Abstract
Present studies were carried out to determine the effect of some growth regulators, their application methods and environmental conditions on root induction in aerial offshoots of date palm cultivar Hillawi. For this purpose different parameters were studied after treating offshoots with growth regulators, viz. indole acetic acid (IAA), indole butyric acid (IBA), naphthalene acetic acid (NAA), 2,4-dichlorophenoxy acetic acid (2,4-D) and gibberellic acid (GA(3)) each at 1000, 2000 and 3000 mg/l along with their combinations. The treatments were applied by two methods (quick dip and injection) and the treated offshoots were then planted in two environmental conditions viz., open field and plastic tunnel. All levels of IAA, IBA, NAA and some of their combinations induced rooting by both methods under these environments but GA(3) did so only @ 2000 mg/l when applied by quick-dip method in plastic tunnel. Interaction between treatment and method was significant in the offshoots in open field only. In contrast, different treatments showed variable behavior to methods of their application in plastic tunnel. Among all the growth regulators under study only IAA, IBA and NAA affected positively either individually or in combination.