Anthracnose disease is caused by a fungus that grows on the green gram, also called mung bean. Several fungi in the genus Colletotrichum are to blame for this disease. Small, deep spots appear on the leaves, stems, and pods when green gram has anthracnose. These spots later turn dark brown or black. As the disease is severe, the parts of the infected plant may dry out and die.
Anthracnose is especially bad for green gram crops, which can lose up to 50% of their yield. The disease is most common in warm, humid places, and it grows best when the dirt and plant surfaces are very wet. The fungus that causes anthracnose can live in dead plants and the soil, which makes it hard to get rid.
Using cultural and chemical means to keep green grams from getting anthracnose would be best. Culture methods include planting types resistant to disease, rotating crops, not watering from above, and removing infected plant debris. Fungicides are used for chemical control and should be used as soon as you notice an issue.
Anthracnose Management in Green Gram/Mung Bean
The Causal Organisms of Anthracnose Disease
Anthracnose disease in green gram is caused by the fungus Colletotrichum lindemuthianum, also known by its sexual stage name, Glomerella lindemuthianum. The fungus produces septate, hyaline, branched mycelium, and conidia in acervuli. The conidiophores are short and hyaline and bear oblong or cylindrical, thin-walled, single-celled conidia with oil globules.
Dark-colored septate setae are also visible in the acervulus. The fungus’s perfect stage produces perithecia that contain a limited number of asci, each of which typically contains eight one or two-celled ascospores with a central oil globule.
The Disease Cycle of Anthracnose Disease
The fungus Colletotrichum lindemuthianum is responsible for the anthracnose disease that affects the green gram. This fungus can be transmitted from seed to plant and cause primary infection. Additionally, the pathogen can survive in infected plant debris in the soil, contributing to secondary spread through the airborne dissemination of conidia. Rain splash is another factor that might contribute to the spread of the illness.
Causes/Conditions Favorable for Anthracnose Disease in the Field
Cold and wet weather conditions can increase anthracnose disease severity in green gram. High soil and plant surface moisture and humidity levels also promote the growth and spread of the fungus. Additionally, poor drainage, overcrowding, and the use of infected seed or plant material can contribute to the development and spread of the disease.
Symptoms of Anthracnose Disease
- Anthracnose disease in green gram can affect all aerial parts of the plant at any growth stage.
- Circular, black, sunken spots with a dark center and bright red-orange margins on leaves and pods.
- Small, irregular watery patches on the leaves, stem, petioles, and pods.
- Spots that have merged transform into sunken lesions with dark centers and brilliant margins.
- In severe infections, the affected parts may wither and die off.
- Seedlings can become blighted due to infection shortly after germination.
- The pathogen responsible for anthracnose can survive on seed and plant debris, leading to secondary spread through airborne conidia.
- The disease usually becomes more severe during cold and wet seasons, and hi