Anthracnose of Sweet Sorghum

(Colletotrichum graminicola (Ces.) Wilson)

  Symptoms

• The foliar symptoms of anthracnose appear 30-40 days after emergence.
• Typical symptoms are small, circular, elliptical or elongated spots usually about 5mm in diameter. These spots develop gray to straw-colored centers with wide margins that may be tan, red, or blackish -purple depending on the cultivar and the pathogen population. Under conditions of high humidity, the spots increase in number and coalesce to cover a larger leaf area.
• The pathogen also infects midrib, leaf sheath and panicles including grains and rachis.
• Variation in foliage and grain symptoms may be due to host reaction, host physiological status, and the prevailing weather conditions.
  
  

Fig 1: Syptoms on the leaf

  Control measures

• Grow anthracnose resistant cultivars,  such  as SPV 386,  SPV 422,  NTJ 2 ICSV 247, CSH 25 and CSH 22SS

• Spraying Captafol 0.2%, benlate or carbendazim (0.5kg ha-1), three sprays at 10-day intervals starting from 30 -day old crop, under rain free conditions.