Vegetables In Tanzania Research Articles

Amplicon sequencing identified a putative pathogen, Macrophomina phaseolina, causing wilt in African eggplant (Solanum aethiopicum) grown in Tanzania and Uganda

African eggplant (Solanum aethiopicum L.) is one of the most common traditional vegetables in Tanzania and Uganda, but its productivity is severely affected by wilt diseases caused by a number of pathogens. Plant stem and root samples were collected in several fields from many neighboring diseased and healthy plants of the Gilo group in Tanzania and from the Shum group in Uganda to identify putative pathogens causing wilt on African eggplants. Through amplicon sequencing of sampled diseased and healthy tissues, we identified putative causal pathogens for the wilt symptoms. Wilting of S. aethiopicum in Uganda is most likely caused by the bacterial pathogen Ralstonia solanacearum whereas, in Tanzania, wilt is most likely caused by the fungal pathogen Macrophomina phaseolina, infecting roots. Infection of stems by Fusarium solani may also contribute to the wilt symptoms in Tanzania. Further artificial inoculation under controlled conditions confirmed that M. phaseolina can cause typical wilting symptoms on S. aethiopcium genotypes. The discovery of different putative causal agents of wilt in the crop demonstrates the need for site specific etiological analysis of wilt before developing and implementing effective control methods. Further research is needed to confirm the results and develop appropriate management measures against specific wilt pathogens.

Effects of transplanting and AMF inoculation on the fruit yield of African eggplants (Solanum aethiopicum and Solanum anguivi) in Tanzania

The African eggplant (Solanum aethiopicum L., Gilo group) is one of the most common traditional vegetables in Tanzania. The yield of the African eggplant in Tanzania is far lower than the potential yield expected, which is due primarily to biotic and abiotic stresses. We conducted experiments at two locations in Tanzania to study whether or not plant growth and the fruit yield of the Gilo group of African eggplant can be significantly improved through transplanting coupled with the inoculation of arbuscular mycorrhizal fungi (AMF) at sowing. Many plants, particularly for the directly sown treatment, died well before harvesting, and, in addition, many surviving plants showed symptoms of wilting. The transplanting of tray seedlings and using AMF inocula at sowing led to an overall significant increase in fruit yield by 30%–40% and 20%–25%, respectively. Increased fruit yield per experimental plot resulted primarily from a greater number of plants that survived and reached the harvesting stage. The exact effect of planting method (i.e., transplanting or direct sowing) and AMF inoculation, however, varied greatly with plant accessions. Further research is needed to understand the cause(s) for plant mortality in order to develop appropriate plant management practices.

Trends and constraints in the utilization of African nightshade (Solanum nigrum complex) in Tanzania: A case study of Kilimanjaro and Morogoro regions

African nightshade (ANS, Solanum nigrum complex) is among the most widely distributed and consumed indigenous vegetables in Tanzania. Several challenges hamper the utilization of ANS. This study sought to assess trends and constraints to ANS utilization in Kilimanjaro and Morogoro regions, Tanzania. Quantitative and qualitative methods were employed to collect information on ANS production, processing, and postharvest handling. Semi-structured questionnaires were used to collect quantitative data, whereas focus group discussion (FGDs) was used to collect qualitative data. A total of 627 farmers participated to fill questionnaire, and about eight FGDs with 6 - 10 participants conducted in Kilimanjaro and Morogoro. The results showed that 72.1% of farmers grow different ANS species, with Solanum scabrum vastly cultivated. Also, 79.4% of ANS farmers use irrigation, handheld hoe (97.6%), pesticides (70.7%), and fertilizer (64.8%) to produce ANS. African nightshade is mainly used as food (96.1%), animal feed (41.3%), and medicine (38%). On average, only 5% of ANS sales contributed to family income. Findings show that the main constraints to ANS utilization were pests and diseases (92.9%), lack of knowledge (58%), fertilizer shortages (51%), shortages of pesticides (50%), inadequate means of transport (50.4%), lack of extension services (48%), improper postharvest handling (41.4%) and inadequate storage facilities (34%). Postharvest losses accounted for 78.4% loss of ANS. Mitigation measures were; harvesting in small quantities (54.5%) and instant selling (61.9%) of fresh ANS. Drying (5.3%) and fermentation (1.1%) were the minimal value addition methods for ANS preservation. Moreover, boiling (63.0%) and frying (45.4%) were the typical methods of cooking ANS. More emphasis should be placed on good agricultural practices, providing knowledge to farmers, and supporting access to agricultural inputs such as pesticides, fertilizers, and quality seeds. Furthermore, knowledge of the processing and preservation of ANS is necessary for farmers to improve utilization, reduce losses, and ensure ANS availability. Also, research should focus on breeding local cultivar, which is resistant to pests and diseases. Key words: African nightshades, Solanum nigrum complex, cultivation, postharvest handling, utilization, processing, preservation

Co-exposure risks of pesticides residues and bacterial contamination in fresh fruits and vegetables under smallholder horticultural production systems in Tanzania.

