Ascochyta sorghi

Ascochyta_sorghi

Ascochyta sorghi

Ascochyta sorghi is a fungal pathogen that affects sorghum plants (Sorghum bicolor). It is a common disease in sorghum-growing regions, causing significant yield losses under favorable conditions. The pathogen primarily infects the leaves, stems, and grains of sorghum plants, leading to symptoms such as leaf spots, stem cankers, and grain discoloration.

Symptoms

The symptoms of Ascochyta sorghi infection vary depending on the part of the plant affected. Leaf spots caused by the pathogen are typically small, circular lesions with a dark brown margin and a gray center. Stem cankers appear as elongated lesions on the stems, often leading to wilting and lodging of the plant. In grains, Ascochyta sorghi causes discoloration and reduced quality.

Disease Cycle

Ascochyta sorghi survives in infected plant debris and soil, where it can overwinter. In the spring, the pathogen produces spores that are spread by wind, rain, and insects to healthy sorghum plants. Upon contact with a susceptible host, the spores germinate and penetrate the plant tissues, initiating infection. The disease progresses under warm and humid conditions, with symptoms becoming more severe as the infection spreads.

Management

Effective management of Ascochyta sorghi involves a combination of cultural practices, chemical control, and resistant varieties. Crop rotation, removal of infected plant debris, and proper irrigation practices can help reduce the spread of the disease. Fungicides may be used to protect sorghum plants from infection, especially during periods of high disease pressure. Planting resistant sorghum varieties is also an important strategy to minimize the impact of Ascochyta sorghi on crop yield.