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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.

One of the main advantages of camelina (Camelina sativa (L.) Crantz) is its wide environmental adaptability and extreme drought tolerance. The availability of both winter and spring camelina biotypes, characterized by different seed sizes, raises the question about possible differences in their response to drought stress at the emergence stage. To address this, a germination test was set up in controlled conditions, comparing six winter and six spring genotypes with differing seed sizes (ranging from 1.83 to 0.88 g/1000-seeds) under increasing levels of osmotic stress (0, −0.4, −0.8, −1.2, −1.4, −1.6 MPa) using polyethylene glycol (PEG). Camelina withstands mild level of osmotic stress (−0.4 MPa) without significant decrease in germination. Even at −1.2 MPa after 10 d, it still had 75% germination. Significant differences in germination were observed between biotypes, where spring biotypes performed better than winter ones. Shoot and radicle lengths were significantly diminished by imposed osmotic stress, but shoot growth seemed more impacted. In general, spring biotypes had longer shoots and radicles than winter ones. Seed size played a role in the response of camelina to drought, but it depended on biotype and stress level imposed. In particular large seeded spring types had the highest germination percentage and resulted less impaired by osmotic stress, otherwise among the tested winter types the small seeded ones were the best performing. The presented data could be useful for breeding purposes for selecting the appropriate camelina type for sowing in drought-prone regions.

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. [ABSTRACT FROM AUTHOR]

One of the main advantages of camelina (Camelina sativa (L.) Crantz) is its wide environmental adaptability and extreme drought tolerance. The availability of both winter and spring camelina biotypes, characterized by different seed sizes, raises the question about possible differences in their response to drought stress at the emergence stage. To address this, a germination test was set up in controlled conditions, comparing six winter and six spring genotypes with differing seed sizes (ranging from 1.83 to 0.88 g/1000-seeds) under increasing levels of osmotic stress (0, −0.4, −0.8, −1.2, −1.4, −1.6 MPa) using polyethylene glycol (PEG). Camelina withstands mild level of osmotic stress (−0.4 MPa) without significant decrease in germination. Even at −1.2 MPa after 10 d, it still had 75% germination. Significant differences in germination were observed between biotypes, where spring biotypes performed better than winter ones. Shoot and radicle lengths were significantly diminished by imposed osmotic stress, but shoot growth seemed more impacted. In general, spring biotypes had longer shoots and radicles than winter ones. Seed size played a role in the response of camelina to drought, but it depended on biotype and stress level imposed. In particular large seeded spring types had the highest germination percentage and resulted less impaired by osmotic stress, otherwise among the tested winter types the small seeded ones were the best performing. The presented data could be useful for breeding purposes for selecting the appropriate camelina type for sowing in drought-prone regions. [ABSTRACT FROM AUTHOR]