The role of carrots in different disaster weather and the preventive measures after the disaster?

Second, low temperature, carrot seeds may be affected by low temperature and vernalization in seedling stage, fleshy root growth period and storage period.

The third is hail. When the damage is serious, carrot leaves will be destroyed. Without leaves, only bare vegetable heads will be left, and the fleshy roots will be bruised, pierced or even smashed by hail, resulting in devastating injuries such as reduced production or even no harvest.

Fourth, typhoon, rainstorm or high temperature and drought. In addition to the rainstorm during the invasion and the dry and hot wind before the invasion, typhoons are also not conducive to the growth of carrots. More importantly, the young roots and stems and leaves of carrots were severely damaged by strong winds and rain. At the same time, typhoons often bring heavy rains and tides, causing waterlogging and leading to the death of carrots.

The growth period of carrots in summer and autumn, especially in the germination and seedling stages, is in a climate of high temperature, rainy or high temperature and drought, which is not conducive to the growth of carrots, resulting in uneven seedling emergence and thin plant growth.

Heavy rain can wash the young roots of carrots out of the ground, causing serious damage to the epidermis of young roots, leading to lack of seedlings, broken ridges and large and small seedlings; The plant was blown crooked and its stems and leaves were broken; After high temperature and heavy rain, the stems and leaves of carrots are attached with sediment, and the stomata on the leaves are blocked, which seriously affects the respiration, transpiration and photosynthesis of carrots. The attack of rainstorm often makes the surface layer of soil harden, which seriously damages the permeability of soil and makes the carrot root system unable to develop normally. The changes of temperature and humidity in topsoil caused by rainstorm are often in an irregular state, which leads to poor root growth of carrots, greatly weakening the stress resistance of carrots and inducing diseases such as carrot soft rot and black rot.

Abnormal high temperature and drought are often encountered in summer and autumn, which will affect the normal growth and development of carrot plants and cause high temperature and heat damage. In the germination and seedling stage of carrots, high temperature will do great harm if it doesn't rain for a long time. First, it will cause dry buds and irregular emergence, especially in plots with uneven soil preparation and insufficient watering; Second, it is easy to cause diseases and insect pests, especially aphids, which are the main vectors of diseases such as virus diseases, and are easy to induce virus diseases of carrots. The higher the temperature, the more serious the disease, resulting in low and unstable yield. In addition, under the condition of high temperature and drought, especially when the temperature is high at night, carrots will stagnate and consume a lot of nutrients, leading to hollowness.

Fifth, wet damage and waterlogging damage.

Both wet damage and waterlogging damage are caused by excessive water content and reduced yield of carrots.

Wet damage is due to long-term poor drainage of soil after waterlogging or rainy weather, which keeps the soil saturated with too much water. The main reason is that soil pores are full of water, which makes them lack oxygen for a long time, affects the supply of mineral nutrients, increases the acidity of soil solution, makes it difficult for carrot roots to breathe, hinders the absorption of fertilizer and water, and then damages the roots and affects their growth. And its harm is not easy to be taken seriously. Wet damage mainly occurs in carrot seedling stage and fleshy root growth stage, which is characterized by brown tip of root hair and gradually weakened fertilizer absorption capacity, which further causes the growth speed of aboveground plant leaves to slow down, the leaf color turns yellow, and the fleshy root lenticels increase, which affects the appearance quality and reduces the yield. ?

Waterlogging damage is often caused by rainstorm or rainstorm for too long and soil water accumulation. When part or all of carrots are submerged by water, the normal growth of carrots will be affected, the growth of plants will be blocked, the leaves will turn yellow and the yield will be reduced. In addition, the roots of carrots will suffocate and die due to short-term lack of oxygen, which is obviously harmful.

Preventive measures for disastrous weather are as follows

1. Establish and improve the disaster weather prevention system.

The prevention of meteorological disasters should mainly start from two aspects: first, strengthen the forecast of disastrous weather and improve the timeliness and accuracy of the forecast; The second is to establish and improve the monitoring, forecasting, early warning and evaluation system of disastrous weather, and establish and improve the rapid transmission system of sudden meteorological disaster information such as rainstorm and flood and disaster prevention decision information. Strive to be a household name and guide vegetable farmers to do a good job of prevention. Cultivation management should be strengthened according to weather forecast in production.

