Effects of nutrient solutions on growth, yield and quality of yardlong bean plant (Vigna unguiculata subsp. sesquipedalis L.) grown in a hydroponic system

<br>This study was conducted toevaluate the effects ofthree nutrient solutions (Hoagland, Knop, and Hydro Umat F) onthe growth, yield, and fruit quality ofhydroponically cultivated yardlong bean (<i>Vigna unguiculata</i> subsp. <i>sesquipedalis</i> L.). Results showed that Hydro Umat F extended the plant lifespan (105.4 days) and flowering time (58.65 days), increased the number of branches per plant, and enhanced leaf SPAD values. Plants grown in Hydro Umat F also exhibited the highest yield, as indicated by the number of flowers per plant (46.12), number of pods per plant (20.81), pod length (54.15 cm), pod weight (20.06 g), and total pod weight per plant (417.45 g). The Hoagland solution also promoted plant growth and yield, with a growth duration of 96.74 days, an average of 17.63 pods per plant, a pod length of 47.34 cm, a pod weight of 17.14 g, and a total yield of 302.17 g per plant. In contrast, the Knop solution, containing only six essential nutrients, shortened the plant’s growth duration (76.37 days) and significantly reduced the growth and yield of the hydroponic yardlong bean. Regarding pod quality, the pods from plants grown in Hydro Umat F had higher vitamin C content (4.12 mg/g), total protein content (3.21 mg/100 g), and reducing sugar content (13.06 mg/g) compared to those grown in Hoagland and Knop solutions. The findings suggest that Hydro Umat F is a suitable nutrient solution for hydroponic cultivation of yardlong bean, contributing to increased plant yield and fruit quality. These results suggest that Hydro Umat F is a promising nutrient solution for enhancing yield and pod quality in hydroponic yardlong bean cultivation, particularly in the context of the decline in available agricultural land and the rise of urban agriculture in Vietnam.