Scielo RSS <![CDATA[Journal of soil science and plant nutrition]]> vol. 18 num. 3 lang. es <![CDATA[SciELO Logo]]> <![CDATA[The nitrogen fixing specie <em>Sophora cassioides</em> (Fabaceae), is nutritionally favored and their rhizosphere bacteria modified when is co-cultivated with the cluster root forming <em>Embothrium coccineum</em> (Proteaceae)]]> Abstract: The hypothesis that Embothrium coccineum, a species able to solubilize P through cluster roots (CR) carboxylate exudation, makes P more available in volcanic depositions, thus facilitating the growth of other plant species such as the N-fixing Sophora cassioides was tested. In this work, seedlings of these two tree species were grown alone or co-cultivated for six months in greenhouse conditions with either pumice, a recent volcanic deposition with low P availability, or an organic commercial mix. Upon analyzing the aboveground growth of the two substrate treatments, we found no clear evidence of facilitation. Despite this, substrate type did influence the relative growth and some characteristics of CR and nodules. On the other side, the number of total soil bacteria, but not Rhizobium spp, was greater when E. coccineum and S. cassioidea were grown together than when only one species was grown alone. Nutritional parameters, such as the concentration of nitrogen (N) and phosphorous (P) in roots and total leaf protein content in leaves, indicated that the nutritional content of S. cassioides was greater when co-cultivated with E. coccineum in pumice. Specifically, co-cultivation tended to reduced P limitation and improved N acquisition by S. cassioides. Based on these results, our hypothesis is partially accepted. <![CDATA[Different soil structure and water conditions affect the growing response of <em>Lolium perenne</em> L. and <em>Bromus valdivianus</em> Phil. growing alone or in mixture]]> Abstract: Restricting plant available water in the soil can negatively affect pasture growth. Lolium perenne L. (Lp) and Bromus valdivianus Phil. (Bv) are important components of the permanent pastures in southern Chile. The aim of this study was to investigate the growth response of Lp and Bv when subjected to soil water restriction, contrasting soil structure conditions and growing as a single species pasture or in a mixture. The treatments were two soil physical conditions (undisturbed (US) and disturbed soil (DS)), two soil water restriction levels (optimum PAW and very-dry PAW), and three pastures (Bv, Lp and Bv+Lp). The US provided more water to plants regardless of the soil water restriction, and Bv and Lp presented more development (highest accumulated herbage mass) in US than in DS, under a similar soil water restriction. The soil structure and soil water restriction did not modify the tiller number of Bv, although Lp showed different tiller numbers under each condition, soil structure and soil water restriction. The conservation of the soil structure (undisturbed soil) has an important role in pasture productivity by providing a continuous pore system, which certainly improved the water accessibility for the growing species. <![CDATA[Can arbuscular mycorrhizal fungi ameliorate the adverse effects of deficit irrigation on tall fescue (<em>Festuca arundinacea</em> Schreb.)?]]> Abstract: With increasing concerns over global warming, the shortage of water supplies has turned to be a disputable problem in the world. Drought stress is one of the most prevalent abiotic stresses that affect turfgrass growth and quality in landscapes of arid or semi-arid regions. Among the common cool-season turfgrasses, tall fescue can tolerate drought more than other grasses. Fungal bio-fertilizers, especially Arbuscular Mycorrhizal Fungi (AMFs) are able to alleviate the harmful effects of abiotic stresses in the plant. This study was conducted in two consecutive years, 2014 and 2015, to evaluate how two types of AMFs (Funneliformis mosseae and Rhizophagus irregularis) would affect the growth characteristics of two cultivars (‘H-d’ and ‘J-r’) of tall fescue (Festuca arundinacea Schreb.) in the greenhouse and field conditions. Three irrigation intervals were applied, i.e. 7, 14 or 21-days. Results showed that by irrigating less frequently, the visual quality of turfgrass decreased, and there were reductions in the fresh weight, chlorophyll content, and relative water content. However, there were increases in the amount of phosphorus in the shoots, root colonization, compatible solutes (proline and glycine betaine) and antioxidant enzymes (superoxide dismutase and peroxidase). However, these changes were more pronounced in turfgrasses that were treated with AMFs. Qualitative and quantitative characteristics were substantially more promising in the greenhouse than in the field. This is the first report on the morpho-physiological and biochemical responses of tall fescue to AMFs. Results of this investigation could inspire further such works on other turfgrasses, given that the inoculation of turfgrasses with AMFs is a new approach with uncharted potentials that aims at reducing