THE EFFECT OF WATER-STRESS ON TOP AND ROOT-GROWTH IN MEDICAGO-MINIMA

Plants of Medicago minima var. minima grown in rootboxes of soil were subjected to water stress treatments in a growth chamber. The soil was returned to held capacity after drying cycles of 7, 14, 21, 28 or 35 days. After a 105-day-study-period water stress significantly decrease d (p < 0.05) the rate of leaf production, live and total leaf number, total length of the central leaflet on live leaves per plant, branch a nd root segment production, and top and root dry weights. However, all plants remained alive, even those exposed repeatedly to - 6.0 MPa. M. minima can thus survive under unfavourable environmental conditions a nd exploit abundant environmental resources when they are available.