Improving production efficiency of African Eggplant (Solanum aethiopicum) for smallholder farmers in sub-Saharan Africa

Lead Research Organisation: National Inst of Agricultural Botany
Department Name: Centre for Research

Abstract

Malnutrition affects one in three people on the planet, with 2 billion people being deficient in one or more micronutrients. In Sub-Saharan Africa malnutrition is a chronic problem. The sustainable production and consumption of biodiverse nutritious horticultural crops provide a key part of the solution to this problem. There are many indigenous vegetable species that are grown in Africa and sold in local markets, mainly by female producers, as a source of income to alleviate their poverty. However, many of these crops are under-researched and their full potential has not been realised. African eggplant, Solanum aethiopicum, is such a crop. It is widely consumed across both West and East Africa as a leafy vegetable and also as a fruit. Solanum aethiopicum is closely related to Solanum melongena, aubergine/eggplant, and to tomato, Solanum lycopersicum and potato, Solanum tuberosum. Similar to these Solanum species, the availability of soil water and the health of the soil, as defined by the presence or absence of diseases, will greatly affect productivity and nutritive content. There is therefore an immense potential to improve the production of African eggplant through better water management strategies, improving soil health and growing varieties that are more resilient to water stress. Here we will adopt two major approaches to maximise African eggplant production: 1) developing new plant and crop management strategies to improve production; 2) characterise the genetic diversity towards identifying more drought resilient accessions of African eggplant.

To inform best practice for irrigating African eggplant we will characterise the current commercial varieties' responses to a range of soil water deficits. Under controlled conditions we will identify the range of soil matric potentials and volumetric water contents that support optimum yields and nutritive quality. We will test the potential of using hyperspectral imaging to identify the onset of plant water stress and its use as a tool to identify water resilient lines. Responses to soil water deficits will be further investigated in pot experiments in Africa prior to testing in the field. We will also determine if nursery plants can be primed for a greater resilience to soil water stress and soil health before planting in the field. This will be done by using a mild wilting stress and the use of arbuscular mycorrhiza to induce better plant performance. Our final plant management strategy is to improve soil health. First we will characterise the DNA present in the soil on African farms to gain understanding of the microbes present and thus soil health. This will inform which soil amendments will have greatest potential to improve soil health, and these will be tested on the farms. We will assess the effect of these management practices on African eggplant productivity and take into account the economic cost and farmer preference towards generating best practice guides.

At the same time as improving crop management we will characterise the extensive germplasm in our collection. To gain understanding of the potential diversity we will resequence the genomes of 20 accessions and identify the variation. We will multiply the seed in our collection and evaluate, in association with farmers, 160 accessions in drought-prone areas and characterise which lines are more resilient to low soil water availability. Based on farmer feedback we will phenotypically characterise in more detail the preferred accessions and initiate crosses of the best performing lines to advance current breeding programmes. To help inform breeding efforts, we will characterise a population of African eggplants that segregate for their ability to grow under increasing soil water deficits. We will identify molecular markers that are linked to better drought resilience that can be deployed in the breeding programmes.

Technical Summary

We will improve African eggplant productivity by developing integrated plant management strategies and novel germplasm resources. We will identify the soil matric potentials below which plant productivity is reduced to inform new irrigation strategies. We will also test the feasibility of identifying spectral indices that can be used to monitor crop performance when under water stress. We will repeat and refine the pot-based experiments in Africa to account for higher evaporative demands before rolling out alternate wetting and drying irrigation regimes on African farms.
We will also develop a system of stress-priming seedlings in the nursery prior to field planting; this will include short-term wilting stress and the use of arbuscular mycorrhizal fungi. Successful priming treatments will be rolled out to African farmers. We will sequence the soil microbiome from three different farming regions to gain insight into soil health, as measured by the presence and absence of pathogenic microbes. We will develop and test soil amendments and quantify effects on soil health and productivity.
Simultaneously we will multiply the seed of 200+ accessions in our germplasm collections and grow out accessions on farms in drought-prone areas to select the ~40 best performing lines for more detailed phenotype analysis. This will include analysis of root and shoot characteristics under soil water deficits. We will sequence 20 accessions to gain insights into the potential diversity in our germplasm collection and to identify SNPs to aid the analysis of a mapping population segregating for responses to limiting soil water availability. We will identify markers linked to improved productivity under soil water deficits. We will initiate crosses of the most promising resilient accessions to advanced breeding lines.
Throughout these investigations, we will involve farmers and breeders to assess crop performance and review the economic potential of any new growing methods and cultivars.

