Biostimulants

The aim of the experiment was to evaluate the use of vegetable protein hydrolysate on Adromischus cooperi and Adromischus cristatus to improve plant growth and quality. The two experimental groups in cultivation were: i) group without protein hydrolysates, irrigated with water and substrate previously fertilized; ii) group with protein hydrolysates, irrigated with water and substrate previously fertilized. The test showed a significant increase in agronomic parameters analysed in plants treated with hydrolysed vegetable proteins, both in Adromischus cooperi and Adromischus cristatus. In fact, all plants treated showed a significant increase in total leaf count, number of new leaves, vegetative and root weight, number of inflorescences and flowering time compared to the untreated control. The application of hydrolysed proteins in plant cultivation and in particular in succulents, allows higher quality standards of the product, higher resistance to biotic and abiotic stress, increased growth rate, very interesting aspects in the field of ornamental plants.

The paper presents the results of research on cacti such as Gymnocalycium baldianum, Gymnocalycium mihanovichii, Notocactus eugeniae and Notocactus leninghausii, aimed at improving plant growth and defense against the pathogenic fungus Fusarium sp., through the use of Gigaspora margarita inoculated in the growing medium. Objectives of the work were: i) use Gigaspora margarita to assess if the use of arbuscular mycorrhizae can lead to an increase in the growth rate of Notocactus and Gymnocalycium, plants generally slow in their growth cycle; ii) to evaluate if the use of mycorrhizae can lead to an extension of the duration of the flower, to promote pollination of bees; iii) to assess if the use of Gigaspora Margarita allows greater protection of the roots against the fungus Fusarium sp. which often affects the roots of these cacti. The two experimental groups in cultivation were: i) group without arbuscular michorriza, irrigated with water and substrate previously fertilized; group with Gigaspora Margarita, irrigated with water and substrate previously fertilized. All plants treated with Gigaspora margarita showed a significant increase in plant height and circumference, vegetative and root weight of the plants, number of new suckers, number of flowers and fruits and flower life. In addition, there was significant control of the fungus Fusarium sp. in plants in which Gigaspora margarita was inoculated into the substrate, in fact a reduced infection of the roots due to this pathogen was found. The application of mycorrhiza in the cultivation of plants can guarantee the possibility to obtain a higher quality product, a higher resistance to biotic stress, an increase in growth rate, very interesting aspects in the succulent and cactus plants sector.

The growth of the Global Agricultural Biostimulants in Turf & Ornamentals Market is driven by the increasing demand from emerging regions worldwide and the rising need to improve crop yield.
http://www.micromarketmonitor.com/reports/bio-stimulants-in-turf-and-ornamentals-8084979273.html

Por sus múltiples interrelaciones, la visión de los cultivos recuerda un ecosistema, tanto más cuando se aplican las técnicas de control y manejo integrado. Y es lógico que así ocurra, ya que basta considerar que los cultivos son vegetales domesticados que, aunque protegidos por el hombre, deben seguir conviviendo con formas silvestres.

Es opinión personal que el futuro forzará un manejo agrícola más comprometido con el medio natural, integrado en este. Ello puede ser inconveniente para el consumidor que demanda fruta de aspecto perfecto, pero creo que a largo plazo debe buscarse sostenibilidad de la actividad agrícola y no la máxima producción de fruta inmaculada, pero con frecuencia insípida, por metro cuadrado. Esto requiere un mayor conocimiento del medio, pero también comporta mayor economía de la producción.

La población mundial no parece que vaya a estabilizarse al nivel actual, tanto menos en una cifra inferior. Si bien las técnicas y los recursos bien utilizados pueden dar alimento a una población mayor que la actual, el problema a resolver es la calidad de vida resultante del esfuerzo productivo, especialmente el agrícola. Calidad de vida estrechamente relacionada con la creciente alteración de los intrincados ciclos naturales, debido a la presión sobre el medio ambiente.

Sumada a un cambio climático global, la presión sobre el medio natural fue el origen de la desaparición de las civilizaciones Mesopotámica y del Valle del Indo, por ejemplo. Desde aquel tiempo hemos avanzado mucho técnicamente, pero no por ello se deja de producir sin previsión, agotando acuíferos, desforestando las cabeceras y márgenes de los ríos, descuidando la diversidad genética, utilizando plaguicidas y fertilizantes sin control adecuado, destruyendo zonas naturales de interés, permitiendo que en un crecimiento no planificado las ciudades sepulten las mejores tierras de cultivo, etc. Ha llegado el momento de la previsión a largo plazo, en definitiva del futuro sostenible.

