PT - JOURNAL ARTICLE AU - Munna Singh AU - Aradhna Kumari AU - Krishan Kumar Verma TI - Physiological, Growth, and Biomass Attributes in <em>Populus deltoides</em> L. (clones G-48 and Kranti) Influenced by Water Stress AID - 10.48044/jauf.2013.029 DP - 2013 Sep 01 TA - Arboriculture &amp; Urban Forestry (AUF) PG - 226--230 VI - 39 IP - 5 4099 - http://auf.isa-arbor.com/content/39/5/226.short 4100 - http://auf.isa-arbor.com/content/39/5/226.full AB - Six-week-old uniform cottonwood seedlings (clones G-48 and Kranti) were raised from stem cuttings and subjected under two different water regimes (full and half field capacity) up to 60 days under open field conditions. The higher and lower regulations of physiological responses were triggered in case these seedlings irrigated up to their full and half-field capacities. The enhanced A value was observed from 13–19 and 12–14 µmol m−2s−1 in clones G-48 and Kranti after subjecting them under irrigation to the level of full field capacity. The withdrawal of irrigation to the level of half field capacity could reduce these values (fi50%), significantly. The decreased CO2 assimilation during drought stress was found to be correlated with decline in transpiration, largely regulated by stomatal dynamics to restrict CO2 diffusion, which also impaired carboxylation. Upon experiencing drought, the progressive loss in maximum quantum yield of photosystem II photochemistry (Fv/Fm) and CO2 assimilation was found to be correlated with the loss in transpiration in both these clones. Consequently, the study reveals that irrigation to the level of half field capacity for a period of 60 days impaired agronomic traits viz., plant height, number of leaves, leaf area expansion, specific leaf area, relative water content, biomass, and harvest index, significantly. It also concludes susceptibility of clones G-48 and Kranti toward drought in relation to plant performance (i.e., CO2 assimilation, Fv/Fm, and biomass yield).