Relative Sensitivity of Several Plants to Dinoseb

Abstract

The I50values obtained with preemergence applications of 2-sec-butyl-4,6-dinitrophenol (dinoseb) for shoot and root growth in soil, or root growth in a bioassay were determined for 68 plant varieties representing 66 species. The I50values in soil indicate a difference of more than 240 fold between the most sensitive species, shepherdspurse (Capsella bursa-pastoris(L.) Medic.) and the most tolerant species, peanut (Arachis hypogaeaL.). The correlations among the I50values for shoot and root growth in soil and the root bioassay were significant. The I50values between susceptibility of plants to soil-applied dinoseb and their seed size are correlated significantly. Large-seeded plant species and larger seeds within varieties, in general, were more tolerant to dinoseb than small-seeded species and smaller seeds within a given variety. However, there appeared to be other factors involved in susceptibility. For example, there were differences in response among families; the Leguminosae were the most tolerant, while the Solanaceae and Cruciferae were particularly susceptible.