This study was carried out to investigate the risks of simultaneous exposure to pesticide residues and bacteria contaminants in locally produced fresh vegetables and vegetables in Tanzania. A total of 613 samples were analyzed for pesticide residues, out of which 250 were also analyzed for bacterial contamination. Overall, 47.5% had pesticide residues, 74.2% exceeded Maximum Residue Levels (MRLs). Organophosphorus (95.2%), organochlorines (24.0%), pyrethroids (17.3%), and carbamates (9.2%) residues dominated. MRL values were mostly exceeded in tomatoes, onions, watermelons, cucumbers, Chinese cabbage, and sweet paper. Tetramethrin (0.0329-1.3733 mg/kg), pirimiphos-methyl (0.0003-1.4093 mg/kg), permethrin (0.0009-2.4537 mg/kg), endosulfan (beta) (0.0008-2.3416 mg/kg), carbaryl (0.0215-1.5068 mg/kg), profenofos (0.0176-2.1377 mg/kg), chlorpyrifos (0.0004-1.2549 mg/kg) and dieldrin (0.0011-0.5271 mg/kg) exceeded MRLs. The prevalence of bacteria contamination was high (63.2%). Enterobacter (55.6%) Pseudomonas aeruginosa (32.4%), E. coli (28.2%), Citrobacter (26.8%), Klebsiella oxytoca (14.8%), and Salmonella (7.7%) were isolated. Furthermore, 46.4% tested positive for both pesticide residues and bacterial contaminants. Vegetables from farms (60.7%) contained more dual contaminants than market-based vegetables (41.8%). This may have resulted from excessive pesticide use and unhygienic handling of fresh fruits and vegetables at production level. Binary logistic regression showed that fresh fruits and vegetables with pesticide residues were 2.231 times more likely to have bacteria contaminants (OR: 2.231; 95% CI: 0.501, 8.802). The contamination levels of pesticide residues and bacterial contaminants could be perceived as a serious problem as most fresh fruits and vegetables recorded values of pesticide residues far above the MRLs with pathogenic bacteria isolated in higher proportions. MRLs was higher in most vegetables consumed raw or semi-cooked such as watermelons, carrots, cucumber, tomatoes, onion and sweet paper. There is an urgent need to develop pesticide monitoring and surveillance systems at farmer level, educating farmers and promoting the use of greener pesticides to mitigate the health effects of pesticides and bacterial contaminants.

Rating consumption of traditional vegetables in Tanzania using the awareness, interest, desire and action (AIDA) model

Traditional African vegetables are important for their nutraceutical benefits and contributions to farm household incomes. Consequently, their consumption, particularly among rural and urban households in developing countries, has been promoted and emphasized in recent years. Despite their multiple benefits, consumer awareness, and preference for traditional vegetables is low. This study uses the awareness, interest, desire and action (AIDA) marketing communication model to evaluate consumer awareness and perceptions and assess factors that influence consumption of traditional vegetables among 258 respondents in the Arusha region of Tanzania. Most of the respondents were aware of the nutritional importance of traditional vegetables, willing to purchase them for home consumption, and had a positive perception of their benefits. Consumers who had participated in the promotional activities were more willing to purchase and grow traditional vegetables than non-participants. The major sources of information about human nutrition and traditional vegetables included health centers, schools, friends, relatives, and radio programmes. African nightshade, African eggplant, amaranth and okra were the most widely consumed traditional vegetables. They were mainly purchased from the market. Regression estimates indicate that the consumption of traditional vegetables increases with positive health perceptions, better training, domestic production of vegetables, and increased promotional activities. Scaling up consumers awareness and home gardening would help to increase availability and consumption of traditional vegetables.

