Leaves contain a lot of chlorophyll, and the color is green. The weather gets cold, the trees grow slowly, and the chlorophyll in the leaves gradually decreases. Finally, only lutein is left, and the leaves turn yellow. Maple leaf contains anthocyanin, which is a special substance opposite to chlorophyll. As the weather gets colder and the number increases, the maple leaves turn red. The planting technique of maple includes soaking the seeds in warm water at 40℃ before treating the seedlings, mixing the seeds with wet sand twice, putting them into the seed bank, taking out the seeds half a month before sowing, drying them in the leeward, accelerating germination in the open air, and when about 65,438+0/3 of the seeds start to crack.

Planting seedlings, after thawing the soil, transplanting before the juice flows out to adjust the density. The emergence time is from late March to early April, and it is appropriate to germinate the seedlings before. According to the size of the maple block, the blood passage at the heart point is greater than 20% of the block diameter. Prune properly before planting, prune damaged branches, prune branches that are too dense, and do a good job in crown shaping. The planting method is to put the tree in the center of the planting hole, correct the tree body, make the direction of the bitter heart consistent with the direction of the crown, fill it evenly and tamp it layer by layer. After planting, water it in time, cover it with water and keep it moist. After the table lamp fixes the maple saplings, the bracket should be fixed in time. Generally, three brackets are used to fix the suitcase, and two-thirds of the height of the suitcase is tied with fixed support points. Cotton cloth or plastic is sandwiched between the trunk and the supports, and the height of the crown is increased by 1~2 supports to ensure the firmness of the trees.

Before the forming spring water flows, the tubular trees are pruned according to the requirements of cultivated trees, and the branch angle and direction are adjusted by straightening and supporting in the growing season. Daily management will remove weeds under the crown projection in time to make them loose. When the soil is dry, water it in time. The accumulated water caused by heavy rain or rainstorm should be immediately drained. Stress response: The red maple leaf is actually the maple tree's response to natural stress. The red maple leaves actually play the role of sunscreen, and the leaves stay on the tree for a longer time, allowing the tree to absorb more nutrients. Studies show that the pressure of nutrition, especially the pressure of nitrogen deficiency, makes the maple leaf turn red earlier.

The internal factors that make leaves look red mainly depend on two substances. One is carotene, which is an orange pigment commonly found in chloroplasts. The other is anthocyanin in vacuole cell fluid. If the cell sap is alkaline, anthocyanins are blue-purple; If the cell sap is acidic, anthocyanins are red. Autumn comes, anthocyanins in yellow leaves increase, the temperature drops, chlorophyll destruction disappears, and green leaves become maple leaves. External factors: When the temperature drops rapidly to a certain extent and the temperature ratio drops much, the leaves will not fall off, most of the chlorophyll will be destroyed, and the temperature difference between day and night will increase, which will help the formation of anthocyanins, so the leaves will turn red soon. The temperature drops slowly, the temperature difference between day and night is not big, chlorophyll is not destroyed, trees wither and will not become beautiful maple leaves.