This experiment dealing with cuttings of red pine "Pinus densiflora" was made in order to know the adequate moisture content in propagating media.
The cuttings were collected from many seedlings I year old, and then were planted in Kanuma soil bed that had been prepared in an open space.
The moisture contents of medium were varied by various intervals of sprinkling, i.e. sprinkling was made every day, every other day or every third day.
The physical properties of Kanuma soil are shown in table 2, and changes of the moisture contents in medium after sprinkling are shown in table 3.
The mean percentage of the moisture contents of medium which had been sprinkled every day was 194 %, that every other day was 184 % and that every third day was 174 %.
The cuttings which had been planted in every day sprinkled medium showed the smallest percentage of rooting, and those in every other day sprinkled medium showed the greatest.
The adequate moisture content of medium, therefore, seems to be 184～174 %.
When a large amount of moisture are contained in medium, the ratio of their moisture content to their air content seems to have great influence upon the rooting respones of cuttings.
The good ratio for the rooting of red pine cuttings was about I : I.
We could prolong the interval of sprinkling in the medium which had been prepared in a glass house.