The effects of atrazine and acetochlor herbicides on biochemical and physiological parameters of Zea mays L. (maize) and Pisum sativum L. (pea) plants

In the present work, atrazine and acetochlor herbicides were applied to Zea mays cv. ?Martha F1? (maize) and Pisum sativum cv. ?Utrillo? (pea) during premergence and postemergence growth periods. In the postemergence applications, the effects of herbicides on photosynthetic pigment system, total carbohydrates content, wet-dry weight, relative water content, some antioxidant enzyme activities parameters were investigated (1st, 5th, 10th and 15th days).Atrazine with the concentration range of 21_222 mM and acetochlor with the range of 0,76_8,1 mM were applied to Z. mays by taking the control group as the base. P. sativum was also treated by atrazine and acetochlor with the concentration range of 42_448 mM by taking the control group as the base.Chlorophyll a, chlorophyll b, total chlorophyll and total carbohydrate levels in Z. mays and P. sativum treated with atrazine were lower than those in the control groups as related to the days. On the other hand, carotenoid levels showed considerable increase in the same groups. Furthermore, while the peroxidase activity and malondialdehyte (MDA) content were shown to become less from 10th day, the activity of ascorbate peroxidase was also reduced in 15th day. In relative water content and wet-dry weight a decrease was also recorded.The amounts of chlorophyll a, chlorophyll b, total chlorophyll and total carbohydrate in Z. mays and P. sativum treated with acetochlor were lower than those in the control groups as related to the days. However, the amounts of carotenoid showed considerable increase in the same groups. Peroxidase activity was decreased in the 15th day in both plants. MDA content and ascorbate peroxidase activity were reduced in Z. mays in 10th day and in P. sativum in 15th day. In relative water content and wet-dry weight a decrease were also determined.The treatment of salicylic acid with herbicide enhanced internal salicylic acid quantity in Z. mays and P. sativum in 24th and 48th hours. Furthermore, it was determined that the treatment of exogenous salicylic acid increased the systemic acquired resistance.When the quantities of herbicides residue were analysed in 1st and 15th days, it was also observed that they caused to highly residue in the plants.KEYWORDS: Zea mays, Pisum sativum, atrazine, acetochlor, chlorophyll, carotenoidtotal carbohydrate, , malondialdehyte (MDA), peroxidaseascorbate peroxidase, salicylic acid