What harm does high temperatures cause to vegetables? How to solve it?

High temperature will have the danger of burning seedlings of vegetables, and in summer, you can choose to cover the sun film and water in time to avoid this burn.

In the summer, the temperature is high, and in addition to the leaves of some vegetables that bloom are burned by high temperatures, the flowers are burned by high temperatures, and the fruits that are stunted and fruiting will also appear deformed, and if they bloom and develop poorly, they will drop and reduce the yield. In summer, vegetable pests and diseases tend to be high. Mainly in the summer, the weather is hot and rainy, and in order to prevent pests and diseases, it is necessary to regulate the temperature and humidity.

Reasonable dense planting, scientific fertilization, improve plant disease resistance. After the occurrence of pests and diseases, vegetables should be removed from diseased plants, weeds in the field, and targeted sprays should be sprayed to prevent the spread of pests and diseases. The adverse effect of high temperature on the growth of vegetables is the basic reason for the autumn light of vegetables.

Except for a few heat-tolerant varieties such as winter melon, pumpkin, bitter gourd, bean pod, water spinach, etc., most vegetables cannot withstand high temperatures. In the middle of summer, not only do you like cold vegetables such as spinach, cabbage, radish, and snow peas, but you can't grow hot vegetables such as tomatoes and peppers.

High temperature and rain, high temperature and drought will lead to the frequent occurrence of various pests and diseases, significantly reduce yield, and even lose harvest, aggravating the occurrence of autumn off-season. When the temperature is above 30, if there is no rain or little rain, soil drought and atmospheric drought may occur, and if the vegetable roots cannot meet the evaporation needs of the plant, the leaves of the vegetable plant will wrinkle and fall off, the quality will deteriorate, the yield will decrease, and the wilt will die. High temperatures and long days increase the males of cucumbers, and females differentiate late.

When the flower eyes of tomato and pepper are differentiated, there are few flowers at high temperatures and they are stunted. The air temperature or ground temperature is higher than the normal growth temperature range of vegetable plants, which will cause some disease-resistant varieties to lose their disease resistance and aggravate the occurrence of diseases.

High temperatures are often accompanied by strong light, and strong sunlight shining on the fruits of vegetables such as eggplants and melons for a long time will cause both sides of the fruits to be burned by the sun, thus causing a spot disease. High temperatures and droughts can adversely affect the flowering process of vegetables such as eggplants and beans, resulting in flower and fruit drop. Drought and lack of water can easily cause dried cabbage, tomato navel rot, etc.

Reasonable leaves should be left in the summer leaves, and the fruits should be hidden under the leaves as much as possible to avoid direct sunlight. Therefore, when tomato vegetables are carried out in high temperatures, they must be avoided in the high temperature of the noon in the strong light, and it is best to choose after 3 p.m. In addition, when summer vegetables are officially eaten, the rows of the stumps should be closely spaced so that the stems and leaves are shielded from each other, so that the fruits are not directly exposed to the sun.

High temperature can affect the normal growth of vegetables, resulting in intensified plant transpiration, dehydration symptoms of vegetables, plant photosynthesis will be weakened, respiration will be strengthened, resulting in a shortage of nutrients in the plant, and the growth of vegetables is inhibited. At this time, the soil will be dry, the water supply will be insufficient, and even dry up and die. The strong light in summer accompanied by high temperatures can cause the south-facing parts of the fruit surface of melons and vegetables to be sunburned by the sun.

Prevent heat hazards by improving the heat tolerance of growing vegetables.

The selection of varieties with good heat tolerance can effectively improve the heat tolerance of planted vegetables. For example, the heat-tolerant tomato variety Zhongza 9 is more resistant to high temperature, can still grow well in summer protected areas, and under a certain high temperature, flower bud differentiation and fruit setting are almost not affected. It can be seen that heat-tolerant vegetable varieties can have a good tolerance to high temperature in summer.

The harm of high temperature weather to vegetables is not small, if you do not take cooling measures, it will cause a reduction in vegetable yield, so you should choose high-temperature resistant varieties for planting vegetables in summer, reasonable dense planting, scientific fertilization, shading nets, and high-pole crops interplanting, so that vegetables can spend summer safely.

Tell you about this based on our experience:

1. The effect of high temperature on the growth of whole vegetables.

Friends know that vegetables generally have a certain tolerance and resistance to high temperatures. It's just that its tolerance and resistance are within a certain tolerance range (different varieties of vegetables have different tolerances and resistances. Tolerance refers to the ability of vegetables to withstand high temperatures.

For example, the peak of high temperature, and the peak of the duration of high temperature. Resistance refers to the ability of vegetables to self-regulate and adapt to their environment when they are close to the peak of high temperature and the peak of high temperature duration). If the peak of the high temperature of the vegetables is exceeded, or the peak of the time, it is possible to close the spring blindness

Vegetables do not stagnate for long; leaves, stems, and plants; Wait a minute.

