Symptoms General manifestations: growth point is apical and apical growth stagnation, root tip necrosis, root hair distortion; young leaves chlorotic, deformation, often hook-shaped, leaf shrinkage, leaf edge curl, yellowing. The top of the soybean stem curled into a hook shape; the peanut leaves were brown dead plaques, the empty pods were more, the kernels were not full, the broad bean pods were deformed, atrophied and blackened; the pea young leaves peduncle withered, the tendrils shrank; the potato was prone to form a small string Tuber; tomato umbilical rot, also known as umbilical rot fruit, the initial expansion of the fruit, the fruit apex of the fruit apex appears water-immersed necrosis, after the diseased tissue collapse, blackening, shrinkage, subsidence; Chinese cabbage rot disease, leaves The edge of the inner blade of the ball is water-immersed to brown necrosis, and it looks like bean curd skin when dry, also known as dry heartburn, dry edge, internal apical fever, etc.; apple fruit has bitter disease, also known as bitter pox, and the surface of the fruit appears depressed. The pulp tissue becomes soft and has a bitter taste. Apple water heart disease is also caused by calcium deficiency. The flesh is translucent and water-stained. It spreads radially outward from the center. Finally, the gap between the flesh cells is filled with juice and causes internal decay. The pear is deficient in calcium, the peel appears on the skin, and the heart is yellow. Or rusting).
Easily occurring environmental conditions (1) Acidic soils with low calcium and exchangeable calcium content such as granite, phyllite, silicified sandstone weathered soil and peat soil. (2) substitution of the sodium high soil salinity, because high salt concentrations inhibit the absorption of calcium. (3) A large number of salt fertilizers (chemical nitrogen fertilizer and potassium fertilizer) are applied. In case of high temperature and drought, soil is dry, and salt is concentrated, calcium deficiency is caused. (4) Planting crops sensitive to calcium deficiency such as alfalfa, tomatoes, Chinese cabbage, beets, soybeans, potatoes and strawberries, and apples.
Diagnosis 1. Morphological diagnosis The symptoms of calcium deficiency are as above. But some calcium deficiency and boron deficiency symptoms are similar, as are the growing point, and apical buds wither and die, buds, new leaves twisted, distorted and so confusing, must pay attention to distinguish, but the lack of boron leaf, petiole thick, coarse, brittle, often a brown substance inside, but no such calcium deficiency symptoms. 2, plant analysis and diagnosis Plant calcium contains a large difference, the general dicotyledonous plants such as cruciferae, legumes and other content is significantly higher than monocotyledonous plants. Calcium threshold or below a critical range of several crops: wheat seedlings <0.14%, potato leaf <0.49%, tomato seedlings <0.79% -1.5%, cucumber (leaf) <2.0%, cabbage, Chinese cabbage <1.8% Apple (leaf) 0.5% -1.4%, citrus (leaf) 0.7% -20% peach (leaf) 0.8% -2.1%, grape (leaf) 0.4% -1.75%. 3, soil diagnosis Southern leaching of strong acid low salt-based soil is prone to calcium deficiency. It is generally believed that when the substitution calcium is less than 5-6 mg/100 g soil, the crop may be deficient in calcium; calcium deficiency is also often found in calcareous soil, which is caused by excessive absorption of calcium by the soil salt concentration. Thus, the diagnosis is to be noted in the soil detecting concentration of salts, the calcium binding plant health comprehensive analysis, judgment.
Prevention and control 1. Application of calcium fertilizer Acidic soil is deficient in calcium, and lime can be applied to provide calcium nutrition and neutralize soil acidity. For neutral and alkaline soils, for reasons of roots absorption hindered, soil application is not effective, should be changed to foliar application, generally 0.3% -0.5% (Chinese cabbage useful 0.7%) calcium chloride solution, even spray Several times. In addition, for tomato umbilical rot, the Japanese azure test was effective in the application of silicic acid, and the silicon and calcium contents of the silicon plant were significantly improved. 2. Controlling the amount of fertilizer A large amount of nitrogen and potassium fertilizers are applied to increase the concentration of soil solution and inhibit the absorption of calcium. Especially for ammonium nitrogen fertilizer, controlling fertilizer and preventing the increase of salt concentration are the basic measures for preventing and controlling calcium deficiency. 3, to prevent soil dry high temperature and drought, soil solution concentration, especially when the crop needs more calcium, such as cabbage cabbage period, tomato fruiting period, etc., in case of drought, it is easy to induce calcium deficiency, should be timely irrigation.
From: "China Cooperation Times"
Easily occurring environmental conditions (1) Acidic soils with low calcium and exchangeable calcium content such as granite, phyllite, silicified sandstone weathered soil and peat soil. (2) substitution of the sodium high soil salinity, because high salt concentrations inhibit the absorption of calcium. (3) A large number of salt fertilizers (chemical nitrogen fertilizer and potassium fertilizer) are applied. In case of high temperature and drought, soil is dry, and salt is concentrated, calcium deficiency is caused. (4) Planting crops sensitive to calcium deficiency such as alfalfa, tomatoes, Chinese cabbage, beets, soybeans, potatoes and strawberries, and apples.
Diagnosis 1. Morphological diagnosis The symptoms of calcium deficiency are as above. But some calcium deficiency and boron deficiency symptoms are similar, as are the growing point, and apical buds wither and die, buds, new leaves twisted, distorted and so confusing, must pay attention to distinguish, but the lack of boron leaf, petiole thick, coarse, brittle, often a brown substance inside, but no such calcium deficiency symptoms. 2, plant analysis and diagnosis Plant calcium contains a large difference, the general dicotyledonous plants such as cruciferae, legumes and other content is significantly higher than monocotyledonous plants. Calcium threshold or below a critical range of several crops: wheat seedlings <0.14%, potato leaf <0.49%, tomato seedlings <0.79% -1.5%, cucumber (leaf) <2.0%, cabbage, Chinese cabbage <1.8% Apple (leaf) 0.5% -1.4%, citrus (leaf) 0.7% -20% peach (leaf) 0.8% -2.1%, grape (leaf) 0.4% -1.75%. 3, soil diagnosis Southern leaching of strong acid low salt-based soil is prone to calcium deficiency. It is generally believed that when the substitution calcium is less than 5-6 mg/100 g soil, the crop may be deficient in calcium; calcium deficiency is also often found in calcareous soil, which is caused by excessive absorption of calcium by the soil salt concentration. Thus, the diagnosis is to be noted in the soil detecting concentration of salts, the calcium binding plant health comprehensive analysis, judgment.
Prevention and control 1. Application of calcium fertilizer Acidic soil is deficient in calcium, and lime can be applied to provide calcium nutrition and neutralize soil acidity. For neutral and alkaline soils, for reasons of roots absorption hindered, soil application is not effective, should be changed to foliar application, generally 0.3% -0.5% (Chinese cabbage useful 0.7%) calcium chloride solution, even spray Several times. In addition, for tomato umbilical rot, the Japanese azure test was effective in the application of silicic acid, and the silicon and calcium contents of the silicon plant were significantly improved. 2. Controlling the amount of fertilizer A large amount of nitrogen and potassium fertilizers are applied to increase the concentration of soil solution and inhibit the absorption of calcium. Especially for ammonium nitrogen fertilizer, controlling fertilizer and preventing the increase of salt concentration are the basic measures for preventing and controlling calcium deficiency. 3, to prevent soil dry high temperature and drought, soil solution concentration, especially when the crop needs more calcium, such as cabbage cabbage period, tomato fruiting period, etc., in case of drought, it is easy to induce calcium deficiency, should be timely irrigation.
From: "China Cooperation Times"
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