Insecticide-induced changes of photosynthetic pigments content in peach leaves

Abstract

In this study, the impact of insecticides on the chlorophyll and carotenoid contents in peach leaves was assessed. Applied insecticides are registered in Republic of Serbia and some EU countries for the control of the oriental fruit moth (Grapholita molesta Busck) in peach orchards. The experiments were set up in peach orchards (variety “Royal gem”) at the localities of Čelarevo and Šišatovac (northern region of the Republic of Serbia). The applied spray liquids from different chemical groups based on cyantraniliprole (a.i. 100 g/l), chlorantraniliprole (a.i. 200 g/l), spinetoram (a.i. 250 g/l), indoxacarb (a.i. 150 g/l), acetamiprid (a.i. 200 g/kg), deltamethrin (a.i. 25 g/l), pyriproxyfen (a.i. 100 g/l) and chlorpyrifos (a.i. 250 g/l), were foliar applied at a concentrations of 0.06, 0.02, 0.02, 0.05, 0.025, 0.05, 0.1 and 0.25%, respectively. Leaves were sampled 3 and 7 days after treatment and analysed for the contents of photosynthetic pigments. Results showed the most adverse impact on the total chlorophyll; their content decreased after application of chlorantraniliprole (32.6-52.7%), indoxacarb (31.1-47.5%), chlorpyrifos (32.4-36.9%), pyriproxyfen (19.5-37.7%) and cyantraniliprole (22.8-33.4%). However, the carotenoid content was increased (16.3 to 117.1%) in the analyzed samples three and seven days after the treatment at both localities, except spinetoram which reduced carotenoids content by 2%. In general, the tested pigments in peach leaves showed a different biochemical reaction depending on the applied insecticides.