Sofia Kourmpetli

Potato is the fourth most consumed crop in the world. More than half of the crop is stored for three to nine months at cold temperatures (3–10 °C) for the fresh and seed market. One of the main causes of fresh potato waste in the retail supply chain is the processing of fungal and bacterial rots during storage. Dry rot is a fungal disease that mainly affects the potato crop during storage and is responsible for 1% of tuber losses in the UK. It is produced by Fusarium spp., such as Fusarium sambucinum and F. oxysporum, which can lead to the accumulation of mycotoxins in the potato tuber. Little is known about the impact of environmental factors on the accumulation of mycotoxins in potato tubers. Understanding the ecophysiology of these fungi is key to mitigating their occurrence under commercial storage conditions. Therefore, this work aimed to elucidate the effect of three different temperatures (5, 10, and 15 °C) and two different water activities (a_w; 0.97, 0.99) on the ecophysiology and mycotoxin accumulation of F. sambucinum and F. oxysporum in a potato-based semi-synthetic medium. The mycotoxin accumulation was then studied in vivo, in potato tubers cultivated under organic farming conditions, stored for 40 days at 8.5 °C. Results showed that higher temperatures and a_w enhanced fungal growth, lag time, and mycotoxin accumulation in vitro. Growth rate was 2 and 3.6 times higher when the temperature increased from 5 to 10 and 15 °C, respectively. Six different mycotoxins (T-2, HT-2, diacetoxyscirpenol, 15-acetoxyscirpenol, neosolaniol, and beauvericin) were detected in vitro and in vivo. T-2 was the most abundant mycotoxin detected in vitro, observing 10⁶ ng of T-2/g media after 21 days of incubation at 10 °C and 0.99 a_w. Due to the long period of time that potato tubers spend in storage, the fluctuations of environmental factors, such as temperature and relative humidity, could promote the development of fungal rot, as well as mycotoxin accumulation. This could result in important food and economic losses for the potato market and a threat to food safety.

Urban agriculture can contribute to food security, food system resilience and sustainability at the city level. While studies have examined urban agricultural productivity, we lack systemic knowledge of how agricultural productivity of urban systems compares to conventional agriculture and how productivity varies for different urban spaces (e.g., allotments vs. rooftops vs. indoor farming) and growing systems (e.g., hydroponics vs. soil‐based agriculture). Here, we present a global meta‐analysis that seeks to quantify crop yields of urban agriculture for a broad range of crops and explore differences in yields for distinct urban spaces and growing systems. We found 200 studies reporting urban crop yields, from which 2,062 observations were extracted. Lettuces and chicories were the most studied urban grown crops. We observed high agronomic suitability of urban areas, with urban agricultural yields on par with or greater than global average conventional agricultural yields. “Cucumbers and gherkins” was the category of crops for which differences in yields between urban and conventional agriculture were the greatest (17 kg m⁻² cycle⁻¹ vs. 3.8 kg m⁻² cycle⁻¹). Some urban spaces and growing systems also had a significant effect on specific crop yields (e.g., tomato yields in hydroponic systems were significantly greater than tomato yields in soil‐based systems). This analysis provides a more robust, globally relevant evidence base on the productivity of urban agriculture that can be used in future research and practice relating to urban agriculture, especially in scaling‐up studies aiming to estimate the self‐sufficiency of cities and towns and their potential to meet local food demand.

Sustainably ensuring food security and safety for the urban population is a major challenge. In this perspective, we present the concept of 'rurbanisation' (the ruralisation of urban areas through ...

As urban areas and land-use constraints grow, there is increasing interest in utilizing urban spaces for food production. Several studies have uncovered significant potential for urban growing to supplement production of fruit and vegetables, focusing on one or two cities as case studies, whilst others have assessed the global scale potential. Here, we provide a national-scale analysis of the horticultural production potential of urban green spaces, which is a relevant scale for agri-food and urban development policy making using Great Britain (GB) as a case study. Urban green spaces available for horticultural production across GB are identified and potential yields quantified based on three production options. The distribution of urban green spaces within 26 urban towns and cities across GB are then examined to understand the productive potential compared to their total extent and populations. Urban green spaces in GB, at their upper limit, have the capacity to support production that is 8× greater than current domestic production of fruit and vegetables. This amounts to 38% of current domestic production and imports combined, or >400% if exotic fruits and vegetables less suited to GB growing conditions are excluded. Most urban green spaces nationally are found to fall within a small number of categories, with private residential gardens and amenity spaces making up the majority of space. By examining towns and cities across GB in further detail, we find that the area of green space does not vary greatly between urban conurbations of different sizes, and all are found to have substantial potential to meet the dietary needs of the local urban population. This study highlights that national policies can be suitably developed to support urban agriculture and that making use of urban green spaces for food production could help to enhance the resilience of the national-scale food system to shocks in import pathways, or disruptions to domestic production and distribution.

