The chapter provides an overview of the importance of fruit and vegetable regarding food and nutrition security. It looks at the global consumption and production data and discusses their influencing factors. Selected examples of food-based approaches including fruit tree portfolios – addressing seasonal availability of fresh fruits, home gardens, food diversity and the potential of indigenous and wild species to improve nutrition and health are presented. In the concluding remarks challenges and opportunities for mainstreaming a diversity of fruits and vegetables into production and consumption systems are discussed.
Tag: crops
Gendered knowledge on food trees for addressing food security and nutrition in Uganda and Kenya
Food trees provide fruits, nuts, leaves and seeds that contribute substantially to food and nutrition security of African rural households. Farmers have a wealth of local knowledge on food tree species for cultivation and use for various household needs. This knowledge is influenced by gender and age-related factors often neglected in research and development endeavors. This study sought to understand gendered and age-related knowledge on food trees use in Uganda and Kenya. The purpose was to identify context-specific food tree portfolios that can sustainably address food and nutrition gaps while responding to the needs and strategic interests of different gender and age groups. Data collection was conducted through genderand age-segregated focus group discussions in two sites in Uganda, Nakaseke and Nakasongola, and two sites in Kenya, Kitui and Mwingi west. Participatory research using seasonality calendars and score – ranking was conducted with sixteen focus groups and comprised of a total of 160 participants to understand knowledge and preferences for food trees. A total of 61 food tree species were listed with differences among countries. In Uganda, the total species number was 47 (including 58% exotic species), and in Kenya 55 (65% exotics). In Uganda, knowledge on food tree species differed between genders, with older women listing the greatest number of priority species (22), followed by younger women (19) and older and young men (15). In Kenya, older women and men identified 38 and 36 species respectively, whereas younger women identified 26 species and younger men 23 species. In all four sites, both men and women preferred exotic food tree species such as Mangifera indica, Passiflora edulis and Persea americana. Both men and women especially valued food trees that contribute to improved health, nutrition and income, those whose products have a good taste, and with medicinal properties. For old and young women, the main reasons for selecting food trees species was their availability and role as children’s food. Findings show diverse food tree species that fill food and nutrition gaps and the value of gender-sensitive participatory research for understanding local knowledge, needs and constraints, to inform project implementation decisions.
Nutritional value of commonly consumed desert date tree products
The desert date (Balanites aegyptiaca, Del. L.) is one of the neglected staple crops of growing importance in the drought and famine-prone areas of Uganda. Unfortunately, information on its nutritional composition is still lacking, thus limiting their wider use and promotion. This study was designed to determine the nutritional composition of various parts of B. aegyptiaca eaten by Ugandans. Samples were collected from Katakwi, Adjumani and Moroto districts in Uganda. Dry matter content of the leaves, flowers and fruit pulp ranged from 95% in fruit pulp, to 98% in leaves and flowers. Ash content of the leaves and flowers was 8.07%; while that of the fruit pulp was 6.97%. Fat content of the leaves (2.29%) was significantly higher than that in fruit pulp (0.37%). Similarly, crude protein content was greater in the leaves and flowers (16.95%) than in the fruit pulp (5.4%). The leaves and flowers were generally richer in macronutrients than in fruit pulp in the order of K>Na>Mg with mean values of 19.54, 3.32 and 1.26 mg g-1. Iron was the most abundant micronutrient in all Balanites parts. This was followed by Mn, Zn and Cu with mean values of 452.21, 60.65, 35.69 and 25.49 g g-1, respectively. A similar trend was found in fruit pulp. There is a need to determine the level of anti-nutritional factors in Balanites products and the effect of different leaf preparation methods on nutrient availability to further guide their wide usage.
