Search Results (24)

Soybean cultivation plays a crucial role in the global food system, providing raw materials for both the food and feed industries. To enhance cultivation efficiency, plant biostimulants are used to improve metabolism and stimulate growth. A key aspect of modern cultivation is the ability to rapidly and non-invasively assess crop status. One such method involves the use of drones equipped with multispectral cameras. This paper presents the results of an experimental study on soybean cultivation involving a natural biostimulant in the form of Epilobium angustifolium extract (commonly known as fireweed) and a commercial seaweed-based biostimulant, Kelpak. The research was conducted at an experimental farm in eastern Poland. The effectiveness of the preparations was evaluated using a drone-mounted multispectral camera. Changes in the values of selected spectral indices were analyzed: the Normalized Difference Red Edge Index (NDRE), the Leaf Chlorophyll Index (LCI), and the Optimized Soil-Adjusted Vegetation Index (OSAVI). The study included a control group treated with pure water. Mathematical and statistical analyses of the mean values and standard deviations of the indices were conducted. The results demonstrated that multispectral scanning allows for the detection of significant differences between the effects of the E. angustifolium extract, the seaweed-based biostimulant, and the water control. These findings confirm the utility of this method for assessing the effectiveness of biostimulant applications in soybean cultivation. Full article

Biostimulants play an active role in sustainable crop production. While biostimulants are thought to have long-term effects on plant growth, little research has been conducted to confirm this hypothesis. In this study, we investigated the long-term residual effects of biostimulants applied exclusively during the onion seedling stage on subsequent plant growth. Three onion cultivars (‘Carta Blanca’, ‘Don Victoro’, and ‘Sofire’) were evaluated with the application of nine microbial biostimulants (LALRISE Mycorrhizae, LALRISE Bacillus velezensis, Mighty Mycorrhizae, MycoApply, Spectrum, Spectrum DS, Spectrum Myco, Tribus Original, and Tribus Continuum), one seaweed extract (Kelpak), and two fertilizer types (conventional and organic fertilizer). Plant morphology and biomass were investigated during the early bulb stage of onion growth. Parameters such as plant height, neck diameter, bulb diameter, and the fresh and dry weights of the shoot, bulb, and root were measured. The results indicated significant cultivar-specific effects of microbial biostimulant and fertilizer type, as well as their interactions, on onion early bulb growth. While seaweed extract exhibited minimal residual impact, specific microbial biostimulants, such as Mighty Mycorrhizae and MycoApply, significantly enhanced bulb growth in the red onion ‘Sofire’. Tribus Continuum was found to increase bulb growth of the yellow onion ‘Don Victoro’. Positive effects of microbial biostimulants on onion growth were also observed with LALRISE Bacillus velezensis, Spectrum Myco, Spectrum, and LALRISE Mycorrizae. Furthermore, microbial biostimulants demonstrated more significant positive effects on onion growth when applied in conjunction with organic fertilizer. In conclusion, microbial biostimulants exhibited long-term positive effects on onion plant growth even when applied solely during the seedling stage prior to transplanting. However, these effects were significantly influenced by onion cultivar and fertilizer type, with the greatest benefits observed when combined with organic fertilizer. We recommend MycoApply and Mighty Mycorrhizae for growers seeking to enhance onion productivity, particularly in organic cultivation, as the two products enhanced bulb and leaf growth in ‘Sofire’ and ‘Don Victoro’. Full article

