Chapters 5.43: Difference between revisions

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(Created page with "<div> <div class="title"><h3>5.43 -Drought Tolerant Bean Varieties (Phaseolus vulgaris) Utilized to Overcome the Negative Effects of Climate Change </h3><br><h3 class="ch-owner">Jordan Candido, University of Guelph, Canada </h3></div> <div class="hero-img-2"> 300px <p>Suggested citation for this chapter.</p> <p>Candido,J. (2022) Drought Tolerant Bean Varieties (Phaseolus vulgaris) Utilized to Overcome the Negative Effects of Climate Change, In Farmpedia,...")
 
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  <div class="title"><h3>5.43 -Drought Tolerant Bean Varieties (Phaseolus vulgaris) Utilized to Overcome the Negative Effects of Climate Change </h3><br><h3 class="ch-owner">Jordan Candido, University of Guelph, Canada </h3></div>
  <div class="title"><h3>5.43 -Adoption of Sweet Potato as a Crop for Smallholder Farmers Challenged with Climate Change</h3><br><h3 class="ch-owner">Kate Elizabeth Maggiacomo, University of Guelph, Canada </h3></div>
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<p>Suggested citation for this chapter.</p>
<p>Suggested citation for this chapter.</p>
<p>Candido,J. (2022) Drought Tolerant Bean Varieties (Phaseolus vulgaris) Utilized to Overcome the Negative Effects of Climate Change, In Farmpedia, The Encyclopedia for Small Scale Farmers. Editor, M.N. Raizada, University of Guelph, Canada. http://www.farmpedia.org</p>
<p> Maggiacomo,Kate E. (2022) Adoption of Sweet Potato as a Crop for Smallholder Farmers Challenged with Climate Change, In Farmpedia, The Encyclopedia for Small Scale Farmers. Editor, M.N. Raizada, University of Guelph, Canada. http://www.farmpedia.org</p>
       <h3 class="title-bg">Background</h3>
       <h3 class="title-bg">An Introduction to Climate Change</h3>
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           <p>During the formation of the International Centre for Tropical Agriculture, or CIAT, in 1967, headquartered in Colombia, the vast majority of starving and malnourished people residing in tropical and sub-tropical regions were smallholder farmers (CIAT, 2017). Thus, the goal of increasing yield potential became a primary priority for CIAT (CIAT, 2017). The current areas of concern are in regard to common bean (Phaseolus vulgaris) production systems, the landscapes where its production occurs, and its yield potential (CIAT, 2015). Millions of farmers within Africa and Latin America depend on high yield outcomes from their bean crops not only to provide food but also to provide an income for themselves and their families. However, due to the high demand of the crop and the drastic effects of climate change, farmers continue to struggle to meet the needs of consumers (CIAT, 2015).</p>
           <p>Agricultural practices play a crucial role in the development, economy, and food security throughout the developing world, all of which are at risk due to the detrimental impacts of climate change on crop production and sustainability (Müller et al., 2011). Strategies must be implemented to create greater resiliency for farmers and enable them to maintain productivity (Morton, 2007). The adoption of sweet potato (Ipomoea batatas) as a secure and sustainable crop represents an opportunity for smallholder farmers to combat agricultural deprivation (Motsa et al., 2015).</p>  
<p>Throughout the previous several decades, the impacts of climate change have been worsening (IFPRI, 2009). Climate change projections state that regions in Sub-Saharan Africa, Latin America, and the Caribbean will be greatly affected by an increase of drought conditions and a rise in average annual temperatures. Due to these conditions, the threats to agricultural production within these land areas are escalating (IFPRI, 2009). Within these regions, the common bean is a staple crop; beans are often referred to as “the meat of the poor” (CIAT, 2016). They contain high levels of protein, fibre, vitamins and micronutrients. An estimated 400 million people residing in the tropics consume beans in their daily diet due to their high nutritional content (CIAT, 2016).</p>
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       <h3 class="title-bg">Benefits of Drought Tolerant Bean Varieties to Small Scale Farmers </h3>
       <h3 class="title-bg">Background to Sweet Potato  </h3>
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<p>Sweet potato, or Ipomoea batatas from the Convolvulaceae family, originated in tropical South America (Karyeija et al., 2007). Sweet potato varieties were introduced to Asia, Africa, and India from Portugal (Srisuwan et al., 2006). Asia currently produces the largest amount of sweet potatoes, with Africa being the world’s second greatest producer, specifically in Uganda and Rwanda (Glato et al., 2017; Rose & Vasanthakaalam, 2011). Following the introduction of sweet potato into African agriculture, sweet potato became an indigenised crop as a result of its quick adaptation to the tropical and subtopical environments (Motsa et al., 2015). Sweet potato cultivation is a significant part of African agriculture as it represents a crop that promotes food security and nutrition((Karyeija et al., 2007). Production throughout Africa averages over 7 million tonnes, representing 5% of global production, which is estimated to increase substantially (Ewell, 2010). Most production throughout Africa is by smallholder farmers as a form of subsistence agriculture, with only 20% being traded or used for income (Andrade et al., 2009). Sweet potato represents a promising crop in the context of climate change, as it grows with 750-1000 mm of rainfall, but some varieties can tolerate as little as 500 mm of rainfall (Woolfe, 1992). </p>
<p>The world’s largest and most diverse collection of beans is preserved by CIAT (CIAT, 2015). Beans were domesticated within the neo-tropics thousands of years ago, which is where the majority of CIAT’s germplasm originated. With such an extensive range of beans available, the seed bank contains many options for farmers; a variety of colours, nutritional content, and production requirements can be found within these different strains (CIAT, 2015).</p>
<p>Hundreds of sweet potato varieties have been identified with over 200 varieties being cultivated in Rwanda alone (Rose & Vasanthakaalam, 2011). Sweet potato varieties and their traits are impacted by genetics and environmental influences (Ochieng, 2019; Andrade et al., 2009). The varietal diversity includes variation in the flesh, skin, root, shape, and size (Ochieng, 2019). Sweet potato flesh can vary from yellow, orange or white, and the skin can vary from yellow, orange, red, white, or purple (Rose & Vasanthakaalam, 2011). Other agro-morphological characteristics used in distinguishing varieties include vine growth, stem length and diameter, leaf size, storage root thickness and diameter, and root yield (Ochieng, 2019). The improvement of crop yield relies on access to successful, high-yielding varieties adapted to the local growing environment and needs (Ochieng, 2019).</p>
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<p>Within the previous 15 years, researchers at the Consortium of International Agricultural Research Centres (CGIAR), CIAT’s umbrella organization, have created incredible advances towards solving issues surrounding drought, and increasing the heat-tolerance and nutritional content levels within common bean varieties (CIAT, 2015). CIAT researchers have been able to identify lines that display a tolerance to a 3˚C increase in temperature. These lines derive from a variety of crosses between common and tepary bean species (Phaseolus acutifolius). Currently cultivated traditional bean varieties have been projected to suffer a 20-50% loss by 2050, whereas heat-tolerant bred beans are projected to suffer minimal losses within that same time period (CIAT, 2015).</p>  
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<p>In order for the new bean varieties to have drought resistant qualities, different traits from different genetic groups were required (Beebe, 2014). Many of the traits which are linked to drought resistance were found within both bean roots and shoots. In order to guarantee a higher success rate of the bean plant, a lengthy root system was required. Additionally, early maturation of the bean crops was a common tactic to combat drought tolerance. A total of 36 genotypes were tested in 2009 during a growing season with significant drought stress. Table 1 shows the field trial results of 5 genotypes grown under different field conditions (Beebe, 2014).</P>
      <h3 class="title-bg">Nutrients  </h3>
 