Using a combination of biochemical, transcriptomic, and physiological analyses, we elucidated the mechanisms of physical and chemical withering of tea shoots subjected to UV-C and ethylene treatments. UV-C irradiation (15 kJ m^–2) initiated oxidation of catechins into theaflavins, increasing theaflavin-3-monogallate and theaflavin digallate by 5- and 13.2–4.4-fold, respectively, at the end of withering. Concomitantly, a rapid change to brown/red, an increase in electrolyte leakage, and the upregulation of peroxidases (viz. Px2, Px4, and Px6) and polyphenol oxidases (PPO-1) occurred. Exogenous ethylene significantly increased the metabolic rate (40%) and moisture loss (30%) compared to control during simulated withering (12 h at 25 °C) and upregulated transcripts associated with responses to dehydration and abiotic stress, such as those in the ethylene signaling pathway (viz. EIN4-like, EIN3-FBox1, and ERFs). Incorporating ethylene during withering could shorten the tea manufacturing process, while UV-C could enhance the accumulation of flavor-related compounds.

Household food insecurity and poor well-being have increased during the coronavirus disease 2019 (COVID-19) pandemic and resulting lockdown measures. Home food growing has been associated with improved food access and well-being, but it is unknown what role it plays during food supply crises and lockdown. It is also unclear how home food growing and social restrictions may affect opinions about growing food in urban areas (i.e. urban agriculture; UA). A cross-sectional online survey was conducted during the UK national lockdown in March-April 2020 to measure home food growing, perceived food insecurity, well-being, and opinions of UA. The participants were 477 UK-based adults (369 female, mean age 39.57 years ± 13.36); 152 participants were engaged in home food growing prior to the pandemic. Responses were compared to data collected from a separate sample of participants before the pandemic (N=583) to explore potential shifts in opinions about UA. Participants who engaged in home food growing had lower levels of food insecurity (U_­=19894.50, z=−3.649, pr=−0.167) and higher well-being (U=19566.50, z=−3.666, pr=−0.168) than those not engaged in home food growing. Perceived food insecurity partially mediated the relationship between home food growing and well-being; home food growing was associated with less food insecurity, which in turn was associated with better well-being. There were no differences in opinions of UA compared to the sample of participants from before the pandemic. Home food growing may have had a protective effect over perceived food security and well-being in the early stages the pandemic. Opinions of UA were positive and unchanged compared to data collected pre-pandemic. Policies that support home food growing and access to suitable growing spaces and resources may be beneficial for food system resilience and well-being.

Household food insecurity and poor well-being have increased during the coronavirus disease 2019 (COVID-19) pandemic and resulting lockdown measures. Home food growing has been associated with improved food access and well-being, but it is unknown what role it plays during food supply crises and lockdown. It is also unclear how home food growing and social restrictions may affect opinions about growing food in urban areas (i.e., urban agriculture [UA]). A cross-sectional online survey was conducted during the UK national lockdown in March-April 2020 to measure home food growing, perceived food insecurity, well-being, and opinions of UA. The participants were 477 UK-based adults (369 female, mean age 39.57 years ± 13.36); 152 participants were engaged in home food growing prior to the pandemic. Responses were compared to data collected from a separate sample of participants before the pandemic (N = 583) to explore potential shifts in opinions about UA. Participants who engaged in home food growing had lower levels of food insecurity (U ­= 19894.50, z = -3.649, p<.001, r = -.167) and higher well-being (U = 19566.50, z = -3.666, p<.001, r = -.168) than those not engaged in home food growing. Perceived food insecurity partially mediated the relationship between home food growing and well-being; home food growing was associated with less food insecurity, which in turn was associated with better well-being. There were no differences in opinions of UA compared to the sample of participants from before the pandemic. Home food growing may have had a protective effect over perceived food security and well-being in the early stages the pandemic. Opinions of UA were positive and unchanged compared to data collected pre-pandemic. Policies that support home food growing and access to suitable growing spaces and resources may be beneficial for food system resilience and well-being.