Effect of the pesticide treatment dose on the biochemical response of the potato plants (solanum tuberosum l.)

In order to enhance and protect crop yields from different pests, the use of pesticides has increased. In Algeria, most often farmers do not respect the recommended dose of pesticides. The aim of this study is to investigate the dose effect of applying pesticides in field conditions at standard and double doses (agronomic dose, AD; agronomic double dose, ADD) on the morphological and biochemical responses of potato plants (Solanum tuberosum L.). Our result showed significant effect of pesticide application on the biochemical and antioxidant properties of the plant. Higher contents of phenolic and flavonoid were noticed in plants treated with AD and ADD. The accumulation of malondialdehyde increases lipid peroxidation due to the excessive reactive oxygen species production. The significant increase of catalase, ascorbate peroxidase and phenylalanine ammonia lyase activities were recorded in the final growth stage compared with control. AD increases proline content in the final growth stage, but a decrease for chlorophylls and carotenoids. In addition, the decrease in thiols level was observed for both growth stages. In conclusion, the results demonstrated that treatments with pesticides at higher doses than recommended caused oxidative disturbances in potato plants and lead to an enhanced capacity of antioxidant enzymes.