The effect of container porosity on root environment and plant growth

Summary The effect of container porosity on water relations in the substrate and on plant growth was examined. With clay containers the proportional effect of the wall on water loss varied with season, being responsible for 42 per cent of the total loss in winter and 25 per cent in summer. Water loss from plastic containers was 55 per cent of that from clay containers in winter, and 66 per cent in summer. Wall porosity also had a significant effect on water distribution within the container under high radiation conditions. Tomato plants grown under three water regimes showed no effect of matric stress in winter, but growth was significantly reduced for each increase in stress in summer. There was no interaction between container type and water stress. Non-porous containers gave a higher water-use efficiency and had a lower irrigation requirement than porous ones, their greatest advantage being under conditions of low transpirational loss and high evaporative loss.