Stinging Nettle (Urtica dioica L.) as an Aqueous Plant-Based Extract Fertilizer in Green Bean (Phaseolus vulgaris L.) Sustainable Agriculture

Foliar application of nettle and Japanese knotweed extracts on Vitis vinifera: impact on phenylpropanoid biosynthesis and antioxidant activity during veraison and harvest of cv. Touriga Franca

BACKGROUND

Plant-based extracts have been recently used as sustainable tools to improve biotic and abiotic stress tolerance and increase grape (Vitis vinifera L.) quality. However, knowledge about the effect of these extracts on secondary metabolism compounds, that are fundamental for grape and wine quality, is still scarce. In this study, a trial was installed in an experimental vineyard with the variety Touriga Franca located at University of Trás-os-Montes e Alto Douro, Baixo Corgo sub-region of the Douro Demarcated Region, Portugal in two growing seasons: 2019 and 2020. The aim was to evaluate the effect of foliar application of nettle (Urtica spp.) extract (NE) and Japanese knotweed (Reynoutria japonica) extract (JKE) on grapevines leaves and berries bioactive compounds contents and antioxidant activity, at veraison and harvest.

RESULTS

The application of NE increased the total carotenoids in leaves and the total phenolics content and the antioxidant activity (ferric reducing antioxidant power, FRAP) in berries while JKE increased flavonoids content in leaves and the antioxidant activity (2,2-diphenyl-1-picrylhydrazyl, DPPH) in berries.

CONCLUSION

These extracts seem to have a stimulatory effect on grapevine, enhancing bioactive compounds contents and antioxidant capacity and, consequently, the physiological performance of the plant and the quality of the berries. © 2024 Society of Chemical Industry.

Research progress in physiological effects of resistant substances of Urtica dioica L. on animal performance and feed conversion

Several members of family Urticaceae are mainly found in the temperate and subtropical zones of the Northern Hemisphere and are important medicinal plants. Among them, Urtica dioica L. (Urticaceae) is an annual or perennial herb that has been used for feeding and medicinal purposes since long time and is the most exploited species of Urticaceae. Recently, it has received attention to be used as animal feed, as its fresh leaves fed to animals in moderate, dried, and other forms. This review details the advantages of U. dioica as an alternative feed in terms of germplasm specificity, nutritional composition, and feed application status. Its roots, stems, leaves, and seeds are rich in active ingredients. It has also been found to have anticancer effects through antioxidant action and promotion of apoptosis of cancer cells. In shady conditions, U. dioica is highly adaptable while under stressful conditions of drought; it also reduces light absorption and ensures carbon assimilation through light energy conversion efficiency. Therefore, it can be added to animal diets as a suitable feed to reduce costs and improve economic efficiency. This paper investigates the feasibility of using U. dioica as a feed and systematically presents the progress of research and exploitation of U. dioica.

Antioxidant Activity of Urtica dioica: An Important Property Contributing to Multiple Biological Activities

Urtica dioica (UD) is a multi-functional plant known to be used as both food and medicine from ancient times. The plant has the potential to be used as a fertilizer and for biological pest control. It is also used in textile and related industries for its quality fibers. In the recent past, the plant has received great attention for its numerous important biological activities and food applications. The antioxidant activity of UD is the crucial factor supporting its important biological activities, such as anticancer, antidiabetic and anti-inflammatory properties. The antioxidant activity of UD is also found to be protective in different organs, including the brain, liver, lungs, kidney, ovary, and uterus, and may also be protective against diseases associated with these organs. Few clinical studies have endorsed the antioxidant potential of UD in patients. The current work is an attempt to comprehensively compile and discuss the antioxidant activity of UD from in vitro, in vivo and human studies. The insights of the current study would be helpful in getting a panoramic view of the antioxidant potential of UD, and provide direction for optimizing and developing it for therapeutic applications against important diseases and conditions in the near future.