Biostimulants such as seaweed extracts are emerging as crop management products that can enhance crop productivity and nutritional quality under abiotic stress conditions. Therefore, this study aimed to assess the effectiveness of a seaweed-derived biostimulant (Kelpak^®) in alleviating salinity stress in spinach. A greenhouse experiment which consisted of five treatments (T₁ = Control plants (no NaCl or seaweed extract (SWE), T₂ = plants subjected to 300 mM NaCl without SWE, T₃ = 300 mM NaCl + 1% dilution of SWE, T₄ = 300 mM NaCl + 2.5% dilution of SWE, and T₅ = 300 mM NaCl + 5% dilution of SWE) was conducted. The results showed that salinity without the addition of SWE reduced crop growth, relative water content, chlorophyll, and nutritional quality. Similarly, salinity induced severe oxidative stress, indicated by excessive amounts of superoxide radicals, malondialdehyde and the upregulation of catalase, peroxidase, polyphenols, and flavonoids. Interestingly, plants treated with 5% SWE displayed a substantial enhancement in crop performance, reduction in oxidative stress, and improved nutritional quality, characterised by considerable amounts of minerals, proximate constituents, and vitamins. These results support the use of seaweed extract (Kelpak^®) as a biostimulant in enhancing growth and nutritional quality of spinach under saline cultivation. Full article

Maize (Zea mays L.) is the major produced crop in South Africa, but numerous abiotic/biotic stressors threaten its production. Herbicides are mainly in the agricultural sector to minimise crop yield losses caused by weed competition. However, with most weeds becoming resistant to glyphosate, South African farmers have used higher herbicide concentrations than typically recommended. This study was conducted to determine the effect of two biostimulants (brassinosteroids and KELPAK) and glyphosate on the morphophysiological parameters of maize seedlings. Experiments were carried out in the glasshouses of the Department of Soil, Crop, and Climate Sciences at the University of the Free State in Bloemfontein for eight weeks over two seasons, 2017/2018 and 2018/2019. The treatments did not significantly affect all maize morphological parameters except the plant dry mass. Compared to the control, plant dry mass was significantly (p < 0.05) increased by 15.72 g when glyphosate was applied in combination with brassinosteroids during the 2019 growing season. The application of glyphosate, brassinosteroids, and KELPAK differed significantly (p < 0.05) between weeks across the physiological parameters in the two seasons: an irrefutable significant increase was recorded in the rates of transpiration between the weeks. Although significant differences were recorded in the chlorophyll fluorescence, chlorophyll, and carotenoid content, these parameters were similar to the control, especially in the last week of data collection. During the early developmental stage of maize, farmers can administer biostimulants—brassinosteroid (5 g ai ha⁻¹) and KELPAK (5% ai ha⁻¹)—alone and in combination in glyphosate-resistant maize cultivars treated with glyphosate to aid maize seedlings. Full article

Onion (Allium cepa L.), a globally cultivated vegetable crop, possesses a shallow root system, making it vulnerable to abiotic stresses. The increasing frequency of extreme weather events in recent years necessitates sustainable solutions to enhance onion growth. Biostimulants offer a promising and accessible approach to promote onion growth and quality in an environmentally friendly and sustainable manner. This study investigated the effects of nine commercial microbial biostimulants (LALRISE Mycorrhizae, LALRISE Bacillus, Mighty Mycorrhizae, MycoApply, Spectrum DS, Spectrum Myco, Spectrum, Tribus Original, and Tribus Continuum) and one non-microbial commercial biostimulant (Kelpak—seaweed extract) on the seedling growth of three onion cultivars: Carta Blanca (white), Don Victoro (yellow), and Sofire (red). The results indicated that biostimulants did not significantly affect onion seed germination, but germination rates did vary among the onion cultivars. These cultivars also exhibited significant morphological and biomass differences, with principal component analysis revealing a more obvious effect on root growth compared to shoot growth. Kelpak seaweed extract increased the plant height, leaf area, and shoot fresh weight and dry weight of onion seedlings but decreased the root-to-shoot dry-weight ratio. The effects of microbial biostimulants on onion seedling growth depended on both the onion cultivar and Kelpak seaweed extract. In general, LALRISE Mycorrhizae, Mighty Mycorrhizae, Spectrum Myco, Spectrum DS, and Tribus Continuum exhibited positive effects on seedling growth in certain onion cultivars. Furthermore, the benefits of microbial biostimulants were amplified when combined with Kelpak seaweed extract application. These findings suggest a synergistic interaction between microbial and non-microbial biostimulants, leading to enhanced onion seedling growth. Further research is required to evaluate the long-term effects of these biostimulants on onion plant growth after transplanting to fields. Full article