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<p>Table 1. Drought associated traits associated with improved bean genotypes </p>
<p>While peoples in Africa and the global subtropics face significant rates of malnutrition, vitamin A deficiency, and other various health disorders, sweet potatoes are seen as a medicinal, nutrient rich crop that can help improve food resources and nutritional access (Kwak, 2019). Sweet potatoes are a source of carbohydrates, significant macronutrients and micronutrients, vitamin C, B complex, A, E, and folic acid (Motsa et al., 2015). Per 100 grams, sweet potatoes contain 114 kilocalories, 2.4 grams of dietary fibre, 26.3 grams of carbohydrates, 0.4 grams of fat, and 1.7 grams of protein. Sweet potatoes provide considerable amounts of vitamin A through Beta-carotene, making it an affordable and nutrient rich crop that can contribute to reducing the occurrence of vitamin A deficiency which contributes to immune system weakness in humans (Motsa et al., 2015; Andrade et al., 2009). The leaves and roots of the sweet potato can be a modest source of protein with 2.99 grams per 100 grams (Bovell-Benjamin, 2007; Sun et al., 2014). Two important storage proteins identified in sweet potato roots are Sporamins A and B which are rich in lysine and methionine, respectively (Maeshima et al.,1985). However, while significant amounts of lysine and methionine can be found in sweet potato roots, they are not significant in the other organs of the sweet potato (Maeshima et al.,1985). The nutritional content of the leaves includes up to 26.4% iron, 1.2% calcium, 15.8% vitamin E, and 34.7% carotenoid per 100 grams. Consumption of sweet potato can also be associated with health benefits including chemo preventive activities in which enzymes found in sweet potatoes can help to suppress cancer cells, along with anti-inflammatory, increased eyesight, and anti-diabetic properties (Bovell-Benjamin, 2007; Rabah et al., 2004).</p>
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<p>The crops were managed by the irrigation systems for up to 25 days following planting. In order to induce drought stress, the crops were fed a total of 105 mm of water initially followed by an allotted amount of 59 mm of rainwater. An analysis of these trials recommended that the most elite drought tolerant lines expressed heightened stomatal control of transpiration and contained Mexican genetics (Beebe, 2014).</p>
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<p>Since 1996, The Pan-Africa Bean Research Alliance (PABRA) has released over 550 new drought resistant bean varieties to many of the countries within Africa in co-ordination with assistance from CIAT (CIAT, 2016). Utilizing germplasm available, the new varieties of beans (known as BIO101 and BIO107) contain 60% more iron and 50% more zinc than those of traditional bean crops. Following the creation of these specially bred beans, a trial with pregnant and young women in Rwanda discovered that the new varieties of beans reduced iron-deficiency and increased immune system strength in each of the women (CIAT, 2016). With these new advances, PABRA will assist future production by making the crops more resilient to climate change threats while simultaneously targeting direct effects on the human population (CIAT, 2015).</p>
      <h3 class="title-bg">Growth and Reproduction  </h3>
 
