EFFECT OF WATER AND NUTRIENT SUPPLY ON PHOTOSYNTHESIS AND YIELD OF ENERGY BEET GENOTYPES

摘要

The responses of two energy beet (sugarbeet) genotypes, AR355 and AC211, to three (high, medium, and low) water and nutrient supply (WNS) regimes were investigated in an attempt to find an optimal water and nutrient rate for selected sugarbeet (Beta vulgaris L.) genotypes. The results showed that photosynthesis rate (P-N), transpiration rate (E), and stomatal conductance (g(s)) decreased with the reduction of WNS. As a consequence of the reduction in stomatal conductance, decline in the intercellular CO2 concentration was also observed. The temperature difference between the leaf and air (T-l-T-a) increased with the decrease of WNS. Under medium WNS, both genotypes had the highest sugar yield. Sugar yield was significantly affected by WNS, but it was not significantly influenced by genotype and the interaction between genotype and WNS. WNS, genotype, and the interaction between genotype and WNS had significant effects on the shoot/root ratio of sugarbeet. Irrigation water productivity based on sugar and fresh mass above ground were negatively correlated with WNS.