Ornamental horticulture and breeding, as well as urban landscape architecture, are facing increasing challenges driven by an intensely changing climate and urbanisation. The expansion of cities should be combined with an overall growth of green spaces, where ornamental plant species and cultivars will have to withstand a diverse range of environmental conditions, whereby they are often exposed to multiple stress factors. One of the most widely used ornamental shrub species Weigela florida ‘Eva Rathke’ was treated with the growth promoters Bistep with humic and fulvic acid, Kelpak^® seaweed extract, and Yeald Plus with a high zinc content to test their applicability in a plant nursery. Bistep decreased the physiological parameters (the transpiration rate by 60%, the evapotranspiration rate by 56.5%, and the proline stress enzyme content level by 82.2%), indicating the stress level of the treated plants. The activity of β-glucosidase decreased with all growth-promoting treatments (11.5% for Kelpak and 9.5% for Yeald Plus), as did β-glucosaminidase (22.1% for Kelpak and 9.8% for Yeald Plus), but Bistep treatment reduced the activity of the enzymes less (9.9% for β-glucosidase and 3.3% for β-glucosaminidase). The measured alkaline phosphatase enzyme activity increased with treatment (by 10.7% for Kelpak, 11.7% for Yeald Plus, and 12.63% for Bistep). Based on the results, it was concluded that Bistep and Yeald Plus may be suitable for use in the studied variety, whereas Kelpak^® may not be suggested in plant nurseries for growing W. florida ‘Eva Rathke’ plants. Full article

Biostimulants and other plant growth promoters can provide an effective solution to the challenge of urbanisation and climate change. Viburnum opulus ‘Roseum’ is a globally popular deciduous shrub species that can be made more resistant to urban influences by using natural growth-promoting substances. In our study, we investigated the effects of growth promoters Kelpak^®, Bistep and Yeald Plus on the species, both histologically and physiologically (proline stress hormone measurement). Our measurements were complemented using the analysis of rhizosphere alkaline phosphatase, β-glucosidase and β-glucosaminidase enzymes, to obtain a more complete picture of the combined effect of biostimulants and species. We found that the Bistep biostimulant had an outstanding effect on the leaf tissue culture results of the variety. The transpiration and evapotranspiration findings also confirmed the efficacy of biostimulants. In the case of POD activity and rhizosphere enzyme measurements, Bistep and Yeald Plus obtained statistically higher values than the control group. Kelpak produced better results than the control group in several measurements (alkaline phosphatase levels; evapotranspiration results), but in other cases it resulted in lower values than the control treatment. The use of Bistep and Yeald Plus can greatly assist growers in the cultivation of V. opulus ‘Roseum’ in an urban environment. Full article

Weed control during common buckwheat cultivation is hindered by the crop’s high sensitivity to agrochemicals. This study evaluates whether biostimulants (Asahi SL, Kelpak SL, B-Nine) could reduce the adverse effect of abiotic stress caused by these substances on buckwheat’s vegetation indices and yield. To this end, a four-factor field experiment was performed according to the 3 ⁴⁻¹ Box–Behnken design on chernozem soil with silt texture at the Experimental Station of the Agricultural University of Krakow (Poland, 50°07′ N, 20°04′ E). The results showed that calcium cyanamide fertilization was effective in reducing the abundance of dicotyledonous weeds by 39% and the dry weight of weeds per unit area by 20% relative to ammonium nitrate-fertilized sites. However, the most effective method of weed control was the application of metazachlor together with clomazone. The mixture of these active substances reduced the abundance of monocotyledonous weeds, dicotyledonous weeds, and dry weight of weeds by 83%, 40.5%, and 36.4%, respectively. The use of herbicides adversely affected the leaf area index (LAI). Nitrophenol treatment of buckwheat grown on soil fertilized with calcium cyanamide resulted in increased achene yield and number of seeds per plant compared to ammonium nitrate fertilization. The application of daminozide on chemically protected plants resulted in improved vegetation indices such as normalized difference vegetation index (NDVI) and soil plant analysis development (SPAD) compared to sites not exposed to herbicides. Full article