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<p>The regions within Latin America, Oceania and Sub-Saharan Africa contain the highest percentage of women participating in the agricultural sector. It is within these regions that 60% of the total agricultural production is completed by women (Huyer, 2016). In the world’s least developed regions, 79% of the women contributing to their national economy report that they work in the agriculture sector (Huyer, 2016). When women engage in the agricultural production (with new technologies such as heat-tolerant bean varieties) it creates a sense of empowerment and thus builds essential assets, which the women are then able to use in all other aspects of their lives (Muriel, 2019). With the climate change innovations available within common bean variety crops, female farmers are considered to be important influences (Huyer, 2016). When the women’s knowledge of available innovative resources and access to information increases, it establishes an increase in food supply as well as a more resilient community. Likewise, an attempt is made to close the gender gap, thus providing a higher chance for equal opportunities between both men and women (Huyer, 2016), which would in turn help to positively shape the future of those regions affected.</p>  
<p>Sweet potatoes grow in tropical and subtropical environments, able to adapt to temperate climates (Paneque-Ramirez, 1992). They should ideally be grown in a climate of 20-25°C during the day and 15-20°C during the night, however any temperature below 15°C is not favourable (Paneque-Ramirez, 1992). Sweet potato can be planted and harvested anytime throughout the year, under the right conditions (Motsa et al., 2015). The growing season ranges from 3.5-7 months, going through stages of planting to tuber formation, tuber formation to leaf development, and leaf development to final tuber development (Paneque-Ramirez, 1992). Sweet potato propagation is commonly asexual, requiring planting the tuber and stems (not seeds), ideally within 4 days of their cutting (Paneque-Ramirez, 1992). Planting should be done in rows at a depth of about 10 cm, and can be intercropped. Sweet potatoes can be grown in diverse soils, with the best being friable and humic soil, and with a depth greater than 25 cm, with good drainage. The ideal pH ranges from 5.5-6.5, hence a slightly acidic or neutral soil. The soil should remain moist through the growing season, at intervals of 7-10 days. As already noted, sweet potato prefers 750-1000 mm of rainfall but some varieties can tolerate as little as 500 mm of rainfall (Woolfe, 1992). CIP, also known as the International Potato Centre in Peru, is invested in improving global sweet potatoes to enhance climate change adaptation (International Potato Center, 2020). Their scientists have been able to produce more productive agronomic approaches, climate smart varieties and accelerate breeding efforts. To improve drought tolerance, they have developed the Triple S technique wherein sweet potatoes can be stored in sand and used to develop vines for when the rain starts again and the sweet potatoes are able to be planted. Additionally, CIP has bred sweet potato varieties, termed climate smart varieties, that have climate resilient traits and against severe drought and heat (International Potato Center, 2020). Sweet potatoes should be fertilized with phosphorus and potassium to improve yield. Weeding should be done after seed cutting and repeated every 60 days, and can be done either manually, mechanically, or chemically (Paneque-Ramirez, 1992). </p>
<p>Following the growth and development of the sweet potato, the harvesting time differs between varieties, but ranges from 3-6 months after planting (Paneque-Ramirez, 1992). Harvesting can be performed manually, semi-manually, or mechanically, with the most common method being manually by smallholder farmers. Once harvested, sweet potatoes can be stored if kept in the proper conditions. Damaged sweet potatoes, insects, and fungus should be removed, and then can be stored in a dark area that is cool with low humidity (Paneque-Ramirez, 1992). Post-harvest loses are often influenced by damage, cracks, and other physical traits that are seen as negative (FAO, 2020). In order to improve the production and value addition of sweet potatoes, a greater understanding of production and post-harvest methods should be shared (FAO, 2020)</p>
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      <h3 class="title-bg">How the Sweet Potato Can Help Combat Climate Change </h3>
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<p>Sweet potatoes can play a significant role throughout developing countries, representing a crop that is tolerant and adaptive to environmental conditions (Motsa et al., 2015). Sweet potato requires low input and technology to have a fast yield and to increase production capacity (Woolfe, 1992). This crop has a high water efficiency, needs less pesticides and fertilizers than many other crops, and can be used as a cover crop to suppress weeds and prevent water/soil loss (Kwak, 2019). It can provide security, as the roots can be left planted and used when needed, increasing access to a potential food supply (Motsa et al., 2015). Sweet potatoes can help combat malnutrition through their micro and macronutrient supply. They can be completely utilized as the entire sweet potato and roots can be eaten raw or cooked; the leaves can be eaten as a leafy vegetable, or they can be used in animal feed (Kwak, 2019; Motsa et al., 2015). </p>
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       <h3 class="title-bg">Gender Issues Associated with Production of Drought Tolerant Bean Varieties </h3>
       <h3 class="title-bg">How Sweet Potato Can Be Adopted by Smallholder Farmers </h3>
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<p>If the farmers, though especially female farmers, are not able to utilize and benefit from these new seed varieties, the food supply decreases and the gender gap increases, which diminishes the resiliency of the community (Huyer, 2016). Additionally, since very little information is available with regards to how poor regions with higher gender discrepancy respond to the threats and impacts of climate change within agricultural production, it is difficult to forecast results for future decades (Huyer, 2016).</p>
<p>As opposed to other crops, sweet potato crops have improved heat and drought tolerance (International Potato Centre, 2020). In order to improve the adoption of sweet potatoes for smallholder farmers, increased access and information of where to obtain seeds should be provided as well as improved guides for growing and maintaining sweet potato crops. Fortunately, the International Potato Centre (CIP, Peru) is able to work with farmers to produce research and sustainable practices for greater crop development (Wheatley & Loechl, 2008).  Smallholder farmer organizations can obtain materials through seed exchange programs and CIP. Manuals produced and provided by CIP explain varietal information, helping farmers understand which varieties they should crop and how to do so (Stathers et al., 2018).</p>
 
