Tree Peony. Diseases. Continuation

2024 Author: Gavin MacAdam | [email protected]. Last modified: 2023-12-16 13:38

Throughout the growing season, it is necessary to monitor the state of the tree peony so as not to miss the moment of infection with pathogens. When the first signs of the disease appear, urgent measures are taken to destroy the infection. With a massive defeat, it is much more difficult to fight harmful microorganisms. Let's continue to analyze measures to combat the most common diseases

Spotting

The tree peony is affected by several types of spotting:

• septoria;

• phylostictosis;

• brown spotting.

The signs of disease are different from each other. The causative agents are different types of fungi, against which comprehensive control measures have been developed.

Septoriasis

It appears on the leaf plates of the lower tier on both sides in early spring. Initially, small angular yellow spots with a dark rim around the lesion are formed. Then they increase in size, acquiring a grayish-brown hue. The black dots in the center of the spot are filled with spores. Gradually, the disease moves to the upper tiers, capturing the stems.

In case of mass infestation, most of the leaves dry out, remaining attached to the branches for a long time. Infected plants bloom poorly, stunted. Spores overwinter on stems and plant debris.

Phylostictosis

The disease manifests itself in early spring on the stems, leaves of peonies in the form of rounded, small brown spots. During the growing season, the size of the lesion increases in size, taking the form of concentric circles.

Over time, the loss of dead areas occurs. By autumn, black dots, carriers of fungal spores, are formed at the sites of infection. When massively spread, the leaves seem to be burnt. Hibernates on plant debris.

Brown spot

The disease is most dangerous in conditions of high humidity. It affects all parts of the plant: buds, young growths, leaves. It manifests itself in the form of irregular brown spots on the upper side, in the lower part it acquires a purple tint with a smoky bloom of pycnidia containing fungal spores.

Infected buds turn brown, petals fall off prematurely. Hibernates in soil, on plant debris.

Spot control measures:

1. Burning cuttings in the fall.

2. When the first signs of a disease are detected, remove parts of the plant by cutting off the affected areas.

3. Spraying in early spring with copper oxychloride or 1% Bordeaux mixture solution. The treatment with the first preparation is repeated after 10 days.

4. Planting healthy material with increased stain resistance.

Root system cancer

The rod-shaped bacterium penetrates through the wounds into plants, causing massive, uncontrolled cell division. On the root collar, growths of various sizes and shapes are formed, of a dense consistency, similar to a tree.

Weakened bushes are more often affected by the disease, the cancers on them are larger. Weakly alkaline, neutral soil reaction, contributes to the rapid spread of infection. The acidic environment inhibits the development of the pathogen. At a pH below 5, bacteria lose their ability to multiply. Lack of moisture in the soil leads to the rapid growth of the disease.

Affected bushes lag behind in growth, with the massive spread of pathogens they die. Bacteria overwinter in the soil.

Control measures:

1. Planting tree-like peonies in areas clean from the disease.

2. Use as a precursor: cereals, legumes, mustard.

3. The introduction of physiologically acidic phosphorus-potassium fertilizers.

4. Regular watering, bushes care.

5. Acquisition of healthy planting material.

6. Blocking the spread of the disease by the following method:

• digging out infected plants;

• removal of growths to a healthy place;

• disinfection for 10 minutes with 0.2% boric acid or 1% copper sulfate;

• rinsing in clean water for 5 minutes;

• landing at a new location.

Unlike herbaceous forms, tree peonies are more resistant to disease. Preventive measures: a high agricultural background, a good planting site, help to avoid many diseases. In private gardens, amateur flower growers achieve a positive result without chemical treatments.