Phytostimulators are attracting considerable attention for replacing mineral fertilizers, which are of environmental concern, being especially forbidden in organic farming. The benefit of applying such products based on microorganisms (e.g., algae extract) or minerals of nano-meter-sized particle (e.g., nanofertilizers) is that plants can uptake them faster than soil fertilizers, targeting plant growth by regulating their phytohormones, as well as improving plant tolerance to unfavorable environmental conditions (e.g., cold stress). The aim of this study was to test and evaluate the effects of three commercial phytostimulators, called biostimulants (a seaweed-based extract—Kelpak^®, mineral nanoparticles—Nano Active^®, zinc nanoparticles—Dynamic Cresco^®) on yield, chlorophyll content, level of CO₂ assimilation and the effectiveness of PSII under cold stress. The values of all chlorophyll fluorescence and photosynthetic parameters significantly decreased under cold, which indicated a strong inhibition of light-phase photosynthesis in maize leaves. Predicted by the regression analysis minimum, 20 days was enough for maize plants to recover from the inhibition caused by stress damages in their photosynthetic apparatus. At the final measurement in maize growth stage BBCH 65, all the tested phytostimulators showed significant effects in increased values of effective quantum yield of photosystem II, maximum photosynthetic efficiency of PSII and electron transport rate. At this stage, Dynamic Cresco^® and Nano Active^® treatment significantly increased the value of maximum net photosynthetic rate (15.37% and 18.85%, respectively) and leaf chlorophyll content (7.8% and 8.7%, respectively). The application of Dynamic Cresco^® significantly promoted total dry weight by 43.4% in comparison to control under stress growth conditions with cold. These phytostimulators can be used to enhance yield and physiological status of plants after abiotic stress (such as cold) to improve crop productivity, especially in organic farming. Full article

Fraser’s photinia ‘Red Robin’ (Photinia x fraseri Dress, Rosaceae family) is an important primary ornamental landscaping species with optimal hedge or screen effects and low maintenance, but it is difficult to root when propagated by cuttings, although high concentrations of phytohormones are used to optimize rhizogenesis. To our knowledge, there is currently no feasible enhanced method for photinia vegetative propagation through stem cuttings, using seaweed extract-based biostimulants as root promoters. Given the economic importance of the species, this research aims to assess the effects of indole-3-butyric acid (IBA) and seaweed extract-based stimulators on the quality of photinia ‘Red Robin’ cuttings, in terms of rooting indicators and ground and aboveground agronomic features. The treatments applied were different concentrations of commercial rooting stimulators compared to an untreated control: C0: distilled water; Rhizopon AA: 1% IBA (R1); Kelpak^®: 2 mL L⁻¹ (K2); Kelpak^®: 3 mL L⁻¹ (K3); Goteo^®: 2 mL L⁻¹ (G2); Goteo^®: 3 mL L⁻¹ (G3). The first results showed different responses to adventitious rhizogenesis under IBA and both seaweed extract treatments. At 70 DAC (days after cutting), the seaweed extract stimulated the production of over 80% of cuttings with callus; at 240 DAC, the percentage of rooted cuttings treated under R1 was the highest = 34.3%; the worst results were obtained by both biostimulant treatments at the highest doses: K3 = 21.3% and G3 = 20.7%. Furthermore, R1 produced 3.07 roots per cutting, which was 50% higher than the average of all other treatments. The applications of Kelpak^® and Goteo^® biostimulants, at both concentrations, resulted in an inhibition of root length with values below the untreated control. Rooted cuttings under R1 showed the highest ground (0.35 g) and aboveground (0.47) dry value. Neither seaweed extract, Kelpak^® or Goteo^®, at different concentrations, improved both the ground and above-ground weights of rooted cutting, compared to the untreated control, indicating that these natural products are not suitable for Fraser’s photinia ‘Red Robin’ propagation using this methodology. The overall quality of cuttings in IBA treatment was the strongest, with 1%, being the optimum concentration. Further research must be conducted to propose effective agronomic protocols by investigating application methods, doses and number of applications, and to clarify the biochemical and molecular mechanisms of action of these seaweed extracts. Full article