Planned Impact

Our vision is to carry out our research to directly benefit African farmers and consumers by improving human nutrition and poverty alleviation through the enhanced production of African eggplant.

From the beginning of the project until the end we will engage with farmers and breeders in Uganda and Tanzania towards delivering solutions in increasing the production of this crop.

The main beneficiaries will be male and female smallholder farmers and their dependants. They will gain from being able to help select new accessions from our collections that will enter the breeding programmes or be directly adopted. They will also gain from being shown how irrigation methods can improve productivity. Working with farmers and showing how priming nursery seedlings can improve crop performance will be an additional plant management methodology that farmers will gain. They will also directly gain experience and understanding in how soil amendments will help improve soil health and future crop performance.
Ultimately smallholders' income will improve from the increased resilient production and selling more in local markets, which will make paying for medical care and school fees easier thus improving general domestic harmony.

Breeders of African Eggplant will gain from being able to view the accessions being grown during our seed multiplication and drought resilience assessments. They will be able to select lines for crossing into their breeding programmes not only based on drought resilience but on key horticultural traits that they are targeting for improvement. Breeders will also benefit from the genome sequences, SNP data and molecular markers linked to drought resilience that we will identify. This help in speeding up their development more drought resilient lines. Similarly the development of an image based system that will indicate when reduced water level is impacting on growth and development will help breeders rapidly phenotype and select more drought resilient plants in their segregating populations. Breeders will also profit from access to any initial crosses between lines that we generate during the course of our research.

The above are direct beneficiaries of our research. There will be many indirect beneficiaries through the improved production of African Eggplant and the translation of our research to other vegetable crops. Local African communities will benefit from the enhanced availability of more nutritious local produce that will help to improve their health and well-being. In peri-urban areas where supply chains are developed retailers will benefit from consistent supply of produce. Ultimately producer organisations working in Africa exporting vegetables to Europe will also gain from a more resilient and sustainable source of vegetables.

Publications

10 25 50
 
Description This award is still active and all research is on-going.

We initially engaged with farmers in the Tanzania and in Uganda through carrying out a baseline survey to learn more about methods of growing African Eggplant (Solanum aethiopicum) and the challenges they face. In Tanzania a major focus is on the production of Gilo type which is grown for fruits whereas in Uganda the Shum type is grown as a leafy vegetable. The data from these surveys are being made ready for publication.

We have carried out farmer participatory screening of Solanum aethiopicum germplasm that has taken place to identify lines that have water stress resilience. In Uganda this has been carried out at three locations and in Tanzania at two. In Uganda the engagement included both farmers and farm leaders representing a further ~ 30 farmers. In Tanzania similar farmer participatory screening has taken place with ~50 farmers at each site. Gender disaggregated screening of germplasm at World Vegetable Center was carried out. From these screens preferred germplasm has been identified and taken forward for more detailed experiments to understand how different germplasm responds to water stress. In a trial in Chambezi led by TARI farmer/gender preference in the taste and yield of different varieties was seen. Similar data was obtained in Luwero Uganda

Challenges have been encountered whilst carrying out the screens in Africa. The normal dry and wet seasons have not been usual with dry seasons being wetter than normal, leading to problems in screening for resilience to water stress. There have also been losses in the crops due to wilt infections. Other challenges have been observed with heterogeneity being in the selected entries and further genetic investigation of this material is being carried out. Such heterogeneity makes the more detailed investigation into water stress resilience in the UK more challenging as it is difficult to observe uniform responses to water stress.
We are making progress in our research to identify the potential soil borne causal agent of the wilt disease in solanum aethiopicum. Soil, root and stem samples from infected and uninfected plants have been sequenced and preliminary sequence analysis suggests candidate causal organisms. More detailed analysis is underway to confirm candidate causal organisms.
We have also initiated experiments to see if soil amendments can help improve plant growth in response to stress. We have preliminary good results and these need to be confirmed.

Our more detailed analysis of water stress responses in solanum aethiopicum is on-going with confirmation of our current observations needing to be confirmed.
We continue to engage with multiple stakeholders including farmers, academics, students the general public and policy makers as can be seen in the multiple engagement activities associated with the projects.

