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The Effect of High Concentration of Negative Ions in the Air on the Chlorophyll Content in Plant Leaves
2001
Jovanić, B. R. | Jovanić, S. B.
This research was done on the effectof high concentration of negative ions in the air onchlorophyll contents and photosynthetic efficiency in leavesof Zea mays L. In vivo reflectance and chlorophyllfluorescence were measured in intact maize leaves before andafter exposing to the high concentration of negative ions inthe air. Reflectance, yield of chlorophyll fluorescence, redshift in chlorophyll fluorescence and blue shift inreflectance are observed in exposed species. These resultsindicate that high concentrations of negative ions inair cause significant change in: a) chlorophyll content andb) photosynthetic efficiency.
Show more [+] Less [-]Rainwater Composition at a Regional Representative Site of a Semi-Arid Region of India
2001
Singh, S. P. | Khare, P. | Satsangi, G. S. | Lakhani, A. | Maharaj Kumari, K. | Srivastava, S. S.
Rainwater samples (N = 51) were collected at Rampur, an areafree from anthropogenic activity during the monsoon of 1997 and1998. The concentration of ions follows a general pattern as Ca> NH₄ > Mg > SO₄ > Cl > F >Na > NO₃ > K > HCOO >CH₃ COO. The pH of precipitation ranges between 5.9 and 7.4. The levels of Ca and Mg at this site are higher than otherremote sites, probably dominated by particles of soil origin.Good correlation between Ca, NO₃, SO₄, HCOO and CH₃COO indicate that a fraction of NO₃, SO₄, HCOOand CH₃COO may be derived from soil or associated with Ca and Mg after neutralization. The order of neutralization factorCa (2.19) > NH₄ (1.26) = Mg (1.26) indicates that majorneutralization occurred by Ca. Factor analysis suggested thatCa, Mg, Na, K, NO₃, SO₄, HCOO and CH₃COO arecontributed by soil. NH₃ is known to exist as(NH₄)₂SO₄, NH₄NO₃ and NH₄Cl. Theymay be formed in the atmospheric water droplets by scavenging ofaerosols and reaction of gaseous species.
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