Deficiency and excess symptoms of main nutrient elements in growing cotton

I. symptoms of nitrogen deficiency and excess in cotton

The cotton plant is short of nitrogen, the plant is short and lignified, the leaf color is yellow and green, the leaf becomes smaller, the petiole shortens, the lateral branch is few, and the number of leaves decreases. The lower leaves of cotton plants are most obviously affected by nitrogen deficiency, the top stops growing, the number of flowers is small, and often only the flower bolls on the first fruit node of the lower fruit branches. In this case, if nitrogen fertilizer is applied in time, the leaf color will turn green. In the case of serious nitrogen deficiency, the lower leaves turn yellow and brown, and finally dry up and fall off, which will also cause the shedding of young bolls. Although the root development of nitrogen-deficient cotton plants was better than that of aboveground parts, the boll setting was earlier and the yield was not high because of slow vegetative growth. On the contrary, the supply of nitrogen is too much, the cotton plant is tall, the field cover is serious, the boll and bud drop is serious, the yield is reduced, and the fiber quality becomes worse.

II. Symptoms of phosphorus deficiency in cotton

The cotton plant is short of phosphorus, the plant is short, the leaf is small, the leaf color is dark green, and the maturity of boll stage is delayed. When the phosphorus deficiency is serious, the leaves are purple, the red-green ratio of stem and petiole is out of balance, the growth is slow, it is easy to drop flowers and buds, peach is less, boll opening is delayed, root system is underdeveloped and drought resistance is weak.

Symptoms of potassium deficiency in cotton

The cotton plant is deficient in potassium, the plant is short and the stem is thin and soft. The leaf color changes from light yellow to dark green, yellow and white patches appear between the veins, and gradually turn brown, and then the whole leaf is wrinkled and brittle. The edge of the leaf is reddish brown and ruptured, and even the petiole falls off, sometimes festering and curling downward. The leaves turn reddish brown, dry and early. For potassium deficient cotton plants, brocade bolls are small and difficult to mature, and the fiber quality of seeds and lint decreases.

Symptoms of sulfur deficiency in cotton

The cotton plant is sulfur deficient, the aboveground and underground parts are short or short, the leaves are small and yellowish, the chlorophyll between the veins disappears, then turns purple, and the veins remain green. These symptoms first occurred in the young leaves, especially the root formation was significantly different from that of the normal roots, and the lateral roots became shorter. Due to the weak foundation of vegetative growth, cotton bolls are often small and easy to fall off.

5. Symptoms of calcium in cotton

When the cotton is deficient in calcium during the growing period, the aboveground part is smaller, the number of roots is less, and the lateral roots are also very few. The lower petiole of cotton seedling is bent and drooping, often festering.

VI. Symptoms of magnesium deficiency in cotton

The cotton plant lacks magnesium, the leaf vein is green, the leaf vein is purplish red, and the cotton boll falls off before maturity. The symptoms of magnesium deficiency often appear in the lower lobe first.

VII. Symptoms of boron deficiency and excess in cotton

When the soil is seriously boron deficient, causing cotton "buds but not flowers", cotton seedlings may appear the above-mentioned symptoms, which are easy to drop buds, do not blossom and do not bear peaches, and the symptoms first appear on the leaves. In the case of moderate or mild boron deficiency in soil, there may be bands on the petiole, which should be paid special attention to in cotton field diagnosis.

On the contrary, when the cotton is overnourished with boron, the cotyledons are small, the edges are withered and yellow, and the ladle-shaped leaves are formed and fall off prematurely. The upper leaf chlorosis between the veins, the lower old leaf edge first appeared brown patches, severe patches and extended to the center of the leaf, resulting in leaf withering and shedding, and even the whole plant died.

Symptoms of zinc deficiency in cotton

Cotton plants are zinc deficient. From the first true leaf, the young leaves appear bronze, interveinal chlorosis, leaf thickening, brittleness, edge curling upward, and short internodes. The plant is small and clumpy, and the growth period is delayed.

IX. Symptoms of manganese deficiency in cotton

The cotton plant is lack of manganese, the formation of chlorophyll is hindered, and there are chlorosis spots on the leaves.

Symptoms of copper deficiency in cotton

The cotton plant is deficient in copper, the plant is weak, the root system is poor, the bud and boll fall off, and the flowering or maturity is late.