Abstract
This study examined the phyto-toxic effects of a commonly named non-selective herbicide glyphosate (Roundup™) on onions (Allium cepa Linn.). The study was necessitated due to the indiscriminate use and release of Roundup™ for weed control in the Niger Delta soils of Nigeria. The Organisation for Economic Co-operation and Development (OECD) standard protocol # 208 was adopted. The short-term phyto-toxic consequence on onion (A. cepa L.) was determined after a 4-day exposure to varying concentrations of the test chemical at 0.625, 1.25, 2.5, 5 and 10 mg/L, respectively. The percentage growth rate decreased as percentage growth rate inhibition efficiency increased, which implies that the effect of the herbicide was concentration dependent. The mean percentage growth rate inhibition efficiency relative to the control was 28, 47, 61, 73 and 96%, respectively. The effective concentration (EC50) for % Inhibition efficiency was 1.550 mg/L with a 95% confidence interval of 1.269 to 1.848 mg/L. The biological alterations on the onions in the test solutions varied in order of increasing concentrations. Some observations made include decolouration of the test solutions and stunted growth especially at the highest concentration of 10 mg/L. Other effects include: bulb deformation, tissue and root damage. There was significant difference between the exposed species and the control at P < 0.05. The use of the herbicide Roundup™ with such hazardous effects can harm plants especially onion which is a very viable food product of man. This could lead to likely distortion on the ecosystem balance of onions (A. cepa) and similar plants and subsequent effect on human, the major end user. Key words: Herbicide, glyphosate (roundup), onion (Allium cepa Linn.), phytotoxicity.
Highlights
Pesticides are substances or mixture of substances intended for preventing, destroying, repelling, mitigating or controlling any pest
The results of root growth inhibition evaluation of glyphosate (RoundupTM) on onion (A. cepa) for the 4days phytotoxicity assay are presented in Figures 1 to 3
There was significant growth in the control experiment for the test duration, which indicated that the test conditions were appropriate and growth inhibition recorded in the test solutions could be attributed to the effect of the test chemical
Summary
Pesticides are substances or mixture of substances intended for preventing, destroying, repelling, mitigating or controlling any pest. Glyphosate (RoundupTM), which was assessed in this study is one of the most widely used non-selective herbicide with applications in agriculture, forestry, industrial weed control, garden and aquatic environments (Baerson, 2002; Tomlin, 2006; Cavusoglu et al, 2011). Glyphosate is resistant to chemical degradation, stable to sunlight, relatively non-leachable, and has a low tendency to runoff. It is relatively immobile in most soil environments as a result of its strong adsorption to soil particles. It is known to cause damage to soil organisms (Dalby et al, 1995)
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
