THE EFFECT OF NUTRIENT SOLUTIONS ON GROWTH AND YIELD OF RAPIDO 344 LETTUCE VARIETY GROWN IN THE CIRCULATING HYDROPONIC SYSTEM AT THAI NGUYEN UNIVERSITY OF AGRICULTURE AND FORESTRY

Abstract

The research was conducted in the winter crop, 2020 at Faculty of Agronomy, Thai Nguyen University of Agriculture and Forestry with the aim of selecting the suitable nutrient solution for the RAPIDO 344 lettuce variety. The experiment was designed in a Complete Randomized Design (CBD) with 4 treatments and 4 replications. In which, 4 treatments correspond to 4 nutrient solutions (1- Thailand, 2- Grow Master, 3- Hydro Greens, 4- Hydro UmatV). The results showed that there was no significant (P>0.05) difference in the growing time and number of leaves per plant of the RAPIDO 344 lettuce variety (GT: 45 days, number of leaves: 11.15 - 11.65 leaves) among 4 nutrient solutions. However, the different nutrient solutions showed significant (P<0.05) difference in plant height and canopy diameter, in which Hydro Greens solution had the highest plant height (22.07 cm after sowing 45 days) and the largest canopy diameter (26,4 cm). The effects of nutrient solutions on yield and potential yield were similar (potential yield : 2.40 - 2.66 quintals/100 m2 and yield: 1.57 - 1.77 quintals/100 m²) and nutrient solutions did not affect the quality of RAPIDO 344 lettuce variety (NO₃- content in harvest time ranged from 90 - 210 mg/kg of product) below the permitted concentration (safe concentration for lettuce is less than 1,500 mg/kg of product). Grow Master nutrient solution showed the highest interest rate (2,538,000 VND/100 m²), followed by Hydro Greens nutrient solution (2,453,000 VND/100 m²).