Developing Pop-up horticulture for quality high-yielding salad crops

  • Giovanni Sanfratello

Student thesis: Doctoral ThesisDoctor of Philosophy

Abstract

Meanwhile the world faces climate change, ecosystem degradation, land and water vulnerability making today's food production methods increasingly unsustainable. Further, the rapid population growth, putting a strain on the planet's life-support, encourages the need for sustainable way of food production. The indoor pop-up horticulture is an approachable method for growing crops sustainably and efficiently in unused spaces supplying crops in response to demand. The exploration of pop-up horticulture was performed through the assembly of low-cost and rapid growing systems by means of hydroponics, soil-less growing method with beneficial environmental attributes. In order to maximize crop productivity and high quality produce, this study investigates abiotic stress manipulation and cultural methods for enhancing antioxidant and nutritional quality of high-yielding salad crops including tomato, rocket, and Brassica microgreens. Abiotic stressors such as induced-drought stress and induced-salinity stress were explored in combination with Salicylic acid (SA), naturally occurring phytohormone in plants and research-based tool for mitigating drought and salinity stress. A foliar spray of SA on induced-drought cherry tomato plants is an effective method for enhancing the overall antioxidant activity of the produce by 40%. Similarly, the short-term application of SA resulted a strong method for the mitigation of NaCl induced-salinity stress on hydroponically grown salad and wild rocket crops. A pre-treatment with SA-enriched nutrient solution improves plant response to salinity by enhancing photosynthetic performances preventing productivity losses and further producing final yield with 27% higher antioxidant capacity compared to Control as result of the interaction between SA and NaCl. A customized pop-up system capable of heating the nutrient solution was implemented to
induce the manipulation of root zone temperature (RZT). A fluctuating +5°C RZT results a strong tool for enhancing root and shoot growth rates, increasing leaf expansion and nutrient uptake in early stage cherry tomato seedlings without altering their leaf antioxidant status. Finally, a low-cost experimental pop-up systems was assembled for growing microgreens crops. The explored intercropping method, by mixing different species, results a valid lowcost practice for producing healthy ready-to-eat microgreen salads mix, yet nutritional properties are strongly influenced by the growing temperature. Total phenolic content was enhanced by growing together Rocket and Broccoli at 16°C, whereas Rocket/Red cabbage, Broccoli/Red cabbage and their 1:1:1 intercropping system grown at 20°C resulted the most well-performing by producing marketable yields with increased Ascorbic acid and carotenoid content.
Date of Award2021
Original languageEnglish
Awarding Institution
  • Aberystwyth University
SponsorsKnowledge Economy Skills Scholarships
SupervisorIain Donnison (Supervisor), Paul Robson (Supervisor) & Dylan Gwynn-Jones (Supervisor)

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