The Covid-19 pandemic has impacted on our progress and a no cost extension has been provided to help complete our research

A web page has been developed that outlines our project.
https://www.niab.com/research/research-projects/sassa-sai/about-sassa-sai

And our research collaboration has featured in a BBSRC newsletter and blog.
Exploitation Route It is too early in our project to say to what extent our findings may be taken forward. However, as shown in the multiple engagment activities we have engaged with farmers to identify their preference of varieties and shared our knowledge and understanding of how to grow this crop.


This engagement offers future avenues of interaction and ways in which our research can have direct impact.
Sectors Agriculture, Food and Drink

URL https://www.niab.com/research/research-projects/sassa-sai/about-sassa-sai
 
Description African Orphan Crop Consortia ICRAF-SASSA-SAI 
Organisation World Agroforestry Centre
Country Kenya 
Sector Charity/Non Profit 
PI Contribution Collaboration in determining sequencing strategies in the shared project.
Collaborator Contribution Partners to carry out plat genomic analysis.
Impact No outputs as yet
Start Year 2018
 
Description TARI -SASSA-SAI 
Organisation Tanzania Agricultural Research Institute
Country Tanzania, United Republic of 
Sector Public 
PI Contribution NIAB EMR providing expertise in 1) Water stress responses in plants 2) Disease analysis of soils and plants 3) Soil amendments
Collaborator Contribution TARI providing expertise and resources in 1) Farmer engagement in Tanzania 2) Farm sites in Tanzania 3) field analysis of diseases.
Impact Farmer participatory analysis of germplasm. Manuals in Swahili
Start Year 2018
 
Description UCU SASSA-SAI 
Organisation Uganda Christian University
Country Uganda 
Sector Academic/University 
PI Contribution NIAB EMR providing expertise in 1) Water stress responses in plants 2) Disease analysis of soils and plants 3) Soil amendments
Collaborator Contribution UCU providing expertise and resources in 1) Germplasm 2) Farmer engagement in Uganda 3) Farm sites in Uganda
Impact Screening of germplasm for water stress reslience.
Start Year 2018
 
Description World Vegetable Center SASSA-SAI 
Organisation AVRDC - The World Vegetable Center
Country Tanzania, United Republic of 
Sector Charity/Non Profit 
PI Contribution NIAB EMR providing expertise in 1) Water stress responses in plants 2) Disease analysis of soils and plants 3) Soil amendments
Collaborator Contribution WorldVeg providing expertise and resources in 1) Germplasm 2) Farmer engagement in Tanzania 3) Farm sites in Tanzania
Impact Screening of Solanumaethiopicum Germplasm
Start Year 2018
 
Description 1st Farmer participatory evaluation of Solanum aethiopicum genotypes in Luwero Uganda 
Form Of Engagement Activity Participation in an activity, workshop or similar
Part Of Official Scheme? No
Geographic Reach Regional
Primary Audience Industry/Business
Results and Impact Farmer evaluation of field grown crops. Farmer knowledge of the crop increased and there is now greater potential for them to grow new varieties.
Year(s) Of Engagement Activity 2019
 
Description 1st Farmer participatory evaluation of Solanum aethiopicum genotypes in Wakiso Uganda 
Form Of Engagement Activity Participation in an activity, workshop or similar
Part Of Official Scheme? No
Geographic Reach Regional
Primary Audience Industry/Business
Results and Impact Farmer evaluation of field grown crops. Farmer knowledge of the crop increased and greater potential for them to grow new varieties.
Year(s) Of Engagement Activity 2019
 
Description 2nd Farmer participatory evaluation of Solanum aethiopicum genotypes in Mukono Uganda 
Form Of Engagement Activity Participation in an activity, workshop or similar
Part Of Official Scheme? No
Geographic Reach Regional
Primary Audience Industry/Business
Results and Impact Farmer evaluation of field grown crops. Farmer knowledge of the crop increased and greater potential for them to grow new varieties.
Year(s) Of Engagement Activity 2019
 
Description 2nd Farmer participatory evaluation of Solanum aethiopicum genotypes in Arusha Tanzania Feb 2021 
Form Of Engagement Activity Participation in an open day or visit at my research institution
Part Of Official Scheme? No
Geographic Reach Regional
Primary Audience Industry/Business
Results and Impact A total of 45 farmers (20 female farmers and 25 male farmers) conducted the selection of preffered accession of Solanum aethiopicum using a 0-4 scale on 18 February 2021.
Year(s) Of Engagement Activity 2021
 
