Effects of GA3 Concentrations and Mechanical Scarification on Germination and Seedling Growth Performance of Sour Orange (Citrus aurantium L.) Rootstock

The current experiment was conducted in Agriculture Faculty Lab (pro trays), at Nangarhar University, Afghanistan. As the germination of the sour orange seed is very poor and needs a long time for their competent germination, it was aimed to enhance germination and produce standard seedlings for proper growth and development. The experiment was laid out in a completely randomized design (CRD) having six treatments, T1 (50 ppm + scarification), T2 (100 ppm + scarification), T3 (150 ppm + scarification), T4 (200 ppm + scarification), T5 (250 ppm + scarification) and T6 (Control) with three replications. The scarification was done manually for seed coat removal after the extraction of seeds from fruits. Analysis of variance revealed to be significant for most of the characters under study. The study revealed that among all treatments, T5 (250 ppm + scarification) was the best treatment for growth and root parameters, followed by T4 (200 ppm + scarification) while the lowest of growth and root parameters were registered in T6 (control). This investigation confirmed that high concentration of GA3 significantly affected the seed germination of sour orange.