Occurrence of these situations:

1. The light is too strong; Longer duration of bright light; The ambient temperature is too high, resulting in the normal photosynthesis of vegetable stems and leaves, and the transport of water from the stems, stems, leaves, and water becomes slow, and the water evaporation is more than the absorption and transport, and the stems and leaves are dehydrated.

2. Due to the influence of external strong light and high temperature and other factors, the surface temperature also rises. As a result, the heating of the surface layer of the empty soil has a great inhibition effect on the growth of rhizomes and nutrient absorption of vegetables. As a result, the transport and absorption of nutrients by the whole vegetable plant are inhibited, and the negative process of vegetable dehydration and dehydration is accelerated.

3. Under the influence of the above two points, coupled with the radiation of high temperature in the environmental space, the whole plant or the whole vegetable field is "roasted", and the vegetables are burned, dehydrated and withered, the soil layer is whitened, and the growth and absorption are inhibited, frustrated and hindered.

Second, the response measures in the face of vegetables roasted at high temperatures.

1.Reservoirs can be excavated to appropriately reduce the ambient temperature in the vegetable area. Dig a water tank around the vegetable field and between the alleys, and fill the water tank with water, when the light is strong or the high temperature comes, it absorbs part of the heat due to the evaporation of the water, so as to reduce the temperature of the vegetable area.

2.Water is applied in the morning and evening to reduce the water volatilization consumption of the stems and leaves of the vegetables themselves.

3.During high temperature periods, the fog of the vegetable garden is humidified to reduce the ambient temperature and the ambient humidity is added to cool down.

4.Shade nets should be used to cover during high temperature periods and at noon, or to intercrop tall crops to reduce light and suppress temperature from the side.

5.Appropriate supplemental fertilizer, especially the reasonable and appropriate application of phosphate fertilizer. Strengthen the removal and management of pests and diseases and weeds in the field, timely harvesting, reasonable dense planting, etc.

Summary: For the management of vegetable planting in the high temperature season, the reasonable environment should be optimized; rational dense planting; strengthening fertilizer and water management; Actively take measures such as hydration, cooling, and sunlight prevention to carry out proper vegetable field management。In order to ensure the management purpose of high quality and high yield of vegetables in high temperature environment.

When the temperature is high, the flowers of some vegetables that bloom are burned by high temperature, and the fruits that are stunted and fruiting will also have stunted and fruit-bearing fruits, and if they bloom and are stunted, they will decline and reduce the yield. In summer, vegetable pests and diseases tend to be high. When summer vegetables are officially eaten, the row spacing of the stump should be tight, so that the trembling mold and stems and leaves are shaded by each other, so that the fruit is not directly exposed to the sun.

The growth rate decreases, which is easy to lead to diseases and insect pests, which is not conducive to the growth of vegetables, resulting in the decline of the speed of vegetable growth and poor quality; Shade the vegetables, shade a sunscreen umbrella in front of a stool, regularly dismantle and water the dates, apply fertilizer regularly, and spray some pesticides.

The "Nutritional Dietary Guidelines for Chinese Residents" stipulates that no less than 500 grams of vegetables and fruits should be eaten every day, and this 500 grams refers to vegetables and fruits that have not been solved through production. The very simple method is to eat raw directly, but eating raw directly is not a dietary structure that everyone can accept, and some dishes must indeed be produced and processed to be able to eat, which requires some selection in cooking methods, the basic guidelines are:

Try to use raw eating methods such as radish, tomato, loofah, oilseed lettuce, cabbage, etc., which must pay attention to food hygiene and safety, including using liquid water when cleaning, CNC blades and cutting boards for shredded potatoes should be separated from raw and cooked, and try to expose these in the sun after use. Vegetables and vegetables are the most nutritious and healthy way to eat them with fresh fruits and sour milk, and there is basically no outflow of various nutrients.

Generally speaking, fruits and vegetables are rich in vitamins and minerals, and some vitamins can be destroyed and exported after being cooked at high temperatures. Especially the longer the cooking time, the more nutrients come out.

The following are simple standards for cooking vegetables that can also reduce the outflow of nutrients:

1.Vegetables and fruits with skin such as winter melon, cucumber, and green beans generally contain more nutrients on the skin, so if you can eat the skin, wash it and eat it as much as possible. However, if it is a leafy vegetable and fruit, because there are more pesticide residues on the surface, the outermost layer of green leaves should be removed before eating.

2.The way to clean up vegetables and fruits is to put the vegetables in a basin full of water, clean them with liquid water, and rub them gently and slightly, and the posture should be fast, and there is no need to flush the tap water for a long time, otherwise the water-soluble vitamins are easy to flow out.

3.Vegetables should be soaked before cutting. When you want to cut it after washing, you don't have to cut it too finely, and the nutrients are easy to leak out.

4.The nutrients in vegetables and fruits, such as vitamin C and folic acid tablets, are more likely to be warmed, while others are less harmful. In general, after cooking, the retention rate of vitamin C is about 50%, carotene can reach more than 90%, and methylcellulose and minerals are stored 100%.