Description 1st Farmer Participatory screening of Solanum Aethiopicum accessions at TARI Mikocheni Tanzania 
Form Of Engagement Activity Participation in an activity, workshop or similar
Part Of Official Scheme? No
Geographic Reach National
Primary Audience Industry/Business
Results and Impact Farmer evaluation of field grown crops. Farmer knowledge of the crop increased and there is now greater potential for them to grow new varieties.
Year(s) Of Engagement Activity 2019
 
Description 1st Farmer Participatory screening of Solanum Aethiopicum accessions at UCU, Mukuno Uganda 
Form Of Engagement Activity Participation in an activity, workshop or similar
Part Of Official Scheme? No
Geographic Reach Regional
Primary Audience Industry/Business
Results and Impact Farmer evaluation of field grown crops. Farmer knowledge of the crop increased and there is now greater potential for them to grow new varieties.
Year(s) Of Engagement Activity 2019
 
Description 1st Farmer Participatory screening of Solanum Aethiopicum accessions at WorldVeg Arusha Tanzania 
Form Of Engagement Activity Participation in an activity, workshop or similar
Part Of Official Scheme? No
Geographic Reach National
Primary Audience Industry/Business
Results and Impact Farmer evaluation of field grown crops. Farmer knowledge of the crop increased and there is now greater potential for them to grow new varieties.
Year(s) Of Engagement Activity 2019
 
Description A poster depicting SASSA project objectives and project partners was displayed at African Traditional Vegetables Summit 2021 conference in Arusha, Tanzania 
Form Of Engagement Activity A talk or presentation
Part Of Official Scheme? No
Geographic Reach International
Primary Audience Professional Practitioners
Results and Impact A poster presentation depicting SASSA-SAI project objectives and project partners was displayed at African Traditional Vegetables Summit 2021 conference in Arusha, Tanzania. More than 100 people participated in person in the conference.
Year(s) Of Engagement Activity 2021
 
Description African Traditional Vegetables Summit 2021 participant visit to WorldVeg Solanum Aethiopicum trial site Jan 2021 
Form Of Engagement Activity Participation in an activity, workshop or similar
Part Of Official Scheme? No
Geographic Reach International
Primary Audience Professional Practitioners
Results and Impact 81 partitipants of the African Traditional Vegetables Summit 2021 visited the SASSA project 2020/2021 trial and seed increase plots on 28 January 2021.
Year(s) Of Engagement Activity 2021
 
Description Annual Review meeting and tours of UK facilities 
Form Of Engagement Activity Participation in an activity, workshop or similar
Part Of Official Scheme? No
Geographic Reach International
Primary Audience Professional Practitioners
Results and Impact Annual meeting including visiting NIAB EMR -WET Centre, research labs, research orchards and research glasshouse facilities. Visit to NIAB CUF including tour of research fields and presentations by Dr Mark Stalham andDr Marc Allison. Impact via research knowledge exchange.
Year(s) Of Engagement Activity 2019
 
Description Farmer Particiapatory evaluaiton of germplasm Feb 2021 Luwero, Uganda 
Form Of Engagement Activity Participation in an activity, workshop or similar
Part Of Official Scheme? No
Geographic Reach Regional
Primary Audience Industry/Business
Results and Impact On the 4th/February/2021 we harvested one of our participatory evaluation on-farm trial in Luwero Uganda. The objective of the trial was to introduce the concept of sustainable farming to the farmers. COVID-19 SOPs were maintained and only selected farmers from 2 different farmer groups were involved. Twenty-five farmers overall were involved in the assessment. A sensory evaluation was also conducted on the genotypes grown to see the effects of the soil amendment treatments on taste of the vegetables. The sensory evaluation was also done with a trained panel from the School of Food Science, Nutrition and Bio-engineering - Makerere University.

