Domestication of Irvingia gabonensis: 3. phenotypic variation of fruits and kernels in a Nigerian village

Domestication of Irvingia gabonensis, a fruit tree grown in agroforestry systems in West and Central Africa, offers considerable scope for enhancing the nutritional and economic security of subsistence farmers in the region. Assessments of phenotypic variation in ten fruit, nut and kernel traits were made on twenty-four ripe fruits from 100 Irvingia gabonensis trees in Ugwuaji village in southeast Nigeria, a center of genetic diversity for this species. There were important differences between the young planted trees of this study and the older unplanted trees of a similar study in Cameroon. Significant and continuous tree-to-tree variation was found in fruit mass(69.0–419.8 g), flesh mass (59.5–388.8 g), nut mass (9.5–40.6 g), shell mass (4.9–30.9 g) and kernel mass (0.41–7.58 g); fruit length (49.2–89.3 mm) and width (46.2–100.5 mm) and flesh depth (12.9–31.4 mm), as well as considerable variation in flesh colour, skin colour, fruit taste and fibrosity. Some fruits were considerably bigger than those found in Cameroon. These quantitative results will help in the development of cultivars within participatory approaches to agroforestry tree domestication, and so promote poverty alleviation and sustainable agriculture.

Domestication of Irvingia gabonensis: 1. Phenotypic variation in fruits and kernels in two populations from Cameroon

Twenty four fruits from each of 52 Irvingia gabonensis trees from two villages (Nko’ovos II and Elig Nkouma) of the humid lowland forest zone of Cameroon (West Africa) were assessed to determine the extent of variation in ten fruit, nut (endocarp), and kernel (cotyledon) characteristics. Highly significant differences were found in fruit length (Range = 46.2 to 77.3 mm), fruit width (45.1 to 72.5 mm), flesh (mesocarp) depth (11.2 to 21.8 mm), fruit mass (44.5 to 195.4 g), kernel mass (0.54 to 6.9 g) and shell mass (5.4 to 18.6 g). In each of these traits there was continuous variation. Differences were also observed in fruit taste and fibrosity. The most frequent skin and flesh color was yellow (Methuen Color Code 4A8). Mean fruit length, fruit width, fruit mass, shell mass and kernel mass differed significantly between villages, but did not differ between different landuses (homegardens, cocoa farms, crop fields or fallows). These results represent the first quantitative assessment of tree-to-tree variation in fruit traits for this species and are discussed with regard to the domestication potential of I. gabonensis.

Price satisfaction and producer loyalty: the role of mediators in business to business relationships in Kenyan mango supply chain

Purpose – The purpose of this paper is to investigate which dimensions of price satisfaction influenceproducers’ trust in buyers and assess the mediating role of such trust in the relationship between pricesatisfaction and producer loyalty in fresh fruit supply chains.Design/methodology/approach – A cross-sectional study design using both semi-structuredinterviews and structured questionnaires was used. The study was conducted in the Eastern part ofKenya and included 600 smallholders. Data were analysed using structural equation modelling.Findings – The results show that price fairness, price reliability, and relative price are dimensions ofprice satisfaction that affect producers’ trust in the buyer. Moreover, trust between the producer andthe buyer is found to be a strong mediator between price satisfaction and producer loyalty.The findings support recent studies about trust and its mediating role.Research limitations/implications – The paper is based on a cross-sectional study design, limitingthe causal inferences which can be drawn. Producers’ preferences change with time and future studiesshould be based on longitudinal designs.Originality/value – This paper shows the relationship between the multi-dimensional nature of pricesatisfaction and producer loyalty with trust as a mediating variable in the business-to-business (B2B)context. Although B2B relationships have been shown to be of great importance for smallholders inenhancing business performance with their buyers, little attention has been given to the role of trust asa mediator. This study offers interesting insights into the how trust plays a mediating role betweenprice satisfaction and loyalty in a developing country context.

Application of DRIFT-FTIR spectroscopy for quantitative prediction of simple sugars in two local and two Floridian mango (Mangifera indica L.) cultivars in Kenya

Background: Mangoes are fruits of nutritional importance in Kenya. The fruits vary in their sugars depending on cultivar type and ripening stage. Current methods of sugar content analysis are based on HPLC methods, which are accurate but expensive and time-consuming. We evaluated the potential of diffuse reflectance infrared Fourier transform (DRIFT) spectroscopy as a rapid tool for quantitative prediction of fructose and glucose sugars in the pulp of Kenyan mangoes.Methods: Principal component analysis and partial least regression models were developed using the first derivative DRIFT spectra (400–4000 cm1) to predict fructose and glucose sugars. A factorial analysis of variance compared effects of site (three locations), cultivar type (four cultivars), fruit position (inside/outside), and their interactions on fructose and glucose contents.Results: The principal component analysis scores plot using components 1 and 2 explained 75 and 8% of the variance, respectively, with no clear grouping either by sites or cultivars. The PLS range for glucose was R2 = 0.80, SECV = 0.55, and RPD = 11.52 and fructose R2 = 0.70, SECV = 0.28, and RPD = 11.52. Site (F (2, 265) = 18.12, p < 0.05, 2 = 0.02), cultivar type (F (3, 256) = 4.44, p < 0.05, 2 = 0.05), and fruit position (F (1, 259) = 7.62, p 0.05. In general, fruits outside the canopy had higher fructose and glucose contents than those within the canopy.Conclusions: DRIFTS coupled with chemometric

