Abstract
The report states about the results of the experiments and observations on the saprophytic propagation of Hypochnus centrifugus in the soil.
(1) Hypochnus centrifugus grows and forms sclerotia on the agar culture media prepared with coarse powder of rice-straws, pine needles, sweet-potato vines and leaves, grass weeds, Thuja dolabrata, barley straws and soja bean plants. When the soil is mixed with these materials, the fungus develops and forms the sclerotia; in the case of an insufficient quantity of mixing materials it forms mycelia, but comes to no formation of sclerotium, leaving the mycelia blasted afterwards.
In this cultivation experiment, when we make steam-sterilization of the soil mixed with organic materials, the fungus is observed to be rather poor-developed, in comparison with the case non-sterilization. In the soil not mixed with organic materials we also find the same tendency of the mycelia in growth.
(2) From the out door observation, it is found that Hypochuns centrifugus, in the field without host-crops, also saprogenerates and develops itself to form sclerotia on the blighted crops and weeds, no host plants, such as the fallen blades and ears, roots of straws, the dead stump of Oxalis martiana and others. This saprophytic propagation is often found in the soil where Hypochnus centrifugus exists, remarkably in the rainy season.
