Diseases and control methods of Prunus armeniaca

Diseases of Prunus armeniaca: Black spot

symptom

It mainly harms the leaves of Prunus armeniaca, causing them to wither and turn yellow, and the plants to die. It is contagious.

The pathogen overwinters on fallen diseased leaves, produces conidia in the following spring, and spreads by air currents. The disease mainly occurs in summer and autumn, with autumn being more common.

When the disease occurs, nearly circular spots will appear on the leaves of the plum tree. The spots are brown with dark brown rings and covered with black-brown mold. Sometimes the spots are irregular in shape due to the influence of leaf veins and can merge into larger patches.

Prevention and treatment methods

When planting, choose excellent disease-resistant varieties and increase plant quarantine.

Strengthen the water and fertilizer management of Prunus armeniaca to improve the disease resistance of the plant.

Spray 5 degrees Baume lime sulfur mixture once before bud break in spring for prevention. If disease occurs, spray with 700 times diluted 80% mancozeb wettable granules or 500 times diluted 70% mancozeb. Spray once every 7 days. Spray 3 to 4 times in a row to effectively control the disease.

Diseases of Prunus mume: Root cancer

symptom

Pathogenic bacteria invade parasitic plants through wounds or through stomata.

In the early stage of the disease, small, nearly round nodules appear at the roots of the plants, which then gradually grow larger and harden, with a rough and cracked surface. The color changes from light to dark brown or black brown, and the inside of the nodule becomes lignified.

Due to the damage to the root system, the diseased plants grow slowly, and in severe cases the whole plant dies.

Prevention and treatment methods

Before planting, various underground pests should be controlled in time.

On diseased plants, use a sterilized knife to remove the tumors, and then apply white paint or Bordeaux liquid on the diseased parts.

Diseases of Prunus mume: Leaf spot

symptom

The leaf spot pathogen overwinters in diseased remains or on the surface of the ground, and is spread by wind and rain to infect the host during the disease period the following year.

Nearly circular spots will appear on the leaves and gradually expand, forming patches, causing the leaves to turn yellow and fall off.

Prevention and treatment methods

In winter, combine plant pruning and branch and leaf tidying up, promptly remove the spots and residues left over from the disease, and burn them in a concentrated area.

In the early stage of the disease on the plants, spray 900-1400 times of 75% thiophanate-methyl wettable powder or 800 times of 75% thiophanate-methyl wettable powder in time.