Impact of water stress on the root and shoot growth of litchi seedlings

Experiment was conducted with potted sandy cultured seedlings of litchi (Litchi chinese Sonn. cv. Nuomici) for studying the effect of water stress on the growth of roots and shoots. Three water levels (7.5%,15.0% and 22.5% by volume) were arranged to indicate serious drought, medium drought and appropriate moisture in the sand. The treatment lasted for 7 months from July 2000 to January 2001. The results indicated that water stress seriously inhibited the growth of shoots and lateral roots. Under water stress conditions, shoot biomass, shoot length, number of leaves, leaf area, and leaf thickness were significantly reduced than those under normal water conditions; Water stress significantly decreased the length and surface area of lateral roots but increased these two parameters of the fibrous roots. Leaf starch content was decreased while it was increased in roots. In addition, the ratio of root to top was increased as water stress occurred.