Abstract

It has been pointed out by many investigators in several instances that 2, 4-Dichlorophenoxy acetic acid, applied in herbicidal concentrations leaves toxic effects in the soils. Attempts have been made by workers to assess the persistence of its toxicity and in almost all these studies the emergence of certain seedling like tomato, cucumber and beans have been used as criteria. Nutman et al (1945) reported that 2, 4-D when applied in small quantities of herebicidal concentrations had some toxic effect on soil but it disappeared in a course of 30 days. Mitchell and Marth (1048) found soils kept in dry conditions were toxic even at the end of 18 months. De Rose (1946) Taylor (1947) and Kries (1947) all noted that 2, 4-D persists in soils and supresses germination and growth of plants. Brown and Mitchell (1948), Carlson and Hamner (1948), Hernandez and Warren (1948), Akamine (1951) have shown that the inactivation of 2, 4-D was greatly influenced by factors like temperature, soil moisture, pH, soil type, organic matter, autoclaving, rainfall, and other environ- mental factors.

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