Physalospora obtusa

Physalospora obtusa is a fungal species belonging to the Botryosphaeriaceae family. It is known for causing a disease known as black rot in apple trees, but can also affect other fruit trees and plants.

Description

Physalospora obtusa is a necrotrophic fungus, meaning it feeds on dead or dying tissue. It produces small, black, spherical fruiting bodies known as pycnidia. These pycnidia contain spores which are released in wet conditions and spread by wind or rain splash.

Disease Cycle

The disease cycle of Physalospora obtusa begins when spores land on a susceptible host. The spores germinate and penetrate the plant tissue, causing necrotic lesions. The fungus continues to grow and spread, eventually leading to the death of the infected tissue. The fungus then produces new pycnidia in the dead tissue, completing the disease cycle.

Management

Management of Physalospora obtusa involves a combination of cultural practices and chemical control. Cultural practices include pruning and removing infected plant material to reduce the source of inoculum. Chemical control involves the use of fungicides to prevent infection.

Economic Impact

Physalospora obtusa has a significant economic impact, particularly in apple production. The fungus causes black rot, which can lead to significant yield losses. In addition to direct yield loss, the disease can also reduce the quality of the fruit, further impacting the economic value of the crop.

See Also

• Black rot (apple)
• Botryosphaeriaceae
• Fungus