water consumption in the landscape environment. <![CDATA[The influence of Boron on pepper plants nutritional status and nutrient efficiency]]> Abstract: Boron may affect total uptake of various nutrients and their nutrient use efficiency (NUE) which results in high productivity and low fertilizer cost. Therefore, the objective of this study was to investigate the effect of boron concentration in nutrient solution on total uptake of the various nutrients and their utilization efficiency in pepper plants (Capsicum annuum L.). Four cultivars (Osho, Solario, Odysseo and Arlequin) were treated with 0.5-10 mg B L-1. Each treatment included five replications with 3 plants and after 20, 40 and 70 days in culture one plant per pot was removed, divided into leaves, shoots and roots and analysed. The cultivars Odysseo and Arlequin have the greatest total phosphorus absorption at 0.5-2.5 mg B L-1 and more Ca at 1-2.5 mg B L-1, while Odysseo absorbed more magnesium (Mg) per plant at 1 mg B L-1 and 70 d per plant than the other cultivars. Furthermore, Solario, Odysseo, and Arlequin absorbed at 70 days more B. Differences were recorded also among the cultivars concerning the rest of the nutrients. The maximum nutrient use efficiency of Solario and Osho for phosphorus and potassium was recorded at 5 mg B L-1, and in Solario for calcium. Boron use efficiency was maximum for Solario, Osho and Odysseo at 0.5 mg B L-1 and for Fe at 10 mg B L-1 for all the cultivars. The effect of boron on magnesium, manganese and zinc use efficiency was variable. <![CDATA[Iron-bearing minerals from soils developing on volcanic materials from Southern Chile: Application in heterogeneous catalysis]]> Abstract: Chilean soils derived from volcanic ashes are a natural source of iron oxides. Due to their properties, mineralogy, and surface characteristics, iron oxides from Chilean soils are potential candidates for technological applications such as heterogeneous catalysis. However, before a direct application in catalysis, pre-treatment methods are necessary to concentrate iron oxides from bulk volcanic soils. Here, we provide a comprehensive review of pre-treatment strategies for iron oxide concentration including physical separation and selective chemical dissolutive methods for application in catalytic processes, such as the water gas shift (WGS) and Fenton reactions. For preparation of WGS catalyst from volcanic soils, thermal treatment has been demonstrated to be effective, yielding enhanced results for Andisols compared to Ultisols. Based on mineralogical characterisation, it seems that WGS reaction efficiency depends on mineralogical phase shift and the changes of Fe2+/Fe3+ ratio, produced through heating. In addition, Ultisols have shown as efficient catalysts in Fenton and Fenton-like processes, after application of physical and chemical pre-treatments to different size-fractions of the soil sample, improving the yield performance of catalysts. Magnetic separates from the Ultisol sand fraction (compared to the silt+clay fractions) demonstrate the best catalytic performance as Fenton reagent due to their natural magnetite and titanomagnetite content. Application of NaOH selective dissolutive treatment to silt+clay fraction of volcanic soils also produces Fenton and Fenton-like catalyst with improved performance. Our review indicates that catalytic performance can be explained not only by the iron oxide mineral content but also by their characteristics and magnetic properties. The application of the appropriate physical and chemical pre-treatment methods can modulate and enhance the catalytic capabilities of iron oxides from volcanic soils. <![CDATA[Evaluation of natural fertilizer extracted from expired dairy products as a soil amendment]]> Abstract: Dairy products contain high level of minerals and organic materials. The disposal of these materials is a source of environmental pollution and recourses loss. Recycling of expired dairy products is the ideal practical solution for an integrated ecosystem. Thus, a greenhouse trails were carried out to investigate the effectiveness of natural fertilizer extracted from expired dairy products. Expired dairy products powder (EDPP) was applied to wheat (Triticum aestivum vulgar) plants grown on pots filled with a sandy soil. The experiment contained three treatments: (C) control without any fertilization, (IF) inorganic fertilization (a mixture of inorganic fertilizers at a rate of 500 mg N + 150 mg P + 100 mg K /pot) and (EDPP) at a rate of 1% (10 g/pot). EDDP increased the degree of soil aggregation and water holding capacity by 24 and 38% in comparison to inorganic fertilization. The measured soil quality characteristics were improved as a result of the EDDP addition and this led to a remarkable improvement in wheat growth. EDPP elevated all the recoded growth parameters of wheat and increased the total chlorophyll by 22% in comparison to the IF treatment. The application of EDPP significantly raised N, P and K uptake by 45, 73 and 95% compared to IF. EDPP minimized the pH of the soil by 10% and