Response of asiatic lily to nutrient solution recycling in a closed soilless culture.

摘要

A study was conducted to evaluate the growth and yield responses of Asiatic lily (Lilium hybrida cv. Zsa Zsa) to different levels of electrical conductivity of a circulating nutrient solution. Lily bulbs were planted in black tuff and grown under greenhouse conditions. The plants were fertigated starting with a fresh nutrient solution at 1.4 mS/cm. The drain solution was automatically recycled and mixed with the fresh solution to form the supply solution, which was recycled several times until its EC reached 1.6, 1.8, 2.0 or 2.2 mS/cm. The supply (recirculating) solution was then replaced with a fresh nutrient solution. This strategy was adopted until harvest (9 weeks after shoot emergence). Results indicated that 1.6 mS/cm of the supply solution was superior to the other EC values with respect to growth and flowering. Stem height, shoot dry weight, and peduncle length decreased as EC increased up to 2.0 mS/cm, beyond which they did not change. A supply solution at 1.6 mS/cm exhibited the lowest pH and highest contents of P and K. As EC increased, concentrations of N, Na, Cl, Ca, Mg, Zn, and Mn in the supply solution increased. Over a period of 22 days of recirculation, pH and concentrations of N, Na, Cl, Ca, and Mg increased and those of P and K decreased with time. At harvest, the highest levels of P and Mo were detected in plants receiving a solution at 1.6 and 2.2 mS/cm, respectively. Furthermore, Cl concentration was higher in plants receiving a solution at 2.0-2.2 mS/cm compared with 1.6-1.8 mS/cm. Concentration of other nutrients in the leaves was not affected by EC..