<p>To improve the post-harvest yield and value of sweet potatoes, they should be sorted before storage and kept out of direct sunlight (Stathers et al., 2018). Harvested sweet potatoes should be stored in plastic or wooden crates with the heaviest at the bottom, making sure not to overpack the crate. The harvest should be sold from the market within 3-7 days to ensure rotting does not occur (Stathers et al., 2018).</p>
<p>The role of African women throughout sweet potato production is significant, as subsistence farming of this crop is often performed by the women. Needs assessments can be implemented to help smallholder women farmers growing sweet potatoes (Stathers et al., 2018; Andrade et al., 2009). These programs can also introduce them to community groups to understand the market and how to improve the value chain of sweet potatoes (Stathers et al., 2018). By increasing the supply and developing better marketable characteristics, contracts between farmers and processors can be created (Wolfe, 1992). The expected profit of sweet potato crops is $567 USD per hectare, with production costs being $268 USD per hectare, meaning that the net return would be $298 USD (Kassali, 2011). The total cost breakdown is 68% for labour costs including harvesting, weeding, cultivation, fertilization, and transportation (Kassali, 2011). Growing sweet potatoes is seen to have a profitable return and by using the methods mentioned above, the production of sweet potato products will have increased value and supply availability (Kwak, 2019).</p>
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       <h3 class="title-bg">Production of Drought Tolerant Beans (Phaseolus Vulgaris) in Arid Regions </h3>
       <h3 class="title-bg">Critical Analysis</h3>
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<p>It is necessary that farmers are equipped with all of the relevant information required to achieve the highest quality results from their newly adapted bean varieties (PABRA, 2016). Becoming knowledgeable about land preparation, crop management and harvesting is vital to ensuring success within production systems. Integrated crop management (ICM) is a holistic approach utilized by PABRA that assists farmers throughout their cultivation. The desired outcome from ICM is to give smallholder farmers access to cost-effective, climate change resistant crops. This is achieved by working with many international partners. Multiple techniques exist within ICM such as pest management, soil quality, planting and intercropping. With such techniques, approximately six million farmers have been able to improve their bean yields. The ICM research encompasses a variety of areas:</p>
<p>Major pests and diseases impactful to sweet potato crops include whiteflies, feathery mottle virus, weevils, and chlorotic stunt virus. CIP sweet potato varieties can be used as they are bred for resistance, in addition to incorporating integrated pest management techniques and insecticides (Stathers et al., 2018; Paneque-Ramirez, 1992). In order to improve the adoption and cultivation of sweet potatoes, improved varieites with greater temperature and drought resistance can be accessed from CIP as well as extension manuals. Livelihoods can be improved by participatory approaches, educational provisions, a farm-to-market focus, and post harvest strategies.</p>  
<p>-   Cropping systems: Assessing the different varieties of beans while comparing the benefits of intercropping and rotation.</p> 
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<p>-    Inputs: Evaluating the varieties of fertilisers available which are best suitable for the farmer’s chosen bean variety.</p>
<p>-    Water Management: In order to combat the negative effects of climate change and drought, improved practices regarding irrigation and water conservation are fundamental. </p>
<p>-   Soil Fertility: By working with the technologies available within the private sector, this promotes biological nitrogen fixation capabilities which increases yield potential.</p> 
<p>-    Pest and Disease Management: Bean varieties are frequently affected by an array of pests and diseases which have very negative effects on crop yields. PABRA analyses integrated pest management systems with utilization of both biological and chemical methods (PABRA, 2016).</p>  
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       <h3 class="title-bg">Helpful Links to Get Started </h3>
       <h3 class="title-bg">Links to Useful Resources to Get Started and Further Reading</h3>
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<p>Resource for Requesting Seeds:</p>
<p>https://www.youtube.com/watch?v=Q4pLslnulDc
<p>https://genebank.ciat.cgiar.org/genebank/inforequestmaterial.do</p>
→ Describes the impact of improved cultivation practices on African women </p>
<p>CIAT innovations on heat-tolerant beans:</p>
 
<p>https://blog.ciat.cgiar.org/heat-tolerant-wild-beans-tapped-to-breed-commercial-beans-for-hotter-climates/</p>
<p>https://www.youtube.com/watch?v=MNpKIVEwnp8
<p>What is ‘Seed Security’?</p>
→ Explains the basics of sweet potato production /p>
<p>https://www.youtube.com/watch?v=xvqSaw49wnE</p>
 
<p>Agricultural Business Skills for seed-producers:</p>
<p>https://borgenproject.org/sweet-potatoes-africa/
<p>https://cgspace.cgiar.org/bitstream/handle/10568/54569/handbook_3_english.pdf</p>
→ Introduces the Harvest Plus OFSP initiative /p>
<p>Crop Management:</p>
 
<p>https://www.nrcs.usda.gov/wps/portal/nrcs/detail/national/newsroom/features/?&cid=nrcs143_023350</p>
<p>https://www.npr.org/sections/thesalt/2012/08/15/158783117/saving-lives-in-africa-with-the-humble-sweet-potato
<p>Smallholder Farmers Stories Who Have Adopted Drought Tolerant Bean Varieties:</p>
→ Explains biofortification and the impact they can have in Africa /p>
<p>https://www.youtube.com/watch?v=O2UqFbnOc6U</p>
 
<p>https://www.youtube.com/watch?v=x3D3DiZ4I-8</p>
<p>https://scinnovent.wordpress.com/2014/02/26/african-traditional-foods-and-nutrition-making-consumption-of-orange-fleshed-sweet-potatoes-a-big-deal/
<p>https://www.youtube.com/watch?v=Qd4RS66FMJM&t=8s</p>
→ Interview with a Ghanaian researcher on the benefits of sweet potato for child nutrition /p>
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<p>https://www.cgiar.org/annual-report/performance-report-2019/biofortified-sweet-potato-fights-micronutrient-malnutrition-in-sub-saharan-africa/
→ A report on the use of sweet potatoes to fight poverty and malnutrition/p>  
 
<p>https://www.usaid.gov/hy/news-information/videos/node/208971
→ Three stories of African women using sweet potato to empower and support their families/p>
 
<p>https://www.youtube.com/watch?v=5RBegs2jRlQ
→ OFSP production and market in Ghana/p>
 
<p>https://www.almanac.com/plant/sweet-potatoes
→ This source gives an overview of sweet potatoes and step by step reccomendations for growth/p>
 
<p>https://cdn-ext.agnet.tamu.edu/wp-content/uploads/2014/09/how-to-grow-sweet-potatoes.pdf
→ Manual explaining the steps of sweet potato cultivation/p>
 
<p>http://cdn.newsproutfarms.com/downloads/New-Sprout-Sweet-Potato-Slip-Care-and-Planting-Guide.pdf
→ Sweet potato growing guide/p>
 
<p>http://www.cardi.org/wp-content/uploads/2011/07/SweetPotato_TechnicalManual.pdf
→ A technical manual for sweet potato producers/p>
 
