What are the symptoms of nitrogen deficiency in fruit trees?

Nitrogen deficiency. Insufficient nitrogen supply for fruit trees, slow growth of new shoots and sparse branches and leaves; Chlorophyll content decreases, leaves become pale, old leaves turn yellow, premature aging, easy to fall off; Branches are aging, crown expansion is blocked, and tree potential is accelerating aging; There are few flowers and fruits, the fruit is not full, it matures early, and the yield and quality decline. All kinds of fruit trees have different symptoms of nitrogen deficiency, which are described as follows: apple: it can occur in spring, summer and autumn all year round. When the symptoms of nitrogen deficiency appeared, the lower leaves of apple branches turned yellow evenly and developed to the upper leaves. The new leaves are small and thin, light green or purple; Older leaves are orange, red or purple; Leaves fall off easily; The shoots are small and short, and the elongation stops at the early stage of fruit branches. Flower buds, flowers and fruits are reduced, and fruits are small; The angle between the petiole and the new tip becomes smaller, and the new tip appears brownish red.

Citrus: New buds grow slowly and old leaves turn yellow. Some leaves first form irregular green and yellow patches, and finally the whole leaf turns yellow and falls off. Flowers are few and small, but there are many fallen flowers and fruits. When nitrogen is seriously deficient, the branches will die, and the trees will decline extremely, forming a bare crown.

Loquat: the branches are short and thin; Thin, small and sparse leaves, pale or yellow leaves, easy to fall off; There are few flowers, poor flower quality, few and small fruits and low yield.

Pear tree: In the early stage, the lower old leaves faded, the new leaves became smaller and the new shoots grew weak. When nitrogen deficiency is serious, all leaves fade to varying degrees, mostly light green to yellow, old leaves are red and deciduous early; With the senescence of branches, the formation of flower buds decreases and is not full; The fruit becomes smaller, the stone cells in the pulp increase, the yield is low, the quality is poor, and it matures early.

Peach tree: the leaves turn green and yellow-green, the basal leaves are reddish brown, and the leaves fall off early; The branches are small, short and hard, and the skin is light brown to lavender; The vegetative growth of the whole tree is weakened, and the young trees grow into "small old trees"; Adult trees accelerate aging, flower buds are not full and flowers are few; Fruit yield decreased and quality became worse.

Myrica rubra: nitrogen deficiency at tasseling stage is yellow-green with narrow and thin leaves, and the angle between petiole and branch becomes smaller and sharper; Branches are thin and long, and branches stop growing at an early stage. Continued nitrogen deficiency, the lower leaves turned from yellowing to brownish red, and the leaves fell seriously; The bud is thin, the flower quantity drops sharply, and the flower and fruit drop are serious; The fruit is small and hard, and it ripens and falls off early.

Grape: the branches are short and thin, reddish brown, and grow slowly, and stop growing when it is serious; The old leaves first turned green and gradually developed to the upper leaves. The new leaves are small and thin, yellow-green, easy to fall off and premature aging; There are few flowers, buds and fruits, small ears and fruits, and low yield.

Plum tree: the old leaves turn green, or red or purple, and the new leaves become smaller and lighter; Branches are small and aging, flower buds are not easy to form, and there are few flowers and fruits; The fruit expansion is blocked and the growth is poor.

Coconut: the old leaves turn yellow in the early stage of nitrogen deficiency, and with the increase of nitrogen deficiency, the young leaves turn green and the old leaves turn green and golden yellow; A large number of panicles were aborted, and the number of female flowers on inflorescences decreased; The growth was severely inhibited, and the top of the trunk became as thin as a pencil tip, leaving only a few short leaves on the crown, and finally the top was bald, withered and died.

Avocado: the plant grows slowly, with slender branches and brownish yellow branches; Old leaves lose green seriously, the leaves are small, yellow to light green, dull, young leaves are pink, and leaves with serious nitrogen deficiency produce white areas, and then die and fall off.

Mango: The growth of the plant is seriously inhibited, the leaves are small and yellow, and the yellowing symptoms spread from the old leaves to the top leaves.

Longan and litchi: Yellow-green leaves, small. In the late stage, the leaves are yellow-green, green near the veins, and yellow-green at the leaf margin, sometimes twisted. Yellow-brown spots appear on the top of the upper leaves of the plant and gradually expand downward.

Pineapple: The leaves are light green or even yellow, with few buds and small fruits.