The use of biopesticides in the cultivation and growth of plants is part of the concept of "sustainable agriculture". More and more research shows that an increasing number of essential oils and plant extracts have been tested against a wide range of pests with promising results. Thus, it has been shown that various biologically active compounds from plant sources have high efficacy, multiple mechanisms of action, low toxicity to mammals, which has led to the accelerated growth of interest in using them as biopesticides in a stabilized and easy to handle form. The paper aim is to present the results of the experimental researches regarding the investigation of the effectiveness as bioinsecticidal effect of alcoholic plant extracts from spontaneous flora of Moldavia and Bucovina (Romania) (i.e. Artemisia absinthium; Primula veris; Origanum vulgare; Achilleia millefolium) in the pests control during the seeds storage (insect bean-Acanthoscelides obsoletus). Obtaining of the plant extracts was achieved by two extractive techniques: Maceration (M) and ultrasound assisted extraction (UAE) + Maceration (M). The efficiency of the processes (expressed as the degree of extraction) was investigated considering several physical parameters, such as solid / liquid ratio: 1/10, 1/15 and respectively, 1/20, extraction time: 10 minutes and 15 minutes, temperature: 30°C and 40°C. The extracts obtained are considered environmentally friendly since they do not affect the crop plants, but instead they protect it. The experimental results showed that the most efficient method of obtaining plant extracts with a high content of bioactive substances is the combined method ultrasound assisted extraction (UAE) + Maceration (M). In the case of the control sample, there are no abnormal manifestations, the individuals feed constantly and naturally. Regarding the effectiveness of plants in controlling pests of the species Acanthoscelides obsoletus, the descending order is the following: Origanum vulgare, Artemisia absinthium, followed by Achilleia millefolium and Primula veris, whose efficiency is almost identical.

biopesticides, maceration, vegetal extract, ultrasound assisted extraction combined with maceration

biology

Presentation: oral