Impact of Particulate Pollution on Photosynthesis, Transpiration and Plant Water Potential of Teak (Tectona grandis L.)

The study on teak Tectona grandis L. under particulate pollution stress caused by deposition of cement dust revealed that various physiological functions were hampered due to these pollutants. The dust accumulation was highest during summer (0.299 mg/sq. cm) in the polluted plot in comparison to control plot (0.037 mg/sq. cm). The effects of particulate pollution on T. grandis also varied with season, with a general trend of particulate pollutants having maximum effect on vegetation during summer and least during monsoon. The rate of photosynthesis was halved due to particulate pollutant deposition. Particulate pollution decreased the water potential of T. grandis during summer. The rate of transpiration in particulate pollution-affected trees was highly erratic, being the highest during monsoon and least during summer in comparison to those not exposed to pollution. All these induced morphological changes such as reduced height, girth, etc. and also reduced the effective growing days by shedding leaves in the trees exposed to particulate pollution. Leaf area index, which is an indicator of plant productivity, was almost half in pollution-affected trees than control trees. T. grandis can serve as an effective barrier in controlling the spread of pollutants. However, it is ineffective during summer, due the deciduous nature.