In the greenhouse experiments the antipathogenic activity of new polycomponent biostimulants Regoplant, Stimpo had been investigated at cultivation of different varieties of winter wheat, soybean
and corn plants on infectious backgrounds. The best biological efficiency against phytopathogens was obtained at presowing seed treatment and spraying of crops in vegetation period by Regoplant
(up to 98%) and Stimpo (up to 89%), according to control (without treatment with biostimulants). At 2nd generation of the wheat and chickpea plants (infected by pathogenic micromycetes of Fusarium L.
genus without treatment with biostimulants) the increased resistance to pathogenic micromycetes of Fusarium genus was found too. Using DOT-blot hybridization method the considerable difference between mRNA of control winter wheat and chickpea seedlings and small regulatory si/miRNA of experimental seedlings (obtained from seeds of the 1st generation of plants infected by pathogenic micromycetes of Fusarium genus and treated with biostimulants) was found. It is proposed that
indicated difference connected with partial reprogramming of plant cell genome under the impact of biostimulants – inducers of si/miRNA synthesis with antipathogenic properties.
Keywords: plant resistance to pathogenic and parasitic organisms, biostimulants, si/miRNA, DOT-blot hybridization si/miRNA with mRNA

Serendipita (=Piriformospora) indica is a fungal endophytic symbiont with the capabilities to enhance plant growth and confer resistance to different stresses. However, the application of this fungus in the field has led to inconsistent results, perhaps due to antagonism with other microbes. Here, we studied the impact of individual bacterial isolates from the endophytic bacterial community on the in vitro growth of S. indica. We further analyzed how combinations of bacteria and S. indica influence plant growth and protection against the phytopathogens Fusarium oxysporum and Rhizoctonia solani. Bacterial strains of the genera Bacillus, Enterobacter and Burkholderia negatively affected S. indica growth on plates, whereas Mycolicibacterium, Rhizobium, Paenibacillus strains and several other bacteria from different taxa stimulated fungal growth. To further explore the potential of bacteria positively interacting with S. indica, four of the most promising strains belonging to the genus Mycolicibacterium were selected for further experiments. Some dual inoculations of S. indica and Mycolicibacterium strains boosted the beneficial effects triggered by S. indica, further enhancing the growth of tomato plants, and alleviating the symptoms caused by the phytopathogens F. oxysporum and R. solani. However, some combinations of S. indica and bacteria were less effective than individual inoculations. By analyzing the genomes of the Mycolicibacterium strains, we revealed that these bacteria encode several genes predicted to be involved in the stimulation of S. indica growth, plant development and tolerance to abiotic and biotic stresses. Particularly, a high number of genes related to vitamin and nitrogen metabolism were detected. Taking into consideration multiple interactions on and inside plants, we showed in this study that some bacterial strains may induce beneficial effects on S. indica and could have an outstanding influence on the plant-fungus symbiosis.

Impact of new microbial bioregulators: Avercom, Avercom nova-2, Violar and Phytovit on induction of callus formation and regeneration of plantlets of wheat (Triticum aestivum L.) of cultivar Zimoyarka on the MS nutrient media was studied under in vitro conditions. The increase of frequency of formation of callus cells (from 43 up to 74 %) was observed on the apical meristem of 4-5-day-old seedlings of wheat placed on the MS media supplemented with microbial bioregulators used at the concentrations ranging from 10 up to 60 μl/l in combination with 1 mg/l auxin 2.4-D as compared with lower frequency of formation of callus cells obtained on the MS media supplemented with only auxin 2.4-D used at the concentration 1 mg/l (control). The increase of efficiency of regeneration of wheat shoots (from 35 up to 65 %) was observed on the 3-4-week-old callus tissue grown on the MS media supplemented with microbial bioregulators used at the concentrations ranging from 20 up to 100 μl/l in combination with 1-2 mg/l cytokinin BAP and 0.5-1 mg/l auxin IAA as compared with lower efficiency of regeneration of wheat shoots obtained on the MS media supplemented with 1-2 mg/l cytokinin BAP and 0.5-1 mg/l auxin IAA (control). The rooting of shoots was shown on the MS media supplemented with microbial bioregulators used at the concentrations ranging from 10 up to 100 μl/l. We conducted also physiological and molecular-genetic studies of resistance of wheat plants obtained under in vitro conditions to plant parasitic nematodes. In vitro experiments showed that wheat plants grown on MS media with microbial bioregulators had 20-37 % of infestation with cereal cyst nematode Heterodera avenae, significantly lower when compared with 73 % of infestation of the control plants grown without bioregulators. Bioregulators increased morphometric parameters of the wheat plants obtained under in vitro conditions and further grown under greenhouse conditions on the natural invasive background: stem height increased 13.6-37.5 %, flag leaf length 18.0-19.3 %, ear length 6.8-24.6 %, and ear weight 27.0-54.5 %, when compared with control wheat plants. The difference in the degree of hybridized molecules mRNA and small regulatory si/miRNA from control and experimental wheat plants increased: 15-39 % in plants grown under in vitro conditions on the invasive background created by H. avenae and 33-56 % in seeds of plants grown under greenhouse conditions on the natural invasive background. The silencing activity of si/miRNA from wheat plants grown on MS media with bioregulators increased: 20-51 % in plants grown under in vitro conditions on the invasive background created by H. avenae or 38-64 % in plants grown under greenhouse conditions on the natural invasive background. Our studies confirm the RNAi-mediated resistance to plant nematodes of wheat plants grown under in vitro and greenhouse conditions.
Keywords: MS media, phytohormones, microbial bioregulators, wheat callusogenesis and organogenesis, plant resistance to parasitic nematodes, small regulatory si/miRNA.

