Albinism was also induced in plants grown from replantings made 45 days after the initial treatment with 4000 ppm concentrations of bisthiocarbamyl hy-drazine and 1, 2-diacetyl-3, 5-diamino-1, 2, 3, 5-tetrahy-dro-1, 2, 4-thiadiazole without any further addition of chemical. This fact demonstrates the strong persistence of the active agent in soil. Spraying plants with solutions of the three compounds was found much less effective than applying the chemicals directly to the soil. The compounds are apparently systemic in their mode of action in that they are taken up from the soil through the root sys-tem with subsequent development of albinism.