Sugarcane Smut - Hosts and Symptoms

Hosts and Symptoms

Sugarcane smut infects all sugarcane species unless the species is resistant. The damage caused depends on the susceptibility of the species. Sugarcane fields are planted using vegetative cuttings from mother plants so they have the same genetic make-up of the parent plant. Seeds are not used in propagation because sugarcane is a multi-species hybrid and therefore is difficult to breed. Sugarcane smuts can also infect some other grass species outside of sugarcane. However, mostly it remains on plants of the genus Saccharum.

Two to four months after the fungus has infected the plant, black whip-like structures, instead of a spindle leaf, emerge from the meristem, or growing point, of the plant. The developing whip is a mixture of plant tissue and fungal tissue. The whip reaches maturity between the sixth and the seventh month. When spores that are contained inside the whip are released, the core of the whip remains behind and is a straw-like color.

Plants infected with the fungus usually appear to have thin stalks and are often stunted. They end up tillering much more than normal and this results in leaves that are more slender and much weaker. They sometimes appear more grass-like than non-infected plants. Less common symptoms of the disease are stem or leaf galls and proliferating buds.