Apple deficiency is defined as the lack of certain mineral nutrients in the apple tree, which leads to physiological disorders, which are manifested by the special symptoms presented by branches, leaves, flowers, and fruits. In severe cases, the plants are weakened or even die. Nitrogen deficiency disorders first appeared on new shoots and old leaves. The new shoots were short and fine, and the leaves were small. After the shoots were wooded, they turned reddish-brown. The leaves of the base of the shoots are yellowed and gradually develop towards the top of shoots, causing the young leaves of the shoots to turn yellow, and even causing fallen leaves and physiological fruit drop.
Control methods: timely topdressing urea, ammonium nitrate and other nitrogen fertilizers. Phosphorus deficient disease initially appeared on shoots and leaves. The leaves were small and thin. The branches and leaves were gray-green. The petioles and the veins on the back were purple-red. The flowering leaves were delayed, and the new branches had fewer fine branches. When phosphorus is severely depleted, the old leaves turn into yellow-green and dark-green mosaics, sometimes producing red or purple patches, and the hemipelas necrotic spots appear on the leaf margins and fall off quickly. Phosphorus deficiency also leads to poor flower bud differentiation, poor stress resistance, and vulnerability to freezing damage.
Control methods: After leaf spreading, 0.5%~1% superphosphate was sprayed on the leaves; phosphate fertilizer particles were applied on the root distribution layer. The potassium-depleted condition first emerges from the middle or lower leaves of the shoot, and the leaf tip and the leaf margin usually occur as early as purple and then brown, and the leaf tissue near the spot is still growing, causing the leaf to shrink. When the potassium deficiency is severe, the entire leaf is scorched, but it does not fall off. Small flower buds, small and light fruit coloring area.
Control methods: Grassland ash, potassium dihydrogen phosphate, potassium chloride, potassium sulfate, potassium nitrate and other potassium fertilizers are applied from June to July. The concentration of foliar applied grass is 3% to 10% of the leachate, and the other is 0.5% to 1%. , and pay attention to increase organic fertilizer, a reasonable ratio of NPK. The iron-deficiency disease initially appeared on young shoots. The young leaves and leaves lost green and yellow, but the old and young leaf veins remained green on both sides. The leaves of the young leaves showed green reticular formation; when the iron deficiency was severe, the veins became Yellow, with brown patches and blemishes, shoots at the tip of the shoots, severely weakening the tree's vigor and affecting yield.
Control methods: For the fruit trees with severe iron deficiency, 0.5% ferrous sulfate solution was sprayed during the germination period, and 0.1%-0.2% ferrous sulfate solution or ferric citrate solution was sprayed once every 20 days during the growing season. It is also possible to mix ferrous sulfate with organic fertilizer and then dig into the distribution range of the root system. Zinc deficiency mainly occurs on shoots and leaves. The diseased shoots grow late, the internodes become shorter, the tip leaflets are clustered or bald, the leaflets are narrow, the texture is brittle and hard, the leaves are yellow, and when severe, the tip shoots are dry, and the lower part of the dry branches can be The new shoots were made again. At the beginning, the leaves were normal and soon they became narrow and long, resulting in spotted spots. Flowers less and less easy to set fruit, the fruit is small and deformed.
Control methods: increase organic fertilizers and pay attention to the application of NPK fertilizers in proper proportions; about half a month before germination, whole trees spray 3% to 5% zinc sulfate solution, and spray 0.2% zinc sulfate solution 0.3% after 3 weeks of blooming. Urea. The leaves of the base of the magnesium-deficient seedlings began to shed the chlorosis, and finally only a few thin, soft, pale green leaves remained on the top of the shoot; the vegetative edge of the old leaves of the aged tree leaves and the veins first became green and gradually turned yellow-brown or dark brown. New shoots and shoots are relatively slender, cold resistance is significantly reduced, flowering is inhibited, and the fruit is small and bad in taste.
Control methods: Mild magnesium deficiency can be sprayed 3~4 times from June to July 1%~2% magnesium sulfate solution; magnesium deficiency can be magnesium sulfate and organic fertilizer, potassium fertilizer, phosphate fertilizer according to 1~1.5kg magnesium per mu. Calcium and other fertilizers are mixed into the soil. In the absence of manganese and manganese deficiency, the leaves exhibit isosceles triangles. From the edge of the old leaves, they begin to lose their green color and turn yellow-green. They gradually expand to chlorosis between the main veins. In severe cases, the entire leaves turn yellow and brown spots appear at the tip.
Control methods: Add organic fertilizer or mix manganese oxide, manganese chloride, etc. with organic fertilizer. From May to July, spray 0.2%～0.3% manganese sulfate solution every 20 days, and spray 3～4 times. Spray Bordeaux mixture or lime sulphur mixture together. Boron deficiency mainly occurs in fruits, shoots, and young leaves. When boron deficiency occurs, root tip elongation and cell differentiation are hindered, and thick and brittle leaflets are clustered and the veins turn red. Sharp tips when severe. In the spring, the germination is not normal, and the thin and weak branches will soon die. In the dead part, many delicate branches will be formed again, and the plexus will generate a "broom stick." Dew on the fruit surface, browning and lignification inside.
Control methods: pay attention to the application of organic fertilizer, can spray 0.1% ~ 0.3% borax aqueous solution before sprouting, before flowering, full flowering, falling flower and other stages. Calcium deficiency Mild calcium deficiency in the initial stage, no obvious symptoms above the ground, because the new roots stop growing early, the root is short and thick. When the calcium deficiency is severe, the young roots gradually wither from the root tip, and a new root is formed at the back of the dead place to form a thick and short root group with many branches. Above the shoots, the leaves appear to be small, with faded green to brown necrotic spots on the young leaves, and withering or flower atrophy when severe. The fruit is prone to erythrodhostic scab, bitter pit disease, and water heart disease during the near mature period and the storage period.
Control methods: Spray 200 times calcium chloride in the growing season, spray 3~4 times, the last time should be 3 weeks before the harvest; timely irrigation in the dry season, timely drainage in the rainy season; increase organic fertilizer, suitable amount Use nitrogen fertilizer to increase the effectiveness of calcium. In the absence of molybdenum, molybdenum is slightly deficient in molybdenum, yellow spots appear on the leaves; in severe cases, the tips of the initial leaves are first scorched and gradually expand along the leaf margins and develop into the leaves, the leaves curl downwards, and brownish parts of the leaf margin often accumulate nitric acid. salt.
Control methods: Apply molybdenum fertilizer to nitrogen, phosphorus and potassium fertilizers and apply it to the soil; when buds are sprayed, 0.01% to 0.05% ammonium molybdate is sprayed 1 to 2 times. In the early period of copper deficiency and copper deficiency, brown spots appeared in the leaves and gradually turned dark brown, causing fallen leaves. The tops of new shoots dried up from 10 to 30 centimeters. The following year, the new shoots sprouted from the lower part of the dry, repeated times, forming thin branches of clumps. .
Control methods: When copper deficiency is serious, spray 0.05% copper sulfate solution before budding or spray 0.01% copper sulfate solution during the growing season, and apply copper sulfate to the soil in 1 to 2 kilograms per acre.
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