**1. Introduction**

Rising incomes in low-income countries are driving changes in dietary patterns and increasing the demand for safe and nutritious food [1]. However, to equate future demand and supply of safe and healthy agricultural food, global food production will need to increase at a rate of 1.3 percent every year [2]. Sustainably achieving such a growth rate will require increasing plant-based food production. Such an effort will promote long-term food security without sacrificing nutrition [3] and will provide increased employment opportunities for farm workers [4].

The two commonly documented approaches for increasing plant-based food production are agricultural intensification and cropland expansion [5]. While both have contributed to global food security substantially, several limitations have also been reported. For example, the former has been challenging to achieve in geographic areas affected by climate change, especially as it pertains to increasing crop yield [6]. Meanwhile, the latter constitutes a potential threat to biodiversity by driving habitat loss. Additionally, cropland expansion impacts carbon storage through the loss of biomass and soil carbon [7].

Given these limitations, numerous studies have suggested postharvest loss (PHL) reduction as an essential and complementary approach to meeting the increasing demand for safe and nutritious food [8]. PHL can be defined as a measurable reduction in agricultural products that arise from changes these products undergo during postharvest handling [9]. Therefore, PHL reduction efforts, especially in sub-Saharan Africa (SSA), could be a catalyst for increasing profit for food value chain actors while at the same time improving food

**Citation:** Chikez, H.; Maier, D.; Sonka, S. Mango Postharvest Technologies: An Observational Study of the Yieldwise Initiative in Kenya. *Agriculture* **2021**, *11*, 623. https://doi.org/10.3390/ agriculture11070623

Academic Editor: Isabel Lara Ayala

Received: 12 June 2021 Accepted: 29 June 2021 Published: 1 July 2021

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**Copyright:** © 2021 by the authors. Licensee MDPI, Basel, Switzerland. This article is an open access article distributed under the terms and conditions of the Creative Commons Attribution (CC BY) license (https:// creativecommons.org/licenses/by/ 4.0/).

security [10]. Given the importance of PHL reduction, several PHL mitigation studies have been initiated over the last decade, focusing on improving food security in SSA, which remains the most food-insecure region in the world [11].

For example, notable PHL mitigation studies in SSA include introducing the Purdue Improved Crop Storage (PICS) hermetic bags, which prevent storage losses due to insects in maize and other grains without chemical pesticides [12]. The commercialization of this technology, funded by the Bill and Melinda Gates Foundation, led at least five other manufacturers to introduce hermetic storage bag technology products [13]. In 2016, the Rockefeller Foundation launched the Yieldwise Initiative (YWI), intending to provide smallholder farmers (SHF) access to markets, technologies, training, and financing [14] to reduce PHL of mangos in Kenya, maize in Tanzania, and tomatoes in Nigeria. More recently, the Consortium for Innovation in Postharvest Loss and Food Waste Reduction launched as a collaborative effort between the Foundation for Food and Agriculture Research (FFAR), the Rockefeller Foundation, Iowa State University (ISU), and several other academic and research institutions around the world (reducePHL.com (accessed on 2 June 2021)) to address social, economic, and environmental impacts from food loss and waste.

Over time several additional PHL mitigation projects have emerged [15], with a focus on either quantifying PHL by stages of a food value chain [16,17] or comparing the effect of postharvest interventions on PHL incurred at a single stage of a food value chain. However, relatively few PHL mitigation projects have compared the effect of several postharvest technologies on PHL incurred at several stages of a food value chain. Therefore, this study analyzed the YWI dataset generated within the Kenyan mango value chain to evaluate the effect of five YWI promoted technologies (harvesting tools, cold stores, plastic crates, fruit fly traps, and ground tarps) on PHL incurred at three value chain stages (harvest, transportation, and point of sale).

Over the past decades, mango farming in Kenya has expanded considerably, involving several value chain actors such as non-governmental organizations, farmer cooperative groups, aggregation centers, financial institutions, mango processors, and others [18]. Additionally, annual mango production in Kenya is estimated at 1,024,500 metric tons, with approximately 80% being sold to local markets [18]. Thus, mango farming is considered a major income earner for many SHF households in Kenya [19]. However, mango production is accompanied by major PHL estimated at 40–50%, which are mainly the result of a lack of suitable technologies for the postharvest handling and processing into a wide range of value-added mango products [18]. Therefore, comparing YWI promoted technologies and identifying the value chain stage at which they are most effective, is a key step in reducing PHL along the entire value chain and improving SHF livelihoods.

#### **2. Materials and Methods**
