Search Results (5)

Algal biostimulants are increasingly integral to vegetable cultivation due to their capacity to boost yield, alleviate abiotic and biotic stress, and enhance overall crop quality. This study evaluated the impact of two commercially available algal-based biostimulants on cucumber (Cucumis sativus L.), examining their effects on yield, number of fruits, dry weight, color, flesh thickness, skin thickness, plastid pigments, and tocopherol content. Both biostimulant treatments resulted in a roughly 13% decrease in yield and fruit number compared to the control treatment. Notably, the biostimulants positively influenced the fruit brightness parameter (L*), leading to darker fruits. Fitostim^® algal biostimulant exhibited a positive effect on dry weight during the initial harvest. The predominant pigments were chlorophyll a and chlorophyll b (constituting 80% of all analyzed pigments), and the most abundant tocopherol was α-tocopherol, comprising 80% to 90% of tocopherols. Skin tissues contained significantly higher levels of pigments and tocopherols compared to flesh. Both biostimulants caused a notable decrease in total tocopherol content in the skin at the first harvest, with reductions of 19.91 mg/kg DW for Phylgreen^® and 9.43 mg/kg DW for Fitostim^® algae. The study underscores the variable efficacy of biostimulants, emphasizing their dependence on the specific biostimulant type and fruit part. The application of biostimulants has the potential to substantially enhance the internal quality of cucumbers, particularly in terms of plastid pigments and tocopherols, offering potential health benefits for consumers. Full article

The use of biostimulants and biofilms in agriculture is constantly increasing, as they may support plant growth and productivity by improving nutrient absorption, increasing stress resilience and providing sustainable alternatives to chemical management practices. In this work, two commercial products based on Trichoderma afroharzianum strain T22 (Trianum P^®) and a seaweed extract from Ascophyllum nodosum (Phylgreen^®) were tested on industrial tomato plants (Solanum lycopersicum var. Heinz 5108F1) in a field experiment. The effects of single and combined applications of microbial and plant biostimulants on plants grown on two different biodegradable mulch films were evaluated in terms of changes in the metabolic profiles of leaves and berries. Untargeted metabolomics analysis by LC-MS Q-TOF revealed the presence of several significantly accumulated compounds, depending on the biostimulant treatment, the mulch biofilm and the tissue examined. Among the differential compounds identified, some metabolites, belonging to alkaloids, flavonoids and their derivatives, were more abundant in tomato berries and leaves upon application of Trichoderma-based product. Interestingly, the biostimulants, when applied alone, similarly affected the plant metabolome compared to control or combined treatments, while significant differences were observed according to the mulch biofilm applied. Full article

The world’s population continues to grow while available natural resources, such as arable land, water, and quality soil, are decreasing. Therefore, it is essential to implement environmentally friendly crop management strategies, which include the use of biostimulants. This study analysed the effects on strawberry plants of Actysei^TM and Phylgreen^®, two commercial biostimulants based on extracts of the seaweed Ascophyllum nodosum. The study was conducted under field capacity (regular irrigation) and at 50% field capacity (mild water stress conditions) for 12 weeks. Different growth parameters of the aerial parts of the plants were measured weekly, such as the number of leaves, length of the longest leaf, leaf area, and the number of flowers and fruits produced, as well as the chlorophyll content, determined with a single-photon avalanche diode (SPAD) detector. At the end of the experiment, the plant material was collected, and the roots and aerial parts were weighed separately to obtain the fresh and dry weight of the samples. Fruit quality was assessed by analysing morphological parameters (weight and size) and some biochemical variables (proline, total soluble sugars, and antioxidant compounds contents). Actysei^TM application generally enhanced plant growth in control plants and under mild water stress conditions, even though root weight was reduced. In contrast, no significant effect of Phylgreen^® on vegetative growth was observed, except for stimulating the root growth of plants watered at field capacity. Both biostimulants, Phylgreen^® to a greater extent, showed an impact on the plants already seven weeks after their initial application, stimulating flower and fruit production, especially at field capacity. 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

Plant stress induced by high temperature is a problem in wide areas of different regions in the world. The trend of global warming is going to enhance the effects of heat stress on crops in many cultivation areas. Heat stress impairs the stability of cell membranes and many biological processes involving both primary and secondary metabolism. Biostimulants are innovative agronomical tools that can be used as a strategy to counteract the detrimental effect of abiotic stresses, including heat stress. In this work, two biostimulants based on Ascophyllum nodosum extracts (named Phylgreen) and based on animal L-α amino acids (named Delfan Plus) were applied as priming treatments to Arabidopsis thaliana plants subjected to heat stress exposure. Plants at the vegetative stage were treated with biostimulants 12 h before high temperature exposure, which consisted of maintaining the plants at 37 ± 1 °C for 4 h. Transcriptional profiles, physiological, and biochemical analyses were performed to understand the mode of action of the biostimulants in protecting the plants exposed to short-term heat stress. At a physiological level, chlorophyll, chlorophyll a fluorescence, phenolic index, total anthocyanins, reactive oxygen species (ROS) were measured, and significant variations were observed immediately after stress. Both biostimulants were able to reduce the oxidative damage in leaves and cell membrane. Transcriptomic data revealed that upregulated genes were 626 in Phylgreen and 365 in Delfan Plus, while downregulated genes were 295 in Phylgreen and 312 in Delfan Plus. Bioinformatic analysis showed that the biostimulants protected the plants from heat stress by activating specific heat shock proteins (HPS), antioxidant systems, and ROS scavengers. The results revealed that the biostimulants effectively induced the activation of heat stress-associated genes belonging to different transcription factors and HSP families. Among the heat shock proteins, the most important was the AtHSP17 family and in particular, those influenced by treatments were AtHPS17.4 and AtHPS17.6A, B, showing the most relevant changes. Full article