Seed germination is the operation process that allows the seed to swell, breathe, increase enzyme activity, promote metabolism, and increase germination potential and germination rate under suitable temperature, moisture, and oxygen conditions. The traditional method of germination, because it is difficult to control the environmental conditions, resulting in uneven germination, low seedling rate, and prone to burning, rotten species, so the choice of suitable germination equipment is very important. The selection method of the vegetable seed germination equipment is described below. I. Selection of equipment capacity and temperature control accuracy The current pre-emergence germination equipment on the market includes wall heat-insulating germination chambers and insulation-covered soft sheds. The seedling volume can reach several thousand liters or 10,000 liters and can be used for large seedlings. Base use. There are computer-controlled temperature, humidity, light, ventilated floor-standing artificial climate chamber, used for germination, nursery, tissue culture, cycle cultivation, working volume is 200 ~ 400L, suitable for laboratory use. There are also 1 to 20L small desktop germination machines and less than 1L germination boxes, which can be used by professional vegetable house seedlings and seed business units to detect germination rate. The unit volume is 0.1~0.2kg/L. The accuracy of temperature control is expressed in terms of temperature deviation and its degree of fluctuation. The accuracy of the digital temperature controller is high, its deviation and fluctuation are about 0.5°C, and the accuracy of the analog is lower, generally 1.5°C. Second, the temperature range and operating voltage allowable fluctuations The scope of temperature measurement and control, depending on the equipment application. General laboratory constant temperature and humidity incubator, humidification temperature range of 0 ~ 50 °C; light incubator, full light temperature range of 10 ~ 50 °C, light intensity ≤ 3000Lx; artificial climate box, humidification, full light temperature range For 15 ~ 50 °C, light intensity ≤ 3000Lx. The precipitator for production generally has no refrigeration device, and the lower limit of the temperature control is the ambient temperature, and the upper limit is generally 50° C., and some can reach 100° C., so as to meet the needs of the 55° C. hot soup soaking, hot seeding, and dry heat treatment and insecticidal sterilization. The operating voltage should be wider. Since the rural voltage can sometimes be as low as 160V, or as high as 250V, if the voltage fluctuation range is allowed to be narrow, the instrument will malfunction or burn. Third, pay attention to the germination room humidity due to the low humidity seed is not easy to germinate, high humidity is easy to bad species, so the high-end climate chamber with humidity control device, the relative humidity can be maintained at 50% to 90%, and some can reach 95% . The simple germination equipment does not have a dedicated humidity control device, and its humidity is usually taken to ensure the following two measures: First, the use of electric heat pipe to directly boil water to generate steam heated germination chamber, its relative humidity with a small change in temperature, generally can be maintained at 80 % ~ 95%; Second, the use of electric heating (plate) to heat the air, the humidity through the moisturizing plate or intermittent watering to ensure that generally can be controlled between 60% to 90%, if not timely water will affect the germination. Fourth, strive to uniform temperature and moderate temperature and light germination neatly. The temperature uniformity of the artificial climate box is less than 1°C, and the temperature uniformity of the light box is less than 1. At 5°C, the temperature unevenness of the large and medium priming chambers was less than 2°C. Since most of the seeds germinate without lighting, the general germination machine is not provided with lighting equipment, and there are a few medium and low-light devices, while the artificial climate box and light box have perfect lighting equipment of 3000 to 30000 Lx. The temperature and light unevenness can be solved by adjusting the disk. V. Technical Elements of Seed Germination 1. Pregerminating seeds must be seeded, dried, soaked, and sterilized. Seeds that are difficult to absorb are soaked in hot water at 70-80°C or warm water at 50-55°C. The solanaceous fruit and melon vegetables seeds are treated at lower temperature (1~5°C) for 6~8h, then treated at higher temperature (25~32°C) for 6~8h, alternately, lettuce and celery are at 5 Treatment at 1～2 days under low temperature conditions at ~10°C can promote germination. Cucumber green spot mosaic virus can be killed after treatment at 70°C for 2 days under hot and dry conditions. 2. The suitable temperature of the thermophilic vegetable germination is 25-30°C, and the cold-resistant vegetable is 15-20°C. The initial temperature of the germination is low, and the germination gradually increases. After germination, the temperature is gradually reduced. After germination, the shoots can be removed to prevent dehydration and freezing. 3. During the germination period, every 4 to 5 hours, wash and change the air, remove the mucus, and prevent bad seeds. Germination standard germ white, root length 1 ~ 2mm is appropriate. Liu Junwang, Researcher of Sichuan Agricultural Machinery Research and Design Institute, 610066
