Correction of Nectarine physiological Disease-nitrogen deficiency

Soil nitrogen deficiency can make the leaves of the whole plant light green to yellow. Petioles and veins turn red. At this time, the growth of new shoots is hindered, the leaf area decreases, and the branches and leaves become relatively hard. If the nitrogen deficiency is too serious, the mesophyll between the large veins will appear red or reddish brown spots within 1-3 weeks. In the later stage, many red spots develop into necrotic spots. The leaves gradually formed detachment and fell off, starting from the base of the new shoots growing in the same year, and gradually developed upward. At the top of the new shoot, the growth is short, the flower bud is many, and the fruit setting rate is reduced. In the case of severe nitrogen deficiency, the whole shoot is short and thin, the flower buds are less than the normal plants, and the leaves are also small, light green, much like potassium-deficient trees. But when potassium is deficient, the apical tip is thinner and the Internode is longer. Red spots on mesophyll are the characteristics of nitrogen deficiency. The fruit of the plant with low nitrogen content matured early. The color is good. The pulp of walnut is light in flavor and contains much fiber. The noodles are not plump enough, and the flesh is close to the heart. [occurrence conditions] the peach orchards with poor soil, extensive management, lack of fertilizer and weeds in ① were easy to show the symptoms of nitrogen deficiency. ② young trees growing in sandy soil show nitrogen deficiency within a few days when they encounter heavy rain during the growing period. [treatment] ① generally apply chemical fertilizers such as urea, ammonium sulfate, ammonium bicarbonate, etc., the symptoms of nitrogen deficiency will disappear. ② in the rainy season and autumn shoot rapid growth period, the tree needs a lot of nitrogen, and at this time the soil nitrogen is easy to lose, 0.5% ammonium sulfate or ammonium hydrogen sulfate solution can be sprayed in the canopy.