What are the growth characteristics of the extension shoots of jujube trees?

The extension shoot of a jujube tree, also known as the growth shoot or vegetative shoot, is the basis for forming the framework of the jujube tree and the central axis of the fruiting branch system. It holds a leading position among the branches and is also called the jujube head. The extension shoot sprouts from a main bud, has vigorous growth capacity, and extends along a single axis, thickening very quickly. As the jujube head grows, the secondary buds on it also gradually sprout from bottom to top, growing into secondary shoots, while the secondary buds on the middle and upper secondary shoots continuously sprout tertiary shoots, which can flower and bear fruit every year.