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Research Papers Published by DBB

The root lengths in ammonia-exposed Crotalaria and Cyamopsis were affected. In Crotalaria the roots were shorter by 2.4 cm and Cyamopsis by 1.2 cm with respect to their control. The root was slightly longer than the control in fumigated Abelmoschus. However, there was no difference in the root size of control and fumigated Trigonella plants (Table 1). The shoot lengths were also found to be affected in Crotalaria and Cyamopsis. In Crotalaria seedlings from fumigated seeds had the shoots reduced by 2.0 cm as compared to the control while in Cyamopsis the reduction was 4.6 cm. The shoot length in case of fumigated Abelmoschus i.e., 5.4 cm, that is, longer than in the controls which was 2.9 cm only. There was no difference in shoot lengths in fumigated and control plants of Trigonella (Table 1).

The root-shoot ratio in seedlings from fumigated seeds of Abelmoschus and Crotalaria was reduced showing that the growth of root was more affected than shoot. Reverse was true for Cyamopsis while there was no change in case of Trigonella indicating equal effect on both root & shoot (Table 1). Unlike Trigonella and Abelmoschus, the 15-day old plants of Cyamopsis and Crotalaria 24 hr after a 3-hr ammonia fumigation showed visible damage symptoms on leaves. The leaf area damage was 40% and 54% respectively. The percentages of leaves damaged in the two plant species were 55% and 70%. The damage index (product of % area damage and % of leaves damaged on each plant) was 2,200 for Cyamopsis and 3,780 for Crotalaria (Table 2).

The total chlorophyll, chlorophyll a and chlorophyll b contents of leaves were slightly reduced in the 15-day old plants of Abelmoschus, Crotalaria and Cyamopsis as a result of fumigation with ammonia, the reduction being limited to 1.3 mg / g fresh weight. In Trigonella, however, the effect was more severe, giving 63% loss of total chlorophyll, 58% loss in chlorophyll a and 70% loss in chlorophyll b. The ratio of chlorophyll a to b was also visibly affected in Trigonella (Table 2).

The shoot length was reduced by ammonia in all the plants studied, though the effect was more obvious in Abelmoschus and Crotalaria than in Cyamopsis. The reduction in shoot length was accompanied by the formation of fewer leaves in Crotalaria, where the number of nodes was reduced to almost half. The length of the fourth internode from the top was also slightly affected in Cyamopsis and Crotalaria. The shoot mass was more severely affected in Abelmoschus compared to Cyamopsis. Dry matter yield reduction was highest (73%) in Crotalaria. The Trigonella plants could not survive for 30 days after fumigation and hence readings could not be taken (Table 3).

Table 2 : Effect of a 3-hr fumigation with 50 ppm ammonia

Table 3 : Growth performance 30 days after ammonia fumigation

CONCLUSION

The seed germination and growth of seedlings were adversely affected due to ammonia fumigation. The percentage germination was significantly reduced. Root and shoot lengths were smaller in fumigated plants except in Abelmoschus where shoots showed a stimulatory effect. 15-day old Cyamopsis and Crotalaria plants exhibited visible leaf injury. Chlorophyll contents were reduced maximally in Trigonella while Abelmoschus showed minimum impact. Shoot length, nodes, internode length and dry matter production were lower in fumigated plants with no full recovery after 30 days. Sensitivity order based on dry matter accumulation: Trigonella > Crotalaria > Abelmoschus > Cyamopsis.

ACKNOWLEDGEMENT

The authors are thankful to Prof. B. C. Haldar, Director and Dr. V. D. Tilak, Head of the Botany Department, The Institute of Science, Bombay, for encouragement. The assistance of Dr. P. K. Paria of the Institute and Mr. H. V. Rane of SOCLEEN laboratories, for standardisation of the technique for ammonia emission and estimation is highly appreciated.

REFERENCES

• ARNON, D. I. 1949. Copper enzymes in isolated chloroplasts, polyphenol oxides in Beta vulgaris. Plant Physiol, 24 (1) : 1—15.
• BRENNAN, E., I. A. LEONE and R. H. DAINES. Ammonia injury to apples and peaches in storage. Plant Dis. Rep., 46 : 792—795.
• CARLEY, E. H. and R. D. WATSON. 1968. Effects of various aqueous plant extracts upon seed germination. Bot. Gaz., 129 (1) : 57—62.
• CHOLAK, J. 1952. The nature of the atmosphere in a number of industrial communities. Presented in 2nd Nat. Air Pollut. Symp. Stanford Res. Inst; Los Angels, California.
• LEVEGGI, D. A., W. SIW and M. FELDSTEIN. 1973. Nesslerization method for estimation of ammonia. Air Poll. Cont. Assoc. J., 23 : 30.
• RAMSEY, G. B. 1953. Mechanical and chemical injuries. In Plant Disease, U.S.D.A. Year Book. pp. 835–837.
• THRONTON, N. C. and C. SETTERSTROM. 1973. Toxicity of ammonia, chlorine, hydrogen sulphide and sulphur dioxide gases on green plants. Contrib. Boyce Thompson Inst., 11 : 343—356.
• TRESHAW, M. 1970. Environment and plant response. McGraw Hill Book Co., N. Y. pp. 362—363.
• ZUTSHI, P. K. 1971. Greater Bombay—Its geographical location, meteorological characteristics and the magnitude and distribution of the major sources of air pollution. Report from Air Monitoring Division, Bhabha Atomic Research Centre, Bombay.