Phytotoxicity of pesticides mancozeb and chlorpyrifos: correlation with the antioxidative defence system in Allium cepa

Abstract

Pesticides are a group of chemical substances which are widely used to improve agricultural production. However, these substances could be persistent in soil and water, accumulative in sediment or bio-accumulative in biota depending on their solubility, leading to different types of environmental pollution. The present study was done to assess the impact of pesticides-mancozeb and chlorpyrifos, via morphological and physiological parameters using test system. Phytotoxic effects of pesticides were examined via germination percentage, survival percentage, root and shoot length, root shoot length ratio, seedling vigor index, percentage of phytotoxicity and tolerance index. Oxidative stress on seedlings caused by pesticides was also assessed by investigating the activity of antioxidative enzymes viz. catalase, peroxidase and superoxide dismutase. Correlation was worked out between morphological parameters and antioxidative enzymes to bring out the alliance between them. Mancozeb and chlorpyrifos concentrations were significantly and positively correlated with the activity of antioxidative enzymes and negatively correlated with morphological parameters. Significant positive correlation between various morphological parameters showed their interdependency. However, negative correlation was obtained between activity of antioxidative enzymes and morphological parameters. The enzymes however, showed positive correlation with each other. Based on our result we can conclude that all morphological parameters were adversely affected by the two pesticides as reflected by phytotoxicity in . Their negative correlation with activity of antioxidative enzymes indicates that upregulation of antioxidative enzymes is not sufficient to overcome the toxic effect, thereby signifying the threat being caused by the regular use of these pesticides.

Synthesis, insecticidal activity, and phytotoxicity of novel chiral amides

“…The lowest concentration of these compounds (100 µmol L −1 ) stimulated root elongation but higher doses inhibited it, albeit marginally when compared to the herbicide S ‐metolachlor. Elongation tests with the insecticides Chlorpyrifos, α‐cypermethrin and λ‐cyhalothrin in onion and tomato presented a similar pattern (growth stimulation at lower concentrations and inhibition at higher) . Higher adverse effects of insecticidal molecules on root growth compared to shoot elongation, as observed in this study, have been reported for cypermethrin elsewhere …”

Effect of Vegetable Commercialization on Food Safety

“…Mancozeb and metalaxyl were often in use among small-scale farmers growing tomatoes, least among small-scale farmers growing kales. The results agree with those of Fatma, et al (2018) who noted that mancozeb and chlorpyrifos have been proved to be effective in the reproduction in large scale system including and not limited to increasing vegetable production and these pesticides have recorded environmental persistence are highly toxic towards aquatic ecosystem including fish. De Silva et al (2010) add that these pesticides are also toxic to pollinators such as bees and have been associated with reduced bee populations.…”

GENOTOXICITY AND ANTIOXIDANT ENZYME ACTIVITIES INDUCED BY THE CAPTAN FUNGICIDE IN THE ROOT OF BELL PEPPER (Capsicum annuum L. var. grossum L. cv. Kandil)

“…Further, it increased the antioxidant enzyme activities including CAT, POX and GR in tomato seedlings (Yüzbaşıoğlu & Dalyan 2019). Another study has indicated that mancozeb and chlorpyrifos increased CAT and POD activities in A. cepa seedling in a time and concentration-dependent manner (Fatma et al 2018).…”

“…Another study has indicated that mancozeb and chlorpyrifos increased CAT and POD activities in A. cepa seedling in a time and concentration-dependent manner (Fatma et al 2018).…”