NOVELTY - Preparing growth-promoting agent involves preparing endophytic spiral bacterial culture and growth-promoting agents, and storing at -80 degrees C. The endophytic spiral bacterial culture is inoculated in a nutrient broth (5mL), shaken at 150 revolutions per minute (rpm) and incubated overnight at 37 degrees C. The bacteria is accessed to the fresh Leuria Bertani (LB) medium, in the 1:100, and cultured at a temperature of 28-37 degrees C and rotational speed of 200rpm for 6-8 hours, till the optical density of the culture reaches 1.0-1.2 at 600nm.    USE - Method for preparing growth-promoting agent used for regulating sprouts within a tea tree (claimed).    ADVANTAGE - The method enables to prepare growth-promoting agent in a cost-effective, simple and eco-friendly way, which shows vigorous growth, dark green leaves, and increased length and weight of newborn buds in the tea tree.    DETAILED DESCRIPTION - Preparing growth-promoting agent involves preparing endophytic spiral bacterial culture and growth-promoting agents, and storing at -80 degrees C. The endophytic spiral bacterial culture is inoculated in a nutrient broth (5mL), shaken at 150 revolutions per minute (rpm) and incubated overnight at 37 degrees C. The bacteria is accessed to the fresh Leuria Bertani (LB) medium, in the 1:100, and cultured at a temperature of 28-37 degrees C and rotational speed of 200rpm for 6-8 hours, till the optical density of the culture reaches 1.0-1.2 at 600nm. The bacterial broth is then collected, glycerol (1%) is added, stored at 4 degrees C. The obtained inoculum is diluted for the regulation of growth-promoting agent. The nutrient broth comprises tryptone (10 g), beef powder (3 g), sodium chloride (5 g), spectinomycin (10 micrograms/mL), ampicillin (5 micrograms/mL) and water to a volume of 1000 ml. The LB liquid medium comprises tryptone (10 g), beef powder (5 g), sodium chloride (10 g), spectinomycin (10 micrograms/ml), ampicillin (5 micrograms/ml) and water to a volume of 1000 ml.    An INDEPENDENT CLAIM is included for a method for applying growth-promoting agent on the tea tree, which involves:    (A) diluting the growth-promoting agent with water in the ratio of 0.5-2:1;    (B) performing conventional pruning of tea tree by cutting the top of the tea tree with an electric cutting machine, so incision is produced on the upper branches;    (C) spraying the growth-promoting agent solution diluted with water on top of the tea tea using a sprayer, with an amount of 50-100ml/square meter; and    (D) managing field by conventional method after completion of spraying.