I. Types of winter wheat injury The types of winter wheat freeze injury that affect wheat production are mainly winter freeze injury, early spring frost damage (downside-spring damage) and low-temperature chilling injury.
1. Freezing damage in winter In winter, freezing injury is the result of cold injury caused by the cooling of cold during winter and winter. In severely frost-damaged wheat fields, the main stalks and the Oita pods are frozen to death, and the heart is dried up, mostly occurring in jointed wheat fields. In general, freeze-damaged wheat fields show signs of dry tip.
2. Freezing damage in early spring (cold spring) In early spring, cold injury (falling cold) refers to the fact that the wheat has passed the “spring†season and entered the period of returning green joints. Due to the arrival of cold waves, the surface temperature drops below 0oC and the frost damage occurs. Because at this time the climate has gradually warmed, and suddenly came the cold wave, it is also known as late spring. In the wheat fields that suffered from frost damage in early spring, the leaves were soaked with boiling water, and they gradually dried up after exposure to sunlight. The spikelets on the top of the stem have their meristematic cells more sensitive to hypothermia than leaf cells. The degree of fronding in juvenile ears varies according to the developmental process. Generally speaking, it has been susceptible to freezing in the stamen and stamen differentiation stage (joining stage), and the ear has been atrophied and finally dried up; but it is in the florets differentiation stage or in the oleum stage. The young ears of the (starting period) were still transparent crystals after being frozen and were not frozen. This is the reason that wheat stems often show that the main stem is frozen to death, the tillers are not frozen to death, or one ear is partially frozen, and the late sowing of wheat is lighter than that of early sowing of wheat.
3. Low-temperature chilling injury The growth of wheat enters the booting stage. The damage caused by low temperatures above zero degrees is called cold damage. The reason why wheat suffers from low temperature chilling: After the jointing of wheat to the flagging stage of the booting, it is in a period with more water content and young tissue, and its ability to resist low temperature is greatly weakened. The average daily temperature is between 10-15 oC before and after wheat ear development to the tetrads formation period (booting stage), which is extremely sensitive to environmental low temperatures and water deficits, especially sensitive to low temperatures, if the minimum temperature is lower than 5-6oC. Will suffer. The cold chilling of wheat is characterized by the fact that the stems and leaves are not affected by it, and there is no abnormal performance. The affected part is all or part of the spikelets of the ear, which is characterized by delayed heading or empty spikelets, or spikelets in the ears. Alas, only a part of the fruitfulness has seriously affected the yield.
Second, freeze damage defense measures
1. Selecting suitable varieties for broadcast in the areas where freezing damages occur frequently, the area of ​​semi-wintering varieties with better cold resistance and late jointing should be appropriately increased, especially in dryland wheat, the area of ​​weak spring varieties should be controlled to prevent freezing damage.
2. Strictly control the optimum sowing date for winter wheat suitable for sowing date from October 8-12, and the best sowing date for weak spring variety is October 15-20.
Strengthening field management and nurturing strong seedlings are effective measures to prevent freeze damage to wheat. For excessively prosperous wheat fields, growth should be moderately inhibited. The main measure is the suppression of early spring suppression and the spraying of Zhuang Feng'an at the beginning.
3. Timely irrigation According to the local weather forecast, irrigation should be carried out before the cold current hits, raising the temperature near the ground and leaf surface to form a microclimate that can prevent or mitigate damage. Generally, the irrigation effect is the best one to three days before cooling, and antifreeze is used to select the breeze or calm wind.
4. Smoke, frost and frost When frost occurs, the method of fumigating smoke in the field has a good anti-frost effect.
Irrespective of irrigation and antifreeze, or smoke protection and frost protection, priority must be given to priority areas that are prone to frost damage and varieties that are prone to frost damage.
Third, the remedial measures after frost damage Wheat has a strong adaptability, when the stem and the main stem and Dendrobium frozen, the roots still absorb nutrients and water, the underlying part of the buds of the buds quickly germinate and grow, as long as timely remedial measures are taken, they have May be strong in heading. Timely topdressing a small amount of available nitrogen fertilizer, apply urea 5-7.5 kg per acre, combined with irrigation, cultivator loose soil protection, to remedy.
