Effect of concentrations , periods of soaking in Gibberellic acid solution and shading percentage on germination and growth Aleppo pine seedlings (Pinus halepensis Mill.) in Kerbala governorate

Abstract

The experiment had been carried out in mid of Feb. 2015 to the end of May 2016 at University of Kerbala / Collage of Agriculture , to study the effect of concentration of Gibberellic acid (0, 150 ,300 mg.L-1) , periods of soaking (24 , 48 , 72 hours) and shading percentage (0 and 50%) on germination and seedling growth of Allipo Pine . Completely Random Block Design (CRBD) was used to analysis the experiment results. The levels of the Gibberellic concentration used were (0,150, 300 mg.L-1) while the periods of soaking of Gibberellic solution were (24, 48, 72 hours). The third factor was used in two ways without shadow and with 50 percentage shadow. The results obtained that the treatment of Gibberellic solution at 300 mg.L-1 gave significant effect on germination, high sapling and the relative moisture content of the leaves. In addition, the treatment of Gibberellic solution at 150 mg.L-1 caused a significant effect on leaves chlorophyll content compared to the control treatment. Furthermore, the treatment at 72 hours soaking effected energy germination speed of seeds. Moreover, the interaction between the Gibberellic solution at 150 mg.L-1 and the treatment at 72 hours of soaking affected on percent of germination speed compared to the control treatment. While , the interaction between 150 mg.L-1 of Gibberellic solution and 50% shading percentage caused a significant effect on leaves chlorophyll content . Finally, the interaction between 300 mg.L-1 Gibberellic for 72 hours of soaking and 50% shading caused high relative moisture content of the leaves compared to control treatment