Effect of Pulsed Electromagnetic Field on Growth, Physiology and Postharvest Quality of Kale (Brassica oleracea), Wheat (Triticum durum) and Spinach (Spinacia oleracea) Microgreens

Abstract

Microgreens’ popularity is increasing worldwide, and many efforts are focused on novel techniques that could increase fresh production without affecting the quality and the shelf life of the young plants. Three species of microgreens (kale, durum wheat, and spinach) were cultivated in a greenhouse experiment in November–December 2020. Pulsed electromagnetic field (PEMF) was applied at three different growth stages (seed, newly developed plant, and before harvest) and three different times of exposure at each stage, while untreated seeds were used as control. According to the results, certain PEMF treatments increased fresh weight for all three plant species, while dry weight was higher in the treated plants for wheat and spinach, compared to the control. As for the color parameters L*, a*, and b*, at the harvest and postharvest, PEMF treatments had no negative effects, either at harvest or at green color retention, during storage. Moreover, PEMF treatments improved green color in wheat, and restricted yellow color in spinach. An important finding regarding respiration was that PEMF treatments increased both O2 consumption and CO2 production for durum wheat and CO2 production for spinach.