The Effect of Gibberellins on Flowering of Rose (Rosa hybrida L.)

Roses (Rosa hybrida L.) are prevalent ornamental flowers used as cut and sow flowers. This study aims to examine the effect of gibberellins on the acceleration of flowering of roses planted in pots in Rahma Village, South Lubuklinggau I District, Lubuklinggau City, South Sumatra (-3°018’10”, 102°054’41”) with a height of 110.5 meters above sea level, from September to December 2021. The planting media consisted of Ultisol soil, cow dung, and rice husk (1:1) of 10 kg/pot. Gallica varieties of roses are given gibberellins (GA3) sprayed every 7 days until the plants are 98 days old. Harvesting is done when the flowers are in full bloom. The first harvest is from day 57 to day 116, a total of 17 harvests. The treatment of gibberellin concentration is tested at 6 levels, namely: 0 ppm (Z0), 50 ppm (Z1), 100 ppm (Z2), 150 ppm (Z3), 200 ppm (Z4), and 250 ppm (Z5), with 4 groups and each consists of 3 pots. From the study results, it can be concluded that the administration of gibberellins (GA3) with concentrations between 50 ppm to 200 ppm accelerated flowering time between 2.88 to 10.5 days. Z3 increased the number of flowers by 32.5 buds, and Z2 produced flowers with the largest diameter of 7.16 cm. The length of the stalk and the number of petals on roses cannot be increased by giving gibberellins. For the flowering of roses, it is recommended to administer gibberellin with a concentration of 150 ppm (Z3).