<p>https://cgspace.cgiar.org/bitstream/handle/10568/98338/CIP_SP_T6_SweetpotatoProductionAndManagement_v40.pdf?sequence=10&isAllowed=y
→ CGIAR sweet potato guide to sweet potato production and management/p>
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       <h3 class="title-bg">References </h3>
       <h3 class="title-bg">References </h3>
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<p>1. Andrade, M., Barker, I., Cole, D., Fuentes, S., Gruneberg, W., Kapinga, R., Kroschel, J., Labarta, R., Lemaga, B., Loechl, C., Low, J., Ortiz, O., Oswald, A., & Thiele, G. (2009). Unleashing the potential of sweetpotato in Sub-Saharan Africa Current challenges and way forward. In Unleashing the potential of sweetpotato in Sub-Saharan Africa Current challenges and way forward. CIP Working Paper 2009-1. 197 p. https://doi.org/10.4160/0256874820091</p>
<p>2. Bovell-Benjamin, A. C. (2007). Sweet Potato: A Review of its Past, Present, and Future Role in Human Nutrition. Adv Food Nutr Res 52:1-59.
https://doi.org/https://doi.org/10.1016/S1043-4526(06)52001-7</p>
<p>3. Ewell, P. (2010) Sweet potato production in Sub-Saharan Africa: Patterns and key issues. International Potato Centre, Peru. Retrieved from https://www.sweetpotatoknowledge.org/files/sweetpotato-production-patterns-key-issues/</p>
<p>4. FAO. (2020). Value Chain Analysis Highlights: Sweet potatoes in Lanao del Sur. Food and Agriculture Organization of the United Nations, Rome. Retrieved from http://www.fao.org/publications/card/en/c/CA7552EN/</p>
<p>5. Glato, K., Aidam, A., Kane, N. A., Bassirou, D., Couderc, M., Zekraoui, L., … Vigouroux, Y. (2017). Structure of sweet potato (Ipomoea batatas) diversity in West Africa covaries with a climatic gradient. PLoS ONE, 12(5), e0177697.  https://doi.org/10.1371/journal.pone.0177697</p>
<p>6. International Potato Center. (2020). Case for investment: Climate change adaptation. 4 p. Retrieved from https://cgspace.cgiar.org/handle/10568/106939</p>
<p>7. Karyeija, F., Gibson, W., & Valkonen, P. (2007). The Significance of Sweet Potato Feathery Mottle Virus in Subsistence Sweet Potato Production in Africa. Plant Disease, 82(1), 4-15. https:/doi:10.1094/pdis.1998.82.1.4</p>
<p>8. Kassali, R. (2011). Economics of sweet potato production. International Journal of Vegetable Science 17, 313-321. https://doi.org/10.1080/19315260.2011.553212</p>
<p>9. Kwak, S.-S. (2019). Biotechnology of the sweetpotato: ensuring global food and nutrition security in the face of climate change. Plant Cell Reports, 38(11), 1361–1363. https://doi.org/10.1007/s00299-019-02468-0</p>
<p>10. Maeshima, M., Sasaki, T., & Asahi, T. (1985). Characterization of major proteins in sweet potato tuberous roots. Phytochemistry, 24(9), 1899–1902. https://doi.org/https://doi.org/10.1016/S0031-9422(00)83088-5</p>
<p>11. Motsa, Nozipho M., Modi, Albert T., & Mabhaudhi, Tafadzwanashe. (2015). Sweet potato (Ipomoea batatas L.) as a drought tolerant and food security crop. South African Journal of Science, 111(11-12), 1-8. https://dx.doi.org/10.17159/sajs.2015/20140252</p>
<p>12. Morton, J. F. (2007). The impact of climate change on smallholder and subsistence agriculture. Proceedings of the National Academy of Sciences, 104(50), 19680–19685. https://doi.org/10.1073/pnas.0701855104</p>
<p>13. Müller, C., Cramer, W., Hare, W. L., & Lotze-Campen, H. (2011). Climate change risks for African agriculture. Proceedings of the National Academy of Sciences, 108(11), 4313 LP – 4315. https://doi.org/10.1073/pnas.1015078108</p>
<p>14. Ochieng, L.A.. (2019). Agro-Morphological Characterization of Sweet Potato Genotypes Grown in Different Ecological Zones in Kenya. Journal of Horticulture and Plant Research. 5. 1-12. https://doi.org/10.18052/www.scipress.com/jhpr.5.1</p>
<p>15. Paneque-Ramirez, G. (1992). Cultivation, harvesting and storage of sweet potato products. Food and Agriculture Organization of the United Nations, Rome. Retrieved from https://agris.fao.org/agris-search/search.do?recordID=XF9325337</p>
<p>16. Rabah, I. O., Hou, D. E. X., Komine, S. I., & Fujii, M. (2004). Potential chemopreventive properties of extract from baked sweet potato (Ipomoea batatas Lam. Cv. Koganesengan). </p>
18. Journal of Agricultural and Food Chemistry 52(23):7152-7. https://doi.org/10.1021/jf049368w</p>
<p>17. Rose, I., & Vasanthakaalam, H. (2011). Comparison of the Nutrient composition of four sweet potato varieties cultivated in Rwanda. American Journal of Food and Nutrition 1(1), 34-38. https://doi.org/10.5251/ajfn.2011.1.1.34.38</p>
20. Srisuwan, S., Sihachakr, D., & Siljak-Yakovlev, S. (2006). The origin and evolution of sweet potato (Ipomoea batatas Lam.) and its wild relatives through the cytogenetic approaches. Plant Science, 171(3), 424–433. https://doi.org/https://doi.org/10.1016/j.plantsci.2006.05.007</p>


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Revision as of 09:41, 4 July 2022

5.43 -Adoption of Sweet Potato as a Crop for Smallholder Farmers Challenged with Climate Change


Kate Elizabeth Maggiacomo, University of Guelph, Canada

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Suggested citation for this chapter.

Maggiacomo,Kate E. (2022) Adoption of Sweet Potato as a Crop for Smallholder Farmers Challenged with Climate Change, In Farmpedia, The Encyclopedia for Small Scale Farmers. Editor, M.N. Raizada, University of Guelph, Canada. http://www.farmpedia.org

An Introduction to Climate Change

Agricultural practices play a crucial role in the development, economy, and food security throughout the developing world, all of which are at risk due to the detrimental impacts of climate change on crop production and sustainability (Müller et al., 2011). Strategies must be implemented to create greater resiliency for farmers and enable them to maintain productivity (Morton, 2007). The adoption of sweet potato (Ipomoea batatas) as a secure and sustainable crop represents an opportunity for smallholder farmers to combat agricultural deprivation (Motsa et al., 2015).

