Search Results (8)

Blue (400–500 nm) and red (600–700 nm) light regions have been investigated for their effects on photosynthesis and plant growth, yet evidence for specific blue light wavelengths in plant research is lacking. Investigations into amber (595 nm) light are similarly limited. To ‘shed light’ on these two important wavelengths, this study investigated the combined effects of blue and amber light on plant growth and development in two model plants: tomato (Solanum lycopersicum cv. Beefsteak) and lettuce (Lactuca sativa cv. Breen). Plant growth responses were determined with four light treatments: B+BA (blue + broad amber, 455–602 nm), RB-NA (royal blue + narrow amber, 430–602 nm), RB-BA (royal blue + broad amber, 423–595 nm), and high-pressure sodium at a PPFD of 250 µmol m⁻² s⁻¹. After 21 days, the highest fresh and dry mass for both plant species was obtained under the RB-BA light treatment. Shifting the blue wavelength from 430 nm to 455 nm with broad amber lighting led to 40% less fresh mass for tomatoes, whereas only an approximate 5% reduction in fresh mass was observed for lettuce plants. Our findings demonstrate that an alternate and combined blue + amber light spectrum is effective for optimizing plant productivity. Full article

Humic substances are a type of biostimulant used in greenhouse production to promote plant growth and health. Our goal was to evaluate the effect of three commercially available biostimulants containing humic and/or fulvic acids (HumaPro, FulviPro, and Micromate) on the performance and tissue nutrient concentration of Solanum lycopersicum L. ‘Bush Beefsteak’ grown in a peat-based substrate. We conducted four experiments testing application rate and fertility level (50 and 100 mg⋅L^–1 N) (Exp. 1), application rate and frequency (Exp. 2), direct Micromate incorporation into the substrate (Exp. 3), and FulviPro application method (drench vs. foliar spray) (Exp. 4). Plants were fertilized with 20N-1.3P-15.7K. Experiments 2, 3, and 4 were conducted under low fertility (50 mg⋅L^–1 N). Micromate promoted growth when applied as a weekly drench at 40 g·L⁻¹ or when incorporated into the substrate (20 g in 1 L of the substrate). Micromate-treated plants showed high P, S, and Si in the shoot and root tissues. FulviPro showed a negative effect when applied as a drench at higher rates, but foliar application increased greenness (Green Leaf Index). The negative effects of FulviPro might be due to the over-accumulation of Fe and Mn when applied as a drench. Full article

In recent years, the world has experienced conflict. When political conflicts affect consumers’ emotions and alter their perceptions of a country’s image, it can influence their preferences. This study deconstructs the notion of a country image into multiple dimensions and examines their impact on consumers’ willingness to pay for imported beef from Australia, Brazil, and the United States. Using a rank-ordered probit model and data from a survey of 935 respondents, results show that consumers’ perceptions of a country’s friendliness, economy, environment, and quality all have a positive and statistically significant effect on their willingness to pay for beefsteak imported from that country. Among these dimensions of the country image, the quality is the most important, followed by the economy, friendliness, and the environment. This study also finds heterogeneity in consumer perception of friendliness towards the United States, Australia, and Brazil. This study provides valuable insights for assessing the real losses resulting from a deteriorating international environment and suggests policies to enhance competitiveness in the food market. Full article

Full-spectrum light-emitting diodes (LEDs) mainly comprising 460-nm + 595-nm light are becoming a mainstay in the horticulture industry, and recent studies indicate that plant productivity under white LEDs is higher than combined blue and red LED lighting. Different light properties (wavelength and bandwidth) in full-spectrum light, particularly for the blue and amber light regions, have only partly been explored. This research aimed to characterize the effects of amber + blue light wavelengths and bandwidths on tomato (Solanum lycopersicum cv. Beefsteak) growth, morphology, and production efficiency. Tomato seedlings were subjected to four different light treatments for 60 days: narrow amber light (595 nm), narrow blue + narrow amber light (430 nm + 595 nm) with a 1:10 ratio, white LED (455 nm + 595 nm), and a high-pressure sodium (HPS) lamp (control). The highest mean fresh mass yield occurred with the narrow blue + narrow amber light (479 g), followed by white LED at 20% less, HPS at 34% less, and narrow amber at 40% less. Dry mass and plant height were similar among light treatments. Supplementing narrow amber light with 430-nm blue light led to a 20% increase in chlorophyll content. Findings indicate that narrow amber light is more efficient in biomass accumulation than broad amber light and that precise selection of different blue and amber wavelengths can greatly impact the growth and development of tomato seedlings. This energy-efficient narrow-wavelength combination shows improvement over white LED lighting for maximizing tomato growth. Full article

