Is phototropism positive or negative?
Phototropism can be positive and negative.
Tropisms are positively or negatively directed movements of propagated organisms or organs induced by unilateral stimulation. There are several types of tropisms like thigmotropism, gravitropism, chemotropism or as in your case, phototropism.
Phototropism is a motion triggered by unilateral illumination that puts the plant or part of the plant in a more favorable position to the light source. When plant growth bends towards the source of light than we talk about positive phototropism and when it bends to the opposite direction from the light source, we talk about negative phototropism.