J. Penuelas et al., CHANGES IN BIOMASS, CHLOROPHYLL CONTENT AND GAS-EXCHANGE OF BEANS ANDPEPPERS UNDER NITROGEN AND WATER-STRESS, Photosynthetica, 29(4), 1993, pp. 535-542
We experimentally produced moderate water stress that reduced leaf, st
em, root and fruit biomass of peppers, and severe nitrogen (N) limitat
ions that almost stopped their development. Root/shoot ratios (R/S) we
re higher in N-limited plants. Low water availability (and also low N
availability) produced lower stomatal conductance (g(s)). Specific lea
f mass was higher and chlorophyll (Chl) concentration was lower under
low N-availability. The same experimental conditions produced smaller
differences among treatments in beans (with N-fixing symbionts). Water
stress increased its relative importance as shown by the induced incr
ease in root/shoot ratio. N stress was less important as shown by the
absence of effects on Chl concentrations and g(s). Both peppers and be
ans responded to limited availability of nitrogen and water by allocat
ing to structures involved in uptake (roots), by longer organ duration
, and by increasing the efficiency of N and water use.