In this study, the ability of PGPRs to improve the growth and rooting of Portulacaria afra in pots was evaluated. Portulacaria afra is an interesting plant from a medicinal and ornamental point of view, but it shows some difficulties in the early stages of cultivation. The two experimental groups in cultivation were: i) group without beneficial microorganisms (CTRL) (peat 60% + pumice 30% + chabazite 10%), irrigated with water and substrate previously fertilized; ii) group with beneficial microorganisms (PGPR) (peat 60% + pumice 30% + chabazite 10%), irrigated with water and substrate previously fertilized, (1,5g TNC Bactorr S13 per litre of soil). The microorganisms in TNC S13 Bactorr were: Bacillus amyloliquefaciens, B. brevis, B. cirulans, B. coagulans, B. firmus, B. halodenitrificans, B. laterosporus, B. licheniformis, B. megaterium, B. mycoides, B. pasteuri, B. polymixa, B. subtilis (1.3 x 10 11 cfu/Kg). All plants treated with Plant Growth Promoting Rhizobacteria (PGPR) showed a significant increase in the agronomic parameters analysed compared to the untreated control (CTRL), both in Portulacaria afra and in Portulacaria afra variegated. The results show that microorganisms are able to improve the absorption of water and nutrients by increasing the agronomic and physiological characteristics of plants. Very interesting aspects to improve agronomic quality, especially for those who cultivate plants from particular environments and that are poorly adapted to our climates and cultivation methods.

Національний університет біоресурсів і природокористування України НДІ фітомедицини, біотехнологій та екології Факультет захисту рослин, біотехнологій та екології Агенство з трансферу технологій, освіти і науки daRostim Німецький приватний інститут прикладної біотехнології daRostim БІОЛОГІЧНО АКТИВНІ ПРЕПАРАТИ В РОСЛИННИЦТВІ НАУКОВЕ ОБҐРУНТУВАННЯ-РЕКОМЕНДАЦІЇ-ПРАКТИЧНІ РЕЗУЛЬТАТИ Матеріали XV Міжнародної науково-практичної конференції Київ, 25-29 червня 2019 року

Spinach and common bean plants as representatives of leafy and legume vegetables were subjected to some biostimulants to evaluate its effects, against organic and mineral fertilizers, on plant growth, nutrient uptake and nitrate accumulation under field conditions. Individual treatments of humic acid (HS) and seaweed extract (SW) as bio-stimulants were tested in comparison with organic compost and ammonium nitrate as mineral fertilizer. Fresh and dry weight of spinach and common bean plants were significantly positively affected by application of seaweed extract and humic acid, respectively. Incorporation of organic compost resulted in fresh and dry biomass yields of spinach leaves, common bean green vegetative part and pods nearly closed or slightly lower than those recorded with ammonium nitrate fertilizer. In most cases, seaweed extract was superior over other treatments. Both of humic acid and seaweed extract relatively increased fresh or dry weights of both crops by about 50% in average over the plants fertilized with ammonium nitrate or treated with organic compost. Application of seaweed extract and humic acid had reduced the nitrate content in spinach leaves as compared to plants treated with ammonium nitrate but nearly closed to those of organic compost. Either organic compost or biostimulants (SW and HS) produced edible leaves of spinach with lower nitrate content that makes it marketable according to permissible level organized by European Commission Regulation (3500 mg kg-1 FW). Nitrogen, phosphorus and potassium uptake by leaves of spinach and pods of common bean were positively significantly increased with application of all tested treatments in comparison to the untreated control, but seaweed extracts and to somewhat extent the humic acid resulted in NPK values more or nearly closed to those recorded with either mineral fertilizer or organic compost additive. These results gave the chance to accept the biostimulants in addition to organic additive as alternative and sustainable tools complementing a high yield with premium quality.

Keywords: Biostimulants, Common bean, Mineral fertilizer, Organic compost, Spinach

