High temperature heat damage and defense measures
Since the beginning of this year, the temperature in most of our province has been high. July is the season with the highest temperatures in the year. What are the risks to agriculture in high temperature conditions? What measures should be taken at high temperature to reduce damage to agriculture? The following highlights the impact of high temperatures on agricultural production and its defense strategies. Vegetables at noon on sunny days in summer, the temperature of the topsoil in vegetable fields often reaches 40-50°C, and the high temperature suppresses the growth of roots and plants, and induces pests and diseases. In addition, the high temperature and strong light will burn the plants, cause the leaves to wilt, reduce the ability of photosynthesis, reduce the accumulation of dry matter, and lack the basis for high yield. If the sun shines after sunny summer, the temperature of the soil surface rises sharply, and the heat of vaporization of the soil can easily burn the leaves, resulting in fruit and vegetables falling and fruiting. In the summer season, thermophilic vegetables such as tomatoes and sweet peppers should not be planted in plain areas. Even hot (or heat-resistant) vegetables such as tribute vegetables and small mustard plants, etc., prolonged high temperatures, especially at night, will accelerate their aging. , The vegetable fiber is more, the quality is poor; Eggplant, beans will also produce premature failure due to high temperature and low yield. To reduce the harm caused by high temperature to vegetables, we should actively use modern technology to improve the external environment of vegetable fields to meet the needs of vegetable growth. We should use the multifunctional advantages of gardening facilities for cooling and rain-proof cultivation. The plain area has vigorously established various types of production bases for vegetable lands in order to improve the microclimate ecological conditions of vegetable fields, promote, control and regulate the growth and development of vegetables, and improve the ability to withstand high temperatures, heavy rain, and tropical cyclones in summer. Make full use of the climate resources in the high-altitude mountain areas that are cool in the summer, have little impact from tropical cyclones, and have large temperature differences between day and night, and establish a large-scale summer production base to avoid the high temperature, heavy rain, and tropical cyclone climate in the plains in summer to meet the growth of vegetables. The development and yield form a requirement for the external climate and environment, so as to achieve the purpose of supplementing, subsidizing, exporting and evenly listing the vegetables. During the high temperatures in the middle of summer, we must strengthen the management of vegetable fields, promote the rejuvenation of plants, implement a variety of fast-growing vegetables, and do a good job of comprehensive pest control. In recent years, Guangzhou has cultivated, introduced and promoted many varieties with wide adaptability, strong resistance, and high quality, and has vigorously promoted the use of summer shade net cover cultivation techniques and high-yield comprehensive cultivation techniques to increase the level of scientifically grown vegetables. The goal of high quality, high output, multiple varieties, balanced listing, and morning market has been achieved. The high temperature of flowers makes the transpiration of flowers increase, and the moisture absorbed by the roots lacks the transpiration expenditure, which causes the flower growth rate to decline. Under high temperature conditions, the respiratory depletion nutrients of the plant increase, sometimes over the photosynthetic accumulation, leading to rapid aging of the plant. In the absence of light, the hazard of high temperature is greater. Under the bright summer sun, the fruit of the resulting flower will appear "sunburn disease." In addition, the high temperature can make the leaf color of the foliage plants retreat green, the flowering period of the ornamental flowers is shortened, or the petals are agitated due to the sun; the high temperature can also cause the pollen viability to decline and the stigma to shrink, making it unable to pollinate and fertilize. Seed and seeding can not reproduce future generations. Control measures: 1 Shade, in the presence of high-temperature and strong light, the flower plants are placed in a shed under conservation. 2Sprinkle water to cool the temperature and reduce the loss of water in the leaves. 3 avoid the hot sun showers. 4 ventilation, the flower field temperature can be properly reduced. In the higher temperature range of livestock and poultry, as the temperature rises, the feed intake of livestock and poultry gradually declines, and the extent of decline is related to the age and weight of livestock and poultry. The larger the age, the more obvious the decline. When the temperature is 30-38°C and the relative humidity is 80%-90%, the feed intake and weight gain rate of livestock and poultry will be significantly reduced. Therefore, protective measures should be taken in livestock houses during the high summer season to increase shading and ventilation so as to reduce the radiant heat and convection heat in the houses. Sprinkle cold water on the car body or pour cold water on the ground, which can accelerate conduction heat dissipation and evaporation, and reduce the temperature inside the house. Properly arranging the daily life of livestock and poultry and improving the living environment of livestock and poultry will enable livestock and poultry to lose their lives and become less ill during the summer. The high temperature has a great influence on dairy cows, which can cause the calorie imbalance of dairy cows and seriously affect the milk production of dairy cows. It will directly affect the calorie imbalance of dairy cows, increase of body temperature, shortness of breath, rapid pulse, and reduced feed intake, resulting in a decrease in milk production. High temperatures can also affect dairy cows' estrus, breeding, and calving, which can easily cause cows to run empty or die. To reduce the above-mentioned high temperature heat damage, measures should be taken to improve the microclimate conditions of the cowshed: 1 The site of the cattle farm should be selected in a dry and ventilated place. 2 When the height of the barn is increased appropriately, the sun's elevation angle should be observed to prevent direct sunlight from entering the barn. 3 Sheding the roof for cooling treatment, such as water spray, put branch cover and so on. 4 Thicken the wall and increase convection ventilation. In addition, scientific management measures should be adopted according to local conditions to adjust the schedule, feed structure, and feed feeding density according to climate change. The high temperature of aquatic products adversely affects the reproduction of various fish and shrimps and the reproduction of seed and seedlings. Summer is the season in which fish eat and grow. However, high water temperature will reduce the amount of dissolved oxygen and make the oxygen in the water insufficient. The oxygen consumption of fish and shrimp will increase at high temperatures. Excess feed and organic matter on the bottom will also consume large amounts of oxygen. In addition, zooplankton rapidly breeds oxygen, which further deteriorates the lack of oxygen in the water, causing fish and shrimp to float or even die in a very short period of time. If it turns to high temperatures after the rain, it is the most likely to cause oxygen-free floating of fish and shrimp. In order to avoid the floating of fish and shrimp, the main measure is to set up aerators in the high temperature period, and often change the water, reducing the number and quantity of feedings. When fish and shrimp appear floating head, fresh water should be drawn into the pond immediately, but to prevent muddy pond water, oxygenation agent should be used if necessary.