Prevention of abnormal condition of early bolting and cracking Root and Green head Carrot

When planting carrots, there are often problems such as root cracking, serious early bolting and green head, which seriously affect the yield and quality of carrots. The causes and preventive measures of abnormal carrots are introduced as follows.

Abnormal situation of carrots

Early bolting: after early bolting of carrots, the fleshy root hardens and loses its edible value. The main reason: the low temperature of a certain period after sowing makes the carrots bolting early through vernalization. Some data show that carrots with 7 leaves can pass the vernalization stage at a low temperature of 4.5 ~ 15 ℃ for 25 ~ 30 days, resulting in a large number of bolting and flowering before harvest. In pursuit of early listing, carrots are often blindly sown early, leading to early vernalization of carrots. To prevent early bolting of carrots, bolting tolerant varieties should be selected and sowing date should be arranged reasonably. In addition, lack of water, insufficient supply of nitrogen fertilizer and serious diseases and insect pests can cause early bolting of carrots, so it is necessary to strengthen water and fertilizer management and pest control during carrot growth.

Split root: improper water management. In the carrot fleshy root expansion period, uneven watering, insufficient water supply in the early stage, slow growth of fleshy root, heavy precipitation or sudden massive watering in a short period of time in the later stage, the root system expanded rapidly and cracked after absorbing water. In this regard, in the carrot fleshy root expansion period, we should pay attention to water management, so that the soil dry and wet, there are drip irrigation or sprinkler irrigation conditions, you can pour a little water before the heavy rain. In addition, if the harvest is not timely, it will also cause root cracking, so the production should be controlled when the fleshy root length 18~20cm and crude 3~4cm are harvested.

Green head: the soil cover is too shallow, do not pay attention to soil cultivation in the process of fleshy root expansion, resulting in the top of fleshy root exposed to the soil surface, irradiated by the sun, producing chlorophyll, thus turning green. In the carrot field planted with small ridge single row or large ridge double row, the soil should be covered in time after removing the plastic film, and the top of the carrot should not be covered with too much soil in the early stage. With the growth of carrots, the top of the fleshy root will be exposed to the ground, and the soil can be covered again 3 weeks before harvest, so that the green head formed at the top of the succulent root can be prevented and the green head formed after light can gradually return to normal.