High-yield and high-efficiency cultivation techniques for bitter gourd 3. In the greenhouse temperature regulation, the thermal insulation standard of the thermophilic vegetables can be achieved. Under the normal temperature management conditions such as insulation and covering, the absolute minimum temperature (nighttime) in the severe winter shed is not lower than 8°C, while the time below 10°C is short (less than 2 hours), generally, the temperature in the night shed can be controlled above 12°C; in the morning and one and a half hours after the exposing of the grass, the temperature in the shed can rise above 18°C, and it is not ventilated and cooled at noon on a sunny day in cold winter. Under the circumstances, the air temperature in the shed can be as high as 32°C or more; in the afternoon, when the weather is covered with grass (before and after 6:00 in the winter), the air temperature in the shed can be maintained at 21-22°C. To achieve the above-mentioned requirements warming insulation standards of winter warming shed, it is only suitable for bitter gourd off-season cultivation. Veterinary Solution Disinfectant Veterinary Solution Disinfectant,Povidone Iodine Disinfectant,Ivermectin Pour On Solution,Povidone Iodine Disinfectant Solution Shandong Unovet Pharmaceutical Co.,Ltd. , https://www.unovetcn.com
The greenhouse with good lighting and strong insulation is selected as the gardening facilities for back-season cultivation of bitter gourd. Compared with cucumber, sponge gourd, and zucchini, the light intensity required for the growth and development of bitter gourd is relatively large, the temperature is relatively high, and the low temperature and poor light resistance are poor. . If the bitter gourd seedlings lack of light will reduce the cold resistance, the lack of light during the result period is not conducive to photosynthesis, can cause falling flowers and fruit swelling and slow speed. Bitter gourd germinates at a temperature below 13°C. It stops growing at below 12°C. If it is below 10°C for more than 2 hours, it will suffer chilling injury. If it is below 8°C for more than 4 hours, it will suffer freezing injury. Therefore, in the northern regions of China, using winter greenhouse sheds (sunshine greenhouses) to protect bitter gourds in cold winter and spring seasons, it is necessary to apply winter greenhouses with high light-collecting rates, rapid warming, and good heat preservation. Warm greenhouses reach the following indicators:
1. The optimal range of the shed angle is the same as the local geography latitude minus the latitude (-2327′) of the “winter solsticeâ€, and then the 33-35 degree decrement. For example, the optimum range of the angle of the ceiling of the 38 degrees north latitude = 38-(-2327')-33 to 35 = 2627' to 2827'. In this kind of shelter angle, even in the “winter solstice†with the lowest solar height, the solar projection angle on the transparent surface of the front slope of the greenhouse is 55 to 57 degrees (that is, the incident angle is 35 to 33 degrees), and the transmittance of the shed film reaches 82%. the above.
2. The walls and back slope layers of the winter warming shed should reach the required thickness. The wall requirement of the Shouguang Dongneng shed is earth-built. Because the volumetric heat capacity of dry soil is 2.5 Joules/cm 21C, it is 2,000 times the air volume heat capacity of 0.0003 card/cm 21C. Therefore, the wall not only plays a role in preventing the cold, but also has a heat storage effect. The large-walled winter warming greenhouse has a large amount of heat storage and strong heat preservation, and can effectively reduce the temperature drop in the night shed, so that the night minimum temperature in the winter shed is not too high. Low, can prevent "cold damage" and "cold damage" in the shed crops. The thickness of the soil wall of the Shouguang Dongneng shed should have the following: the thickness of the largest permafrost layer in the area plus 50 cm. For example, in the winter where the largest permafrost layer is 80 cm, the wall thickness of the greenhouse should be 130 cm. The back layer of two layers of plastic film sandwich hay and grass mud, which should have a thickness of 1/3 of the thickness of the wall.