Abstract
Experiments were carried out to examine the effect of nucleic-acid on heading-retardation of rice plant grown under cool weather, applying to the soil before transplanting. The results obtained are as follows : 1) Heading-retardation produced by a treatment of 7 days' low-temperature (17°C) was diminished about 1∼3 days with nucleic-acid application at any growing stage. 2) Heading-retardation of the late-variety grown under natural cool weather was diminished about 3∼6 days with nucleic-acid application, but the same application was not effective to the medium-variety. 3) It was faintly suggested that the effect might be caused by the function of nucleic-acid itself but not by that of each component.
