Sugar beet cv. Rizor was grown for five growing seasons (2002-2006) in field conditions in Thessaly, central Greece. A total of 55 samplings took place during the growing seasons and allometric growth of the leaves was monitored. Highly significant (p<0.001) quadratic relationships were found between individual leaf mass (LM), individual leaf area (LA), aboveground dry biomass (ADB), and leaf area index (LAI). Only the LM-LA relationship (LA = 43.444 LM2 - 10.693 LM + 118.34) showed a relatively high r 2 (0.63) and thus could be used for prediction of LA. Specific leaf area (SLA) was significantly related with leaf water content (LWC) (SLA = 26 279 LWC2 - 44 498 LWC + 18 951, r 2 = 0.91, p<0.001) and thus LWC could be a good indirect predictor of SLA in this cultivar. and J. T. Tsialtas, N. Maslaris.
Diurnal variation in net photosynthetic rate (PN) of three-year-old plants of Ginkgo biloba was studied under open, O (receiving full sunlight), net-shade, NS (40 % of photosynthetically active radiation, PAR), or greenhouse, G (25 % PAR) conditions. In all three conditions, PN was higher in morning along with stomatal conductance (gs), and intercellular CO2 concentration (Ci), while leaf temperature and vapour pressure deficit were low. The O-plants exhibited a typical decline in PN during midday, which was not observed in NS-plants. This indicated a possible photoinhibition in O-plants as the ratio of variable to maximum fluorescence (Fv/Fm) and photosystem 2 (PS2) yield (ΦPS2) values were higher in the NS- and G-plants. On the contrary, stomatal density and index, chlorophyll a/b ratio, leaf thickness, and density of mesophyll cells were greater in O-plants. Further, higher PN throughout the day along with higher relative growth rate under NS as compared to O and G suggested the better efficiency of Ginkgo plants under NS conditions. Therefore, this plant species could be grown at 40 % irradiance to meet the ever-increasing demand of leaf and also to increase its export potential. and S. Pandey, S. Kumar, P. K. Nagar.