Effects of silver nanoparticles on wheat seedlings growth evaluated using ultra-weak photon emissions measurements / Efeitos das nanopartículas de prata no crescimento das plântulas de trigo avaliadas através de medições de emissões de fótons ultra fracos

Ultra-weak photon emission (UWPE) is used to evaluate the effects of silver nanoparticles (AgNP) on wheat seeds germination. Three test series, using wheat seed samples in triplicate, irrigated by three different solutions: AgNP colloid, deionized water and sodium citrate dihydrate solution, had their UWPE data acquired for 24 hours at the fifth day of germination, inside an especially designed dark chamber. The photon-counts summation of each test was calculated, and correlated to its respective germination parameters – total biomass gain and total elongation of seedling aerial part. AgNP tests presented inferior total photon-counts summation and germination parameters levels, as compared to the tests using the other two solutions. Besides, the UWPE temporal profiles decreased over time for the AgNP tests, while for the other two test solutions the emission increased over time. Those results points changes in physiologic functions as deleterious effects of the AgNP contaminant. Principal Component Analysis (PCA) was applied, and the AgNP tests could be separated of the other tests due to germination parameters and UWPE data. The proposed method using UWPE measurements seems to be feasible to evaluate germination parameters of wheat seed in the presence of AgNP, and potentially in the presence of other contaminants.

Influence of selected plant growth stimulators in enhancing germinability and germination parameters of Zea mays L. under microgravity conditions simulated by a two-dimensional clinostat

The earth has become increasingly overcrowded as a result of rapid urbanization and population growth, predicting that its carrying capacity could be overstretched. As a result, it is important to test the possibilities of growing plants under space exploration conditions, especially gravitational balance. Since microgravity impedes plant development, to what extent can plant growth stimulators reverse or enhance this trend? A total of 12 maize seeds were weighed and placed sideways in petri dish and inoculated with plant growth stimulators such as indole acetic acid (IAA), gibberellic acid (GA), and ascorbate (AA) and the clinorotated at different rates (0.5, 1.0 and 2.0 rpm), while control seeds were just placed on a table. Results showed that at 72 hrs, the maize seeds under microgravity showed reduced germination percentage with increasing clinorotation rates as against the control. But when stimulated with IAA, GA and AA, improved germination percentage was observed as against the control even under microgravity condition. The seedling dry weight, germination time and other germination parameters also showed similar improvements. Comparatively, the three growth stimulators showed no major variations in their ability to improve germination percentage under microgravitational impact. However, IAA showed more improvement on seedling vigor as against others, while GA showed more effect on the peak time and rate of germination. This research confirmed the possibilities of improving germinability of maize seeds under space exploration condition.

Allelopathic Potential of Green Manure Cover Crops on Germination and Early Seedling Development of Goose Grass [Eleusine indica (L.) Gaertn] and Blackjack (Bidens pilosa L.)

Green manure cover crops (GMCCs), which are recommended for improving soil fertility, also have the potential of reducing weed populations in cropping systems through allelopathy. The objective of this study was to evaluate the effect of eight GMCCs on the germination and seedling development of two weeds of divergent morphology, namely, goose grass [Eleusine indica (L.) Gaertn] and blackjack (Bidens pilosa L.). Aqueous leaf, stem, and root extracts of hyacinth bean (Lablab purpureus L), red sunnhemp [Crotalaria ochroleuca (G.) Don], showy rattlebox (Crotalaria grahamiana Wight & Arn.), common bean (Phaseolus vulgaris L.), common rattlepod (Crotalaria spectabilis Roth.), radish (Raphanus sativus L.), tephrosia (Tephrosia vogelii L.), and black sunnhemp (Crotalaria juncea L.) at 0, 1.25, 2.5, 3.75, and 5% wv−1 were applied to weed seeds in Petri dishes to determine their effect on germination, radicle and plumule growth, and germination vigor index. The experimental design was 3(tissue types) ∗ 5(concentrations) treatment combinations replicated four times in a completely randomized design. In the pot study, 25 seeds of either goose grass or blackjack were planted separately in approximately 400 g of soil mixed with cover crop tissue powder at 1% concentration per pot. The experimental design was cover crop residues + control replicated four times in randomized complete blocks. There was a significant ( p < 0.05 ) extract ∗ concentration interaction on all germination parameters across all GMCCs. The different cover crop aqueous extracts differentially reduced all germination parameters of both weeds in the order leaf > stem > root extract except for radish root extracts being most inhibitory to all germination parameters of goose grass. The leaf, stem, and root soil-incorporated residues of GMCCs significantly ( p < 0.05 ) affected seedling emergence, dry weight, and vigor indices of both weeds. Based on the results of this study, it was concluded that the different GMCC tissues contain allelochemicals that inhibit the emergence of both monocotyledonous and dicotyledonous weeds.

Statistical Optimization of a Hyper Red, Deep Blue, and White LEDs Light Combination for Controlled Basil Horticulture

This study aims to optimize artificial LEDs light conditions, for “Genovese” basil germination and growth in an indoor environment suitable for horticulture. Following a previous study on the synergic effect of LEDs light and a tailored fertilizer, in this study, the effect of white LED in combination with hyper red and deep blue, as well the plants–lights distance, was correlated to 14 growth and germination parameters, such as height, number of plants, etc. A design of experiments approach was implemented, aiming to derive mathematical models with predictive power, employing a restrained number of tests. Results demonstrated that for the germination phase, it is not possible to derive reliable mathematical models because almost the same results were found for all the experiments in terms of a fruitful germination. On the contrary, for the growth phase, the statistical analysis indicates that the distance among plants and lights is the most significant parameter. Nevertheless, correlations with LED light type emerged, indicating that white LEDs should be employed only to enhance specific growth parameters (e.g., to reduce water consumption). The tailored models derived in this study can be exploited to further enhance the desired property of interest in the growth of basil in horticulture.

