Pak. J. Bot., 37(4): 913-920, 2005. | Back to Contents | ||||
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Updated: 09-07-09 | ||||
FOLIAR SPRAY OF MINERAL ELEMENTS ANTAGONISTIC TO SODIUM ? A TECHNIQUE TO INDUCE SALT TOLERANCE IN PLANTS GROWING UNDER SALINE CONDITIONS RAFIQ AHMAD AND RIZWANA JABEEN
Abstract: Plants growing in saline substrates show deficiencies in absorption
of some essential mineral elements through roots due to presence of
excessive sodium in the rhizosphere. Sodium being antagonistic to other
cations does not let them enter in roots and hence apart from its own
toxicity in metabolism, the plants suffer with deficiencies of some
mineral elements necessary for growth. Potassium an essential mineral
element is much affected due to this antagonistic behavior of sodium
ion. Lagenaria siceraria being a broad leaf vegetable was selected
for these experiments. Plants growing at saline substrate was sprayed
with specially prepared spray material containing different dilutions
of potassium nitrate. The anatomy of leaf with special reference to
that of stomata was also studied to ensure absorption of required minerals.
Plants were grown in Lysimeters filled with sandy loam and irrigated
with 0.2% (EC iw 3.4 dSm-1) and 0.4% (EC iw 6.1 dSm-1) dilutions of
sea salt. They were further subjected to four treatments viz., i) non
- spray, ii) foliar spray with water, iii) foliar spray with 250 ppm
KNO3, iv) foliar spray with 500 ppm KNO3 respectively. Those sprayed
by 250 ppm KNO3 under saline conditions not only inhibited toxic effects
of salt on fruit formation, but also increased their production 76.91
% by weight per plant, Spray with higher concentrations of KNO3 did
not show much benefit. Biosaline Research Laboratory, Department of Botany, University of Karachi, Karachi, Pakistan. |
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