Effects of growing substrates and seed density on yield and quality of radish (Raphanus sativus) microgreens

摘要

Microgreens are a new class of edible fresh vegetable salads gaining more popularity as a new culinary ingredient which are harvested when cotyledons fully expanded before the true leaves completely emerge (7 to 21 days after germination). Being new to the market proper substrate and seed density are yet to be determined in order to increase the productivity. This present study was conducted during 2019 at the high-tech greenhouse, Vin Eco Company, Vinh Phuc province, Vietnam to evaluate effects of growing substrates and seed density on yield and quality of radish microgreens in greenhouse conditions. The studied growth parameters were germination rate, fresh weight, dried weigh and quality of radish microgreens grown on different substrates of white sphagnum peat and coco-coir dust. Results showed that white sphagnum peat and coco coir dust had no effects on germination rate, dried matter yield and shoot height of radish microgreens. The use of higher fertilizer concentration as coco coir substrate did not make fresh shoot yields higher than white sphagnum peat substrate with lower fertilizer concentration. Seed density significantly affected fresh shoot yield of radish microgreens grown on white sphagnum peat and coco coir substrate. Radish microgreen cultivation obtained highest fresh yield when sown seeds with density of 8 seeds/cell (approximate 109 g seeds). Nitrate level and microbiological contamination (E. coli and Salmonella spp.) of radish microgreens grown on these substrates are within legal and in safe limit and therefore can be considered as a safe and good fresh vegetable salad in the human diet.