Control of storage rot of potato caused by Rhizopus oryzae

Solutions of six fungicides, Benlate, Dithane M 45, Captan, Cupravit, Brestan and Borax, were tasted for control of soft rot in potato caused by Rhizopus oryzae. Low temperatures in isolation or in combination with the fungicides as well as storage in open laboratory, farm barn, and well drained soil pits were also separately evaluated against natural infections of the tubers by the fungus. Captan, benlate and cupravit at 400-500ppm were consistently effective against spore germination, mycelial growth and rot development by the rot-causing organism. Low temperatures (0-5 degrees C) completely inhibited the spore germination and rot development by the pathogen. A low temperature-captan or benlate combination involving the dipping of harvested potato tubers in 300 ppm captan or benlate and storing at 10 degrees C proved very effective against the rot incited by the pathogen. Storage of potato in well drained soil pits particularly in open sites significantly reduced natural infection of the tubers by the fungus.