EFFECT OF WATER SALINITY AND LEVELS GIBBERELLIC ACID SPRAYING ON SOME GROWTH CHARACTERS OF WHEAT CULTIVAR IBA 99

Abstract

A field experiment was carried out at the Field Crops Research Station of the Diyala Department of Agriculture during two winter seasons 2012 and 2013 to determining the role of gibberellic acid spraying at different concentrations in reducing the salinity of irrigation water and its effect on some growth characteristics of wheat cv. Iba 99 by using the arrangement of splints with RCBD design at three replicates. The main plots included saline levels (salt water 7, 14 and 21) ds. m-1 in addition to comparison treatment (river water 1.3 ds.m-1), while sub-plots plates included gibberellic acid spraying at four levels (0, 150, 300 and 450) mg. L-1. The results showed that the high salt level of irrigation water (21 ds. m-1) reduced the height of the plant (70.40 and 71.50 cm), flag leaf area (21.60 and 19.90 cm2) and its content of chlorophyll, dry matter at the booting (2.71 and 3.42 t .ha-1) and flowering stages (5.61 and 4.70 t.ha-1, potassium to sodium percentage, and increased the concentration of sodium and chloride percentage in plant for both seasons, respectively. On the other hand, the highest levels of gibberellic acid (450 mg. L-1) gave highest means of plant height (79.11 and 88.81 cm), flag leaf area (27.52 and 26.91 cm2) and its content of chlorophyll (50.21 and 43.24 microgm. cm-2), dry matter at the bloom and flowering stages for both seasons. However, the increasing level of gibberellic acid concentration of resulted in increasing the concentration of potassium in the plant and the ratio of potassium to sodium, and reducing the concentration of sodium and the chloride percentage in plant for both seasons.