Anthracnose disease of soybeans-1

Anthracnose is a major yield reducing fungal disease of soybeans. It is caused by Colletotrichum dematium pv truncate and several related species i.e. Gloeosporium sp. The perfect stage of the fungus is Glomerella sp. The disease is generally late season (i.e. pod set and harvest) disease but it can occur earlier. All growth stages may be affected, including post harvest stages. As it is seed borne fungi, reduces seed quality (as measured by germinability). Fungi can reduce soybean quality also.

Systematic position of the causal organism: 

Kingdom: Fungi
  Division: Eumycota
  Sub-Div: Deuteromycotina
  Class: Coelomycetes
  Order: Melanconiales
  Family: Melanconiaceae
  Genus: Colletotrichum
  Species: C. dematium pv truncatum

Symptoms:

 Leaves, petioles, stems, pods and pedicels are susceptible to this disease. 
 Symptoms of anthracnose can develop in soybeans at any stage of crop development. Most commonly, however, symptoms appear in the early reproductive stages on stems, pods and leaf petioles as irregularly-shaped brown blotches. Blotches are embedded with black fungal bodies which have small, but visible, spines. These structures can be seen with the unaided eye but may be visible more easily with a hand lens.
 Foliage develops brown lesions on the veins and cankers on the leaf petioles.
 Spots or lesions may coalesce and enlarges the lesion or spots.
 Leaves may roll and defoliate prematurely and plants may be stunted. 
 Infected pods may be shriveled and contain no seed; or more two-seeded pods, with shriveled moldy seed, may be evident. 
 Pods can be diseased and the seed may be infected, but symptoms are not always evident in the seed.
 When infected seeds are planted, many of germinating seedlings are killed before emergence. 

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Written By:-

Bismark Bangali,        

Training And Media Communication Officer,

SAFE, Khulna- Bangladesh.