Abstract
Considering that the growth-inhibiting sub-stances are contained in the leaf-litter of Aka-matsu (Pines densiflora SILB. et ZUCCl.), Sugi (Cryptomeria japonica D. DON.) and Hinoki (Chamaecyparis obtusa SCEB. et ZUCC.), thewriter carried out experiments to ascertainwhether these substances could inhibit the germi-nation of seeds or not.
The outline of the results is as follows:
1.The water extract from the leaf-litter couldnot only inhibit the germination of seeds, of thesame species, but also could remarkably inhibitgermination of others.
2. The inhibiting effect of the water extract from the leaf-litter could be arranged in theorder of Hinoki, Sugi and Akamatu.
3. On the soil seed-bed which was admixedwith the leaf litter dust, it was recognized thatthe occurance of seedlings was few due to theeffect of the inhibiting substances, and also thegrowth of seedlings was not very good.
4.From the above-mentioned facts, it wasconsidered that the inhibiting substances for thegermination of seeds and the growth of seedlingswere contained in the leaf-litter.