raised the availability of N, P and K by 54, 67 and 14 in comparison to the IF treatment. EDPP fertilizer caused a remarkable increase in wheat growth and improved soil properties. Based on the obtained results, the expired dairy products powder can be used as an organic fertilizer. <![CDATA[Amendment with high and low C/N residues- Influence of rate, order and frequency]]> Abstract: It is unclear if the effect of residue mixes on soil respiration, microbial biomass and nutrient availability over time is influenced by amendment frequency and how the effect differs from that of the same residues added sequentially. There were six treatments differing in number of amendments and order in which residues were added, total amendment rate in all treatments was 20 g kg-1 with 10 g kg-1 of each high (H) and low (L) C/N residue. In treatment names, order of letters indicates order of residues, e.g. HL is H followed by L. In treatments with two amendments, residues were added on days 0 and 20 at 10 g kg-1: 10-LH, 10-HL or a 1:1 mixture of L and H added twice [10-(HL)x2]. In treatments with four amendments, residues were added on days 0, 10, 20 and 30 at 5 g kg-1: 5-HLHL, 5-LHLH, and 5(HL)x4. In 5-HLHL, microbial biomass N (MBN) increased only after the first L addition although available N increased after both additions. Differences between measured and expected value depended on residue addition frequency and parameter. In 10-(HL)x2, MBN, microbial biomass P and C (MBP and MBC) were greater than expected and this was accompanied by lower than expected available N and P. In 5-(HL)x4 on the other hand, the difference between measured and expected MBN and available N changed over time, possibly because the proximity of microbes decomposing different residues changes. The study showed that with repeated addition of H and L, N availability and MBN are influenced by residue rate and order. <![CDATA[Dual inoculation with mycorrhizal and saprotrophic fungi suppress the maize growth and development under phenanthrene exposure]]> Abstract: Polycyclic aromatic hydrocarbons (PAHs) belong to the group of persistent organic pollutants with detrimental impact on the environment and its living organisms. Soil acts as the main PAH sink why strategies to remediate PAH contaminated soil are needed. Inoculation with plant growth promoting and stress alleviating fungi such as arbuscular mycorrhizal (AM) fungi and saprotrophic fungi could be an efficient bioremediation strategy for PAH contaminated soils, but information about their compatibility is missing. In a greenhouse pot experiment we examined interactions between the AM fungus Rhizophagus irregularis and the saprotrophic fungus Trichoderma viride and their single and dual effects on maize plant growth performance and communities of rhizosphere microorganisms in a Phenanthrene spiked soil. Phenanthrene reduced maize plant growth independent of both fungal inoculants, which were also both inhibited by Phenanthrene. On the other hand strong mutual inhibition between R. irregularis and T.viride was observed, which mitigated their plant growth promoting effects independent of Phenanthrene. In conclusion, the observed mutual inhibition between R. irregularis and T. viride underline the importance of testing for compatibility between microbial inoculants when these are used in combination. <![CDATA[Assessment of a new bio-organic remediation as a bio-fungicide in fusarium-infested soils of watermelon monoculture areas from China]]> Abstract: Sustainably managed soils can increase soil quality, biodiversity, and reduce soil erosion and nutrient losses. In several regions of China, long-term monocultures such as watermelon are leading to severe degradation of soil biological functions due to contamination by dominant and deleterious microbes, particularly Fusarium spp., resulting in decreased soil productivity and quality. The main goal of this study was to assess a new bio-organic fertilizer in monoculture areas by testing the interactions between Fusarium oxysporum f. sp. niveum and microbial communities to inhibit it. The results showed that the tested organism significantly reduced Fusarium wilt in a watermelon monoculture plantation in China. The rate of wilt incidence following bio-fertilizer treatment was decreased by 70% at 63 days and the Fusarium counts in the watermelon rhizosphere declined too. Moreover, total abundance of bacteria increased, but total abundance of actinomycetes decreased. The beneficial microbes increased and became dominant while deleterious microbes, particularly Fusarium spp., were inhibited. The main conclusions of this study were that: i) a controlled bio-organic fertilizer stimulated the growth of ecologically beneficial microbes and naturally existing autochthonous antagonistic microbes; and, ii) the beneficial population structure and soil functions recovered following the reconstruction of functional microbial communities. Our results will add more useful information to understand how long-term crop monocultures can lead to detrimental effects on