In the horticultural sector, the achievement of an efficient and eco-friendly sustainable production of plants is nowadays challenging. Indeed, in plant vegetative propagation of woody ornamentals, the substitution of chemical products used to promote rooting of cuttings with natural extracts would be a desirable goal. Thus, the aim of this work was to test the replacement of synthetic phytoregulators, such as auxins and brassinosteroids, with biostimulants, such as seaweed extracts, for the rooting promotion of rose cuttings. The rooting rate and biometric parameters of control cuttings treated with distilled water were compared with those of cuttings treated with synthetic hormones, i.e., auxins or 22(S),23(S)-homobrassinolide, or two commercial products based on low temperature seaweed extracts, i.e., Kelpak^® and Phylgreen. Two scented hybrid tea rose cultivars were used to assess possible genotype-dependent effects, i.e., ‘Michelangelo^®’ and ‘Cosmos^®’. Auxins confirmed their role in root growth enhancement in ornamental plant cuttings. Like these phytoregulators, Kelpak^® improved the survival rate and root biometric parameters of both rose cuttings, highlighting its suitability for the replacement of synthetic products used for rooting promotion in rose propagation. Brassinosteroids showed a species-dependent effect, increasing the root biomass in ‘Cosmos^®’ while it resulted as distilled water in ‘Michelangelo^®’. Phylgreen did not improve the rooting of both rose cuttings, highlighting the necessity of evaluating the applicability and methodology for this product before its use. In conclusions, our results highlighted the possibility to replace chemical products in rose cutting production. Full article

Biostimulant application during the cultivation of underutilized crops is an environmental-friendly approach for their production and utilization to promote food security and human health. This study investigated the effect of two commercial biostimulants (a seaweed-based extract, Kelpak^® (1:100, 1:40, and 1:20, dilutions), and plant growth promoting rhizobacteria, PGPR (1:5, 1:10, and 1:15, dilutions)) on the growth, yield, phytochemical content, and nutritional quality of five selected Abelmoschus esculentus genotypes. Biostimulant application significantly influenced vegetative growth and yield in a dose-dependent manner. Plant height, chlorophyll content, stem diameter, number of pods, and total pod fresh and dry weights increased with a decrease in dilution of the biostimulants. The application of PGPR (1:5) significantly promoted both the vegetative growth (plant height, chlorophyll content, and stem diameter) and yield (number of pods, total fresh weight, and total dry weight) when compared to the control (untreated plants) and other biostimulant dilutions. Genotype and biostimulant application had an interactive effect on all the phytochemical (total phenolics, flavonoids, and condensed tannins) and nutritional (β-carotene, vitamin C, calcium, iron, potassium, magnesium, sodium, and zinc) qualities evaluated. This study demonstrated the differential effect of biostimulant application on A. esculentus genotypes. These biostimulants can be used to enhance growth, yield, biochemical, and nutritional contents of underutilised crops such as A. esculentus, depending on the crop genotype, in order to improve crop productivity and combat food insecurity especially in food insecure communities. Full article

