The biological activity (contact and contact-digestive toxicity, repellent and fumigant effects, effect on the insect’s development and life cycle parameters) of industrial hemp (Cannabis sativa L.) ethanolic extract was assessed against Plodia interpunctella, the most destructive storage pest of sunflower. Additionally, the study aimed to examine the phytotoxic activity of the extract in order to assess its potential as a sunflower grain protectant. Phytotoxicity assessment was based on the effect on germination energy and seed germination and the activity of antioxidative enzymes, enzymes of the polyphenolic metabolism, and the intensity of lipid peroxidation in sunflower seedlings. The antioxidant capacity and content of phenolic compounds (total phenolics and total tannins) were also measured in seedlings. In the experiments, 70% ethanolic extract of dried flowering buds of industrial hemp (variety Helena) was applied at 0.5%, 1.0% and 2.0% concentrations directly on sunflower seeds. Ethanol solution (70%) was the control. The hemp extract (1% and 2%) revealed medium repellence for P. interpunctella larvae (L3–4) while at 2% concentration it caused 42.5% larval mortality after 72 h. Moreover, the insect’s development was prolonged and fecundity significantly reduced in hemp treatments. The extract did not exhibit fumigant activity. Germination energy and germination of sunflower seeds were stimulated in treatment with 2% hemp extract, while most biochemical parameters of the seedlings were not significantly affected by the hemp extract.
30 March 2022 in Studia Universitatis Babeș-Bolyai Chemia
Late blight (LB) caused by the Phytophthora infestans is a devastating tomato disease, distributed worldwide. Tomato wild species could be a potential source of resistance, however, there are little data about their biochemical response to LB infection. Therefore the aim of the study was to evaluate total phenolic and total flavonoid content and antioxidative activity in the leaves of wild (Solanum pimpinellifolium) and cultivated genotype (Bizon) depending on disease severity. S. pimpinellifolium compared to Bizon was less susceptible and had five times lower disease severity index (11% and 55% respectively). Additionally, during the disease progression wild genotype showed a much slower decrease of total biochemical parameters compared to the cultivated one. Parameters such as total phenolic content (TP), DPPH (2,2-diphenyl-1-picrylhydrazyl) radical scavenging test and ABTS (2,2′-azinobis-(3-ethylbenzothiazoline-6-sulfonic acid)) radical scavenging activity in the symptomless leaves and the leaves infection 10-25% remained the same in S. pimpinellifolium. The susceptible genotype Bizon had about 40% of leaves with the disease severity 25-50%, and a rapid decrease of all biochemical parameters. A strong negative correlation was observed between late blight infection and biochemical parameters in Bizon, while in S. pimpinellifolium late blight infection negatively correlated only with TP, TF (total flavonoid content) and total antioxidant activity (TAA).
Pepper and tomato are two of the most important vegetable crops in Serbia. Postharvest diseases affecting these crops can cause substantial losses, especially in Mediterranean and dry temperate regions. With the progression of climate change, the impact of these diseases is expected to increase under local agroecological conditions. This paper is a review of the two most prominent fungal species responsible for postharvest diseases in pepper and tomato: Botrytis cinerea and Alternaria alternata.
20 June 2025 in Studia Universitatis Babeș-Bolyai Chemia
Cherry stalks, as primary by-products of sour cherry (Prunus cerasus L.) and sweet cherry (Prunus avium L.) harvesting, are often considered agricultural and industrial waste. However, cherry stalks are recognized in traditional and ethno medicine for their therapeutic properties, due to their high content of natural antioxidants. In this study, the concentrations of total phenolic and total flavonoid compounds, as well as antioxidant activity, were evaluated in different cherry stalk extracts (aqueous, methanol, ethanol, and acetone) obtained from sweet cherry cultivars, sour cherry cultivars, and a wild cherry sample. The results depended on the cultivar and the solvent used for extraction. The highest concentrations of total phenolic and total flavonoid compounds were observed in acetone extracts. In various antioxidant tests, the antioxidant activity varied depending on the genotype.
28 November 2025 in Journal of Plant Diseases and Protection