What are the typical symptoms of rape lack of nitrogen, phosphorus, potassium and other elements?

Rape is a very important oil crop, but also has a certain ornamental value, pieces of rape flowers look golden, very beautiful, attractive. In the process of rape planting, if the lack of corresponding elements will show some symptoms, leading to yield reduction, reduction phenomenon, let's take a look at the rape lack of nitrogen, phosphorus, potassium and other elements what are the typical symptoms?

1. Phosphorus deficiency

Phosphorus plays an important role in genetic variation; phosphorus is involved in the metabolism and transport of carbohydrates; phosphorus plays an important role in nitrogen metabolism; improve the ability of plants to resist drought, cold, disease, lodging, acid and alkali resistance; promote plant growth and development, promote flower bud differentiation and shorten the time of flower bud differentiation, promote early flowering and maturation of crops.

When the rape is phosphorus deficient, the plant grows slowly and short, and the number of leaves is 2 to 3 pieces less than the normal plant, and the leaf color is dark green or gray green, lack of luster, the petiole is purple, there are purplish red spots or patches on the leaf edge, the lower leaves turn yellow and fall off, the root system is underdeveloped, the bolting is slow, and the moss is red.

2. Nitrogen deficiency

Nitrogen is the main component of protein, nucleic acid and phospholipid; nitrogen plays an important role in matter and energy metabolism; nitrogen plays a regulatory role in life activities; nitrogen is a component of chlorophyll, which is closely related to photosynthesis.

Nitrogen deficiency in rapeseed showed poor growth potential and short plants. First of all, the old leaves turn red, then gradually develop to the new leaves, the chlorophyll decreases and is yellowish. In case of drought and de-fertilization at seedling stage, red leaves are easy to appear; in the middle and later stage of nitrogen deficiency, the branches decrease, the number of pods and filled grains decrease sharply, the grain weight decreases, and the yield decreases obviously.

3. Magnesium deficiency

Magnesium is a component of chlorophyll and phytin. The main symptoms of magnesium deficiency in rapeseed are green deficiency in leaves and yellowing of old leaves at the base. Especially in the bolting period, a large amount of magnesium is needed, otherwise it will cause physiological diseases such as plant dwarf.

4. Potassium deficiency

Potassium is the activator of enzymes. The potassium deficiency of rape is characterized by chlorosis and yellowing of mesophyll at seedling stage, thickening and thickening of leaves, obvious deepening of leaf veins and slow growth. When there is a serious lack of potassium, the heart leaves wither and die, and when they bloom, the edges of the leaves are scorched and curled, the leaves are uneven, and the texture is brittle and hard. The podding stage showed that the plant was short, with few branches, few pods and more shady horns, resulting in a decrease in yield.

5. Zinc deficiency

Rape zinc deficiency, first from the leaf edge, the leaf color faded into gray, and then developed to the middle of the leaf, showing yellow-white irregular disease spot, no necrosis. Both sides of the veins remained green, and the outer edge of the diseased leaves did not show wrinkling. in severe cases, the middle and lower diseased leaves turned out, and the leaf tips drooped downward. Zinc deficiency in the middle and later stage, first of all, the mesophyll showed small white spots or yellow-white spots, the disease spot continued to expand, the whole leaf was yellow-white or withered yellow, but both sides of the leaf veins remained green, and in serious cases, the leaves of the whole plant lost green.

6. Sulfur deficiency

The symptoms of sulfur deficiency and nitrogen deficiency in rape were basically similar, the seedlings were narrow and yellowing, and the leaf veins were green, which gradually spread throughout the whole leaves and on the stems and inflorescences during bolting and flowering in the later stage; the yellowish flowers often turned white and bloomed continuously, and there were flowers and buds on the mature plants in addition to mature and immature pods. The pod tip is withered, and about half of the seeds are stunted. The plant is short and the stem is easy to be lignified or broken.