As with any tuber, sweet potatoes are susceptible to a number of diseases, primarily fungal. One such disease is called sweet potato foot rot. Foot rot of sweet potato is a fairly minor disease, but in a commercial field can result in significant economic losses. While disaster potential for sweet potatoes with foot rot is relatively inconsequential, it is still advisable to learn how to control foot rot in sweet potatoes.
Symptoms of Sweet Potato Foot Rot
Foot rot in sweet potatoes is caused by Plenodomus destruens. It is first observed from mid-season to harvest wherein the stem base blackens at the soil line and the leaves closest to the crown yellow and drop. Fewer sweet potatoes are produced and those that are develop a brown rot at the stem end.
P. destruens may also infect seedlings. Infected seedlings yellow starting on their lower leaves and as the disease progresses, wilt and die.
When sweet potatoes infected with foot rot are stored, affected roots develop a dark, firm, decay that covers a large portion of the potato. Rarely is the entirety of the sweet potato affected.
How to Manage Foot Rot of Sweet Potato
Rotate crops at a minimum of two years to avoid transferring diseases. Use seed stock that is resistant to other diseases or plant cuttings from healthy plants. The cultivar ‘Princesa’ has been found to resist the incidence of foot rot more than other cultivars.
Inspect seed roots and plants for diseases and insects prior to planting or transplanting. Practice good garden sanitation by cleaning and sanitizing tools, removing plant debris, and weeding the area.
There should be no need for chemical control in the home garden, as the impact of the disease is minor.