1. After more than one year of cultivation, the fleshy roots begin to dry up, which may lead to lignification. The stems become brown and hard to touch, which is also a normal situation, not black rot. The process of lignification is that the lignin produced in the cell is gradually deposited. After lignification, the stem and root will be more robust, which can ensure that they will not be broken and can support the upper part of the gradually heavier
2. After lignification, the cell wall has no elasticity, and the cells in it will not absorb water and become swollen, thus avoiding excessive growth in the later period.
1. More sunlight: the fleshy roots become lignified, which has many advantages and is conducive to the formation of old piles. In order to promote the root lignification as soon as possible, more sunlight is needed to ensure good illumination. The fleshy roots without sunshine are difficult to form lignification. But summer is special, the intensity of the sun's light is large, can't be exposed to the sun
2. Reduce nitrogen fertilizer: it is necessary to apply fertilizer reasonably in the growth process. If the soil contains rich nitrogen elements, it will affect the synthesis of lignin, so in order to promote the root lignification as soon as possible, the application of nitrogen fertilizer should be reduced.