Aim of the study: Plant parasitic nematodes are dangerous pests that damage various agricultural crops
and decrease their productivity. The aim of our work was to obtain new lines of wheat (Triticum aestivum
L.) plants with increased resistance to plant parasitic nematodes under in vitro conditions on the nutrient
MS media containing bioregulators of microbiological origin.
Material and methods: Here we conducted the studies of the effect of nutrient media with bioregulators
of microbiological origin (Avercom, Avercom nova-2, Phytovit and Violar) on the resistance to cereal cyst
nematode H. avenae of wheat plants of cultivar Zimoyarka grown under in vitro conditions using
phenological and molecular-genetic indices for wheat plants. We also studied the resistance to various
species of nematodes of wheat plants obtained under in vitro conditions on MS media with bioregulators
of microbiological origin and further grown under greenhouse conditions using morphometric and
molecular-genetic indices for wheat plants.
Results: In vitro experiments showed that wheat plants grown on MS media with bioregulators of
microbiological origin had 20-37 % of infestation with cereal cyst nematode Heterodera avenae,
significantly lower when compared with 73 % of infestation of the control plants grown without
bioregulators. Bioregulators of microbiological origin increased morphometric parameters of the wheat
plants obtained under in vitro conditions on MS media and further grown under greenhouse conditions on
the natural invasive background: stem height increased 13.6-37.5 %, flag leaf length 18.0-19.3 %, ear
length 6.8-24.6 %, and ear weight 27.0-54.5 %, when compared with control wheat plants. The difference
in the degree of hybridizated molecules mRNA and si/miRNA from control and experimental wheat plants
increased: 15-39 % in plants grown under in vitro conditions on the invasive background created by H.
avenae and 33-56 % in seeds of plants grown under greenhouse conditions on the natural invasive
background. The silencing activity of si/miRNA from wheat plants grown on MS media with bioregulators
of microbiological origin increased: 20-51 % in plants grown under in vitro conditions on the invasive
background created by H. avenae or 38-64 % in plants grown under greenhouse conditions on the natural
invasive background.
Conclusion. Our studies conducted under in vitro and greenhouse conditions confirmed the possibility of
application of the bioregulators of microbiological origin on the nutrient MS media to obtain new lines of
wheat (Triticum aestivum L.) plants with increased RNAi-mediated resistance to plant parasitic
nematodes.
Acknowledgements: This work has been carried out with support of the project “Obtaining of cell lines of
agricultural plants with increased resistance to pathogenic and parasitic organisms by the way of inducing
of RNA-interference process using bioregulators of microbiological origin” of the complex interdisciplinary
program of the scientific researches of the NAS of Ukraine “Molecular and cellular biotechnologies for
medicine, industry and agriculture” for the 2015-2019 years (confirmed by the decision of Presidium of the
National Academy of Sciences of Ukraine from 11.02.15, No. 22).
Keywords: wheat, resistance to parasitic nematodes, bioregulators of microbiological origin.

The aim of the experiment was to evaluate the use and influence of Bat guano and Nettle slurry on the growth, flowering and mineral absorption of Delosperma cooperi and Sedum rubrotinctum plants. The 3 experimental groups in cultivation were: (1) group without biostimulants (CTRL), irrigated with water and previously fertilized substrate; (2) group Bat guano (BG) and fertilized substrate; (3) group Nettle slurry (Urtica dioica L.) (UD) and fertilized substrate. Treatments with Nettle slurry and Bat guano resulted in a significant improvement in the growth and flowering characteristics of Delosperma cooperi and Sedum rubrotinctum. The test showed in fact a significant increase in the agronomic parameters analysed in plants treated with Bat guano and Nettle slurry. In fact, all the plants treated with (BG and UD) showed a significant increase in the number of leave, flowers and inflorescences, in the vegetative, radical and inflorescence weight, in the flowering time. The test also resulted in an increase in the NPK mineral absorption and chlorophyll content of plants treated with bat guano and nettle slurry.Interesting aspects that make Bat guano and Nettle slurry valid alternatives to be used as plant biostimulants, when the plants are subjected to biotic and abiotic stresses, in particular transplant, water and salt stress.

In this study an extract of Aschophyllum nodosum was used to improve growth and flowering in plants of Rebutia heliosa and Sulcorebutia canigueralli. The two experimental groups in cultivation were: i) group without the use of Ascophyllum nodosum (CTRL), irrigated with water and fertilized every two weeks; ii) group treated with 10% Ascophyllum nodosum (AS) powder mixed with the substrate, irrigated with water and fertilized every two weeks. All plants treated with Ascophyllum nodosum showed a significant increase in the agronomic characteristics analysed. The cacti (Rebutia heliosa and Sulcorebutia canigueralli) grown in the algae treated substrate showed a significant increase in plant height, suckers number, vegetative and roots weight, plant circumference, flowers number and flower time and seed germination. Effects certainly due to an improvement in the nutritional status of the plants induced by an increase in nutrient assimilation, which manifests itself in increased stress tolerance. Positive effects can be found especially on plant species that have difficulty in germinating, rooting and flowering or as in this experiment on plants that are slow to grow or have difficulty in being grown in greenhouses and in climatic conditions different from those in which they originated.

Plant growth stimulators (growth regulators + biostimulants; PGS) are
chemical substances (organic/inorganic), helpful in plant growth and development. These are not considered as the replacement of fertilizers but can help in improved crop and soil quality. Both compounds can amplify the root biomass, nutrients translocation, enzymatic activities, crop yield, physiology, and nutrient uptake. Biostimulants are rich in minerals, vitamins, plant hormones, oligosaccharides, and amino acids. These compounds have a serious role to improve soil health, fertility,
sorption, and desorption of nutrients. Hence, have a vital character in nutrients cycling, abiotic stress control, heavy metals bioavailability, and greenhouse gaseous emission. This chapter focuses on the discussions about the influence of plant growth regulators and biostimulants in crop production, soil health, heavy metal cycling, greenhouse gases emission with environmental sustainability. Whereas, the impact of biostimulants on greenhouse gases is a research gap.

Soil nutrient cycling in the soil-plant system of crops relies on the effects of the agronomical practices on soil conditions, especially soil microbial population mediating soil carbon transformation (either mineralization or stabilization), nitrogen cycle including soil nitrogen transformation, uptake and return from plants, and nitrogen losses, and the fate of other elements mediating these trade-offs, including phosphorous. Arbuscular mycorrhizal fungi (AMF) are widespread, soil-borne microbes living in an obligate symbiotic status with most of the land plants. Such symbiosis can bring considerable benefits to plant growth, uptake of nutrients, and soil conditions. However, such benefits are not frequently seen in the field since the agronomical practices, especially tillage and use of fungicides, impair its development, which can partly be overcome by inoculation. Also, the increase of CO2 concentration with climate change and nitrogen fertilization could negatively affect the ...

