Many investigations have been conducted on hormonal herbicides like 2, 4-Dichlorophenoxy acetic acid and similar compounds but relatively few studies have been made on 2-chloro 4, 6-bis (ethylamino)-S-triazine (simazine). The general processes of absorption, translocation, growth regulation, and mechanism of herbicidal action of a broad spectrum of herbicides have been reviewed recently (9, 10,22,25,30,33,37). Most of the investigations with sima. zine have dealt primarily with corn and have been largely concerned with symptomatology and toxicology. The chemistry, absorption, translocation, metabol-ism and toxicity of triazine herbicides have been summarised (17, 26). A few investigations have dealt wholly with the absorption and translocation aspects of. simazine (6, 11, 31). It was' estab lishad by Exer (12) and Moreland et at, (27) that simazine acts as a c;trong inhibitor of the Hlll reaction (Phototysis of water). A series of studies by Gysin and associates (16 & 17) have given Impetus to relating chemical structure to phytotoxicity.