1 species of carrots were selected for seed production - generally planting seeds. Before and after the beginning of winter, field selection should be carried out at the time of harvest. Leaf selection should be selected, leaf color should be positive, leaf stalks should be erect, fleshy roots should be small, and the shape should be neat. The roots should be fine, the color should be dark, the skin color should be bright, and the epidermis should be smooth and non-segregating. No bifurcation, no pest infestation, several excellent individuals that met the typical traits of this species, leaving 1 cm long petioles to cut the leaves as the seedlings. The winter storage of 2 kinds of strains of planting strains generally adopts a ditch pit storage and can be excavated with a width of 1m wide, 80cm deep, and an unlimited length. A thin layer of fine wet soil is sprinkled in the ditch, and the carrot layer is as high as 40-- When it is 50cm deep, it covers 10cm thick wet soil. Afterwards, the layered cover soil may be changed over with the weather, and the thickness of the cover soil should be suitable for freezing the seed strains. 3 Planting time and method Carrot strains have weaker root growth potential after colonization, and most of the roots that grow out are fibrous roots. The drought resistance and absorptive capacity are poor. Therefore, the farming system should be applied with reasonable fertilization and advanced fine soil preparation. This is to increase the seed production. basis. 3.1 Isolation of species In addition to the 2,000 m spacing between different varieties, the wild carrots surrounding the remaining fields should be removed to ensure the purity of the seeds. 3.2 Planting time The soil thawing in late spring, when the soil temperature is stable at 8-10 °C (Shandong Province is generally in the middle and late March) planting colonies from the pit. Practice has proved that if the seedlings are placed outside the pit for a longer period of time, the roots of the flesh will shrink, the growth will not prosper after planting, and the yield will drop significantly. Therefore, it is best to plant the seedlings along with the planting; Plants can be covered with wet soil to prevent atrophy of fleshy roots. 3.3 Planting method Before planting, apply 60,000 kg/ha of decomposed ring fertilizer as the base fertilizer and deep-see tilling the soil to make it. When planting, row spacing is 50cm, and plant spacing is 30cm. When planting, first half soil and then watering, etc., after water infiltration and then capping, the root of the top can be level with the surface or slightly higher than 1cm, after planting in real time and timely conservation tillage. 4 Field Management 4.1 Cultivated and Weed Seedlings Before planting till the convulsions, the outside temperature is low and the plants grow slowly. The main task of this stage is the cultivating loose soil, in order to improve the ground temperature and preserve the root growth. When the temperature rises gradually and the inflorescences are withdrawn, cultivating and weeding are combined to ensure that there is no weeds in the fields before the ridges are enclosed, so that the flowering results of the plants are in good environmental conditions. 4.2 Fertilizer and Water Management Seedlings in various growth stages should be topdressed according to their needs. Normally, nitrogen-phosphorus-potassium compound fertilizer (225--300kg/ha) should be applied when the inflorescence is as high as 15--20cm and watered. Water, otherwise seriously reducing the yield, it is advised to keep the surface dry and wet. Flowering time can be recovered 1 time fertilizer, ammonium sulfate 150 - 225kg/ha, can be flushed with water. 4.3 If the seedlings are erected and supported, the carrots are not pruned, the main branches and the umbrellas at the first, second, third, and ... branches are successively flowered. With the increase of the number of rounds, the flower wheel is also smaller, and the seeds mature slowly. . In order to concentrate the nutrients, the seeds are full and mature, and it is necessary to use pruning techniques to adjust the plant type. The production practice has proved that it is most suitable to leave the main stem and 3--4 robust lateral branches and to remove all other lateral branches. Pruning is generally carried out when the strain is as high as 40--50 cm. At this time, the outside temperature gradually rises, and the lateral branches are pumped in a large amount, and the pruning needs to be performed in time. After flowering, in order to prevent lodging, the seed strains may be tied to the base of the seedlings or brackets. One method is to insert a wooden stick or bamboo stick next to each seedling, and then use a plastic rope to surround the main lateral branch of the whole plant. Fixed on stick or bamboo raft. Another method is to pull two twine or plastic ropes on each side of each strain, and pull them tightly at two ends and in the middle with wooden stakes to support the outer branches of the seedlings to prevent the branches from lodging. 4.4 Diseases and Insect Pest Control The common pests and diseases are soft rot, sclerotia and aphids. The soft rot plant showed that the leaves first withered and turned yellow, then the fleshy roots were softened and rotted, giving off bad odor. The disease should be mainly prevention, and the soil preparation before the winter should be fully sunburned and the bacteria should be eliminated. In addition, we must also prevent and control underground pests in time in order to prevent carrot root damage and infection. After infection with sclerotia, the strains in the sclerotia are softened, and white hyphae appear on the surface. If the sclerotia develop, sclerotia will be formed. The diseased plants will not grow new buds, the lower leaves will be yellowish, drooping, and the aerial parts will shrivel and die. The available pharmaceutical agents are: 50% fast-inking WP 1500 times, 50% thiophanate WP 500 times, 40% sclerotin WP 500--600 times, spraying liquid 750--900 kg/ha, every 7 -10d Spray 1 time. Locusts can be used 50% Pipa mist wettable powder 1500--2000 times liquid, 10% imidacloprid wettable powder 1000--1500 times, 40% chrysanthemum cream 2000--3000 times or 40% omethoate cream 1000 --1500 times liquid foliar spray. 5 Timely harvesting of seeds after 30 days of flowering of carrots can be achieved. When the flower sequence changes from green to yellow after fancy flowers, it can be harvested with flowers. That is, the scion is used to cut the inflorescence in the lower 10cm of the inflorescence. After each 10--20 strains are bundled into a bundle, placed in a ventilated and dry place, dried, after maturation 7-10d, threshing. Clear the stems and impurities, then re-sun 2 - 3d, so that the seed moisture content can be reduced to 14% below packaging storage. China Agricultural Network Editor