The insecticidal activity of Satureja hortensis essential oil and its active ingredient -carvacrol against Acrobasis advenella (Zinck.) (Lepidoptera, Pyralidae).

Nowadays, Acrobasis advenella is considered a pest of the highest economic significance in black chokeberry plantations, negatively affecting the quantity and quality of fruits. The aim of this study was to investigate the effect of Satureja hortensis essential oil and its main constituent, carvacrol, on the life cycle and physiology of A. advenella. The metabolic activity of both preparations was evaluated against insect α- and ß- glucosidase, catalase, peroxidase and polyphenol oxidase. The results showed S. hortensis essential oil and carvacrol, are characterized by insecticidal activity against A. advenella larvae. It found an increase in catalase activity in A. advenella homogenates under the influence of carvacrol and an induction of polyphenol oxidase by S. hortensis EO with no changes in POX activity. Also, it was shown that the activity of α- and ß-glucosidase significantly increased in larvae fed on inflorescences treated with the essential oil and carvacrol. These preparations particularly strongly affected ß-glucosidase activity in the insect homogenates. S. hortensis essential oil reduced emergence the longevity of moths. The obtained results suggest that S. hortensis essential oil and carvacrol can be useful in protecting organic crops of black chokeberry but essential oils may be more effective biopesticides than their active ingredients separately.

Effect of fluazifop-p-butyl treatment on pigments and polyamines level within tissues of non-target maize plants.

Fluazifop-p-butyl (FL) is one of the most popular graminicides from arylophenoxypropionate group. These herbicides act as inhibitors of acetyl-CoA carboxylase (ACCase) that catalyzes the formation of malonyl-CoA during metabolism of lipids and/or of some secondary compounds. On the other hand arylopropionates and cyclohexanediones cause phytotoxic effects by stimulating free-radicals generation and causing oxidative stress in susceptible plants. However, the importance of disturbances in plant pigments and polyamines accumulation for this effect is not clear. The aim of this work is to quantify the phytotoxicity of FL to non target maize plant and to explain how photosynthetic pigments, anthocyanins (ANC) and polyamines participate in this interaction. Obtained results showed reduction of chlorophyll a and b, but only in case of the highest herbicide dose. Lower FL concentrations caused increase of the photosynthetic pigments, or were not effective. A similar effect was stated for putrescine, while spermidine was reduced within epicotyl of leaf tissues. In case of 2-phenylethylamine (PEA), there was observed a lack of significant changes within leaves and an increase in epicotyl under the middle and the highest dose of the herbicide. Moreover, FL induced ANC accumulation in epicotyls of maize seedlings. The activity of such key enzymes of polyamine biosynthesis as: ornithine decarboxylase (ODC) and lysine decarboxylase (LDC), increased in leaves treated with herbicide at the lowest concentration and decreased under the highest. However, in case of epicotyls the decreasing tendency was observed with the exception of ODC under the highest FL dose. The activity of tyrosine decarboxylase (TyDC) was importantly elevated only within epicotyls under the lower FL concentrations. It was concluded that FL inhibits maize growth, and the intensity of the effect is positively correlated with the herbicide concentration. The phenomenon was related to changes in content of pigments, polyamines and activity of studied enzymes.