Major pest and disease identification and management guide for mango, avocado, tamarillo and grevillea

Increasing demand for tree products has led to wide production of exotic and native tree species in forest and agroforestry plans. Pests and diseases incidences are at the same time a growing continental crisis. Diseases spread is accelerated by climate change dynamics and implications are concerning African farmers already challenged by weak intervention capacity, fragmented ecosystems, and porous borders. Impacts may also trigger loss of biodiversity, food crisis and constrain agroforestry adaptations strategies. Field observations in parts of Rwanda and Kenya where mango, tamarillo, avocado and grevillea production is prominent, pest and disease incidence is reducing benefits of these production systems. This guide is therefore intended to provide vital information to help smallholders, extension and rural advisory services identify and mange pest and disease incidence before causing total crop failure. Major pest and diseases found in mango, tamarillo, avocado and grevillea are highlighted and possible management plans to reduce spread and losses are indicated as part of wider strategies to dealing with pest and disease break-outs.

Inside-out strategic coupling for smallholder market integration – Mango production in Malawi as a test case

Starting from the observation that value chain research has informed much of agricultural development interventions in recent decades, this paper identifies five key challenges to current agricultural development policies in low- and middle-income countries (LMICs): access to finance, infrastructure, land tenure, local linkages and knowledge transfer. Based on this review, it is argued that recent theoretical advances in the global production network (GPN) approach can help to achieve a more holistic view of agricultural development policies than the more linear value chain research. In particular, three key concepts from the GPN approach are highlighted: mobilisation of regional assets, strategic coupling and territorial embeddedness. These key concepts are used to propose a framework called ‘insight-out strategic coupling for smallholder integration’, which builds on the concept of strategic coupling in GPN research and applies it as a development tool to agricultural production. Using an in-depth case study approach, the usefulness of this framework is tested by examining the experience of Malawi Mangoes, a company established to promote smallholder exports. Malawi Mangoes was initially funded by private equity, but despite a number of challenges along the way, was soon able to attract development funding and integrate smallholders from surrounding villages throughout-grower schemes. Analysis of the case shows both the usefulness of the framework and the lost potential in implementing agricultural development policy. The authors conclude that the framework is useful for linking current debates on agricultural development interventions, but that the findings of critical GPN research need to be taken into account when developing agricultural development interventions in order to respect the ‘do no harm’ principle.

Effect of elevation on photosynthesis of young mango (Mangifera indica L.) trees

Anticipating warming related to climate change, commercial mango plantations in China have been shifting from lower to higher elevations. Such a practice may expose mangoes to climatic conditions that could affect photosynthesis. Photosynthesis research on mango has previously examined mature plantations but exploring adequate functions before the time of fruit production is necessary for later crop success. Therefore, we established two main commercial mango cultivars, Tainong No. 1 and Jinhuang, at 450 m and 1,050 m and examined their photosynthetic performance. Our results showed that photosynthetic capacity parameters, including maximum photosynthetic rate, apparent quantum yield, maximum carboxylation rate, and photosynthetic electron transport rate, were significantly different between cultivars due to elevation and positively correlated with leaf nitrogen per area. Moreover, the seasonal gas exchange of the two cultivars showed variations due to elevation, particularly during the warmer seasons. Therefore, elevation affects the photosynthetic performance of these mango cultivars.

Effects of degraded grassland conversion to mango plantation on soil CO2 fluxes

Land use changes are of serious concern due to its effects on soil carbon stock, which is second largest anthropogenic source of atmosphere CO2. To better understand these effects in typical and fragile ecosystems like dry-hot valley regions, we quantified changes in soil properties (pH, organic carbon, total nitrogen, phosphorus, microbial biomass carbon contents, activities of β-glucosidase, beta-N-acetyl-glucosaminidase, acid phosphatase) and CO2 efflux before (degraded grassland) and after (mango plantation) land use change in a dry-hot valley region. Most soil chemical properties remained unaffected after conversion due to generally low regional nutrient levels. Principal component analysis revealed the decline of soil heterogeneity of the selected properties (pH, SOC, TN, TP, AP), which will be useful for future unified management. Compared to grassland, CO2 efflux in mango plantation increased by 20–69% after land use change, more factors and their interactions were responsible for CO2 efflux from soil in mango plantations. The temperature sensitivity (Q10: 0.68–1.98) of CO2 efflux in both land use types was low due to the low soil moisture at high temperatures. Soil water content was the primary factor affecting CO2 efflux in the dry-hot valley region, followed by microbial biomass carbon. In summary, the CO2 efflux increased shortly after the land use change (within first year), even though absence of significant quantitative change of soil properties, and low temperature sensitive (Q10) before and after conversion and its difference between land use types is opposite in dry and wet season.

Resilient Landscapes is powered by CIFOR-ICRAF. Our mission is to connect private and public actors in co-beneficial landscapes; provide evidence-based business cases for nature-based solutions and green economy investments; leverage and de-risk performance-driven investments with combined financial, social and environmental returns.

2024 All rights reserved    Privacy notice