In this study the possibility of using a biostimulant based on Inula viscosa L. (Dittrichia viscosa L.) to improve the growth and quality of Spinacia oleracea L. and Lactuca sativa L. plants and protection against Pythium spp. was evaluated. I. viscosa plants play a role agro-ecological very important because: i) show high allelopathic activity as they produce chemical compounds toxic to other plant species; ii) act as a dwelling place for antagonists useful to combat plant pests and therefore fundamental in the biological struggle; iii) find application in the phyto-remediation of contaminated soil in processesn of phyto-extraction, bioaccumulation. The experiments, started in September 2020, were conducted in the greenhouses of CREA-OF in Pescia (Pt), Tuscany, Italy. The five experimental groups in cultivation were: i) group without biostimulant, irrigated with water and substrate previously fertilized; ii) group with microrganisms, irrigated with water and substrate previously fertilized; iii) group with algae, irrigated with water and substrate previously fertilized; iv) group with Inula viscose, irrigated with water and substrate previously fertilized; v) group with INORT: mix microorganisms + Inula viscosa + algae, irrigated with water and substrate previously fertilized. All Lactuca sativa L. and Spinacia oleracea L. plants treated with a biostimulant based on Inula viscosa showed a significant increase in the agronomic parameters analyzed compared to the untreated control. The results show that the use of the biostimulant introduced in the medium can improve the quality of treated plants by significantly increasing seed germination and plant growth. The data also show that the use of this product has effects on the protection of plants from Pithyum spp. Therefore, further interesting and innovative aspects of the use of this plant have been highlighted, given its acknowledged importance from a medicinal, melliferous and biodiversity point of view. Further experiments are currently underway to confirm the use of INORT as a possible product that can guarantee the grower a possible reduction of fertilizers and plant protection in horticulture.

The aim of the experiment was to evaluate the use and influence of Spirulina and Klamath algae on the growth, flowering, germination and mineral absorption of Portulaca grandiflora plants. The 3 experimental groups in cultivation were: (1) group without algae (CTRL), irrigated with water and previously fertilized substrate; (2) spirulina group (SPR) and fertilized substrate; (3) Klamath group (KLT) and fertilized substrate. The test showed a significant increase in the agronomic parameters analysed in plants treated with Spirulina and Klamath algae. In fact, all plants treated with (SPR and KLT) showed a significant increase in plant height and number of stems, number and diameter of flowers, vegetative and roots weight, number of leaves and flowering time. The test showed that the use of Spirulina and Klamath in the culture medium can significantly influence the germination of the Portulaca grandiflora and resulted in a significant increase in chlorophyll content and improved absorption of NPK. These results could be of interest to growers who want to improve the quality of their ornamental crops by using products that are easy to manage and not harmful to the environment.

This study evaluated the effect of foliar biostimulants on fruit quality of adult 'Valencia' orange and 'Biancolilla' olive trees. Half of the selected orange and olive trees were sprayed twice before harvest with the SUNRED® commercial mix containing phenylalanine, methionine, mono-saccharides and oxylipins from plant extracts as well as potassium salts and urea. Orange and olive yields and fruit quality were measured at harvest, and fruit peel color was determined by digital image analysis. Phenolic and sensory profiles were also determined in the olive oil. In orange, the foliar spray increased TSS:acid ratio and peel color uniformity, while in olive, it increased peel color uniformity, oleocanthal, and 3,4-DHPEA-EDA and decreased oil spiciness. The results of this study suggest that foliar sprays with the SUNRED® biostimulant in pre-harvest may improve fruit quality of 'Valencia' orange and 'Biancolilla' olive by advancing and uniforming fruit rip...

The paper presents the results of research aimed at improving the growth of aromatic plants and stimulating microbial communities in the rhizosphere of two test plants (Lavender and Rosemary), using a water structuring device (Alchewat). The experiments, started in November 2019, were conducted in the greenhouses of CREA-OF in Pescia (PT). The experimental groups were: i) group without structured water, irrigated with water and substrate previously fertilized; ii) group with structured water, irrigated with water and substrate previously fertilized. The test showed a significant improvement in the agronomic parameters analyzed in Lavender and Rosemary plants treated with structured water. In particular, all plants treated with structured water showed a significant increase in plant height, vegetative and roots weight, total flowers biomass and total microbial count. In addition, there was a significant reduction in Lavender of the number of plants dried in structured water treatment and a positive trend in Rosemary, but not significant. The results of this experiment are in accordance with literature and field observation data that report a beneficial effect of structured water on plant growth, health, quantity and quality of yields. Also very interesting is the increase in the substrate of the theses treated with structured water of the number of useful microorganisms, which are probably supporters of the improvement of plant growth. The presence of microorganisms in the substrate can also affect the biotic and abiotic stress resistance of plants. These aspects consequently become very interesting for the grower who can reduce the use of water and fertilizers and increase the quality of the plants by using alternative techniques.

