Temperature conditions for the growth of Gastrodia elata

Q: what kind of temperature conditions are needed for the growth of Gastrodia elata? What is the limit temperature?

Answer: this question seems simple, but in fact it is quite complicated. according to the actual situation of our province, we might as well give a brief explanation from the following two aspects.

First of all, the original intention of most farmers who put forward this question should refer to the adaptability of Gastrodia elata tubers to temperature in asexual cultivation. As a kind of plant, Gastrodia elata has no roots and leaves, and its ability to adapt and regulate temperature is weak, which is its growth disadvantage. however, because Gastrodia elata is in the underground environment all its life (except sexual seeds), with the help of stable temperature conditions in the soil, its tubers can grow normally. The temperature we are talking about here refers to the temperature of the underground soil layer of Gastrodia elata, not the air temperature. Generally speaking, when the ground temperature reaches more than 12 ℃, Gastrodia elata cells begin to be active, and they can begin to digest and absorb Armillaria mellea as their own food for their own growth and expansion. With the increase of temperature, the vitality increases, reaching the peak at 20-25 ℃, as in the youth of human beings, life is very active and healthy. However, when the temperature continues to rise above 30 ℃, the biological metabolism will be stopped and the resistance to adverse external conditions will be lost.

According to our experimental statistics, the effective accumulated temperature of Gastrodia elata from young to long is about 3800 ℃, and the commodity is better when it is about 4000 ℃. According to the growth cycle of one year, the most suitable daily temperature is between 10 and 12 ℃. Therefore, under general natural conditions, unprotected cultivation can be carried out in all parts of Shandong Province. If it is in the south of the Yangtze River, it is necessary to properly consider the cooling in summer, such as woodland, orchards, hillsides and other places, the effect is very good. As another example, in Northeast China, the freezing thickness of the soil layer can reach 30 cm or more in winter, then the problems of heat preservation and heating should be considered, such as thickening grass and leaves, or using plastic shed facilities, which can be effectively solved. As long as the soil temperature of Gastrodia elata is higher than minus 4 ℃, it can survive the winter normally, but if it is less than 5 ℃ below zero, freezing damage will occur.

Second, the temperature conditions of Gastrodia elata seeds during sexual breeding are more stringent. Because the sexual seeds of Gastrodia elata are as small as dust, its adaptability and resistance to external conditions are very poor, so it has become one of the difficulties in Gastrodia elata sexual breeding. Under general conditions, Gastrodia elata seeds can germinate at 20: 28 ℃, even at 15 ℃, but there is no possibility of germination when the temperature is below 13 ℃. When the temperature rises to 30 ℃, the seeds are not easy to germinate. We have done a special study on this: 13% 15 ℃, germination rate 13% ℃, germination rate 23% ℃, germination rate 43% 20 ℃, germination rate 76% 23 ℃, germination rate 78%. 26% 28 ℃, the germination rate is 81%, the germination rate is 29% 31 ℃, and the germination rate is 37%, the germination rate is close to zero after 33 ℃.

In addition, in the stage of sexual breeding, sprouting and bolting, flower stem growth, pollen formation and pollination until seed maturity all need certain temperature conditions, which are limited to space and will not be repeated.