the soil microbial communities that will, in turn, affect the growth of plants and normal soil functions. <![CDATA[Beneficial Role of MWCNTs and SNP on Growth, Physiological and Photosynthesis Performance of Barley under NaCl Stress]]> Abstract: MWCNTs (Multi-walled carbon nanotubes), as an important nanomaterial, enters the soil through various anthropogenic sources. Our understanding of MWCNTs effects on plant growth is still not complete and needs to be more studied. In this study, the possible effects of MWCNTs (500, 1000 and 2000 mg kg-1) and 100 μM exogenous sodium nitroprusside (SNP, as NO donor) on growth, physiological and photosynthetic performance of barley plants under 100 and 200 mM NaCl stress were investigated in greenhouse conditions. The most of physiological and photosynthesis characteristics of barley seedling negatively impressed when the plants were grown in different concentrations of NaCl. In the presence of SNP, 500 mg kg-1 dosage of MWCNTs significantly enhanced relative water content (RWC), chlorophyll content, photosynthesis parameters and growth indices. Also, MWCNTs-treated plants combined with 100 μM SNP showed higher antioxidant enzyme activities such as superoxide dismutase (SOD), catalase (CAT), ascorbate peroxidase (APX) and lower malonyldialdehyde (MDA) and hydrogen peroxide (H2O2) content under salinity stress. It is suggested that, MWCNTs in presence of SNP can greatly improve growth, as well as salt tolerance of barley plant by promoting water uptake, activities of antioxidant enzymes and photosynthesis performance. <![CDATA[Pomegranate transplant stress can be ameliorated by <em>Rhizophagus intraradices</em> under nursery management]]> Abstract: Arbuscular mycorrhizal fungi (AMF) establish an obligate mutualistic symbiosis with many plant species, increasing the uptake of phosphorous and other low-mobile nutrients by roots. In addition, AMF improve biotic and abiotic stress tolerance of host plants. Under these conditions, reactive oxygen species (ROS) increase occasional damage to proteins, lipids and DNA. Antioxidative enzymes in plants can play an important role in detoxifying ROS, thereby alleviating oxidative stress. In nursery practices, plants are subjected at least to two transplant conditions before being transplanted outside. It is important to achieve an optimal plant size to withstand environmental or other stresses when plants are transplanted into the field. The transplantation process can be considered a stress because plants have to adapt to new abiotic and biotic (rhizospheric) conditions. The aim of this study was to evaluate the effect of two Rhizophagus intraradices (N.C. Schenck &amp; G.S. Sm.) C. Walker &amp; A. Schüßler strains, GA5 and GC2, single and co-inoculated under two-transplant soil conditions, sterile and non-sterile, using cuttings of pomegranate (Punica granatum L.) as a model plant. These results showed that the GA5 single strain-inoculated plants improved growth and antioxidative enzyme responses to two transplant stress conditions. In conclusion, early mycorrhizal inoculation generates healthy plants that are more protected against environmental conditions, thereby improving plant transplant stress tolerance. <![CDATA[Reasoned fertilization of potato in response to Nitrogen supply in Andisols]]> Abstract: Using the reasoned nitrogen (N) fertilization method in potato crops (Solanum tuberosum L.) requires the validation of its parameters under the probable conditions of crop response. A field experiment in an Andisol was established to assess the parameters of this method and the nitrogen utilization efficiency of the crop. To describe the crop N response, five statistical models were used. Dry matter production and nutrient concentration were measured in tubers, leaves, fruits and roots. At both the beginning and the end of the experiment soil samples were collected to evaluate the mineral N. The quadratic-potential model was the most appropriate to describe the positive response of the potato crop to available nitrogen, from an initial level of nitrogen (the control, zero application ) to a maximum application of 200 kg N ha-1. The relationship between the N doses and the potato yield reached a physical optimal of productivity at a rate of 228 kg N ha-1. Higher rates (300 kg N ha-1) resulted in a decrease in yield, generating phytotoxicity for cultivation. This variation allowed us to evaluate the reasoned application method under different nitrogen availabilities (deficiency, optimal and above-optimal) in addition to the variation of the parameters generated. <![CDATA[<em>Serratia</em> strains isolated from the rhizosphere of raulí (<em>Nothofagus alpina</em>) in volcanic soils harbour PGPR mechanisms and promote raulí plantlet growth]]> Abstract: Raulí is one of the most emblematic tree species of the Chilean temperate forests. Due to the high quality wood, this tree has been used for furniture and handicrafts manufacturing, which has positioned raulí as one of the most important commercial timber species in Chile. Currently, the