Effect of dissolved oxygen concentration on lettuce growth in floating hydroponics.

摘要: Lettuce (Lactuca sativa L., cv. Ostinata) growth experiments were carried out to study the effect of dissolved oxygen (DO) concentration on plant in a floating hydroponic system. Pure O2 and N2 gas supplied system for precise DO control. This made it easy increase beyond maximum (or saturation) possible when bubbling air into water. Eleven day old lettuce seedlings grown 24 days under various concentrations: sub-saturated, saturated, super-saturated. There was no significant difference fresh weight, shoot root dry weights among 2.1 (25% saturated at degrees C), 4.2 (50%), 8.4 (saturated), 16.8 (200%) mg/L. The critical vigorous considered be lower than Neither damage nor delay observed any studied concentrations.