Big wheat is in the process of growth and development. Need a variety of nutrients, if the lack of a certain nutrient elements in the soil, wheat seedlings will show the corresponding characteristics from the external morphology. Therefore, in terms of production, we can look at the seedling rupture disease according to the external symptoms of the wheat seedlings and apply the medicine. The growth and development of nitrogen-deficient wheat seedlings require large amounts of nitrogen nutrition when nitrogen is insufficient. Poor plant growth, short stems, small tiller, seedlings are thin and erect, narrow and short leaves; stems and leaves yellow, dry tips, and gradually develop the upper leaves, and finally withered to the lower old leaves. Nitrogen-deficient wheat seedlings have poor root growth, and their root volume is small and slender. Finally, it resulted in fewer spikelets and less production. Barren soil is prone to nitrogen deficiency symptoms. Remedy: Apply 7 to 8 kg of urea or 20 kg of ammonium bicarbonate per mu or 600 to 700 kg of human waste. Can also use l ~ 2% of urea solution for foliar spray. Phosphorus deficiency wheat seedlings lack of phosphorus, the growth inhibition of root development, less secondary roots, plant thin, less tiller, dark green leaves lack luster, purplish, leaf sheath purple obvious, symptoms from the tip to the base, from the old leaves The development of young leaves, poor cold resistance, easy to die in winter, heading and flowering delay, pollen formation and fertilization process are affected, grain filling is not normal; resulting in 1000-grain weight decreased, poor quality, low yield. Remedial measures: First, topdressing superphosphate, generally 25-30 kg of superphosphate per acre is used to pour water; the second is the spraying of potassium dihydrogen nitrate on the leaves, usually l50~200g/mu for the water and 75kg spray . Potassium-deficient wheat seedlings lack potassium, the plants grow slowly, the stems are short, and the leaves are dark green or blue-green, soft and shed, the tips and edges are brown, and then brown, the veins remain green, the lower leaves are scorched, and they are severe. Leaves dead. Root growth is poor, perishable, wilting plants, premature aging and lodging. Spike small grains, the grain is not full, mature early, poor quality, low yield. Remedy: (1) topdressing potassium chloride, generally 7 to 10 kg per mu. (2) Spreading plant ash, generally l00 kg per acre. (3) foliar spray fertilizer, generally per acre with potassium dihydrogen phosphate l50 ~ 200 g water spray, continuous spray 2 ~ 3 times. Zinc deficiency wheat seedlings suffer from lobular disease when they are deficient in zinc, and the leaf margins are distorted or shrunk. The veins on both sides of the veins change from green to yellow and white, and the edges are still green with yellow, white and green stripes. Heading late, small spikes. Remedy: Use 0.3~0.4% zinc sulphate solution for foliar spray, spray once every 5~7 days, spray 2~3 times continuously. The most typical symptom of boron deficiency in boron-deficient wheat seedlings is "ear but not real." The period of growth is delayed, sometimes the side of the planting is heading and the leaf sheath is sometimes purple-brown. Remedy: Use borax 150-200 g/a with nitrogen, phosphorus, potassium and other fertilizers to dilute with water, or use 50-100 g/mu water 50-60 kg/m2 for foliar spray. Calcium deficiency wheat seedlings lack calcium, the growth point and the tip of the stem die, the plants are dwarf or clustered, the young leaves often do not spread, the roots are short, the branches are numerous, the root hairs are few, the root tips secrete transparent mucus, and the spherical shape sticks to the root tips. on. Calcium-deficient leaves also turn yellow, starting from young leaves. Remedy: Spread 50-70 kg of lime per acre. HSG Catheter,silicone HSG catheter,Catheter,HSG Anesthesia Medical Co., Ltd. , https://www.jssinoanesthesia.com