Background to Sweet Potato

Sweet potato, or Ipomoea batatas from the Convolvulaceae family, originated in tropical South America (Karyeija et al., 2007). Sweet potato varieties were introduced to Asia, Africa, and India from Portugal (Srisuwan et al., 2006). Asia currently produces the largest amount of sweet potatoes, with Africa being the world’s second greatest producer, specifically in Uganda and Rwanda (Glato et al., 2017; Rose & Vasanthakaalam, 2011). Following the introduction of sweet potato into African agriculture, sweet potato became an indigenised crop as a result of its quick adaptation to the tropical and subtopical environments (Motsa et al., 2015). Sweet potato cultivation is a significant part of African agriculture as it represents a crop that promotes food security and nutrition((Karyeija et al., 2007). Production throughout Africa averages over 7 million tonnes, representing 5% of global production, which is estimated to increase substantially (Ewell, 2010). Most production throughout Africa is by smallholder farmers as a form of subsistence agriculture, with only 20% being traded or used for income (Andrade et al., 2009). Sweet potato represents a promising crop in the context of climate change, as it grows with 750-1000 mm of rainfall, but some varieties can tolerate as little as 500 mm of rainfall (Woolfe, 1992).

Hundreds of sweet potato varieties have been identified with over 200 varieties being cultivated in Rwanda alone (Rose & Vasanthakaalam, 2011). Sweet potato varieties and their traits are impacted by genetics and environmental influences (Ochieng, 2019; Andrade et al., 2009). The varietal diversity includes variation in the flesh, skin, root, shape, and size (Ochieng, 2019). Sweet potato flesh can vary from yellow, orange or white, and the skin can vary from yellow, orange, red, white, or purple (Rose & Vasanthakaalam, 2011). Other agro-morphological characteristics used in distinguishing varieties include vine growth, stem length and diameter, leaf size, storage root thickness and diameter, and root yield (Ochieng, 2019). The improvement of crop yield relies on access to successful, high-yielding varieties adapted to the local growing environment and needs (Ochieng, 2019).

Nutrients

While peoples in Africa and the global subtropics face significant rates of malnutrition, vitamin A deficiency, and other various health disorders, sweet potatoes are seen as a medicinal, nutrient rich crop that can help improve food resources and nutritional access (Kwak, 2019). Sweet potatoes are a source of carbohydrates, significant macronutrients and micronutrients, vitamin C, B complex, A, E, and folic acid (Motsa et al., 2015). Per 100 grams, sweet potatoes contain 114 kilocalories, 2.4 grams of dietary fibre, 26.3 grams of carbohydrates, 0.4 grams of fat, and 1.7 grams of protein. Sweet potatoes provide considerable amounts of vitamin A through Beta-carotene, making it an affordable and nutrient rich crop that can contribute to reducing the occurrence of vitamin A deficiency which contributes to immune system weakness in humans (Motsa et al., 2015; Andrade et al., 2009). The leaves and roots of the sweet potato can be a modest source of protein with 2.99 grams per 100 grams (Bovell-Benjamin, 2007; Sun et al., 2014). Two important storage proteins identified in sweet potato roots are Sporamins A and B which are rich in lysine and methionine, respectively (Maeshima et al.,1985). However, while significant amounts of lysine and methionine can be found in sweet potato roots, they are not significant in the other organs of the sweet potato (Maeshima et al.,1985). The nutritional content of the leaves includes up to 26.4% iron, 1.2% calcium, 15.8% vitamin E, and 34.7% carotenoid per 100 grams. Consumption of sweet potato can also be associated with health benefits including chemo preventive activities in which enzymes found in sweet potatoes can help to suppress cancer cells, along with anti-inflammatory, increased eyesight, and anti-diabetic properties (Bovell-Benjamin, 2007; Rabah et al., 2004).

Growth and Reproduction

Sweet potatoes grow in tropical and subtropical environments, able to adapt to temperate climates (Paneque-Ramirez, 1992). They should ideally be grown in a climate of 20-25°C during the day and 15-20°C during the night, however any temperature below 15°C is not favourable (Paneque-Ramirez, 1992). Sweet potato can be planted and harvested anytime throughout the year, under the right conditions (Motsa et al., 2015). The growing season ranges from 3.5-7 months, going through stages of planting to tuber formation, tuber formation to leaf development, and leaf development to final tuber development (Paneque-Ramirez, 1992). Sweet potato propagation is commonly asexual, requiring planting the tuber and stems (not seeds), ideally within 4 days of their cutting (Paneque-Ramirez, 1992). Planting should be done in rows at a depth of about 10 cm, and can be intercropped. Sweet potatoes can be grown in diverse soils, with the best being friable and humic soil, and with a depth greater than 25 cm, with good drainage. The ideal pH ranges from 5.5-6.5, hence a slightly acidic or neutral soil. The soil should remain moist through the growing season, at intervals of 7-10 days. As already noted, sweet potato prefers 750-1000 mm of rainfall but some varieties can tolerate as little as 500 mm of rainfall (Woolfe, 1992). CIP, also known as the International Potato Centre in Peru, is invested in improving global sweet potatoes to enhance climate change adaptation (International Potato Center, 2020). Their scientists have been able to produce more productive agronomic approaches, climate smart varieties and accelerate breeding efforts. To improve drought tolerance, they have developed the Triple S technique wherein sweet potatoes can be stored in sand and used to develop vines for when the rain starts again and the sweet potatoes are able to be planted. Additionally, CIP has bred sweet potato varieties, termed climate smart varieties, that have climate resilient traits and against severe drought and heat (International Potato Center, 2020). Sweet potatoes should be fertilized with phosphorus and potassium to improve yield. Weeding should be done after seed cutting and repeated every 60 days, and can be done either manually, mechanically, or chemically (Paneque-Ramirez, 1992).

