal staple root crop, providing a major source of calories for rural and urban households in Luapula province of Zambia. However, the yields on smallholder farms are relatively low largely due to disease infections. The study was therefore conducted to establish farmers’ perceptions, knowledge and management of cassava mosaic disease (CMD), which is one of the major diseases of cassava, and to establish farmers’ preferred traits, constraints and assess sources of cassava cuttings for planting. Focus group discussions (FGD) and structured interviews involving 156 farmers in Mwense, Mansa and Samfya districts were conducted from December 2008 to March 2009. Knowledge of CMD was limited among the respondents. Only 2.4% of the respondents were aware of the disease despite high CMD incidence in farmers’ fields. The majority of the farmers were aware of the importance of insect pests; however, they could not differentiate between damages due to diseases or insect pests. High yield and early bulking traits were highly ranked. Most of the farmers planted local landraces on small-fields (<1 ha). It was evident that a local breeding programme aimed at developing locally adapted disease and pest resistant cassava cultivars was a pressing requirement.

Postharvest Handling and Storage of Fresh Cassava Root and Products: a Review

The increase in global demand for healthy food products and initiatives to ensure food security in developing countries has focused on the cultivation of drought-resistant and biofortified cassava varieties. Cassava is a staple root crop grown in subtropical and tropical climates. Cassava flour is gluten free, which can be used as composite flour in essential foods such as bread. Thus, the role of postharvest handling of freshly harvested cassava root is essential, owing to the rapid physiological deterioration of the root soon after harvest. This situation confers a limited shelf life and, thus, creates poor utilization of the cassava root. However, processing cassava root into other food forms such as fufu, garri, starch and high-quality flour enhances stability and long-term storage. This article critically reviewed the postharvest handling, processing and storage of fresh cassava root. Highlighting on the role of storage and minimal processing on sustainable cassava production, various spoilage mechanisms of cassava root were identified. In developing countries, cassava root is a valuable food and energy source, and understanding the role of optimum postharvest handling, processing and storage techniques would alleviate some concerns of food insecurity.

Dispatches

Dispatches

Effect of garri processing effluents (waste water) on the cynide level of some root tubers commonly consumed in the south east Nigeria

Root tubers are the important staple food crops in the tropics, Nigeria inclusive. In the South East of Nigeria, the major staple root tuber crops include Dioscorea rotundata,(White yam) Dioscorea alata,(Water yam) Xanthosoma sagittifolium, (Red Cocoyam) Colocasia esculenta, (White Cocoyam) Ipomea batatas (Sweet potato) and Dioscorea dumetorum (Domestic yam). Due to inadequacies in supply, these tubers are always in high demand by consumers. To make up for the high demand, peasant farmers cultivate these tubers in any available space around homes. Around most homes in the villages are garri (cassava flour) processing factories, with the effluents (waste water) allowed to flow into adjoining farmlands without any form of treatment. It has been reported that cassava tubers and their effluents contain high concentrations of cyanide, thus the cyanide in the effluent may be adsorbed by the soil onto which it is disposed. Plants that are grown on soil of low potassium content and high nitrogen content have been reported to have high hydrocyanic acid concentration in their tubers. Numerous studies have described environmental exposure of humans to cyanide in African populations. Little is known about exposure to cyanide toxins from processed or unprocessed root tubers commonly consumed in Africa; and data on the food concentration of cyanide which is a potential poison and systemic toxicant is scanty. This study determined the concentrations of cyanide in some root tubers grown in a cassava processing plant effluent [waste water] contam inated farm land and commonly consumed in South East of Nigeria. Dioscorea rotundata had 10.13±1.9mgHCN/kg, while Dioscorea alata had 9.12±0.93mgHCN/kg. Xanthosoma sagittifolium and Colocasia esculenta were found to have values of 15.19±1.69mgHCN/kg and 11.81±1.19mgHCN/kg , respectively . Ipomea batatas [red cultivar] had cyanide level of 8.44±1.20 mgHCN/kg, while the white cultivar had 8.44±1.20mgHCN/kg . Dioscorea dumetorum [domestic] showed cyanide level of 35.44±1.69mgHCN/kg. These values are significantly [p&lt;0.05] higher compared to values from the control site for the same cultivars , 9.65±1.36 mgHCN/kg, 8.45±1.60mgHCN/kg, 14.77±1.33mgHCN/kg and 10.89±1.55 mgHCN/kg , respectively while I. batatas and D. dumetorum had 7.26±1.34mgHCN/kg, 32.76±0.05mgHCN/kg , respectively . The difference in cyanide content between cultivars from the assumed contaminated site and control site could be as a result of environmental factors, like temperature, humidity, altitude and possibly the cassava effluent [waste water]. This preliminary study highlights the need to study the toxicological implications of chronic low –level exposure to cyanide from African root tubers as a result of poor waste disposal methods.

Meristem culture of selected sweet potato (Ipomoea batatas L. Lam.) cultivars to produce virus-free planting material

SummarySweet potato (Ipomoea batatas L. Lam.) is a staple root crop, consumed as a carbohydrate-rich food source in many tropical countries. The production and productivity of sweet potato is limited by several factors, mainly virus infections. This study was conducted to produce virus-free sweet potato planting material using meristem culture. Meristems without leaf primordia were excised from four virus-positive field-grown local sweet potato cultivars ‘Bellela’, ‘Temesgen’, ‘LO-323’, and ‘Zapallo’. Meristems were cultured in Murashige and Skoog (MS) medium supplemented with different combinations and concentrations of 6-benzylaminopurine (BAP), α-naphthaleneacetic acid (NAA), and gibberellic acid (GA3) for shoot initiation. ‘Bellela’ and ‘Temesgen’ exhibited 100% shoot initiation on 5 mg l–1 BAP, 0.01 mg l–1 NAA, and 1 mg l–1 GA3, although the shoots were bushy. ‘LO-323’ showed 90% shoot initiation with the best shoot quality on 2 mg l–1 BAP, 0.01 mg l–1 NAA, and 1 mg l–1 GA3. Shoot tips and nodes from in vitro-grown plantlets were cultured on BAP (0, 0.5, 1.0, or 2.0 mg l–1) or on BAP (0, 0.5, 1.0, or 2.0 mg l–1) + kinetin (Kin; 0, 0.1, 0.5 or 1.0 mg l–1) for multiple shoot formation. The best shoot proliferation was obtained on MS + 0.5 mg l–1 BAP + 0.5 mg l–1 Kin. In vitro-grown shoots were cultured on MS medium containing 0.0, 0.01, 0.1, 0.5, or 1.0 mgl–1 indole-3-butyric acid (IBA). The best root formation was obtained on IBA-free medium. The plantlets thus produced were tested for the presence of ten sweet potato viruses [Sweet potato chlorotic stunt virus (SPCSV), Sweet potato feathery mottle virus (SPFMV), Sweet potato mild mottle virus (SPMMV), Sweet potato chlorotic fleck virus (SPCFV), Sweet potato caulimo-like virus (SPCaLV), Sweet potato mild speckling virus (SPMSV), C-6 (a flexuous rod virus), Sweet potato latent virus (SwPLV), Sweet potato virus G (SPVG), and Cucumber mosaic virus (CMV)] using nitrocellulose membrane enzyme-linked immunosorbent assay (NCM-ELISA). Ninety-nine percent of plantlets were free from all viruses.

The need to exploit micro staple root and tuber crops in contemporary Nigeria

The need to exploit micro staple root and tuber crops in contemporary Nigeria