Crop damage by nematodes in improved-fallow fields in western Kenya
The rotation of leguminous shrubs and crops is being tested on farms and recommended as a means of improving soil fertility and increasing crop yield in eastern and southern Africa, including western Kenya. However, this improved fallow practice may also increase the nematode population in the soil. An experiment was conducted to monitor the effects of plant-parasitic nematodes on crops after improved fallow. Soil was collected from a maize (Zea mays L.)/bean (Phaseolus vulgaris L.) field, a natural fallow, a Crotalaria (Crotalaria grahamiana Wight & Arn.) fallow, a Tephrosia (Tephrosia vogelii Hook. f.) fallow and a Crotalaria — Tephrosia mixed fallow and used to fill plastic pots placed in a shade. Three successive crop cycles of 2 months were tested in these pots using maize and beans, the most important staple foods in western Kenya. In the first cycle, beans grew poorly on the Tephrosia and Crotalaria — Tephrosia soil due to the high incidence of root knot nematodes, Meloidogyne spp., while maize did not suffer any loss. Although the populations of root knot nematodes reduced drastically in the second and third cycles, both maize and beans experienced heavy losses on the soil under improved fallow probably due to the spiral nematodes, Scutellonema spp., which became dominant in the nematode communities. Despite the use of fertilisers (N, P, K), both crops became highly sensitive to spiral nematodes in the third cycle because of the degradation of the soil physical properties. The study showed that the benefits of improved fallows in terms of crop production may be limited by the high number of plant-parasitic nematodes they help develop in the process.
Tree leafing phenology and crop productivity in semi-arid agroforestry systems in Kenya
The hypothesis that temporal separation of resource use between trees and crops minimises competition for wa ter in agroforestry systems during the cropping period and increases utilisation of annual rainfall was tested at Machakos in semi-arid Kenya. Four popular tree species were chosen to provide a range of leafing phenologies. These included Melia volkensii, which sheds its leaves twice a year, Senna spectabilis and Gliricidia sepium, which shed their leaves during the long dry season, and the evergreen Croton megalocarpus. All four species retained their foliage during the long rains, offering little scope for temporal separation of resource use. Maize (Zea mays) yields were reduced by 50–70% in the agroforestry treatments. Reductions in crop yield were strongly correlated with tree growth (r 2 =0.94) and available soil moisture (r 2 =0.88). G. sepium remained leafless for much of the short rains despite the presence of available soil water, and was least competitive with the bean crops (Phaseolus vulgaris) grown at this time. Reductions in crop yield in the agroforestry treatments were closely correlated with tree growth (r 2 =0.99) and available moisture (r 2 =0.79) during the 1996/97 short rains (158 mm), but not during the much wetter 1997/98 season (608 mm). Shading by trees or shade nets reduced crop yield, in contrast to previous studies in the semi-arid tropics. Low off-season rainfall during the study period (9% of annual rainfall compared to the long-term average of 20%) limited the potential for temporal separation of growing periods. Where the prospects for temporal or spatial separation in resource use are limited, shoot and/or root pruning may be necessary to manage competition between trees and crops.
Can integration of trees and crops contribute to enhanced agricultural productivity, resource utilisation and livelihoods for smallholder farmers? An evaluation of the multifunctionality of agroforestry systems
More trees are needed on farms and in agricul – tural landscapes to produce firewood, timber, fodder, food, and to alleviate erosion and other environmental problems. Trees will also contri – bute to sequester carbon, build soil fertility and restore other ecosystem services, as well as contri – bute to climate change adaptation. This project has investigated whether the integration of trees in crop and livestock production can contribute to enhance agricultural productivity and resource utilization, and thereby contribute to improved living conditions for smallholders. We have evalu – ated the productivity and multi-functionality of agroforestry systems at different scales (field, farm, landscape) by empirical studies (measurements, sampling, interviews), and have surveyed farmers’ strategies to adapt to climate change. We have also studied which soil properties are required for Allanblackia , an African tree with oil-rich fruits that are now being domesticated to be grown by smallholder farmers, to thrive. The results show that in the study areas, farmers are integrating trees into their production systems in order to get products and services including increased adap – tion capacity to climate change. They use a variety of tree species that have different functions in order to obtain synergies and reduce trade-offs with other farm components. This has been a collabo – rative project between SLU and partners in Kenya ( Jomo Kenyatta University of Agriculture and Technology, the Vi Agroforestry and the World Agroforestry Centre-ICRAF). Two PhD students have participated in this work and several student and educational projects have been implemented. We have also participated in conferences and orga – nized courses for advisors, farmers’ organizations and farmers
Spatially Characterised Agroforestry (SCAF)
The Spatially Characterized Agroforestry (SCAF) Database is a central repository of Agroforestry data collected from smallholders across Vietnam.