Following the growth and development of the sweet potato, the harvesting time differs between varieties, but ranges from 3-6 months after planting (Paneque-Ramirez, 1992). Harvesting can be performed manually, semi-manually, or mechanically, with the most common method being manually by smallholder farmers. Once harvested, sweet potatoes can be stored if kept in the proper conditions. Damaged sweet potatoes, insects, and fungus should be removed, and then can be stored in a dark area that is cool with low humidity (Paneque-Ramirez, 1992). Post-harvest loses are often influenced by damage, cracks, and other physical traits that are seen as negative (FAO, 2020). In order to improve the production and value addition of sweet potatoes, a greater understanding of production and post-harvest methods should be shared (FAO, 2020)

How the Sweet Potato Can Help Combat Climate Change

Sweet potatoes can play a significant role throughout developing countries, representing a crop that is tolerant and adaptive to environmental conditions (Motsa et al., 2015). Sweet potato requires low input and technology to have a fast yield and to increase production capacity (Woolfe, 1992). This crop has a high water efficiency, needs less pesticides and fertilizers than many other crops, and can be used as a cover crop to suppress weeds and prevent water/soil loss (Kwak, 2019). It can provide security, as the roots can be left planted and used when needed, increasing access to a potential food supply (Motsa et al., 2015). Sweet potatoes can help combat malnutrition through their micro and macronutrient supply. They can be completely utilized as the entire sweet potato and roots can be eaten raw or cooked; the leaves can be eaten as a leafy vegetable, or they can be used in animal feed (Kwak, 2019; Motsa et al., 2015).

How Sweet Potato Can Be Adopted by Smallholder Farmers

As opposed to other crops, sweet potato crops have improved heat and drought tolerance (International Potato Centre, 2020). In order to improve the adoption of sweet potatoes for smallholder farmers, increased access and information of where to obtain seeds should be provided as well as improved guides for growing and maintaining sweet potato crops. Fortunately, the International Potato Centre (CIP, Peru) is able to work with farmers to produce research and sustainable practices for greater crop development (Wheatley & Loechl, 2008). Smallholder farmer organizations can obtain materials through seed exchange programs and CIP. Manuals produced and provided by CIP explain varietal information, helping farmers understand which varieties they should crop and how to do so (Stathers et al., 2018).

To improve the post-harvest yield and value of sweet potatoes, they should be sorted before storage and kept out of direct sunlight (Stathers et al., 2018). Harvested sweet potatoes should be stored in plastic or wooden crates with the heaviest at the bottom, making sure not to overpack the crate. The harvest should be sold from the market within 3-7 days to ensure rotting does not occur (Stathers et al., 2018).

The role of African women throughout sweet potato production is significant, as subsistence farming of this crop is often performed by the women. Needs assessments can be implemented to help smallholder women farmers growing sweet potatoes (Stathers et al., 2018; Andrade et al., 2009). These programs can also introduce them to community groups to understand the market and how to improve the value chain of sweet potatoes (Stathers et al., 2018). By increasing the supply and developing better marketable characteristics, contracts between farmers and processors can be created (Wolfe, 1992). The expected profit of sweet potato crops is $567 USD per hectare, with production costs being $268 USD per hectare, meaning that the net return would be $298 USD (Kassali, 2011). The total cost breakdown is 68% for labour costs including harvesting, weeding, cultivation, fertilization, and transportation (Kassali, 2011). Growing sweet potatoes is seen to have a profitable return and by using the methods mentioned above, the production of sweet potato products will have increased value and supply availability (Kwak, 2019).

Critical Analysis

Major pests and diseases impactful to sweet potato crops include whiteflies, feathery mottle virus, weevils, and chlorotic stunt virus. CIP sweet potato varieties can be used as they are bred for resistance, in addition to incorporating integrated pest management techniques and insecticides (Stathers et al., 2018; Paneque-Ramirez, 1992). In order to improve the adoption and cultivation of sweet potatoes, improved varieites with greater temperature and drought resistance can be accessed from CIP as well as extension manuals. Livelihoods can be improved by participatory approaches, educational provisions, a farm-to-market focus, and post harvest strategies.

Links to Useful Resources to Get Started and Further Reading

https://www.youtube.com/watch?v=Q4pLslnulDc → Describes the impact of improved cultivation practices on African women

https://www.youtube.com/watch?v=MNpKIVEwnp8 → Explains the basics of sweet potato production /p>

https://borgenproject.org/sweet-potatoes-africa/ → Introduces the Harvest Plus OFSP initiative /p>

https://www.npr.org/sections/thesalt/2012/08/15/158783117/saving-lives-in-africa-with-the-humble-sweet-potato → Explains biofortification and the impact they can have in Africa /p>

https://scinnovent.wordpress.com/2014/02/26/african-traditional-foods-and-nutrition-making-consumption-of-orange-fleshed-sweet-potatoes-a-big-deal/ → Interview with a Ghanaian researcher on the benefits of sweet potato for child nutrition /p>

https://www.cgiar.org/annual-report/performance-report-2019/biofortified-sweet-potato-fights-micronutrient-malnutrition-in-sub-saharan-africa/ → A report on the use of sweet potatoes to fight poverty and malnutrition/p>

https://www.usaid.gov/hy/news-information/videos/node/208971 → Three stories of African women using sweet potato to empower and support their families/p>

https://www.youtube.com/watch?v=5RBegs2jRlQ → OFSP production and market in Ghana/p>

https://www.almanac.com/plant/sweet-potatoes → This source gives an overview of sweet potatoes and step by step reccomendations for growth/p>

https://cdn-ext.agnet.tamu.edu/wp-content/uploads/2014/09/how-to-grow-sweet-potatoes.pdf → Manual explaining the steps of sweet potato cultivation/p>

http://cdn.newsproutfarms.com/downloads/New-Sprout-Sweet-Potato-Slip-Care-and-Planting-Guide.pdf → Sweet potato growing guide/p>

http://www.cardi.org/wp-content/uploads/2011/07/SweetPotato_TechnicalManual.pdf → A technical manual for sweet potato producers/p>

https://cgspace.cgiar.org/bitstream/handle/10568/98338/CIP_SP_T6_SweetpotatoProductionAndManagement_v40.pdf?sequence=10&isAllowed=y → CGIAR sweet potato guide to sweet potato production and management/p>