Plant-derived protein hydrolysates (PHs) are gaining prominence as biostimulants due to their potential to improve yield and nutritional quality even under suboptimal nutrient regimens. In this study, we investigated the effects of foliar application of a legume-derived PH (0 or 4 mL L −1) on greenhouse baby spinach (Spinacia oleracea L.) under four nitrogen (N) fertilization levels (0, 15, 30, or 45 kg ha −1) by evaluating morphological and colorimetric parameters, mineral composition, carbohydrates, proteins, and amino acids. The fresh yield in untreated and biostimulant-treated spinach plants increased in response to an increase in N fertilization from 1 up to 30 kg ha −1 , reaching a plateau thereafter indicating the luxury consumption of N at 45 kg ha −1. Increasing N fertilization rate, independently of PH, lead to a significant increase of all amino acids with the exception of alanine, GABA, leucine, lysine, methionine, and ornithine but decreased the polyphenols content. Interestingly, the fresh yield at 0 and 15 kg ha −1 was clearly greater in PH-treated plants compared to untreated plants by 33.3% and 24.9%, respectively. This was associated with the presence in of amino acids and small peptides PH 'Trainer ® ', which act as signaling molecules eliciting auxin-and/or gibberellin-like activities on both leaves and roots and thus inducing a "nutrient acquisition response" that enhances nutrients acquisition and assimilation (high P, Ca, and Mg accumulation) as well as an increase in the photochemical efficiency and activity of photosystem II (higher SPAD index). Foliar applications of the commercial PH decreased the polyphenols content, but on the other hand strongly increased total amino acid content (+45%, +82%, and +59% at 0, 15, and 30 kg ha −1 , respectively) but not at a 45-kg ha −1-rate. Overall, the use of PH could represent a sustainable tool for boosting yield and nitrogen use efficiency and coping with soil fertility problems under low input regimens.

In an open field trial on two agricultural soils in NW Italy, the impact of two seed-applied biostimulants on the rhizosphere bacterial community of young maize plants was evaluated. The 16S rDNA profiling was carried out on control and treated plant rhizosphere samples collected at the 4-leaf stage and on bulk soil. In both soils, the rhizospheres were significantly enriched in Proteobacteria, Actinobacteria, and Bacteriodetes, while the abundances of Acidobacteria, Cloroflexi and Gemmatimonadetes decreased compared with bulk soil. Among the culturable bacteria genera that showed an increase by both biostimulants, most are known to be beneficial for nutrient uptake, such as Opitutus, Chryseolinea, Terrimonas, Rhodovastum, Cohnella, Pseudoduganella and the species Anaeromyxobacter dehalogenans; others are known to be involved in root growth, such as Niastella, Labrys, Chloroflexia and Thermomonas; or in plant defence, such as Ohtaekwangia, Quadrisphaera, Turneriella, and Actinoallomurus. Both biostimulants were also found to stimulate gen. Nannocystis, a potential biocompetitive agent against aflatoxigenic Aspergillus moulds. Under controlled conditions, both biostimulants enhanced the shoot and root biomass at the 4–5 leaf stage. We conclude that the biostimulants do not decrease the biodiversity of the microbial community rhizosphere of young maize plants, but stimulate rare bacterial taxa, some involved in plant growth and pathogen resistance, a result that may have implications in improving crop management.

Abiotic stresses cause oxidative damage in plants. Here, we demonstrate that foliar application of an extract from the seaweed Ascophyllum nodosum, SuperFifty (SF), largely prevents paraquat (PQ)-induced oxidative stress in Arabidopsis thaliana. While PQ-stressed plants develop necrotic lesions, plants pre-treated with SF (i.e., primed plants) were unaffected by PQ. Transcriptome analysis revealed induction of reactive oxygen species (ROS) marker genes, genes involved in ROS-induced programmed cell death, and autophagy-related genes after PQ treatment. These changes did not occur in PQ-stressed plants primed with SF. In contrast, upregulation of several carbohydrate metabolism genes, growth, and hormone signaling as well as antioxidant-related genes were specific to SF-primed plants. Metabolomic analyses revealed accumulation of the stress-protective metabolite maltose and the tricarboxylic acid cycle intermediates fumarate and malate in SF-primed plants. Lipidome analysis indicated...

Soil nutrient cycling in the soil-plant system of crops relies on the effects of the agronomical practices on soil conditions, especially soil microbial population mediating soil carbon transformation (either mineralization or stabilization), nitrogen cycle including soil nitrogen transformation, uptake and return from plants, and nitrogen losses, and the fate of other elements mediating these trade-offs, including phosphorous.

