Lina Quesada

Banana, cassava, potato, sweetpotato and yam (collectively referred to as roots, tubers, and bananas or RTB crops hereafter) are major contributors to poverty alleviation and food and nutrition security in sub-Saharan Africa (SSA). RTB crops provide nearly 50% of total caloric intake in D.R. Congo, Ghana, Tanzania and Rwanda, 30% in Uganda, and 25% in Africa's most populated country, Nigeria. Moreover, given their role to buffer local food systems against external shocks such as conflicts disrupting global commodity supply chains, climate change, and the forecasted population growth, unprecedent domestic production and value of production growth is forecasted for these crops. To deliver nutritious, affordable RTB foods, and supplies for processors in SSA, this two-year project initiation proposal represents the first phase towards establishing a longer-term plan for an 11-year-long, multi-donor driven portfolio of investments in the genetic improvement of RTB crops. Our overarching purpose is to contribute, through the development of market-preferred, gender-sensitive and climate-resilient varieties, to poverty alleviation, food and nutrition security and overall quality of life of smallholder farmers, processors, and consumers in rural and urban areas. This project will contribute to all the One CGIAR’s Genetic Innovation impact areas, namely: nutrition, health, and food security; poverty reduction, livelihoods, and jobs; gender equality, youth, and social inclusion; climate adaptation and mitigation; and environmental health and biodiversity. We aim to achieve this by implementing state-of-the-art, streamlined breeding approaches, and the market-preferred varieties to be developed are expected to command increased adoption rates and to quickly replace the older varieties and landraces that are currently in use. NC State partner with the One CGIAR to build upon capacities in African countries as well as those within One CGIAR that were developed through extensive prior BMGF breeding investments such as Breeding Better Bananas, GT4SP (NCSU led), NextGen Cassava, RTBFoods, SASHA (NCSU partner), SweetGAINS (NCSU partner), Africa Yam and Excellence in Breeding. Moreover, we will build upon assets, infrastructure and human talent posted at several One CGIAR centers and national and international programs in SSA countries, research, development and extension programs, and advanced research institutions.

Cucurbit crops, such as watermelon, melons, cucumbers, squashes and pumpkins, provide diverse, flavorful and nutritious fruits and vegetables to the American diet. U.S. production of these crops contributed an average of $1.75 billion farm gate value per year (USDA-NASS data, 2016-2018). To maintain competitive industries, it is essential that cucurbit growers, shippers, and processors can provide high quality products produced in an economically viable and environmentally sustainable manner. Plant breeding is undergoing a revolution due to rapid advances in genomics and bioinformatics. Cucurbits are no exception. Recent advances, including those achieved by CucCAP1, make it feasible to use advanced genomic approaches not possible even a few years ago. CucCAP2 aims to bring these tools to the field. We will work in conjunction with the private breeding sector and cucurbit farmers to: (a) develop advanced bioinformatic, pan-genome and genetic mapping tools for cucurbit breeders; (b) utilize genomic approaches to identify, map, and develop markers for resistances to priority diseases identified by the cucurbit industries; (c) introduce and pyramid resistances into advanced breeding lines; and (d) perform multi-location, multi-isolate trials of resistances to improve integrated disease management and determine the economic impacts of disease, and gains from control tools. Extension and outreach activities will be central to each objective to ensure that growers, processors, seed companies, and consumers benefit from our efforts.

The general objectives are to search for the presence of GRKN in the southeast United States (the Carolinas, Florida, Georgia), to screen accessions of cucurbit (cucumber and watermelon), pepper and sweetpotato germplasm for resistance, and to demonstrate that GRKN can be managed and contained efficiently and effectively.

Weed management was identified as a high priority of organic sweetpotato producers who lack chemical control options available to conventional producers. This project will examine the effectiveness of multiple weed management techniques including 1) the use of advanced sweetpotato lines and cultivars with bunching shoot architecture to outcompete weeds for light resources and allow for more efficient use of between-row cultivation, 2) modified planting density to reduce the critical period for weed removal, 3) identification of weed suppressive (allelopathic) lines that can function in a production environment, and 4) utilization of fall-planted cover crops and reduced tillage transplanting operations to reduce the dependence on cultivation. Recognizing that these techniques may have non-target effects, this project will also investigate the insect pest pressure and plant disease occurrences in the test plots. Research-based findings will be shared with stakeholders and the greater scientific community via field days, production meetings, expos, conferences, peer-reviewed journal publications, Extension publications/fact sheets/bulletins, and electronic newsletters, webpages, and social media. Throughout the proposed project, investigators will remain engaged with the US Sweetpotato Stakeholder Advisory Panel to ensure the project remains aligned with industry goals and that meaningful results are effectively communicated to stakeholders nation-wide. Identifying best practices for weed management, in an integrated pest management context, will facilitate the development and improvement of organic sweetpotato production, in line with Goal 1 of the Organic Agriculture Research and Extension Initiative.

Watermelon production in North Carolina has gradually increased over the past five years from 6,300 acres in 2016 to 9,000 acres in 2020. These figures place North Carolina as the 7th largest producer of watermelon in the U.S which has remained consistent over the years. The economic value of watermelon in North Carolina was $34 million in 2020. U.S. watermelon growers are increasingly having to contend with the fusarium wilt disease as the disease continues to be spread to new fields. Fusarium wilt has not been as wide spread in North Carolina than in some of its neighboring states to the south. However, the concern is that Fusarium wilt in North Carolina may become a greater problem over time. Currently international seed companies that breed watermelon are working to incorporate better disease resistance, especially to fusarium wilt. Some triploid or seedless cultivars have good resistance to fusarium wilt race 1. However, there are no known commercial triploid cultivars that have outstanding fusarium wilt resistance to race 2. Currently our group is evaluating the newest triploid cultivars for their ability to withstand fusarium wilt. Some new advanced lines have been included that potentially have some tolerance or resistance to fusarium wilt race 2. As one knows, in order for a triploid watermelon plant to set fruit, it needs viable pollen from a diploid or seeded watermelon plant (pollenizer). Thus, it would do no good to have healthy triploid plants yet have a pollenizer that is susceptible to fusarium wilt resulting in its inability to supply viable pollen for fruit set. Much of the pollenizer cultivar data with respect to fusarium wilt resistance is primarily obtained from seed companies. An exception was some research conducted by Gunter and Egel (2012). The research was conducted in 2006, 2007, and 2008. Many new improved pollenizer cultivars are now grown in 2022 compared to 15 years ago. The information regarding fusarium wilt susceptibility, tolerance, or resistance for many of todays most grown pollenizer cultivars needs to be documented to inform growers so they can better grow their watermelon crop. We propose to work with a seed company to assess what the fusarium wilt race is of the different 20 fusarium wilt isolates that Dr. Quesada’s lab has collected. With this information, we propose to be able to use a Fusarium wilt race 1 and race 2 isolate to discern which pollenizer cultivars are susceptible to the different fusarium wilt races.