Root architecture in relation to tree-soil-crop interactions and shoot pruning in agroforestry
Desirable root architecture for trees differs between sequential and simultaneous agroforestry systems. In sequential systems extensive tree root development may enhance nutrient capture and transfer to subsequent crops via organic pools. In simultaneous systems tree root development in the crop root zone leads to competition for resources. Fractal branching models provide relationships between proximal root diameter, close to the tree stem, and total root length or surface area. The main assumption is that a root branching proportionality factor is independent of root diameter. This was tested in a survey of 18 multipurpose trees growing on an acid soil in Lampung (Indonesia). The assumption appeared valid for all trees tested, for stems as well as roots. The proportionality factor showed a larger variability in roots than in stems and the effects of this variabilily should be further investigated. A simple index of tree root shallowness is proposed as indicator of tree root competitiveness, based on superficial roots and stem diameter. Pruning trees is a major way to benefit from tree products and at the same time reduce above-ground competition between trees and crops. It may have negative effects, however, on root distribution and enhance below-ground competition. In an experiment with five tree species, a lower height of stem pruning led to a larger number of superficial roots of smaller diameter, but had no effect on shoot:root ratios or the relative importance of the tap root.
Organic matter dynamics after conversion of forests to food crops or sugarcane: prediction of the Century Model
The Rewarding Upland Poor for Environmental Services Program is testing mechanisms to reward the upland poor for the environmental services they provide at a number of sites across Asia. Four years since its commencement, the program has learned numerous lessons in establishing payment for environmental services mechanisms in developing countries with particular emphasis on the upland poor as beneficiaries. A market-based approach for environmental services with potential funding from private sectors delineated the first establishment of this program. As the program has progressed, constraints on operating ‘pure’ payments for environmental services have appeared. This leads to a question of whether or not the market-based system for financing environmental conservation in developing countries will actually benefit the poor or be applicable and effective in the context of Asian developing countries. This paper introduces four approaches that describe the different conditions exercised by two contrasting methods – a market-based payment for environmental services and non-market-based system, in this case, Integrated Conservation and Development Program – in achieving the dual goal of environmental conservation and development. Supported by recent publications by notable authors on payments for environmental services issues, this paper will briefly show the shift of RUPES basic assumptions as a result of lessons leaned from RUPES action research sites and its research. Positioning RUPES and its next step will support the progressive development of a pro-poor payments for environmental services concept in the tropics.
Occurrence and abundance of arbuscular mycorrhizal fungi (AMF) in agroforestry systems of Rubavu and Bugesera Districts in Rwanda
Arbuscular mycorrhizal fungi (AMF) help to facilitate mobilization of nutrients from soil to plant. The study was carried out in humid Rubavu and semi-arid Bugesera districts in Rwanda. We hypothesized that the presence of tree species in farming systems enhances mycorrhizal fungal density. The occurrence and abundance of AMF in the soil around main agroforestry tree species in these regions was studied. Tree species in Rubavu included Alnus acuminata, Markhamia lutea, Grevillea robusta and Eucalyptus sp. and in Bugesera Acacia polyacantha, Senna spectabilis, Grevillea robusta and Eucalyptus sp. AMF spores were isolated from soil samples collected under and outside the trees canopies. Results show significant differences in spore density between species. The density of AMF spores was highest under A. acuminata and A. polyacantha and lowest in Eucalyptus sp. and G. robusta in Rubavu and Bugesera, respectively. Generally, the mean spore abundance (spores/g of soil) was significantly higher in Bugesera (3.1-6.6) than Rubavu (1.6-4.4). Spores abundance was also affected by distance from the tree trunk and tree size. The present work is the first attempt to study the AMF communities associated with tree species in agroforestry systems in Rwanda. We propose further studies relating mycorrhizal diversity in the agroforestry systems to performance and yields of crops