Anthracnose severity - Estimation

Observe relative or absolute area of plant tissue affected by yam anthracnose disease and record the severity as a proportion or percentage of plant surface affected.It is visual score in scale under screenhouse, artificial inoculation or under field natural infestation. For artificial inoculation use a suspension of three most virulent strains of Colletothrichum gloeosporioides and inoculate the plants raised from vine cutting in vertical sack or other means by spraying. For natural infestation, scores can be taken 10 to 12 weeks after planting and second scoring about 4-6 weeks before harvesting . Artificial inoculation should be scored at 3 days after inoculation(DAI) , and repeated at 7DAI, 11DAI and 15DAI