Laboratory and Field trials were conducted on garlic cv. "Sids-40" during the two successive winter seasons of 2008/2009 and 2009/2010 at the Experimental Farm of Mallawy Agriculture Research Station, Agriculture Research Center, Giza, Egypt. In lab., treatments were identified and selected based on their pre-planting effect. Clove seeds were soaked for 48h in aqueous solution of ascorbic acid (AA) and salicylic acid (SA) at 100 and 200ppm, gibberellic acid (GA₃), indol acetic acid (IAA), kinetin (Kin), cobalt chloride (Co) at 20ppm and their combinations. Garlic cloves were then placed in petri-dishes, moistened with distilled water when needed and, incubated under 25⁰C ± 2 and 16h photoperiod. After 15 days from incubation, data were recorded for sprouting (%), plantlet height, root length and root number. In the field, the best selected promotive treatments identified in lab were used. Garlic cloves were soaked in H₂O as control treatment, another set of garlic cloves were soaked for 48h in the best selected promotive treatments identified in lab and then planted in the field. The obtained laboratory results revealed that the combination of AA at 100, 200ppm + Kin at 20 ppm +Co at 20 ppm; and AA at 100 ppm + GA₃ at 20 ppm +Co at 20 ppm were the best to get the highest sprouting percentage and plantlet height. AA 200 ppm, Co 20 ppm and the combination of AA 100 ppm + GA₃ 20 ppm + Co 20 ppm had the best stimulatory effect on plant growth, promoting root number and root length. The lowest values were recorded with SA at 100 ppm and when combined with the other tested treatments. Field trial, data revealed that treating garlic cloves with AA 200 ppm and the combination of AA 100 ppm + GA₃ 20 ppm + Co 20 ppm resulted in the best germination percent, plant height, cured bulb diameter, bulb dry matter percent as well as fresh and cured yield (ton/fed.). Salicylic acid at the lowest concentration (100 ppm) gave the lowest weight loss during the curing process.
Key words: ascorbic acid, salicylic acid, growth regulators, cobalt chloride, garlic clove