Bioassay of Residual Fluridone Following Prolonged Wet and Dry Cycles in Coastal Plain Soil of Niger Delta
Year: 2018
Type: article
Abstract: Decades ago, Fluridone was formulated to control aquatic weeds. Recently, Fluridone is used in manipulating plant physiological processes, and also as terrestrial herbicides. Fluridone may enter the soil through different pathways; but its persistence in soils is not clearly understood, especially following a prolonged dry period. Bioassays using responsive plants species are useful in assessing carryover effects of herbicides. Fluridone (three applications of 100 ml of 30 µmol solution each) and No Fluridone control were subjected to 30 days of wet and dry cycles, followed by 77 days of dry periods, and thereafter planted with maize (variety Oba Super 6), i.e., after rewetting the soils. Height and chlorophyll measurements were done on the maize seedlings at 5 DAP and 10 DAP. The morphology of the seedlings was observed throughout the duration of the bioassay study. The shoots of the maize seedlings were harvested at 10 DAP, roots sampled by washing off the soil, and both shoot and roots were oven dried to constant weight. Seedling heights did not differ, but seedlings growth rate from 5th to 10th DAP declined drastically as compared to the period before 5 DAP. Leaf chlorophyll at 10 DAP was significantly reduced in seedlings growing in SA treatments. The leaves of seedlings growing in SA treatment began to whiten by 6th DAP and the bleaching effect progressed up to 10 DAP, apparently manifesting the reduced chlorophyll content. The shoot dry matter contents, root dry weight and shoot:root of the maize seedlings varied significantly (P<0.05) with treatment. This study showed that despite prolonged soil drying preceded by wetting and drying cycles, Fluridone persisted in soil with carryover effects on maize. Therefore, Fluridone is not recommended for soil application in the humid tropics due to its potential to persist in the soils.
Source: Resources and Environment
Authors: Mohammed K. Hamadina, Elsie I. Hamadina
Language: English
Subfield: Pollution
Field: Environmental Science
Domain: Physical Sciences
SDGs: Life on land, Zero hunger
Open Access status: diamond
OpenAlex ID: W2798217940