Farmers appreciated that they needed to consider the final consumer preferences of the vegetables they grow . They also appreciated seeing the various S.aethiopicum in lines.
Year(s) Of Engagement Activity 2021
 
Description Farmer Participatory Screening of Solanum Aethiopicum Germplam April 2020 Chambezi Tanzania (led by TARI) 
Form Of Engagement Activity Participation in an activity, workshop or similar
Part Of Official Scheme? No
Geographic Reach Regional
Primary Audience Industry/Business
Results and Impact Field based evaluation of Solaum aethoipicum lines and taste test at Chambezi Tanzania on 29/4/2020
29 solanum aethiopicum accessions evaluated
25 farmers/consumers participated
Males: 11
Females: 14
There were farmer/gender preferences for different varieties vs yield.
Year(s) Of Engagement Activity 2020
 
Description Farmer Participatory Selction visit of Solanum aethiopicum plots Worldveg Feb 2021 
Form Of Engagement Activity Participation in an activity, workshop or similar
Part Of Official Scheme? No
Geographic Reach National
Primary Audience Industry/Business
Results and Impact Group of 42 farmers (15 female and 27 male farmers) from Mbeya, Iringa, NJjombe, Katavi and Songwe regions of the southern highlands of Tanzania visited the Solanum Aethiopicum trial on the 10th of February 2021.
Year(s) Of Engagement Activity 2021
 
Description Plant Power Blog Oct 2020 
Form Of Engagement Activity Engagement focused website, blog or social media channel
Part Of Official Scheme? No
Geographic Reach International
Primary Audience Public/other audiences
Results and Impact Engaged in providing information for a BBSRC blog.
https://www.ukri.org/our-work/iyph2020/plant-power-building-resources-in-developing-countries/
Providing details of SASSA-SAI Solanum Aethiopicum project for a wide audience.
Year(s) Of Engagement Activity 2020
URL https://www.ukri.org/our-work/iyph2020/plant-power-building-resources-in-developing-countries/
 
Description Poster presentation at XVI Solanaceae Conference (SOL 2019) 
Form Of Engagement Activity A talk or presentation
Part Of Official Scheme? No
Geographic Reach International
Primary Audience Professional Practitioners
Results and Impact Prof G Bishop presented project work to international community researching solanaceae crops.
Year(s) Of Engagement Activity 2019
 
Description Presentation at the World Vegetable Center's Global R&D Week 2019 
Form Of Engagement Activity A talk or presentation
Part Of Official Scheme? No
Geographic Reach International
Primary Audience Professional Practitioners
Results and Impact Achievements of the enabling impact flagship 2019 with emphasis on SASSA project baseline survey. Presented at the World Vegetable Center's Global R&D Week 2019, Taiwan,
Year(s) Of Engagement Activity 2019
 
Description Presentation at the World Vegetable Center's Global R&D Week 2019 
Form Of Engagement Activity Participation in an activity, workshop or similar
Part Of Official Scheme? No
Geographic Reach International
Primary Audience Professional Practitioners
Results and Impact Progress of African eggplant screening for low moisture stress conditions was reported. Presented at the World Vegetable Center's Global R&D Week 2019, Taiwan
Year(s) Of Engagement Activity 2019
 
Description Production of Solanum Aethiopicum booklet in Swahili 
Form Of Engagement Activity A magazine, newsletter or online publication
Part Of Official Scheme? No
Geographic Reach Regional
Primary Audience Professional Practitioners
Results and Impact Booklet in Swahilli to be given to farmers interested in growing Solanaum aethiopicum. Provides information on how to grow and potential diseases.
Year(s) Of Engagement Activity 2020
 
Description Project description to visitors from Punjab Agricultural University and CECOS University 
Form Of Engagement Activity A talk or presentation
Part Of Official Scheme? No
Geographic Reach International
Primary Audience Public/other audiences
Results and Impact Presented the the project aims and view of current experimentation to delegates from Pakistan, visiting the institute.
Year(s) Of Engagement Activity 2019
 
Description Science day exhibition of the Faculty of Science and Technology, Uganda Christian University Poster and demonstration of SASSA project March 2020 
Form Of Engagement Activity Participation in an open day or visit at my research institution
Part Of Official Scheme? No
Geographic Reach National
Primary Audience Undergraduate students
Results and Impact 18th/March/2020 the SASSA-project participated in the Science day exhibition of the Faculty of Science and Technology, Uganda Christian University. A poster presentation on the project objectives was made. The guest of honour was the Minister of Science and Technology of the Government of Uganda. Over 500 people visited the poster presentation including students, academicians, the general public including farmers.
Year(s) Of Engagement Activity 2020
 
Description World Food Day Visitors to SASSA seed increase plots on 16 October 2020 
Form Of Engagement Activity Participation in an open day or visit at my research institution
Part Of Official Scheme? No
Geographic Reach International
Primary Audience Professional Practitioners
Results and Impact ~ 60 Participants of the World Food Day visited SASSA seed increase plots on 16 October 2020
Year(s) Of Engagement Activity 2020