Why do sunflowers always face the sun?

1. Sunflowers turn to the sun, mainly because of the influence of light. The auxin of sunflower is distributed above the stem tip and transported downward continuously, which will be affected by light.

Generally speaking, its auxin is distributed in the backlight, with a relatively low concentration on the side facing away from the sun and a relatively high concentration on the side facing away from the light.

So the backlight side grows faster, while the bright side grows slower, which makes the stem bend against the light and make it always face the sun.

2. Scientists think that the sunflower disk is very sensitive to heat. When the tubular floret is heated by the brazier, the fiber will shrink, so the disk will eventually turn to the brazier, which is why the sunflower faces the heat source.

Extended data:

Growing period of sunflower:

1. Seedling stage

The stage from emergence to germination is called seedling stage. At this stage, the aboveground part of sunflower grows slowly and the underground root grows rapidly, which is the stage with the strongest drought resistance. At this stage, water is poured once a week and fertilizer is applied once every half month to ensure sufficient sunshine.

Step 2: the budding stage

The germination stage is the most vigorous stage in the life of sunflower. In this period, sunflower needs fertilizer and water most. If this stage can't meet the demand of sunflower for water and fertilizer, it will seriously affect the yield of sunflower.

3. Flowering period

Flowering refers to putting the disk from the tongue-shaped bloom into the tubular flower. At this stage, we should adjust the sowing date of sunflower, choose the right time to fertilize and water, control pests and diseases, and adopt methods such as releasing bees or artificial pollination to improve the seed setting rate of sunflower.

Step 4 mature

At this stage, there are differences among different sunflower varieties. The grain formation period is about 15 days after flowering and pollination. In the meantime, it is best to place it in an environment with clear weather and large temperature difference between day and night, and keep proper soil moisture.

Reference source: Baidu Encyclopedia-Sunflower