Silver Nanoparticles Increase Nitrogen, Phosphorus, and Potassium Concentrations in Leaves and Stimulate Root Length and Number of Roots in Tomato Seedlings in a Hormetic Manner

Background Silver nanoparticles (AgNPs) display unique biological activities and may serve as novel biostimulators. Nonetheless, their biostimulant effects on germination, early growth, and major nutrient concentrations (N, P, and K) in tomato ( Solanum lycopersicum) have been little explored. Methods Tomato seeds of the Vengador and Rio Grande cultivars were germinated on filter paper inside plastic containers in the presence of 0, 5, 10, and 20 mg/L AgNPs. Germination parameters were recorded daily, while early growth traits of seedlings were determined 20 days after applying the treatments (dat). To determine nutrient concentrations in leaves, a hydroponic experiment was established, adding AgNPs to the nutrient solution. Thirty-day-old plants were established in the hydroponic system and kept there for 7 days, and subsequently, leaves were harvested and nutrient concentrations were determined. Results The AgNPs applied did not affect germination parameters, whereas their application stimulated length and number of roots in a hormetic manner. In 37-day-old plants, low AgNP applications increased the concentrations of N, P, and K in leaves. Conclusion As novel biostimulants, AgNPs promoted root development, especially when applied at 5 mg/L. Furthermore, they increased N, P, and K concentration in leaves, which is advantageous for seedling performance during the early developmental stages.

Determining optimal process parameters for sprouting buckwheat as a base for a food seasoning of improved quality

In order to determine the influence of temperature and time of germination of the Bogatyr variety buckwheat on a change in the content of vitamins E, C, and B group, the germination parameters were optimized when developing a new type of seasoning. To optimize the germination parameters, the response surface methodology was used. The maximum total content of B, E, and C group vitamins in the sprouted buckwheat (4.591 mg/100 g) was observed at a temperature of 21.5 °C and the duration of germination of 3 days. The Bogatyr variety buckwheat was sprouted for 4 days. Changes in the nutritional and biological value of the sprouted grains were registered after 24 hours. Based on the comparative chemical analysis, it was established that the content of protein, fiber, vitamins, amino acids increases during the germination of buckwheat in comparison with the control sample. The protein content on day 4 increases by 1.38 times compared to control. At the same time, the mass fraction of carbohydrates on day 4 is reduced by 1.57 times; the mass fraction of fat ‒ by 2 times. It was established that the prototype seasoning that contains 30 % of sprouted buckwheat is characterized by a higher content of protein, vitamins, micro-and macronutrients compared to the control sample (without the addition of sprouted buckwheat). Adding the sprouted buckwheat grain to the seasoning has made it possible to increase by 25 % the antioxidant activity of the finished product compared to the control sample, which is 259.09 and 383.72 mg/100 g, respectively. In terms of safety indicators, the new product fully complies with the requirements for sanitary and hygienic safety. The results reported here give reasons to recommend the production of a new type of seasonings of enhanced nutritional value based on the sprouted Bogatyr variety buckwheat, which could expand and improve the quality of nutrition

Control of Vapor Pressure Deficit (VPD) on Black Sesame Seed (Sesamum indicum L) Sprout Production in a Micro-Greenhouse Using Intelligent Control

The demand for fresh and healthy food has been increasing, and different options for growing sprouts have been presented to solve this, such as traditional techniques and cultivation under controlled conditions. However, sprout farming has not explored all the tools available to produce these foods under controlled conditions. This study presents an alternative to produce sesame seed sprouts in a micro-greenhouse applying intelligent control algorithms for vapor pressure deficit. There was an improvement of 56% in the germination percentage, 2.59 in the germination index, 9.7% in the production of proteins, 1.1% in ash and an increase of 77.03 mm in the sprouts’ length collected in the micro-greenhouse in comparison with the traditional technique. This was achieved by maintaining a mean error for soil moisture at 87% and 0.93 kPa for vapor pressure deficit by applying proportional–integral–derivative, fuzzy logic and neural network control algorithms in the micro-greenhouse. The study shows that the nutritional content, the measured germination parameters and the size are improved in sesame sprout production by applying intelligent control algorithms for vapor pressure deficit in a micro-greenhouse.

Pretreatment with H2O2 Alleviates the Negative Impacts of NaCl Stress on Seed Germination of Tartary Buckwheat (Fagopyrum tataricum)

Soil salinization is one of the main abiotic stress factors impacting the growth of crops and the agricultural industry today. Thus, we aimed to investigate the effects of H2O2 pretreatment on seed germination in Tartary buckwheat (Fagopyrum tataricum) seeds under salt stress and to evaluate this species’ salt tolerance. Through the preliminary experiment, this study used 50 mmol L−1 NaCl solution to induce seed stress. After soaking for 12 h in different H2O2 concentrations, seeds were laid in Petri dishes with 50 mmol L−1 NaCl for seven days and the germination parameters and physiological indicators were measured to screen the optimal H2O2 pretreatment concentration and the salt tolerance index. Our results indicated that pretreatment with 5–10 mmol L−1 H2O2 was most effective in alleviating NaCl’s impacts on the seeds’ germination parameters. Furthermore, the growth and material accumulation of seedlings was promoted; catalase, superoxide dismutase activity, and proline content were enhanced; and malondialdehyde content was reduced. Principal component analysis and stepwise regression revealed six key indicators that had a significant impact on the salt tolerance characteristics of F. tataricum, namely, germination potential, shoot fresh weight, root surface area, root average diameter, catalase activity, and superoxide dismutase activity.