Causes and Countermeasures of abnormal Leaf Color of Wheat seedlings

After sowing and emergence, all kinds of abnormal heterochromatic seedlings are often formed due to the influence of natural conditions and cultivation measures. In order to facilitate vaccine management and symptomatic management, they are introduced as follows:

Causes of yellowing of wheat leaves in yellow leaf seedlings.

First, the soil is dry. This kind of situation often occurs in the wheat field where the soil moisture is insufficient or the soil moisture is running away through ventilation. It is characterized by slow birth of tillers, gray-green leaves, short heart leaves, slow growth or stagnation (called by the masses as "shrinking seedlings"), yellow and dry leaves in the middle and lower parts, and few and thin roots. Key points of management: combined with watering, 15kg ammonium bicarbonate per mu.

The second is nitrogen deficiency. The seedlings were thin and erect, the tillers decreased, and the leaves were narrow and short. The lower leaf starts from the leaf tip, gradually turns yellow and dry, and develops to the upper leaf. Key points of management: urea 78kg per mu, or ammonium bicarbonate 20kg, or ammonium bicarbonate 20kg, or human feces 600kg 700kg, ditch application or watering between rows.

Third, the soil is hard. Due to the lack of soil moisture and air, the root system is difficult to stretch, so the wheat leaves are yellow and short, and the tillers can not appear on time. Management points: first timely watering, and then deep ploughing and loosening soil, in order to break the rigid layer.

Fourth, the amount of broadcasting is too large. Its performance is that the seedlings grow crowded, compete with each other for glory, fertilizer and water, and the plants are yellow and thin. Key points of management: first, we should pay close attention to thinning seedlings, especially the "pimple seedlings" in the land, the edge of the ground, and in the field, and then combine with watering, and apply a small amount of nitrogen and phosphorus fertilizer to make up for the excessive consumption of soil nutrients and promote the wheat seedlings to change from weak to strong.

Fifth, insect pests. Wheat aphids or red spiders can also cause wheat leaves to turn yellow. Key points of management: discover the harm and spray it with 40% omethoate 1500-2000 times in time.

The reason why red leaf seedlings form red leaf seedlings.

One is waterlogging. Excessive Rain Water in the autumn seedling stage or waterlogging in the low-lying wheat fields will make the leaves turn dark red and cause rotting roots and dead seedlings in serious cases. Key points of management: timely opening deep ditches for drainage and removing stains, and topdressing a small amount of available fertilizer to promote the early development of seedlings.

The second is phosphorus deficiency. The wheat seedlings are phosphorus deficient, the root system is poor, the secondary roots are few and weak, the leaf color is dark green, the leaf tip and leaf sheath are purplish red, the planting is thin, the tillering stage is delayed, the number of tillers is reduced, even no tillering. Key points of management: combined with ploughing and loosening soil, 20-30kg superphosphate is used per mu, and applied in furrow or watering between rows, the earlier the better.

The third is the harm of saline-alkali. In the land with heavy saline-alkali damage, there are often patches of purplish red "little old seedlings", and when the seedlings are serious, the seedlings die. Key points of management: timely hoe to increase temperature, break indentation, restrain return to salt, and timely apply winter fertilizer to promote strong seedlings. When the wheat gets up in the next spring, it sets the stage to top fertilizer and irrigates water and presses salt.

Fourth, it is frozen. In winter, when the temperature suddenly drops below 0 ℃, the freezing of wheat seedlings will also make the leaves red. Key points of management: combined with hoe and soil around the root, plant ash 75 kg / mu is applied, if necessary, after the wheat enters the overwintering period. A layer of "warm dung" was applied along the ridge to protect the seedlings safely through the winter.

When the purple leaf seedlings were boron deficient, the stems and leaves were thick and curved, and the leaves were purple. The formation of "purple leaf seedling", in the later stage of serious "panicle but sterility", has a great impact on the yield. Key points of management: 150 grams of borax per mu, watering with appropriate amount of nitrogen and phosphorus fertilizer, or 50 grams of 100 grams of borax per mu and foliar spraying of 50 kilograms of water.

When the brown leaf seedling is deficient in potassium, the plant grows slowly, the root system is poor, it is easy to rot, the leaf is dark green or turquoise, and the leaf tip and edge are withered and yellow, and then turn brown to form "brown leaf seedling". Key points of management: 15 kg of potassium sulfate per mu, or 100 kg of plant ash, trenched between rows, or foliar spraying with 0.2-0.3% potassium dihydrogen phosphate solution.