Effect of yeast extracts on higher plants

Summary Effect of yeast autolyzate on the growth of vineless pea plant was investigated.The yield was increased remarkably when yeast autolyzate was added, as compared with the control area in which the plants received only mineral fertilizer solution.The yield stimulation was the highest where 0.1 ppm of the autolyzate was added, the yield increasing by more than 80%. The reason why the yields were lower in the areas where the amount of yeast autolyzate added was incrased to 1 ppm and to 10 ppm, was presumed to be due to the fact that the substances may have been absorbed, decomposed, and utilized by soil microorganisms.