2. Carry out genetic breeding research on carrot stress resistance.

The most fundamental way to solve the influence of disastrous weather on carrot production is to cultivate varieties with strong stress resistance (strong disease resistance, cold and heat resistance, drought and waterlogging tolerance). Breeding new carrot varieties that can resist abnormal climate change and maintain certain quality and yield under unfavorable conditions such as high temperature and drought, low temperature and continuous rain; It is necessary to raise the threshold of examination and approval of carrot varieties, increase the tolerance test to disastrous weather, and improve the ability of varieties to resist disastrous weather. The approval announcement issued by the society should comprehensively explain the matters that should be paid attention to from the aspects of seed characteristics and cultivation techniques, and enhance the awareness of vegetable farmers.

3, reasonable arrangement, prevention in advance.

According to the local climate characteristics, stubble should be arranged reasonably to avoid the season with frequent disastrous weather, so as to achieve the goal of high yield and good harvest. Reasonable intercropping and interplanting can be adopted in summer to avoid high temperature and heat damage. Choose excellent materials and build a suitable shed with reasonable structure and perfect facilities according to the local climate characteristics and geographical location. Reasonable selection of plots and good drainage facilities. Select excellent varieties with strong stress resistance to improve the resistance to bad weather, choose suitable sowing date according to local climatic conditions, and strengthen field management during the growth period.

4. Strengthen facility cultivation.

According to different types of carrots, protected cultivation is carried out in different seasons. In early spring, conservation tillage was adopted to resist the cold and plastic film mulching was vigorously developed. In carrot production in protected areas, when the cold current comes, you can set up a small arch shed, hang a straw curtain, install a stove, and heat it up. Temporarily increase the temperature in the shed and control the temperature in the shed. Covering cultivation with sunshade net and insect-proof net in summer can not only reduce the temperature and shade, but also prevent insects, disperse raindrops, prevent the harm of rainstorm and hail, and improve the yield. Building a simple sunshade covered with branches or crop straws can reduce the temperature by 3 ~ 4℃. When cultivated in greenhouse, covering with sunshade net in summer and autumn can reduce the temperature by 4 ~ 6℃, and avoid the direct harm of carrot by rainstorm, hail and aphid.

5. Do a good job in scientific management of carrot growth period.

In spring, deep furrows and high ridges are used to cultivate carrots in the open field or covered with plastic film, which is beneficial to irrigation and drainage and prevents waterlogging; Timely intertillage is beneficial to soil aeration and increase ground temperature.

In autumn and winter, carrots in the open field have not been fully harvested before the heavy snow cools down, so irrigation should be carried out to keep the soil and the middle and lower space of carrots at a suitable temperature with the help of water storage, which can obviously reduce the freezing injury. Cover the top of the plant with a plastic film to form an inverted trough-shaped small insulation shed, so that the geothermal energy can not be scattered, which has a good snow-proof and antifreeze effect.

During high temperature and drought, shallow intertillage should be carried out to loosen soil, cut off capillary and reduce soil moisture evaporation. Combined with intertillage scarification, weeds are covered on the ground at the base of plants to reduce the ground temperature. For waterlogged plots, it is necessary to drain the accumulated water as soon as possible to reduce the peripheral water level. If the water system is not perfect, it is necessary to do a good job in the field ditch system in time, suddenly dig more drains and ditches, and stop the rain as soon as possible. There is no water in the field ditch. At the same time, the plants should be strengthened, properly cultivated and protected, so that they can carry out various normal physiological activities and resume growth as soon as possible.

6. Grab the harvest in time and quickly

Those seriously affected should pay close attention to harvesting and listing, and try their best to recover losses. After harvesting, the dead leaves, yellow leaves and dead plants in the field should be removed in time to improve the ventilation and light transmission conditions, reduce the humidity in the field and reduce germs.

7, according to local conditions, timely replanting.

Minimize disaster losses. In areas where carrot harvest is lost due to disasters, fast-growing leafy vegetables or other suitable crops should be replanted in time according to local agricultural climatic conditions and market demand to reduce disaster losses.

8, pay attention to pest control

After the disaster, drugs should be sprayed in time to prevent the spread of the disease.