Diseases and prevention methods of Deutzia odorata

Diseases of Deerleaf: Yellow leaf disease

symptom

The yellow leaf disease of Deutzia is also called chlorosis, which is a common and frequent disease of Deutzia, and often occurs in Deutzia planted in alkaline soil in the north.

In the early stage of the disease, the tender leaves at the top of the plant will turn yellow first, and the leaf surface tissue will turn yellow or light yellow, but the leaf veins will not change color and will remain green.

As the disease worsens, the entire leaf turns yellow or yellow-white, the edges of the leaf turn gray-brown, and the leaves gradually die.

Prevention and treatment methods

First of all, you need to choose suitable soil when planting, preferably slightly acidic or neutral loam.

In the early stage of the disease, you can use 200 times diluted ferrous sulfate solution to irrigate the roots and spray with 0.5% ferrous sulfate solution once every 10 days. Continuous watering and misting 3-4 times can significantly change the symptoms.

When applying fertilizer, use more organic fertilizers such as leaf mold, cow and horse manure, etc. to improve soil permeability.

Diseases of Deerleaf: Brown spot disease

symptom

The pathogenic bacteria are ascomycetes that overwinter on the diseased remains of the host plant and are spread by wind, rain and watering. The disease begins in late April to early May, with the peak period of disease being July, August and September.

In the early stage of the disease, gray-brown spots will grow on the edges of the leaves. The spots will expand in irregular shapes, with gray-brown inside and reddish-brown edges.

In the later stage of the disease, the spots gradually expand and may connect into a line to form strip-like spots, which then dry up and turn brown, with black granular substances growing on the spots.

Prevention and treatment methods

Strengthen pruning during daily maintenance to ensure that the plant is placed in a ventilated and light-permeable location.

If it occurs, spray with 800 times diluted 75% thiophanate-methyl wettable granules, 400 times diluted 70% mancozeb wettable granules, or 500 times diluted 50% dichlorvos wettable granules once every 11 days. Spraying 3-4 times in a row can effectively control the disease.

Sprinkler irrigation is prohibited during the disease period to reduce the speed of disease development.