Fruiting body-forming members of the Basidiomycota maintain their ecological fitness against various antagonists like ascomycetous mycoparasites. To achieve that, they produce myriads of bioactive compounds, some of which are now being used as agrochemicals or pharmaceutical lead structures. Here, we screened ethyl acetate crude extracts from cultures of thirty-five mushroom species for antifungal bioactivity, for their effect on the ascomycete Saccharomyces cerevisiae and the basidiomycete Ustilago maydis. One extract that inhibited the growth of S. cerevisiae much stronger than that of U. maydis was further analyzed. For bioactive compound identification, we performed bioactivity-guided HPLC/MS fractionation. Fractions showing inhibition against S. cerevisiae but reduced activity against U. maydis were further analyzed. NMR-based structure elucidation from one such fraction revealed the polyyne we named feldin, which displays prominent antifungal bioactivity. Future studies with additional mushroom-derived eukaryotic toxic compounds or antifungals will show whether U. maydis could be used as a suitable host to shortcut an otherwise laborious production of such mushroom compounds, as could recently be shown for heterologous sesquiterpene production in U. maydis. Full article

We anchored a colourimetric probe, comprising a complex containing copper (Cu(II)) and a dye, to a polymer matrix obtaining film-shaped chemosensors with induced selectivity toward glycine. This sensory material is exploited in the selectivity detection of glycine in complex mixtures of amino acids mimicking elastin, collagen and epidermis, and also in following the protease activity in a beefsteak and chronic human wounds. We use the term inducing because the probe in solution is not selective toward any amino acid and we get selectivity toward glycine using the solid-state. Overall, we found that the chemical behaviour of a chemical probe can be entirely changed by changing its chemical environment. Regarding its behaviour in solution, this change has been achieved by isolating the probe by anchoring the motifs in a polymer matrix, in an amorphous state, avoiding the interaction of one sensory motif with another. Moreover, this selectivity change can be further tuned because of the effectiveness of the transport of targets both by the physical nature of the interface of the polymer matrix/solution, where the target chemicals are dissolved, for instance, and inside the matrix where the recognition takes place. The interest in chronic human wounds is related to the fact that our methods are rapid and inexpensive, and also considering that the protease activity can correlate with the evolution of chronic wounds. Full article

Cooking changes the texture and tenderness of red meat, which may influence its digestibility, circulatory amino acids (AA) and gastrointestinal (GI) hormonal responses in consumers. In a randomised crossover intervention, healthy males (n = 12) consumed a beef steak sandwich, in which the beef was cooked by either a pan-fried (PF) or sous-vide (SV) method. Plasma AA were measured by ultrahigh performance liquid chromatography (UPLC), while plasma GI hormones were measured using a flow cytometric multiplex array. Following meat ingestion, the circulatory concentrations of some of the essential AA (all the branched-chain AA: leucine, isoleucine and valine; and threonine), some of the nonessential AA (glycine, alanine, tyrosine and proline) and some of the nonproteogenic AA (taurine, citrulline and ornithine) were increased from fasting levels by 120 or 180 min (p < 0.05). There were no differences in circulating AA concentrations between cooking methods. Likewise, of the measured GI hormones, glucose-dependent insulinotropic peptide (GIP) and glucagon-like peptide-1 (GLP-1) concentrations increased from fasting levels after consumption of the steak sandwich (p < 0.05), with no differences between the cooking methods. In the healthy male adults, protein digestion and circulating GI hormone responses to a beef-steak breakfast were unaltered by the different cooking methods. Full article

Despite the growing interest of producers and consumers toward grass-fed, local, and organic beef, the supply chain for these products to reach consumers is not always clear-cut. Among the available options are direct-to-consumers and the conventional food supply chain. Although consumers may pay a premium for beef differentiated by quality attributes, the willingness to pay (WTP) difference across point-of-sales is unclear. In this study, we contrast the WTPs for conventional, grass-fed, local, and organic beef by brick-and-mortar supermarkets (B&Ms), farmers’ markets, and via online stores. We conduct a choice experiment with a nationwide online sample of American consumers. The findings indicate that compared to B&Ms, more consumers are reluctant to purchase beef from farmers’ markets and online outlets. Moreover, the WTP for quality-differentiated attributes varies significantly by the point-of-sales. For most consumers, the downside of online or farmers’ markets outweighs the upside of the quality-differentiated attributes sold in those venues. Full article