How to improve the emergence rate of carrots? What factors will affect seed emergence?

Carrot seeds are thin and small, water absorption and germination are slow, and the emergence rate is low, especially when autumn carrots are sown during the period of high temperature and rainy summer, and the soil is difficult to emerge because of Rain Water erosion. How to improve the emergence rate of carrots? What factors will affect seed emergence?

First, choose suitable soil.

The previous crops of carrots should avoid cruciferous crops as far as possible to prevent the occurrence of black rot, black spot and soft rot, and it is best to rotate with onion and garlic vegetables. Although the drought tolerance of carrots is strong, but because of the wax on the back of the seed coat, it is not easy to permeate water and air, so if there is not enough water in the soil, it often does not emerge 20-30 days after sowing. Therefore, the farming group suggested that the cultivation of carrots should choose sandy loam or loam with high and flat terrain, deep soil layer, loose soil, strong water retention capacity, good drainage, rich in organic matter and soil pH 5.3-7.0. At the same time, the soil should be deeply ploughed up, rubble and roots should be removed, and organic fertilizer should be rotten and there should be no chunks. The surface of the soil should be fine and smooth. Otherwise, the soil is flat, the seeds are small, the penetration of the germ is poor, and the emergence of seedlings is often uneven.

Second, make good preparations for sowing

Because the carrot is an umbel, the flowers and seeds formed on the inflorescence are often embryless or maldeveloped, resulting in a low germination rate of carrot seeds, generally about 70%, and even down to 20% in poorer open-field conditions. Therefore, it is necessary to select last year's new seeds as far as possible, and if necessary, germination tests can be carried out to determine the sowing amount, generally 1.0-1.5 kg per mu. Carrot seeds have dense spiny hairs on the surface, which are easy to adhere to and form clumps, which affect the contact between the seeds and the soil, so before sowing, rub and remove the spiny hairs from the seeds, and then choose sunny and windless weather to dry for 1 or 2 days. If necessary, the seeds can be soaked in warm water of 40-50 ℃ for 2 hours, and then germinated under 20-25 ℃. Do not sow until the radicles of most seeds are exposed. As the growth of carrot seedlings is very slow and the absorptive capacity is very weak, available nitrogen fertilizer can be added to the base fertilizer of 8kg / mu. In addition, carrot seedlings are very sensitive to the salt concentration in the soil, and high salt content affects the growth of carrot seedlings.

Third, pay attention to improving the quality of sowing

First, we should pay attention to timely early sowing, small carrot seeds, slow unearthing, slow seedling growth, long growth period, and the growing period of middle and late mature varieties is more than 100 days, so we should sow early at the right time, especially in autumn, so that we can make full use of the growing season to promote its early maturity and high yield. Generally speaking, autumn carrots should be sown 10 to 15 days earlier than radish, cabbage and other vegetables, and the northeast region should not exceed the end of June at the latest.

The second is to adopt appropriate sowing methods to promote early emergence, full emergence and uniform emergence of seedlings. When sowing, you can mix a small amount of wild green vegetables and sow at the same time, making use of the characteristics of fast emergence of green vegetables to shade the sun. It is beneficial for carrot seedlings to be unearthed. In the sowing mode, it is appropriate to adopt the small high ridge sowing method, 2 rows per ridge, and the groove depth is 2-3 cm.

Third, after sowing, the covering soil should not be too thick, and suppression should be carried out, which is conducive to the emergence of seedlings.

Fourth, strengthen the management after sowing

Deal with the soil surface in time, after carrot sowing, in order to prevent rain from loosening the soil, you can cover it with a layer of short wheat straw cut into 2'3 inches long, so as to facilitate the emergence of seedlings. If sowing is too shallow or rain causes hardening, it is difficult to emerge seedlings, cut the soil surface with tools in time to promote seedling emergence, but be careful not to expose the seeds to the ground. Pay attention to keep the soil surface moist, carrot seed germination is very slow, therefore, from sowing to seedling emergence should be continuously irrigated 2 or 3 water, or before sowing enough bottom water. In general, the soil moisture should be maintained at 65%-80%. Too wet or too dry is not conducive to seed germination. It is also a critical period of management after the carrot cotyledons are exposed to the ground to before the real leaves are exposed, especially the autumn sowing carrots are easy to burn seedlings caused by dry heat of the soil, causing the young stems of the seedlings to become a bee waist and die. Special attention should be paid to keeping the soil moist in order to preserve the seedlings. In addition, carrot seedlings are not resistant to waterlogging, summer sowing carrots should also pay attention to timely drainage in the rainy season. And timely removal of weeds, control of diseases and insect pests.