Seed germination is a crucial step in plant propagation, as it controls seedling production, stand establishment and ultimately crop yield. Approaches that can promote seed germination of valuable crops remain of great interest globally. The current study evaluated the effect of biostimulant (Kelpak^® and plant-growth-promoting rhizobacteria—PGPR) biopriming on the seed germination of five (VI037996, VI046567, VI055421, VI050956, and VI033796) Abelmoschus esculentus genotypes. The germination responses of the bio-primed seeds were measured using six parameters, including final germination percentage (FGP), mean germination time (MGT), germination index (GI), coefficient of velocity of germination (CVG), germination rate index (GRI), and time spread of germination (TSG). Biostimulant application significantly affected MGT (1.1–2.2 days), CVG (1.4–5.9), and TSG (1.2–3.0 days). Genotype also significantly influenced the TSG (1–3 days). Significant interaction effect of biostimulant treatment and genotype was evident on the FGP, GI, and GRI of the germinated seeds. The most noteworthy effect was demonstrated by Kelpak^® (1:100) applied to genotype VI037996, with significantly improved FGP (82%), GI (238), and GRI (77%/day) when compared to the control. Overall, the current findings suggest the potential stimulatory effect of biostimulants (especially Kelpak^®) on the germination of Abelmoschus esculentus seeds. However, this influence was strongly dependent on the type of genotype. Full article

Modern viticultural areas are being confronted with the negative impacts of global warming on yield and fruit composition, with especially adverse effects on anthocyanin synthesis. Novel and sustainable tools, such as biostimulants, may represent a viable alternative to traditional cultural practices, thus promoting eco-friendly strategies to enhance the yield, fruit quality and abiotic stress tolerance of grapevines. ‘Crimson Seedless’ is a late-season red table grape variety, and due to climatic warming, its berries are frequently failing to acquire the commercially acceptable red color. Canopy applications of different biostimulants, namely, Kelpak^®, Sunred^®, Cytolan^®, LalVigne™ Mature as well as Ethrel^® Top, were tested on grapevine cv. Crimson Seedless grown under semi-arid Mediterranean conditions in order to evaluate their effects on yield and fruit quality. Some of the products were sprayed in canopies at labeled doses, and some were applied at doses reported in other studies. For the control treatment, canopies were sprayed with water. Sampling started at veraison and was repeated at 10-day intervals to measure the evolution of berry weight, length and diameter, as well as the total soluble solids and titratable acidity of the juice. The grapes were harvested when the berries of one of the treatments attained the commercially acceptable color. The greatest improvements in the red berry color were achieved with Sunred^® (at a dose of 4 L ha⁻¹) and Ethrel^® Top (250 ppm plus glycerol at 1%), each applied at veraison and 10 days later. The different applications had varying effects on productivity and qualitative parameters. Only Sunred^® improved the accumulation of anthocyanin and the overall acceptability of table grapes by consumers. The obtained results clearly demonstrate that applying Sunred^® can improve the yield and qualitative parameters of the red table grape variety ‘Crimson Seedless’, indicating that this biostimulant could be a viable alternative to the most widely used plant growth regulator, ethephon. Full article

The application of biostimulants to prevent stress-related losses and increase productivity is becoming an increasingly common practice. A study was carried out to determine the effect of the type and methods of biostimulant application and long-term storage on the content of antioxidant compounds determining the processes of the enzymatic browning of carrot roots. The natural seaweed biostimulant Kelpak and synthetic Asahi were applied as part of the study. A quality assessment of carrot roots was carried out directly after harvest and after six months of storage in air at a temperature of 1 °C and a relative humidity of 95%. A single application of Kelpak seaweed extract in the four-leaf phase (2 or 3 dm³ ha⁻¹) proved to be the most effective for reducing oxidative darkening processes (by 33.5%). The oxidative potential was most strongly dependent on the anthocyanin (r = −0.477) and chlorogenic acid (r = −0.474) contents. The concentration of polyphenols (r = 0.836; r = 0.719) and flavonoids (r = 0.671; r = 0.729) had the greatest effect on the antioxidant capacity (FRAP and ABTS respectively). It was observed that pectin, polyphenol, chlorogenic acid, flavonoid and anthocyanin concentrations tended to increase after a single application of Kelpak in a dose of 2 dm³ ha⁻¹. A long-term storage period had a stronger effect on the increase in the oxidation potential than on the antioxidant capacity FRAP value. Full article