What are the morphological indicators of strong rapeseed seedlings?

(Agricultural Wealth Network) The morphological indicators of winter-developed strong rapeseed seedlings are 10 to 12 green leaves per plant before winter (by the end of December), with a leaf area index of about 1.5; the morphological indicators of autumn-developed seedlings are 12 to 14 green leaves per plant before winter, a leaf area index of 2.5 to 3, a maximum leaf spread diameter of 50 cm, and the whole field has closed rows. Winter-developed rapeseed seedlings have thick and sturdy roots and stems, strong growth, no early bolting or flowering, and strong cold resistance in the plants, forming an excellent seedling framework and steady growth momentum, laying a solid foundation for the high yield of spring-developed rapeseed.