How to describe the advantages of sunflower?

Sunflower top has strong advantages, big top and naked body; The apical dominance of wheat and soybean is relatively weak, and the apical growth does not forget to bear the growth of lateral branches.

The phenomenon of apical dominance is a double-edged sword in the plant kingdom. For fruiting plants, if the top is developed and the lateral branches are weak, it will affect their yield. Therefore, people will try their best to eliminate the top advantage. For example, topping cotton can promote the growth of lateral branches and increase yield; Pruning fruit trees will make them develop horizontally and produce more fruitful lateral branches. For some plants whose trunks are used by people, people tend to trim the side branches and make full use of the advantages of the top to make them grow tall and straight, and then become useful.

fruit tree pruning

The internal reasons of the top advantage

At present, there is not a very exact statement about the internal cause of the phenomenon of top advantage. However, people have made some progress in studying the role of plant hormones (auxin, cytokinin) in apical dominance:

Effect of auxin

Auxin is the earliest discovered plant hormone, and its chemical name is 3- indoleacetic acid. It is mainly produced at the top of plants, and then polar transportation is carried out to all parts from top to bottom. The main function of auxin is to promote cell elongation and growth, promote rooting and inhibit lateral buds. However, this promotion is related to the concentration. Low concentration promotes growth, while high concentration inhibits growth and even leads to death.