First of all, vernalization
Plant vernalization: It is a phenomenon that some plants need to go through a period of continuous low temperature when they change from vegetative growth to reproductive growth, including seed vernalization and green vernalization. That is, we often see this phenomenon: some crops are sown in autumn, grow nutritionally before winter, then experience cold winter, grow vigorously again in the following spring, and blossom and bear fruit in late spring and early summer.
According to the time and temperature conditions of crops after vernalization, plants can be divided into: winter crops: 0-5℃, 30-70 days; Semi-winter crops: 3-15℃ for 20-30 days; Spring sowing crops: 5-20℃, 7- 15 days; Warm crops: 23-30℃, 5-7 days.
Second, the occurrence conditions
The occurrence of vernalization requires a certain period of low temperature, suitable moisture, sufficient oxygen, indispensable nutrition and light. These external factors need to work together to make vernalization successful. Low temperature: the general vernalization temperature is 0℃- 15℃, that of winter wheat, radish and rape is 0℃-5℃, and that of spring wheat is 5℃- 15℃.
Water content: plants that have been vernalized in the form of seeds need to have a certain water content in the seeds; Nutrients: vernalization requires sufficient nutrient supply to meet the normal growth of plants; Oxygen: sufficient oxygen is a necessary condition for budding seeds to pass vernalization; Illumination: After low temperature, plants need to grow at higher temperature for a period of time before they can blossom under certain sunshine conditions.
Third, the occurrence of crops.
Winter cereal crops (winter wheat, winter rye, winter barley, etc. ) vernalization treatment can be carried out from seed germination stage to tillering stage, and the effect is the best for newly germinated seeds. The bigger the seedlings, the worse the vernalization effect. Some biennial plants (cabbage, radish, garlic, celery, rape, beet, onion, etc. ).
Garlic bolting and bulb formation need to go through the stages of low temperature vernalization, long sunshine and illumination, and high temperature bolting. Chinese cabbage is a vernalization plant. Germinated seeds can feel low temperature to complete vernalization, and then bolting and flowering.