References

1. Andrade, M., Barker, I., Cole, D., Fuentes, S., Gruneberg, W., Kapinga, R., Kroschel, J., Labarta, R., Lemaga, B., Loechl, C., Low, J., Ortiz, O., Oswald, A., & Thiele, G. (2009). Unleashing the potential of sweetpotato in Sub-Saharan Africa Current challenges and way forward. In Unleashing the potential of sweetpotato in Sub-Saharan Africa Current challenges and way forward. CIP Working Paper 2009-1. 197 p. https://doi.org/10.4160/0256874820091

2. Bovell-Benjamin, A. C. (2007). Sweet Potato: A Review of its Past, Present, and Future Role in Human Nutrition. Adv Food Nutr Res 52:1-59. https://doi.org/https://doi.org/10.1016/S1043-4526(06)52001-7

3. Ewell, P. (2010) Sweet potato production in Sub-Saharan Africa: Patterns and key issues. International Potato Centre, Peru. Retrieved from https://www.sweetpotatoknowledge.org/files/sweetpotato-production-patterns-key-issues/

4. FAO. (2020). Value Chain Analysis Highlights: Sweet potatoes in Lanao del Sur. Food and Agriculture Organization of the United Nations, Rome. Retrieved from http://www.fao.org/publications/card/en/c/CA7552EN/

5. Glato, K., Aidam, A., Kane, N. A., Bassirou, D., Couderc, M., Zekraoui, L., … Vigouroux, Y. (2017). Structure of sweet potato (Ipomoea batatas) diversity in West Africa covaries with a climatic gradient. PLoS ONE, 12(5), e0177697. https://doi.org/10.1371/journal.pone.0177697

6. International Potato Center. (2020). Case for investment: Climate change adaptation. 4 p. Retrieved from https://cgspace.cgiar.org/handle/10568/106939

7. Karyeija, F., Gibson, W., & Valkonen, P. (2007). The Significance of Sweet Potato Feathery Mottle Virus in Subsistence Sweet Potato Production in Africa. Plant Disease, 82(1), 4-15. https:/doi:10.1094/pdis.1998.82.1.4

8. Kassali, R. (2011). Economics of sweet potato production. International Journal of Vegetable Science 17, 313-321. https://doi.org/10.1080/19315260.2011.553212

9. Kwak, S.-S. (2019). Biotechnology of the sweetpotato: ensuring global food and nutrition security in the face of climate change. Plant Cell Reports, 38(11), 1361–1363. https://doi.org/10.1007/s00299-019-02468-0

10. Maeshima, M., Sasaki, T., & Asahi, T. (1985). Characterization of major proteins in sweet potato tuberous roots. Phytochemistry, 24(9), 1899–1902. https://doi.org/https://doi.org/10.1016/S0031-9422(00)83088-5

11. Motsa, Nozipho M., Modi, Albert T., & Mabhaudhi, Tafadzwanashe. (2015). Sweet potato (Ipomoea batatas L.) as a drought tolerant and food security crop. South African Journal of Science, 111(11-12), 1-8. https://dx.doi.org/10.17159/sajs.2015/20140252

12. Morton, J. F. (2007). The impact of climate change on smallholder and subsistence agriculture. Proceedings of the National Academy of Sciences, 104(50), 19680–19685. https://doi.org/10.1073/pnas.0701855104

13. Müller, C., Cramer, W., Hare, W. L., & Lotze-Campen, H. (2011). Climate change risks for African agriculture. Proceedings of the National Academy of Sciences, 108(11), 4313 LP – 4315. https://doi.org/10.1073/pnas.1015078108

14. Ochieng, L.A.. (2019). Agro-Morphological Characterization of Sweet Potato Genotypes Grown in Different Ecological Zones in Kenya. Journal of Horticulture and Plant Research. 5. 1-12. https://doi.org/10.18052/www.scipress.com/jhpr.5.1

15. Paneque-Ramirez, G. (1992). Cultivation, harvesting and storage of sweet potato products. Food and Agriculture Organization of the United Nations, Rome. Retrieved from https://agris.fao.org/agris-search/search.do?recordID=XF9325337

16. Rabah, I. O., Hou, D. E. X., Komine, S. I., & Fujii, M. (2004). Potential chemopreventive properties of extract from baked sweet potato (Ipomoea batatas Lam. Cv. Koganesengan).

18. Journal of Agricultural and Food Chemistry 52(23):7152-7. https://doi.org/10.1021/jf049368w

17. Rose, I., & Vasanthakaalam, H. (2011). Comparison of the Nutrient composition of four sweet potato varieties cultivated in Rwanda. American Journal of Food and Nutrition 1(1), 34-38. https://doi.org/10.5251/ajfn.2011.1.1.34.38

20. Srisuwan, S., Sihachakr, D., & Siljak-Yakovlev, S. (2006). The origin and evolution of sweet potato (Ipomoea batatas Lam.) and its wild relatives through the cytogenetic approaches. Plant Science, 171(3), 424–433. https://doi.org/https://doi.org/10.1016/j.plantsci.2006.05.007

18. Stathers, T., Carey, T., Mwanga, R., Njoku, J., Malinga, J., Tumwegamire, S., Andrade, M., (2018). Everything You Ever Wanted to Know about Sweetpotato: Reaching Agents of Change ToT Manual. Topic 3: Sweetpotato Varietal Selection and Characteristics. International Potato Center. Nairobi (Kenya). a. https://doi.org/10.4160/9789290605027T3

19. Stathers, T., Sindi, K., Bechoff., A., (2018). Everything You Ever Wanted to Know about Sweetpotato: Reaching Agents of Change ToT Manual. Topic 8: Harvesting and Post‐Harvest Management. International Potato Center. Nairobi (Kenya). https://doi.org/10.4160/9789290605027T8

20. Sun, H., Mu, T., Xi, L., Zhang, M., & Chen, J. (2014). Sweet potato (Ipomoea batatas L.) leaves as nutritional and functional foods. Food Chemistry, 156, 380–389. https://doi.org/https://doi.org/10.1016/j.foodchem.2014.01.079

21. Woolfe, J. A. (1992). Sweet Potato: An Untapped Food Resource. Cambridge University Press. https://books.google.ca/books?id=_MWmIDzNMSYC

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