Assessment of factors influencing farmers’ nutrition knowledge and intake of traditional african vegetables in Tanzania

Traditional African Vegetables (TAVs) form a significant component of many families’ diets in Tanzania. Traditional African Vegetables contribute to reduction of malnutrition, stunting and poor health among consumers by providing vitamins and essential minerals in family diets. However, the consumption of vegetables is still below the per capita per day intake level recommended by World Health Organization and Food and Agriculture Organization, causing millions of deaths annually due to nutrientdeficiency related diseases. This study examined the factors that influence the nutrition knowledge, frequency intake and farming households’ attitudes towards consumption of traditional vegetables. The Standard Poison and the Generalized Poison models were used for analysis. Factor analysis was used to assess the attitudes towards TAVs consumption. Data were collected from randomly selected 63 households in Arumeru District of Tanzania in the months of July to November 2015. Generalized Poison model results showed that gender of the respondent, years of schooling, age of the respondent, household size and TAVs farm size influenced farmers’ nutrition knowledge. Frequency intake of TAVs is influenced by the farmers’ age, annual household income, household size, TAVs farm size and market price of TAVs. Factor analysis results indicated that medicinal properties of traditional vegetables positively influenced farmers’ intake of vegetables. The “health factor” accounted for 31.4% of the total variance in the principal components analysis. ‘Personal perception factor’ accounted for 13.79% whereas ‘personal taste factor’ accounted for 12.71% of the total variance. It was concluded that rural farming households consume traditional vegetables majorly because of their health attributes. Thus, there is need to improve medicinal and nutritional knowledge of these crops among households. These findings imply that consumption of TAVs can be enhanced by educating households on nutrition importance and medicinal attributes of TAVs. Besides, farmers need training on simple but user-friendly technologies that could prolong storage and preserve freshness as well as nutritional contents of traditional vegetables. Keywords: Traditional vegetables, nutrition knowledge, frequency intake, farmers’ attitude, Arumeru District

Agribusiness development and the role of value chain business associations

PurposeThe purpose of this paper is to explore the rationale for value chain business associations and construct a conceptual framework for establishing and managing a value chain association, using the value chain for dried fruits and vegetables in Tanzania as the empirical basis.Design/methodology/approachTo achieve the objectives of the paper, a conventional approach involving literature review, framework development, and data collection and analysis was used to conceptualise the organisation of a value chain association in a developing country context.FindingsThe study finds rationale for a value chain-based business association based on the literature review, observations and discussions from the stakeholder workshop.Research limitations/implicationsIt has been suggested that upgrading the currently fragmented dried fruit and vegetable value chain to encompass all value chain actors might have implications towards “creativity”, “innovation” and “entrepreneurial abilities” along the value chain, i.e. resources and competences that could enhance the value of the market offer and thus the competitiveness of the whole value chain. A value chain-based business association might be one of the stepping-stones to enhance innovative and entrepreneurial abilities for strong and competitive value chain activities.Originality/valueIf the literature has been relatively silent on business associations understood primarily as industry associations, it has been completely silent on value chain associations. This paper therefore makes explicit contribution on the conceptualization of value chain association with a particular focus on the developing country setting.

The impact of the extensive use of phosphate fertilizers on radioactivity levels in farm soil and vegetables in Tanzania

Soil and vegetables grown in Iringa rural in Tanzania were analysed for radioactivity associated with the use of phosphate fertilizer in farming. The activity concentrations of 226Ra, 228Ra and 40K were determined using gamma spectrometry of Tanzania Atomic Energy Commission, Arusha. Higher activity concentrations of 226Ra and 228Ra in both types of samples were found in samples from fertilized farms than in samples from control. Hence, regular monitoring of radioactivity level in farm soils and agricultural products is recommended.

Technical efficiency of smallholders’ traditional African vegetable production in Tanzania: a stochastic frontier approach

Traditional African vegetables are receiving more attention for their potential contribution to food and nutrition security and enhanced livelihoods for smallholder producers. Although demand is increasing for these nutrient-dense crops, the productivity of traditional vegetables in Tanzania remains low. Technical innovations can reduce yield gaps and increase the productivity of traditional vegetable crops. This paper measures the technical efficiency of farm households that produce traditional vegetables in Tanzania using the Cobb-Douglas stochastic frontier production function. Data was obtained through a survey of 181 households that cultivated traditional vegetables in five regions (Arusha, Tanga, Morogoro, Dodoma and Dar es Salaam). The results show considerable levels of technical inefficiency in the production of traditional vegetables. Technical efficiency among farm households could be increased by 33% through the better use of available production resources. The test for equality of technical efficiency indicated that there were statistically significant differences in technical efficiency across farm size, with larger landholdings having higher observed values than smallholdings. Strengthening farmer associations to encourage knowledge sharing and enhancing the existing cluster approach to farming may help to improve technical efficiency.

