Leaf color management of wheat seedlings before winter

1. The cause and management of yellow leaves of wheat seedlings: first, the soil is dry, and there are often wheat fields with insufficient soil moisture or running moisture through ventilation. It is characterized by slow birth of tillers, gray-green leaves, short heart leaves, slow growth or stagnation (called shrinking seedlings), yellow and dry leaves in the middle and lower parts, and few and thin roots. The key point of management is to apply 15kg ammonium bicarbonate per mu combined with watering. Second, due to the lack of nitrogen, the seedlings were thin and erect, the tillers decreased, the leaves were narrow and short, and the lower leaves gradually turned yellow and dry from the leaf tip and developed to the upper part. The key point of management is to apply urea 7kg / mu or ammonium bicarbonate 20kg / mu or human fecal urine 600kg / mu to ditch or water. Third, the soil is hard, and the root system is difficult to stretch due to the lack of soil moisture and air, so the wheat leaves are yellow and short, and the tillers can not appear on time. The key point of management is to water the soil in time, and then deeply plough and loosen the soil to break the rigid layer. Fourth, the sowing rate is too large, the seedlings grow crowded and compete for glory, fertilizer and water, and the plants are yellow, thin and weak. The key point of management is to first pay close attention to thinning seedlings, especially on the edge of the ground and in the field, and then apply a small amount of nitrogen and phosphorus quick-acting fertilizer combined with watering, so as to make up for the excessive consumption of soil nutrients and promote wheat seedlings to change from weak to strong. Fifth, insect pests, wheat aphids or red spiders can also cause wheat leaves to turn yellow. The key point of management is to spray 40% omethoate EC 1500-2000 times in time when the damage is found.

two。 The cause and management of red leaves of wheat seedlings is waterlogging, too much autumn rain or low-lying wheat fields, making the leaves turn dark red, causing rotting roots and dead seedlings in serious cases. The key point of management is to open ditches and drainage in time, and to apply a small amount of available fertilizer to promote early seedling development. Second, phosphorus deficiency, poor root development of phosphorus deficiency in wheat seedlings, dark green leaf color, purplish red leaf tip and leaf sheath, thin and small plants, reduced tillers or even no tillers. The key point of management is to apply 20kg superphosphate per mu combined with ploughing and loosening the soil. Third, saline-alkali damage, often appear in pieces of purplish red seedlings, serious when the seedlings withered. The key point of management is timely hoe to increase temperature and break stringency, restrain salt return, and timely apply winter fertilizer to promote the growth of strong seedlings. When you get up in the next spring, you should combine forced fertilizer, irrigation and salt pressure. Fourth, it is frozen, when the temperature suddenly drops below 0 ℃, the wheat seedlings will turn red when they are frozen. The key point of management is to combine hoe and soil to surround the roots, apply 75kg of plant ash per mu, and spread a layer of warm dung along the ridge if necessary after the wheat enters the overwintering period, so as to protect the seedlings safely through the winter.

3. Causes and management of purple leaves of wheat seedlings when boron deficiency in wheat seedlings, the stems and leaves were thick and curved, and the leaves were purple to form purple leaf seedlings, and the yield was affected by ear and sterility in the later stage. The key point of management is to use 150 grams of borax per mu, watering with appropriate amount of nitrogen and phosphorus fertilizer, or spraying 50 grams of 100 grams of borax per mu and spraying 50 kilograms of water on leaves.

4. Causes and management of brown leaves of wheat seedlings the growth of wheat seedlings is slow, the root system is poor and easy to rot, the leaves are dark green or turquoise, and the leaf tips and edges are withered and yellow, and then turn brown to form brown leaf seedlings. The key point of management is to use 15 kg of potassium sulfate or 100 kg of plant ash per mu, trench between rows, or foliar spray with 0.2% potassium dihydrogen phosphate solution.

5. Causes and management of yellow and white wheat seedlings leaflet disease occurs when wheat seedlings are deficient in zinc, the leaf edges are twisted and wrinkled, both sides of the leaf veins change from green to yellow to white, and yellow, white and green stripes appear on the edges, forming yellow and white seedlings. The key point of management is to use 1 kg of zinc sulfate per mu to fine dry soil or 1520 kg of organic fertilizer, ditch between the rows, the earlier the better, or with 0.1% zinc sulfate solution foliar spray.