Non-Aerated Common Nettle (Urtica dioica L.) Extract Enhances Green Beans (Phaseolus vulgaris L.) Growth and Soil Enzyme Activity

One of the limiting factors in organic farming is the scarcity of allowed fertilizers and chemicals for plant protection. Plant and compost extracts are a promising solution for fertilization because of their positive effect on plant growth and soil microbial activity. Nettle extract was already successfully applied to some vegetables. Not-aerated nettle extract, obtained from dry nettle leaves, was applied in experiments with green beans in a quantity of 1 L per pot at two-day intervals was studied. A three-factorial experimental design was applied with two soil types (brown-Calcic Gleysol and red-Eutric Cambisol), soil disinfection with dazomet or not, and irrigated with nettle extract or water. Nettle extract application increased all above-ground traits; plant height, leaf area, flower buds, shoot dry weight at flowering, pod length, pod diameter, and shoot dry weight at harvest by 49%, 66%, 43%, 36%, 11%, 9%, and 37%, respectively, the root length at harvest by 59%, total yield by 48%, soil respiration by 91% and 74% in two soil types, and alkaline phosphatase by 30%. Dehydrogenase activity was enhanced by nettle extract application on red soil, while nettle extract application had no effect on root nodulation. The nettle extract application benefits in green bean organic production were attributed to the nutrients and other components present in the extract and not to nitrogen fixation. The optimization of the dose of the extract and experiments in real conditions of green bean production would be the next step toward the implementation of nettle extract as an organic fertilizer.

Soil Fertilization With Medicinal Plant Processing Wastes Suppresses Tuta absoluta (Lepidoptera: Gelechiidae) and Aphis gossypii (Hemiptera: Aphididae) Populations

Organic soil amendments can influence insect pest populations and the damage to plants they cause. In this study, the effects of medicinal plant processing wastes (MPPWs) applied as organic fertilizers on the host preference and performance of Tuta absoluta and Aphis gossypii were investigated on tomato and cucumber plants, respectively. Processing wastes of cumin, rosemary, thyme, artichoke, chamomile, fenugreek, and nettle were applied in four levels of 0, 20, 40, and 80 g dry matter/1kg culture media in pot experiments. Results showed the application of MPPWs, especially 80 g of nettle, reduced the number of T. absoluta eggs (from 0.8 to 0.4 egg/leaf) and their hatching percentage (from 90 to 76%). The highest and lowest number of aphids were observed in control (36 aphids/plant) and treated cucumbers with 80 g of cumin (18 aphids/plant). Also, the lowest intrinsic rate of increase (0.08 d-1) and net reproductive rate (20 offspring) of T. absoluta were observed in tomatoes fertilized with nettle. The highest and lowest net reproductive rate of A. gossypii were obtained on control and treated plants with 80 g of nettle, respectively. Results of damage assessment showed that the percentage of dry weight loss in the aphid-infested plants was reduced by the use of MPPWs, so that lowest weight loss was observed in the treatment with 80 g of nettle. In conclusion, soil amendment using MPPWs could result in lower pest populations and may improve plant tolerance to insect pest stress, thus these by-products could be considered a valuable tool in pest management.

Nettle, a Long-Known Fiber Plant with New Perspectives

The stinging nettle Urticadioica L. is a perennial crop with low fertilizer and pesticide requirements, well adapted to a wide range of environmental conditions. It has been successfully grown in most European climatic zones while also promoting local flora and fauna diversity. The cultivation of nettle could help meet the strong increase in demand for raw materials based on plant fibers as a substitute for artificial fibers in sectors as diverse as the textile and automotive industries. In the present review, we present a historical perspective of selection, harvest, and fiber processing features where the state of the art of nettle varietal selection is detailed. A synthesis of the general knowledge about its biology, adaptability, and genetics constituents, highlighting gaps in our current knowledge on interactions with other organisms, is provided. We further addressed cultivation and processing features, putting a special emphasis on harvesting systems and fiber extraction processes to improve fiber yield and quality. Various uses in industrial processes and notably for the restoration of marginal lands and avenues of future research on this high-value multi-use plant for the global fiber market are described.