Knowledge sharing strategies on traditional vegetables for supporting food security in Kilosa District, Tanzania

Purpose– The purpose of this paper is to examine knowledge sharing on traditional vegetables for supporting food security among farmers and other communities in Kilosa district, Tanzania.Design/methodology/approach– A case study design was employed. Semi-structured questionnaires with both open- and closed-ended questions were used to collect quantitative data in three wards of Kilosa District in Tanzania. Interviews were used to collect qualitative data from three heads of farmer groups, and direct observation was used to validate findings obtained from questionnaires.Findings– The results showed that farmers used a socialisation approach to share indigenous knowledge about traditional vegetables on production, consumption and preservation.Research limitations/implications– The study necessitates a need to conduct regular studies on sharing knowledge of traditional vegetables among different communities for supporting food security.Practical implications– The paper provides a framework for agricultural development planners on how to improve the management of indigenous knowledge on traditional vegetables with scientific knowledge in local communities for improving food security in Tanzania.Social implications– The paper has an implication for improving knowledge-sharing strategies on traditional vegetables in supporting food security in Tanzania, and other parts of Africa and developed countries. There is a need for knowledge intermediaries to develop knowledge database on production, consumption and preservation of traditional vegetable to increase the dissemination of this knowledge and, hence, improve nutrition and food security.Originality/value– The paper provides appropriate knowledge-sharing strategies which are needed to improve sharing of indigenous knowledge about traditional vegetables in Tanzania and other developed and developing countries.

English

Traditional African vegetables are receiving more attention for their significant contribution to food and nutrition security and enhanced livelihoods of smallholders. Although demand is increasing for these nutrients-dense crops, the production of traditional vegetables in Tanzania remains low. Technical innovations can reduce yield gaps and increase the productivity of traditional vegetable crops. This paper measures the technical efficiency of farm households that produce traditional vegetables in Tanzania using a Cobb-Douglas stochastic frontier production function. This study reports data from a primary survey of 181 households that cultivated traditional vegetables in five regions (Arusha, Tanga, Morogoro, Dodoma and Dar es Salaam) of Tanzania. The results show that overall mean technical efficiency is 67%. It indicates that if the average farmer of the sample could achieve the technical efficiency level of most efficient counterpart, then average farmers of the sample could increase their output by 27% with better use of available production resources given the current state of technology. Farmers were observed to be more technically efficient in the Arusha region than in the other study regions. Possible reasons for the observed regional difference include agroclimatic variability, access to extension services, and infrastructure facilities. A linear relationship exists between farm size and technical efficiency. The study concludes that strengthening farmer associations to encourage knowledge sharing and enhancing the existing cluster approach to farming may help to improve technical efficiency. Key words: Smallholders, inefficiency, resource use, inputs, technology.

Diversity and genetic erosion of traditional vegetables in Tanzania from the farmer's point of view

Traditional vegetables in Tanzania have been underutilized by farmers and neglected by research and development programmes. In the framework of the project ‘Promotion of Neglected Indigenous Vegetable Crops for Nutritional Health in Eastern and Southern Africa’ led by the World Vegetable Center (AVRDC) and partners, focus group meetings were conducted in 10–12 villages in each of four districts of north-east Tanzania, which differed in ethnicity as well as in altitude, climate and soil conditions. Farmers named 10–34 different traditional vegetables per village, summing up to an overall of 102 in all four districts, about half of which were only identified by local names. The number of wild traditional vegetables used was always greater than the number of cultivated traditional types, with ratios of wild to cultivated vegetables ranging from 11:9 in an urban highland district to 59:11 in a rural coastal district. Some wild traditional vegetables were found to be threatened with genetic erosion due to changes in land use and eating habits. The degree of urbanization and the availability of infrastructure contributed more strongly to genetic erosion as compared to climatic conditions. Farmers' training encouraged exotic vegetable cultivation and reduced traditional vegetable diversity. At the same time, indigenous knowledge on how and where to collect, cultivate and prepare traditional vegetables was disappearing.