Therefore, increasing the amount of vegetables and fruits should be able to supplement the amount of food lost, and eating them raw is another feasible way.

5.Stir-frying, short-term cooking, blanching or boiling with condiments can also reduce nutrient outflow.

First of all, don't cook vegetables for too long, because vegetables are particularly easy to cook, so you don't need to cook them for a long time, and boiling them in warm water can retain nutrients.

1. Wash first and then cut. Most of the nutrients in vegetables are water-soluble, so washing before cutting can avoid nutrient loss within minutes.

Vegetables contain vitamin C, and too high temperature and too long heating will cause the vitamin C in vegetables to decompose, resulting in nutrient loss. It is recommended to control the heating time within 10 minutes, and the loss is less when stir-frying or capping for a short period of time.

Try not to cook on high heat for too long, and be careful about how you cook it, but also pay attention to the color of the vegetables.

We must boil it in warm water, so that the cooked will be particularly nutritious, and the nutrients will not be easily lost.

Within 10 minutes Vegetables contain vitamin C, too high temperature and too long heating will cause the vitamin C in vegetables to break down.

High temperatures bring vegetables to sunburn. The summer sun is very scorching, even people's ** can't stand it, and they will get sunburned. Vegetables are the same, especially some green leafy vegetables, in the face of high temperature in summer, vegetable leaves will be sunburned gray spots of different sizes, the use of corn tall crops for shading, such as planting coriander, emperor cabbage, cabbage, etc. in summer, the vegetable farmers in our village are planting between the corn rows, and now it is just the period of corn tasseling, and the tall corn plants can shade the vegetables, and the effect is better.

<> pepper flowering and fruiting vegetables, you can consider using a shading net with a relatively thin mesh to properly shade the sun, if not, in addition to soil, it is recommended to cover the periphery of the vegetable roots with dry straw or other weeds, which also plays a role in sun protection and moisturizing; The soil is arid and crops are short of water. In summer, the weather is hot, the temperature is high, the water evaporates relatively quickly, if there is no rain or little rainfall, the soil is dry, and the vegetables planted lack water, the leaves will be rolled, yellowed, and fall off.

First of all, in the vegetable greenhouse, for the prevention of sunburn, or based on the role of the "shade net", in my rural home in Pingliang, Gansu Province, a large shade net will be laid on it during the day when the high temperature lasts in summer. The effect is quite good. What can be cooled can be cooled:

If it is a shed planting, you can properly shade the sun, such as shading nets, spraying greenhouse warming film coolers, sprinkling mud ideas, etc., to reduce the temperature in the shed as much as possible.

Breed selection:The choice of varieties is crucial, such as cabbage, peppers and other vegetables, divided into different varieties, when choosing to understand whether they are strong in disease resistance, whether they can withstand high temperature and other factors. This is the premise of planting, and vegetable farmers cannot ignore it.

Different crops have different requirements for temperature, but the reaction brought by high temperature is the same, that is, the water evaporates faster and the crops grow faster, so the first thing to do at this time is to cool down and prevent heatstroke.

When the temperature is too high, it is easy to produce drought and cell dehydration, which affects the physiological and metabolic activities of plants. When the ambient temperature is higher than the optimal temperature requirement of the plant, it will adversely affect the plant and cause harm to the plant, that is, it will cause high temperature stress to the plant.

High temperature will lead to abnormal metabolism, ammonia poisoning and protein destruction, and gradually cause plant damage Leaf color becomes lighter, leaf and root growth is stunted, and plants show leaf dehydration and yellowing in a short period of time.

1. Shade. The use of corn tall crops for shading, such as planting coriander, emperor cabbage, cabbage, etc. in summer, the vegetable farmers in our village are planting between the corn rows, and now it is just the period of corn tasseling, and the tall corn plants can shade the vegetables, and the effect is better.

Build a shade shed, the summer sun is strong, the temperature is high, most of the vegetables are planted in greenhouses or small arch sheds, covered with shade film, can significantly reduce the temperature in the shed.

Second, the selection of high-temperature resistant varieties, such as the selection of Baiyang, Xiayang, spring and summer Wang Hao Xiaoza 56 and other Chinese cabbage varieties. Jinyan No. 5, Jinyan No. 7, Jinchun No. 5 and other cucumbers. Purple blood cowpea, red-billed swallow, Yang Cow No. 40, Zhi Cow and other cowpeas.

3. Frequent watering, summer planting vegetables should master frequent watering and shallow watering to reduce the surface temperature, keep the soil moist, and fertilize and watering in the evening. Pay attention to drainage after rain.

Fourth, cultivating weeding and soil cultivation, the summer climate is hot, the rain is more, the weeds grow faster, vegetable planting should be diligent in weeding, to prevent grass damage, pay attention to soil, tillage should be shallow, stop cultivating after the closure, the growth of vegetables in the later stage, to remove the old yellow leaves frequently, in order to facilitate ventilation.