There are many factors that affect plant growth. The main conditions include: light (light intensity, light quality, light time), temperature, humidity, air (nitrogen, oxygen, carbon dioxide), moisture, mineral nutrition, etc. It affects the growth of plants by influencing the three major functions of plants (photosynthesis, respiration, and transpiration). The organic matter that helps plants grow comes from the photosynthesis of plants, and both respiration and transpiration consume organic matter.
It was said in high school biology that when plants synthesize organic matter faster than they consume organic matter, plants can grow. This is the conclusion that plants are exposed to light conditions, but in retrospect, plant growth seems to change at night. It is relatively large, and there is almost no light at night. Why can I grow faster than when there is light?
Natural conditions determine this phenomenon. The light intensity during the day is indeed high, and the temperature will be higher. Respiration and transpiration consume organic matter faster. At this time, it gives people the impression that plants grow very slowly. At a certain height, the degree of stomata opening of the plant reaches the maximum, and the water consumption is also the highest at this time. On the other hand, the reason is the influence of light quality. Part of the light quality has an inhibitory effect on the development of plant roots, stems and leaves. The speed of growth is even less noticeable.
In order to explore why plants grow faster at night, experiments were conducted separately, and the following results were obtained (in order to facilitate the control of conditions, the experiment was carried out indoors, the light source was a thick LED plant light, and the measurement indicators were plant height/volume/dry matter accumulation. ).
Condition A: All other environmental factors remain the same and the best growth conditions for plants are maintained. The two groups of plants are also irradiated with LED plant lights for 5 hours, and the growth rate is very close. Then one group of plants continues to use LED plant lights to maintain light for 5 hours, and the other The group stopped lighting for 5 hours, and finally measured and calculated that the growth rate of the plants after 10 hours of light was not very different from the growth rate of 5 hours of light; the third group did not supplement with light and grew very slowly.
Condition B: After two groups of plants are irradiated with suitable LED plant lights for 5 hours under normal environment, one group stops the light for 5 hours, and the other group simulates noon during the day, and uses LED plant lights to increase the light intensity and increase the temperature. Finally, the measurement and calculation show that the growth rate of the plant lamp is faster when the light is stopped for 5 hours;
Condition C: The same two groups of plants are placed in sufficient water, suitable temperature, and the growth rate of the plants with sufficient light is slightly higher than the growth rate of the plants at night.
Studies have concluded that the growth of plants is mainly dependent on the dry matter accumulated by photosynthesis to stimulate growth. Under the condition of sufficient dry matter, light and no light have little effect on plant growth. Secondly, plant growth is affected by the surrounding environment, such as temperature. To a certain extent, it is helpful for the activation of enzymes in the plant, and the temperature is too high to increase the speed of transpiration. Finally, the speed of plant growth is regulated by the photoperiod. The use of LED plant lights can effectively adjust the photoperiod of the plant, shorten the maturity time of the plant, and improve the quality And yield.
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