THE EFFECTS OF SHORT PERIODS OF WATER STRESS ON THE GROWTH OF SUGAR BEET IN POTS

Abstract

SummarySugar beet, broad beans and lettuce growing in soil in pots were subjected to repeated short periods of water stress up to a maximum PF of 4.0. In some experiments the leaf areas of such plants were lower than those of plants grown under conditions of minimum water stress, but there was no significant effect of water stress on dry matter production or Net Assimilation Rate. The loss of water per unit leaf area was not affected by the water regime, but the cumulative water loss from pot and plant over the experiments was greater under the wet regime, partly because the leaf area was greater. In pot culture experiments, where the total amount of water within the root zone is relatively small, it is impossible to impose stress conditions above wilting point for long enough to produce detectable effects on growth. The results of water stress experiments may depend as much on the duration and timing of the periods of stress as on the level of stress imposed.