What is the lack of mineral elements for the appearance of large dark spots on mint leaves? 5

There are many reasons why peppermint leaves turn black. If it is due to insufficient light, it needs to be placed in a sunny place to receive light. If it is due to too much watering, it is necessary to strengthen air circulation and loosen the soil properly to allow the water to evaporate as soon as possible.

If it is due to excessive fertilization, it is necessary to depot the plant, remove the old soil, prune the roots, and replant with new soil. If it is a disease, it is necessary to cut off the diseased branches and leaves and spray Bordeaux liquid to prevent it.

1. Insufficient light.

Peppermint is a long-day crop. Always make sure that there is enough light, if the environment is dark, the leaves of the plant may turn black. In this case, it needs to be placed in a sunny place so that it can receive light throughout the day, and if the light is particularly strong, it can be properly shaded with a 30% shading net.

2. Watering too much.

Peppermint likes moisture, and sufficient moisture is very helpful for the growth of its branches and leaves. However, if there is too much water and the environment is too humid, it may also affect the respiration of the roots, which in turn will cause the leaves to turn black. In this case, it is necessary to improve air circulation and loosen the soil appropriately to allow the water to evaporate as soon as possible.

When watering, you should also pay attention to controlling the amount of water, do not water too much, especially not to produce stagnant water.

3. Excessive fertilization.

The demand for fertilizer is not very high, as long as sufficient basal fertilizer is applied at the time of planting, it is rarely necessary to chase water-soluble fertilizer during the growth period. If you fertilize too much, it can easily cause fertilizer damage, burn the roots of the plant, and make the leaves black. When encountering this problem, you need to take off the pot in time, take the plant out of the pot, wash off the old soil of the roots, check the condition of the roots, cut off the rotten places due to burns, spray a little carbendazim to disinfect, and prepare for replanting after air drying.

Fourth, the disease is caused.

Some diseases can also cause the leaves of mint to turn black, such as rust and spot blight. These diseases are usually caused by fungi, and the surface of the leaves will have dark spots, which in severe cases will cause them to wilt and fall off, and also cause the plants to die. When a diseased plant is found, it is necessary to immediately cut off the diseased leaves and spray them with Bordeaux liquid and other drugs.

The mint leaves have black spots, which may be caused by diseases, and when it is infected with rust and spot blight, the leaves will show black spots. Leaves with dark spots should be cut off immediately and sprayed with drugs such as thiophanate-methyl suspension and Bordeaux liquid.

It could also be a bacterial infestation, which produced plaque. For example, scab is also the case.

(1) Rust (pucciniamenthaepers) is a disease caused by a fungus. It occurs from May to October, and is prone to illness when it rains. In the beginning, there are orange-yellow, powdery piles of summer spores on the underside of the leaves.

In the later stage, winter spore piles occur, black-brown, powdery, and the leaves die and fall off when severe.

Control method: spray with 1:1:200 Bordeaux liquid, and stop spraying 20 days before harvest.

2) Spot blight (

Also known as mint scab, scab is a disease caused by a fungus. It occurs in the leaves from May to October. At the beginning, near-round lesions occur on both sides of the leaf, which are small and dark green; Later, the lesions enlarge, nearly round, diameter, or irregular lesions, dark brown.

The inside of the old lesion fades to grayish-white, white star-shaped, with small black dots on it, and sometimes there are dark brown bands around the lesion. When severe, the leaves die and fall off.

Prevention and control method: spray with 500-600 times of 65 zinc dysenate wettable powder (800 times of 80 times of zinc dysenate wettable powder) or 1:1:200 Bordeaux liquid. Spraying should be stopped 20 days before harvest.

Peppermint has a bright color and fresh smell, and is a very popular decoration in home greenery, but many people will find that their mint begins to turn black when raising its leaves, which affects the appearance very much. So, what should you do when your mint leaves turn black?

1. Water management.

The blackening of the leaves of the mint may be a problem with the watering method, generally when watering the mint, you need to follow the principle of dry watering, do not water the potting soil if it is not dry, and wait for the soil to dry out at one time. When watering, it is best to use rice water, which can provide a certain amount of camp material for mint, and it can also be watered with ordinary water, but it is necessary to be careful not to water directly with tap water, and you need to dry the tap water in the sun for a period of time before using it.

2. Ventilation and light.

Peppermint prefers light, if the light is insufficient, it is easy to cause the leaves to turn yellow and black, so it is best to put it in a sunny place when breeding, if there is no sunny corner in indoor farming, you need to put the potted plant in a sunny place every two or three days to dry for a day or two, and so repeatedly, but it should be noted that in summer to avoid sun exposure, you need to carry out appropriate shading treatment.

3. Processing.

The blackening of mint leaves is also very likely to be caused by **, generally mint will suffer from rust and spot blight, if it is a leaf blackening caused by disease, it should be carried out in time**.

1. Rust: Peppermint rust is a disease infected by fungi, which is generally easy to develop in the rainy season of spring and summer, and is also easy to cause this disease when it is too dry. At the onset of the disease, there will be some yellow powder on the back of the leaves, and black spores will be produced in the later stage, resulting in black leaves, and when the disease is severe, the diseased leaves will dry up and fall off or even the whole plant will die.

**Rust can be sprayed with Bordeaux solution.

2. Spot blight: mint spot blight is also a leaf disease caused by a fungus, which generally occurs in summer and autumn, and some dark green spots will appear on the leaves after the onset, and the spots will slowly expand and turn gray-brown in the later stage, resulting in black and wilted leaves, and in severe cases, it will cause large pieces of leaves to fall off. To prevent and control spot blight, the diseased leaves should be removed in time, and all the infected leaves should be cut off and incinerated to prevent the spread of the disease.

In the process of mint planting, in addition to strengthening management, it is also necessary to apply the water-soluble fertilizer of the Cerfat series to enhance its resistance ability, especially the spraying of foliar fertilizer, the mint leaves will be very healthy.

Dizzy, the small black spot is the poop left by eating leaf insects, wash it, dry the mint leaves, soak in water to drink, cool and detoxify, and sweat away! I planted it when I was a child, but unfortunately, there was nothing left in a big flood! Personal opinion is for reference only!