Persimmon Diseases

Crown gall

Disease symptoms:

• Large galls (swellings) develop around the crown with smaller marble-size galls on larger roots.
• Bacterium enters plants by way of wounds from the soil.
• If the disease progresses too far the plant will turn yellow and become stunted and sickly

Survival and spread:

• Bacterium survives in the soil and infected crop debris.

Favourable conditions:

• High humidity and warm conditions favour the development of disease.

Root rot:

Disease symptoms:

• The Phytophthora fungus causes crown, foot and root rot. Dark areas of sunken bark called cankers form on the trunk; these cankers exude a dark sap that leaves stains or streaks.
• The leaves change colors and fall from the tree, the branches and twigs die, and eventually the entire tree fails.

Survival and spread:

• The pathogens survive in the soil and crop debris.

Favourable conditions:

• Water logged area around the tree may cause this disease.

Cercospora leaf spot

Disease symptoms:

• Small, dark brown spots on both leaf surfaces. The spots are limited by the veins and so become angular in shape. Severely affected leaves fall readily

Survival and spread:

• This disease may spread through affected plant parts

Favourable conditions:

• Temperature of 25°C coupled with approximately 70 % Relative Humidity

Circular leaf spot

Disease symptoms:

• Although not deadly to adult trees, leaf spot does cause black spots to appear on the surface of leaves, and may sometimes affect fruit as well.
• It can also lead to early dropping of leaves

Survival and spread:

• The fungus infects during rainy season
• Spread through infested leaf.

Favourable conditions:

• Temperature ranging from 25.5 to 30.5° C with relative humidity of 86-92% favours this disease

Bitter rot

Disease symptoms:

• Spot occurs on the surface of leaves and fruit as well.
• It can also lead to early dropping of leaves and fruits

Survival and spread:

• It may spread through infested parts

Favourable conditions:

• Continuous rain, Temperature 28-30˚C and high humidity favours the development of disease

Leaf spot:

Disease symptoms:

• Depressed, dark lesions appear on the leaves, causing them to drop early.
• Once this disease infects the tree it is difficult to get rid of it in one season.

Survival and spread:

• Infected leaves and twigs during the growing season and in the fall. Prune the tree in winter to increase air circulation and remove infected branches

Favourable conditions:

• High humidity

Post-harvest fruit rot

Disease symptom:

• Disease symptoms were irregular brownish and soft lesions mainly located under and surrounding the fruit calyx (stem-end) that expanded rapidly at room temperature and turned to dark brown or black colour producing apparent and in some cases abundant white to grey mycelium.

Survival and spread:

• Spreading through infested fruits.

• Fruits are susceptible to chilling injury, temperature and storage time.

Anthracnose

Disease symptom

• Appears as black spots on leaves, may fall from bottom upwards.
• Other symptoms may include black sunken spots on leaf stalks and lesions on bark.

• Pathogens survive in infected plant debris.

Favourable conditions:

• Infections are much more obvious on the flowers and fruit. Outbreaks are common after warm wet weather.
• During the rainy season, the rain water trickling through the diseased leaves is richly laden with the spores of the pathogens to cause further infections.

IPM for Persimmon

To know the IPM practices for Persimmon, click here.

Source: NIPHM Directorate of Plant Protection, Quarantine & Storage