In this study the effect of natural zeolites and zeolites added with microorganisms for the growth of cabbage (Brassica oleracea var. capitata L.) was evaluated, in order to highlight whether the microbiological component is the basis of the functionality of zeolites. The 3 experimental groups in cultivation were: 1) group without zeolites (CTRL) (peat 100%), irrigated with water and substrate previously fertilized; group with natural chabazite (CN) and fertilised substrate; group with chabazite enriched with microorganisms (CM) and fertilised substrate. (Patented formula rif.28106IT/MB/BF). The test showed a significant increase in the agronomic parameters analyzed in plants treated with natural zeolites and zeolites with the addition of microorganisms compared to the control. Also with regard to the physiological analysis of plants there was a significant increase in the parameters analysed, in the thesis treated with zeolites with the addition of microorganisms and natural zeolites compared to the control. Finally, it should be noted that in the thesis treated with zeolites enriched with microorganisms and in that with natural zeolites, the experiment also showed an increase in the percentage of germination of seeds and a significant reduction in the average time of germination compared to the untreated control (CTRL). The use of zeolites, as demonstrated by this test, can guarantee the grower a qualitative improvement of the plants in cultivation, ensuring better management of the use of fertilizers and water for irrigation. The zeolites are able to interact actively with the organic components present in the soil or brought with the fertilization, and have the ability to make more available the mineral and nutritional components present within their crystal lattice, based on the needs of the plant.

Two urban biowaste materials, fermented under anaerobic and aerobic conditions, their soluble and insoluble alkaline hydrolysates, and a commercial biostimulant product, were compared for their capacity to boost Hibiscus crop production and quality. Plants were grown in 4-litre pots, containing peat and pumice as substrate, under optimal growing conditions. A randomized-block experimental design was adopted. Two types (main factors of variability) of treatments were applied, i.e. by blending the above products with the substrate at transplant, and by fertigation using the soluble hydrolysates only. Plant biomass characteristics and ecophysiological parameters were measured. Mean effect of factors and their interactions were assessed by two-way ANOVA. Principal component analysis was performed by using the different dependent variables to summarize the most relevant differences among treatments. Compared with the control (untreated plants), the applied treatments enhanced most of the investigated parameters. The most valuable effects were observed for total biomass accumulation (+25%), plant height (+10%), leaf chlorophyll SPAD index (+15%) and net photosynthesis (+24%). The hydrolysates performed better than the pristine materials. The former ones were comparable to the commercial biostimulant. The results confirmed the hypothesis that biowaste derived products induce biostimulant activity on Hibiscus; their application can improve cultivation sustainability. Abbreviations: D, digestate obtained from the anaerobic fermentation of the organic humid fraction of urban wastes; DAT1, days after T1 (day); DW, plant dry weight (g m −2); E, evapotranspiration rate (mmol m −2 s −1); −F, fertigation treatments ; FERT, treatments applied during the cultivation through fertigation; GC, green compost obtained from the aerobic fermentation of urban gardening wastes; Gs, stomatal conductance (mmol m −2 s −1); ID, insoluble digestate hydrolysate obtained from alkaline hydrolysis of D; IGC, insoluble compost hydrolysate obtained from the alkaline hydrolysis of GC; LAI, leaf area index (m 2 m −2); NO, untreated; NOVA, commercial biostimulant; OM, organic matter (kg m −3); Pn, net photosyn-thetic rate (mol m −2 s −1); SD, soluble digestate hydrolysate obtained from the alkaline hydrolysis of D; SGC, soluble compost hydrolysate obtained from the alkaline hydrolysis of GC; SUB, treatments applied to the substrate as a powder blended with the substrate; T1, beginning of the experimentation (30 days after transplant) (day).

Abstract Modulation of the water availability for the plants can be a sustainable option to reduce agricultural water demand and stimulate the synthesis and accumulation of secondary metabolites. However, information on the reduction of water availability while maintaining yield and functional quality are scarce and fragmentary. This research aimed at elucidating the agronomical, physiological and functional quality (ascorbic acid, phenolic acids and flavonoids) responses triggered by a microbial-based biostimulant containing two strains of arbuscular mychorrizal fungi (AMF) and Trichoderma koningii of greenhouse grown lettuce (Lactuca sativa L.) under well watered (WW), moderate (MDI) or severe deficit irrigation (SDI) regimes. Reducing water availability from WW to MDI did not affect yield, phenolic acids and flavonoids concentration, but reduced both AMF and Trichoderma presence in the roots and soil, respectively, along with plant Mg and Zn concentration by 12.4% and 26.8%, respectively, and almost halved net photosynthetic rate and transpiration. Further reduction in water availability also reduced yields, along with ascorbic acid, total phenols and quercetin. The biostimulant application increased a wealth of traits, including P, Mg, Fe, Mn, and Zn by 20.8%–97.4% and various phenolic acids compared to the non-inoculated control. This effect occurred irrespective of the water availability. In addition, the microbial-based biostimulant increased plant yield, Ca and Cu, and isochlorogenic acid concentrations, but such effects were evident under WW and MDI, only. Luteolin glycoside, that is frequently associated to a plant reaction to water deficit but also to a microbial stimulation, did not vary at reducing water availability in non-inoculated control and progressively increased in the biostimulant inoculated plant. These results suggest that the biostimulant effect on lettuce nutritional and functional quality was mostly independent of the water availability, whereas its effect on fresh marketable and dry yields were evident in WW and MDI, only, through a modulation of the biosynthesis of secondary compounds rather than nutrient uptake. These results have a high practical implication when aiming to improve both plant yield and product quality while reducing water availability.

