果树缺素症（Deficiency of fruit trees）.docVIP

果树缺素症（Deficiency of fruit trees） Fruit nutrient deficiency is a physiological disease or non infectious disease, is a growth environment lacking some nutrient or nutrients can not be absorbed by the root cause, can be corrected by applying the corresponding large or trace element fertilizer. In order to find out the deficiency of fruit trees as soon as possible, and to remedy the disease in time, this article introduces some common diseases of deficiency of fruit trees and their prevention and cure methods. Nitrogen deficiency (N). Shoot short and thin, small leaf blade erect, lower shoot chlorosis gradually turn yellow, and continue to top development, flower bud formation, fruit small early fall, fibrous roots, root, root yellow. Serious nitrogen deficiency, shoot lignification after reddish brown petiole and veins turned red, and even cause serious physiological drop. The barren soil, extensive management, lack of fertilizer and weedy orchard, easy performance of nitrogen deficiency. Usually, ammonium salt and nitrate nitrogen are added to supplement the production. In the rainy season and autumn shoot rapid growth period, the trees need a lot of nitrogen, and at this time the soil nitrogen is easy to lose, can be sprayed with 0.5-0.8% urea solution crown. No Two, phosphorus deficiency (P). Shoot and root growth decreased, while branching thin branches, leaves small and thin, old leaves Chenggu bronze, appear pale green spots between the veins, dark green leaves, petioles, purple or purple red. Severe P deficiency, the old leaves will appear yellow and dark green leaves and white flowers, and even purple, red plaques, leaf margin necrosis stems branches appear half moon, leaves early fall, and the top end long-term retention of a leaf. The shoots at the lower part of the branches are not rich, and the buds do not germinate in spring, The surface of the fruit is small and the color is poor. Poor resistance to trees often results in early defoliation and decreased