Presented By Md. Towhidul Islam and M. A. Sattar Department of Environmental Science Bangladesh Agricultural University Mymensingh-2202, Bangladesh IMPACTS OF TROPOSPHERIC OZONE ON AGRICULTURAL CROPS IN BANGLADESH

Structure of the AtmosphereStructure of the Atmosphere Fig. 1. Position of ozone in Atmosphere

Formation of tropospheric ozone from NO 2 The formation of ozone in the troposphere results from only one known reaction: addition of atomic oxygen (O) to molecular oxygen (O 2 ). NO 2 + hv → NO + O (1) O + O 2 + M → O 3 + M (2) Other sources of ozone formation Hydrocarbons, Volatile Organic Compounds

Table 1. Tropospheric ozone concentrations (ppb) at 28 days mean in Bangladesh during Month Mean ozone concentrations (ppb) at 28 days 17 April – 15 May’ May - 13 June’ June – 11 July’ July – 15 August’ December – 2 January’ January – 2 Febryary’ April – 15 May’

Methodology Crop (Biomonitoring indicator): White clover Two genotype were used such as ozone resistant (NC-R) and ozone sensitive (NS-S) Tiny tag: For recording temperature and relative humidity Ozone passive sampler: To measure the tropospheric ozone

Fig. 3. View of experimental field

Fig. 4. Injury symptom NC-s white clover

Table 2. Dry weight and biomass ratio of clover plant in different harvesting period at Harvesting period Plant biomass (g/plant)BM (NC-S/NC-R) Ozone sensitive (NC-S)Ozone resistant (NC-R) (Mean ± SE) I st harvest11.32± ± nd harvest15.83 ± ± rd harvest21.27 ± ± th harvest26.16 ± ± BM = Biomass ratio (NC-S/NC-R) Conclusion  White Clover is a adaptable crop in Bangladesh.  Always NC-S showed better performances than NC-R.  It may be best indicator to observe tropospheric ozone injury symptoms in Bangladesh.

Table 3. Ozone injury assessment in white clover in Bangladesh during 2007 Harvesting period Occurrence of 1 st ozone injury Total No. of plant (NC-S) suffering to ozone injury Very slight injurySlight injury 1 st Harvesting7 th days nd Harvesting7 th days rd Harvesting21 th days945 4 th Harvesting7 th days844 Comments  Higher Tropospheric ozone concentration in atmosphere reached up to ppb.  Ozone sensitive white clover was suffering from tropospheric ozone injury symptoms.

Table 4. Ozone injury assessment in white clover in Bangladesh during Oct. 07-Feb.08 (2 nd Year) Harvesting period Occurrence of 1 st ozone injury Total No. of plant (NC-S) suffering to ozone injury Very slight injury Slight injury 1 st Harvesting7 th days954 2 nd Harvesting7 th days rd Harvesting7 th days th Harvesting7 th days1165 Comments  Mean Ozone concentration in atmosphere was lower than 1st year, but existing higher temperature insured more injury than 1st year.  Ozone sensitive white clover was suffering from tropospheric ozone injury symptom.

EDU study Continue in Mymensingh Crops: Mungberan, Potato, Indian Spinach

CropsDate of sowing 1 st day of experiment Date of harvesting EDU application Amount (ml) Con. (ppm) Injury Assessment Mungbean Table 5. Outline of Mungbean EDU study

Table 6. Performances of EDU treated and control (treated with water only) Mungbean plant Plant CharactersEDU treatedControl RangeAverageRangeAverage Plant height (cm) No. of Branch/plant No. of leaves/plant No. of pod/plant Dry wt./plant (g)

Figure 5. EDU treated healthy plant of potato

Table 7. Visual ozone injury assessment on control (water treated only) Mungbean plant DateNo. of plant suffering to ozone injury Scoring of injury Very slightSlightMedium Comment  Comparatively hard leaf than Potato and Indian Spinach.

Fig 6. Ozone Injured Mungbean leaf

Table 8. Outline of Potato EDU study CropsDate of sowing 1 st day of experiment Date of harvesting EDU application Amount (ml) Conc. (ppm) Injury Assessment Potato

Table 9. Performances of EDU treated and control (treated with water only) Potato plant Plant CharactersEDU treatedControl RangeAverageRangeAverage Plant height (cm) Leaves/plant Leaf length Damage leaves Shoot dry wt. (g/plant)

Figure 7. EDU treated healthy plant of potato

Table 10. Visual ozone injury assessment on control (water treated only) Potato plant DateNo. of plant suffering to ozone injury Scoring of injury Very slightSlightMedium Comments  Moderate ozone concentration in atmosphere.  Nature of plant leaf (larger and soft).  Existing high temperature with less rainfall.

Figure 8. Ozone Injury plant of potato

Table 11. Outline of Indian Spinach EDU study CropsDate of sowing 1 st day of experiment Date of harvesting EDU application Amount (ml) Conc. (ppm) Injury Assessment Indian Spinach

Figure 9. EDU treated Indian Spinach Healthy plant

Fig 10. Ozone Injured Indian Spinach plant

Table 12. Visual ozone injury assessment on control (water treated only) Indian Spinach plant DateNo. of plant suffering to ozone injury Scoring of injury Very slightSlightMedium Comments  Moderate ozone concentration in atmosphere reached up to 21.5 ppb at 28 days mean.  Softness of leaf.  Higher temperature with less rainfall.

THANKS TO ALL