Hormones are highly specific chemical messengers secreted by an endocrine gland (ductless) that traverses through the blood vessels to its particular ligand of action.
Phototropism:
Phototropism is known as the growth of an organism in response to light.
Sunlight acts as a stimulus for the growth of organisms towards the light (positive phototropism) or away from light (negative phototropism).
Phototropism is mostly found in plants.
Hence, no phototropism is not a hormone, it is a growth response instead.