EFFECET OF GIBBERLLlNE SPRAY ON GROWTH AND SOME CHEMICAL CONSTITUENTS OF Casurina g/auca SEEDLINGS GROWN UNDER DILUTED SEA WATER CONDITIONS.

This study was carried out in National Research Centre, Dokki. Giza in the

two successive seasons 2002 and 2003 to study the effect of different salinity levels of
diluted sea water(3000,6000,9000 and 12000 ppm) and gibberelline spray on growth
and chemical constituents of Casurina g/auca whereas control plants were irrigated
with tap water (250 ppm salts). The obtained results showed that, salinity levels in
most cases led to lower values of plant height, stem diameter,root length, fresh and
dry weight of plant organs, chlorophyll A&B, N,P and K percentages in the two
seasons. While carotenoids, carbohydrates,proline,Na,Ca and Mg percentages in the
aerial parts increased as salinity levels were raised.

GA3 at 200 ppm led to the greatest values of plant height, stem diameter,
root length, fresh weight of stem in the first season, dry weight of stem in both seasos,
fresh and dry weight of branchlets in the second season, fresh and dry weight of roots
in the first season and chlorophyll A&B. On the other hand, dry weight of root,
carbohydrate, N,P,K,Na and Mg contents in both seasons. Ca in the first season
increased by increasing GA3 ppm.
Salinity at 3000ppm and GA3 at 100&200 ppm increased mostly plant height,
stem diameter, dry weight of stem, fresh and dry weight of branch lets and fresh and
dry weight of roots in both seasons.