international market demands sustainable production system for forest production, more specifically in plantlets production. In this regard, plant growth-promoting rhizobacteria (PGPR) inoculants may enhance the growth and survival of plantlets in nurseries, which means an increase in the effectiveness of replanting operations. Therefore, the aim of the present study was to isolate, characterize and screen rhizosphere-associated bacteria with PGPR potential, isolated from raulí that growth in volcanic soils in southern Chile. A total of 1,261 bacterial strains were isolated from different volcanic soils. Out of 1,261 isolates, 100 were selected based on their high levels of indole acetic acid (IAA) production. These isolates were then subjected to screening for 1-aminocyclopropane-1-carboxylic acid deaminase activity, and their ability to fix nitrogen was determined. From the 100 selected isolates, 7 were chosen for producing the highest amount of IAA to continue with genetic characterization based on their 16S rRNA gene sequences. These 7 isolates were characterized as members of the Serratia genus and were used to develop multi-strain inoculant mixtures. Later, a nursery study followed to determine the effect of inoculation with the Serratia strains on the growth of RA88 raulí clone plantlets. The nursery experiment demonstrated that Serratia strains have the potential to increase the root collar diameter, height, relative chlorophyll content, biomass and nitrogen content of raulí plantlets. The study concluded, that Serratia strains have the potential to be used as biofertilizers to increase plant growth in nursery conditions. <![CDATA[Effects of irrigation and green manure on corn (<em>Zea mays</em> L.) biomass and grain yield]]> Abstract: The effect of green manure on the growth of irrigated corn (Zea maysL. cv Cisko) was investigated under different drip irrigation rates on a clay soil in Greece. A feed pea (Pisum sativum L. cv Olympus) crop was established in autumn and incorporated into the soil in spring, about 3 weeks before the sowing of the subsequent corn. During the growing period, the growth stages and yield of corn were assessed under three drip irrigation levels I1 (33% low), I2 (66% moderate) and I3 (100% full of actual evapotranspiration, ETm) and two cultivation practices a) application of green manure and b) experiment without previous green manuring. The positive effects of green manuring were greater in the moderately and fully irrigated plots. Drip irrigation was applied to minimize nitrate leaching which requires low volume of water. In plots receiving moderate or full irrigation, biomass, leaf area index (LAI) and seed yield were much higher in comparison to stressed plants (33% ETm). Increased yield and dry biomass obtained in the plots after incorporation of feed pea residues, may be attributed mainly to the elevated amount of soil organic matter (SOM). The increased yield exceeds the overall cost for green manure application, and this economic incentive is expected to be even more significant taking into account the continuous improvement of soil conditions. <![CDATA[Interactions of the lichen <em>Cladonia salzmannii</em> Nyl. with soil, microbiota, mycorrhizae and <em>Genipa Americana</em>]]> Abstract: The lichen Cladonia salzmannii can influence the arbuscular mycorrhizal formation (AMF) of sandy soils in the Brazilian Northeast, thereby contributing to improved vascular plant growth. The objective of this work was to evaluate how C. salzmannii changes the biological processes of soil in a tropical savannah ecosystem where soils have low nutrient availability, so any lichen-induced effects would be important. The microbial activity, AMF, growth of Genipa americana and chemical-physical characteristics of the soil were analyzed. Soil samples were collected under pillows of lichen thalli or in open spaces without them. Chemical and biological soil attributes were evaluated by analysis of soluble and exchangeable cations, microbial activity and AMF colonization. The presence of barbatic acid (BAR), a major compound of C. salzmannii, was detected in the soil, which positively influenced soil properties. AMF colonization was higher in lichen-covered soil. G. americana seedlings were grown under greenhouse conditions, the experiment was done in a randomized design of 4 inoculation treatments. The inoculated plants with lichens+AMF presented greater growth parameters. The results could indicate that BAR is capable of stimulating the association between plants and AMF, linking the root and the soil system. This arrangement improves a positive feedback loop established between lichen-AMF-vascular plant. <![CDATA[Nutrients losses via runoff from soils amended with cow manure composted with leaf litter]]> Abstract: Application of composted manures has previously been proposed as soil amendments capable of retarding nutrients losses via surface runoff, thereby stimulating infiltration rates. A study was carried out under natural rainfall conditions to assess the effects of cow manure