EFFECT OF AQUEOUS EXTRACT OF LICORICE AND HUMIC ACID ON GERMINATION OF DATE PALM (PHOENIX DACTYLIFERA L.) SEEDS

The current study was conducted at the Agricultural Research Station, College of Agriculture, University of Basrah, Iraq. The seeds were collected at random from the ripe fruits resulting from Barhee female cultivar that pollinated with Ghanami Akhdar male cultivar at three replicates. The female inflorescences of Barhee palms were covered with paper isolation bags to ensure that mixing of other pollen grains did not occur and was raised three weeks after the date of pollination. The study included treatment of seeds with some stimulants for germination, the aqueous extract of licorice at 0, 10 and 20 mg L-1 concentrations and humic acid at 0, 300 and 500 mg L-1 concentrations by soaking the seeds in it for a period of one day, then they were planted in paper tissues that were moistened with distilled water and placed in sealed plastic containers. The results of the study showed the significant superiority of licorice extract with a concentration of 20 mg L-1 in all studied characteristics (the percentage and rate of germination and length of cotyledonary sheath) as it recorded 87%, 11 days, and 26 mm, respectively. The treatment of humic acid by concentration of 500 mg L-1 was significant superior in all studied characteristics (the percentage and rate of germination and length of cotyledonary sheath) as it recorded 90%, 7 days, and 28 mm, respectively. As for the interaction, the treatment of seeds with licorice extract at a concentration of 20 mg L-1 and humic acid at a concentration of 500 mg L-1 gave the highest values for all studied characteristics (99% the percentage of germination, 6 days the germination rate and 32 mm the length of the cotyledonary sheath 32 mm).