All of the mentioned stimuli can encourage the growth of pole beans. However, light is particularly essential, as it is a primary factor for photosynthesis, which is crucial for plant growth. Water is also necessary for irrigation and providing hydration to the plant. Gravity helps guide the upward growth of pole beans, as they require support to climb and coil around a structure. Additionally, touch can stimulate the plant to grow towards and wrap around the object it is in contact with.