In this study the possibility of using liquid Inula viscosa (Dittrichia viscosa L.) to improve the growth and quality of Oscularia deltoides and Corpuscolaria lehmanii plants and protection against Aphis nerii was evaluated. The 3 experimental groups in cultivation were: i) group without the use of Inula viscosa liquid macerate (CTRL), irrigated with water and previously fertilised substrate; ii) group treated with 1% of Inula viscosa liquid obtained from flowers (leaf spraying and soil irrigation), previously fertilized substrate (INU1); iii) group treated with 1% of Inula viscosa liquid obtained from leaves and stems (leaf spraying and soil irrigation), previously fertilized substrate (INU2). The test showed a significant increase in the agronomic parameters analyzed in plants treated with liquid Inula viscosa. In fact, all plants treated with Inula showed a significant increase in plant height, leaves number, vegetative and roots weight, branches and flowers number and flowering time in both Corpuscolaria lehmanii and Oscularia deltoides. An evaluation was also made of the number of individuals of Aphis nerii present on the plants of Corpuscolaria lehmanii and Oscularia deltoides to assess whether the macerate of Inula can be used for the control of these insects. The GC-MS analysis of active fractions strongly suggested costic acid as the compound responsible for contact toxicity against Aphis nerii. Probably in the plant treated with Inula viscosa there is an induction of the defense mechanisms that lead to greater resistance to biotic and abiotic stresses. The application of Inula macerate also improves the plant's defences against attacks by fungal pathogens and insects. Very interesting aspects, especially in view of a possible reduction of fertilizers and synthetic plant protection products.

Abstract Modulation of the water availability for the plants can be a sustainable option to reduce agricultural water demand and stimulate the synthesis and accumulation of secondary metabolites. However, information on the reduction of water availability while maintaining yield and functional quality are scarce and fragmentary. This research aimed at elucidating the agronomical, physiological and functional quality (ascorbic acid, phenolic acids and flavonoids) responses triggered by a microbial-based biostimulant containing two strains of arbuscular mychorrizal fungi (AMF) and Trichoderma koningii of greenhouse grown lettuce (Lactuca sativa L.) under well watered (WW), moderate (MDI) or severe deficit irrigation (SDI) regimes. Reducing water availability from WW to MDI did not affect yield, phenolic acids and flavonoids concentration, but reduced both AMF and Trichoderma presence in the roots and soil, respectively, along with plant Mg and Zn concentration by 12.4% and 26.8%, respectively, and almost halved net photosynthetic rate and transpiration. Further reduction in water availability also reduced yields, along with ascorbic acid, total phenols and quercetin. The biostimulant application increased a wealth of traits, including P, Mg, Fe, Mn, and Zn by 20.8%–97.4% and various phenolic acids compared to the non-inoculated control. This effect occurred irrespective of the water availability. In addition, the microbial-based biostimulant increased plant yield, Ca and Cu, and isochlorogenic acid concentrations, but such effects were evident under WW and MDI, only. Luteolin glycoside, that is frequently associated to a plant reaction to water deficit but also to a microbial stimulation, did not vary at reducing water availability in non-inoculated control and progressively increased in the biostimulant inoculated plant. These results suggest that the biostimulant effect on lettuce nutritional and functional quality was mostly independent of the water availability, whereas its effect on fresh marketable and dry yields were evident in WW and MDI, only, through a modulation of the biosynthesis of secondary compounds rather than nutrient uptake. These results have a high practical implication when aiming to improve both plant yield and product quality while reducing water availability.

Plant-derived protein hydrolysates (PHs) are gaining prominence as biostimulants due to their potential to improve yield and nutritional quality even under suboptimal nutrient regimens. In this study, we investigated the effects of foliar application of a legume-derived PH (0 or 4 mL L−1) on greenhouse baby spinach (Spinacia oleracea L.) under four nitrogen (N) fertilization levels (0, 15, 30, or 45 kg ha−1) by evaluating morphological and colorimetric parameters, mineral composition, carbohydrates, proteins, and amino acids. The fresh yield in untreated and biostimulant-treated spinach plants increased in response to an increase in N fertilization from 1 up to 30 kg ha−1, reaching a plateau thereafter indicating the luxury consumption of N at 45 kg ha−1. Increasing N fertilization rate, independently of PH, lead to a significant increase of all amino acids with the exception of alanine, GABA, leucine, lysine, methionine, and ornithine but decreased the polyphenols content. Interest...

Modulation of the water availability for the plants can be a sustainable option to reduce agricultural water demand and stimulate the synthesis and accumulation of secondary metabolites. However, information on the reduction of water availability while maintaining yield and functional quality are scarce and fragmentary. Accordingly , this research aimed at elucidating the agronomical, physiological and functional quality (ascorbic acid, phenolic acids and flavonoids) responses triggered by a microbial-based biostimulant containing two strains of arbuscular mychorrizal fungi (AMF) and Trichoderma koningii of greenhouse grown lettuce (Lactuca sativa L.) under well watered (WW), moderate (MDI) or severe deficit irrigation (SDI) regimes. Reducing water availability from WW to MDI did not affect yield, phenolic acids and flavonoids concentration, but reduced both AMF and Trichoderma presence in the roots and soil, respectively, along with plant Mg and Zn concentration by 12.4% and 26.8%,...