(a) Three temperature points:
Different crops have their own "three base points" for their temperature requirements, ie the lowest temperature, the most suitable temperature, and the highest temperature. The three-point requirements of crops are generally closely related to their origins. They are native to temperate regions and have a low temperature at the growing base. They generally begin to grow at about 10°C; they originate in the subtropics and begin to grow at 15°C to 16°C; they originate in the tropics. Ask for higher temperatures. Therefore, according to the different temperature requirements, crops can be divided into three categories of cold resistance, semi-cold resistance and cold resistance.
(1) Cold-resistant crops have strong cold resistance and moderate fertility. The biennial species of these plants are generally not tolerant to high temperatures, and when the heat arrives, they grow poorly or die prematurely when they complete the reproductive growth stage. Perennial species or aboveground dead, winter perennial or plant winter. Such crops can generally be cultivated in winter and even overwintered on land by using simple protection facilities such as small sheds in North China. Such as pansy, snapdragon, hollyhock, leeks, spinach, green onions, grapes, peaches, plums and so on.
(2) Semi-cold crops These crops have cold tolerance between cold tolerance and non-cold crops and are resistant to frost but do not tolerate low temperatures below long-term oY. Generally, it can be exposed in winter or in open field in the south of Huanghuai, and facilities cultivation is needed in the north of Huanghuai. Such as violet, calendula, radish, celery, cabbage, cabbage, seedlings, peas and beans. The optimum temperature for the assimilation of these plants is 18°C-25°C; over 25°C, the growth is poor, and the assimilation function is weakened; when the temperature exceeds 30°C, almost no assimilation product can accumulate.
(3) Cold-tolerant crops During the growth period, the higher temperature is required, and the low temperature below o°C cannot be tolerated. Generally, it grows during the frost-free period, and is mostly annual or perennial greenhouse plants. Among them, thermophilic plants such as primrose, cineraria, camellia, cucumber, tomato, eggplant, and kidney bean, etc., have a suitable growth temperature of 20°C to 30°C, and almost stop growing when the temperature exceeds 40°C, and when the temperature is lower than 15°C. At °C, poor growth or pollination, poor fertilization. Therefore, the winter production of such plants can only be carried out in warmed greenhouses.
(b) Flower bud differentiation and temperature:
Many wintering plants and perennial woody plants are required for low temperature in winter, and the necessary low temperature can be achieved to complete flower bud differentiation and flowering. This is very important in the cultivation of fruit trees. When aiming at early maturation, how to break the dormancy is the most important issue in the cultivation of fruit trees. This requires grasping the low temperature demand of different fruit trees to relieve dormancy.
Electrofusion welding is the name given to resistive implant welding of thermoplastic pipes. It is one of two main techniques used for the joining of polyethylene gas and water pipes. Electrofusion welding employs fittings that are placed around the joint to be welded. Metal coils are implanted into the fittings, and electric current is run through the coils to generate heat and melt part of the pipes, forming a joint upon solidification. There are two possible fittings used in electro fusion welding: couplers and tapping tees (electrofusion saddles). Electrofusion Machines/Electrofusion Welders are used for electrofusion fittings welding. Electrofusion Fittings are a heat treatment method compared to butt fusion methods and are used to generate heat. Electrofusion welding is a type of pipe welding and polyethylene fittings, in which there are special connections that have electrical resistance wire to create welding melting temperatures. The electric current is transmitted through the electrofusion welding eequipment and through the control box to the two ends of the connection. Yuda offers a fulll range of EF315 HDPE Electrofusion Welders, EF500 poly pipe electrofusion welding machine, EF630 HDPE Fitting Electrofusion Equipments and EF800 Electrofusion hdpe fittings machines
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