1. Freezing damage in winter In winter, freezing injury is the result of cold injury caused by the cooling of cold during winter and winter. In severely frost-damaged wheat fields, the main stalks and the Oita pods are frozen to death, and the heart is dried up, mostly occurring in jointed wheat fields. In general, freeze-damaged wheat fields show signs of dry tip.
2. Freezing damage in early spring (cold spring) In early spring, cold injury (falling cold) refers to the fact that the wheat has passed the “spring†season and entered the period of returning green joints. Due to the arrival of cold waves, the surface temperature drops below 0oC and the frost damage occurs. Because at this time the climate has gradually warmed, and suddenly came the cold wave, it is also known as late spring. In the wheat fields that suffered from frost damage in early spring, the leaves were soaked with boiling water, and they gradually dried up after exposure to sunlight. The spikelets on the top of the stem have their meristematic cells more sensitive to hypothermia than leaf cells. The degree of fronding in juvenile ears varies according to the developmental process. Generally speaking, it has been susceptible to freezing in the stamen and stamen differentiation stage (joining stage), and the ear has been atrophied and finally dried up; but it is in the florets differentiation stage or in the oleum stage. The young ears of the (starting period) were still transparent crystals after being frozen and were not frozen. This is the reason that wheat stems often show that the main stem is frozen to death, the tillers are not frozen to death, or one ear is partially frozen, and the late sowing of wheat is lighter than that of early sowing of wheat.
3. Low-temperature chilling injury The growth of wheat enters the booting stage. The damage caused by low temperatures above zero degrees is called cold damage. The reason why wheat suffers from low temperature chilling: After the jointing of wheat to the flagging stage of the booting, it is in a period with more water content and young tissue, and its ability to resist low temperature is greatly weakened. The average daily temperature is between 10-15 oC before and after wheat ear development to the tetrads formation period (booting stage), which is extremely sensitive to environmental low temperatures and water deficits, especially sensitive to low temperatures, if the minimum temperature is lower than 5-6oC. Will suffer. The cold chilling of wheat is characterized by the fact that the stems and leaves are not affected by it, and there is no abnormal performance. The affected part is all or part of the spikelets of the ear, which is characterized by delayed heading or empty spikelets, or spikelets in the ears. Alas, only a part of the fruitfulness has seriously affected the yield.
Second, freeze damage defense measures
1. Selecting suitable varieties for broadcast in the areas where freezing damages occur frequently, the area of ​​semi-wintering varieties with better cold resistance and late jointing should be appropriately increased, especially in dryland wheat, the area of ​​weak spring varieties should be controlled to prevent freezing damage.
2. Strictly control the optimum sowing date for winter wheat suitable for sowing date from October 8-12, and the best sowing date for weak spring variety is October 15-20.
Strengthening field management and nurturing strong seedlings are effective measures to prevent freeze damage to wheat. For excessively prosperous wheat fields, growth should be moderately inhibited. The main measure is the suppression of early spring suppression and the spraying of Zhuang Feng'an at the beginning.
3. Timely irrigation According to the local weather forecast, irrigation should be carried out before the cold current hits, raising the temperature near the ground and leaf surface to form a microclimate that can prevent or mitigate damage. Generally, the irrigation effect is the best one to three days before cooling, and antifreeze is used to select the breeze or calm wind.
4. Smoke, frost and frost When frost occurs, the method of fumigating smoke in the field has a good anti-frost effect.
Irrespective of irrigation and antifreeze, or smoke protection and frost protection, priority must be given to priority areas that are prone to frost damage and varieties that are prone to frost damage.
Third, the remedial measures after frost damage Wheat has a strong adaptability, when the stem and the main stem and Dendrobium frozen, the roots still absorb nutrients and water, the underlying part of the buds of the buds quickly germinate and grow, as long as timely remedial measures are taken, they have May be strong in heading. Timely topdressing a small amount of available nitrogen fertilizer, apply urea 5-7.5 kg per acre, combined with irrigation, cultivator loose soil protection, to remedy.
Christmas decoration and gifts
Cute Christmas Decorations,Animal Christmas Ornaments,Christmas Decorations,Christmas Decorations Ornaments
COFCO HEBEI INTERNATIONAL TRADING CO., LTD. , https://www.cofcohb.com