after composting with maple and poplar leaf litter on nutrient runoff from two types of soils, a sandy loam and silt loam. Composted manure without added leaf litter to the soil was considered as a control treatment. Cow manure co-composted with leaf litter at four ratios (1:0, 1:1, 1:2 and 1:3). Soils were packed in the plastic lined wooden trays and the soil surface was mixed with the co-composted manure at rates of 10 and 20 t ha-1. Runoff samples were collected from the sloped trays (5%) during three rainfall events. Inorganic N (NO3 plus NH4), P and K concentrations were measured in the runoff. Application of manure amendments derived from composting with leaf litter to the soil reduced the nutrients losses in the order of 1:3 &lt; 1:2 &lt; 1:1 &lt;1:0 regardless of the kind of leaf litter used. Irrespective of soil and application rates, N losses in the runoff were lowered with manure co-composted with leaf litter. Nutrients losses in the runoff were enhanced with higher manure application rates, depending on the type of the soil treated. It was concluded that application of manure amendments derived from composting with plant leaf litter was a useful option in reducing nutrients losses from soils. <![CDATA[Organic and conventional farming differentially influenced soil respiration, physiology, growth and head quality of artichoke cultivars]]> Abstract: Soil amendment using organic fertilizer has been used widely to dispose animal waste, reduce environmental pollution and improve soil and fruit quality. The objective of this two-year study was to assess the influence of organic and conventional systems on growth, marketable yield, head quality (chlorogenic acid and cynarin concentration) and soil chemical properties of globe artichoke (Cynara cardunculus). Cultivars used were Deserto, Lulu, Romolo, 11-018, 12-179, Green Globe Improved and Imperial Star. Fertilizers were applied to both conventional and organic soil through drip irrigation system. In both years, significant differences were found across cultivars and soil type. Although cultivar response to soil system treatments were inconsistent across the two growing seasons, the cv. Imperial Star had the lowest marketable yield and head quality. Artichoke grown in the conventional field had higher plant height and width, chlorophyll content index (SPAD), leaf area index (LAI), stomatal conductance (gs), photosynthesis (Pn) and marketable yield. Conversely, artichoke head quality from the organic field was higher than conventional. Organic system increased chlorogenic acid by 31% and cynarin by 12% compared to the conventional system. In fact, after two years of soil amendment, organic fertilizer improved soil respiration-CO2 (soil health indicator) by 20-fold compared to chemical fertilizer (conventional field). Overall, based on this two-year study we suggest organic farming as the best system to improve soil and head quality of globe artichoke, but it may not be the best option for farmers when yield is the primary target short-term. <![CDATA[Growth and phytochemical composition of <em>adhatoda zeylanica</em> in response to foliar application of growth hormones and urea]]> Abstract: This study evaluates effects of foliar application of Kinetin, Benzyladenine and urea on growth, phytochemical and quality of active compound vacisine in Adhatoda zeylanica. Five treatments; distilled water (T1) which serves as control, 0.1% urea + 100 ppm kinetin (T2), 0.1 % urea + 100 ppm Benzyladenine (T3), 0.2% urea + 100 ppm kinetin (T4) and 0.2 % urea + 100 pm Benzyladenine (T5) were applied as foliar spray every four weeks. Growth parameters, phytochemical screening and physicochemical properties of the treated plants were evaluated. Also, bioactive compound vicisine from the leaf extract was characterised and compared with standard using High Performance Thin Layer Chromatography (HPTLC). All the treatments had better growth performances than T1, however, in term of yield, T2 has optimum effect. Phytochemical screening reveal presence of alkaloid, tannin, phenolic compounds, steroids, proteins and carbohydrates. Water and alcohol solubility, pH, and total ash values were enhance by the treatments. HPTLC analysis showed that the leaf extract active compound vicisine had same quality as the market standard. The study concludes that foliar application of growth hormones and urea in combinations and different concentrations could be used to improve growth and phytochemical yield of medicinal plants. <![CDATA[Effect of <em>Ulex europaeus</em> L. extracts on polyphenol concentration in <em>Capsicum annuum</em> L. and <em>Lactuca sativa</em> L.]]> Abstract: In this work, the effect of aqueous and methanolic extracts from roots and shoots of Ulex europaeus L. on the total polyphenol content of Capsicum annuum L. and Lactuca sativa L. grown in laboratory and greenhouse conditions was evaluated. Treatments consisted of U. europaeus L. extracts (20, 40, 80, 160 and 320 mg kg-1) as well as caffeine and distilled water as controls, all of which were applied with a manual sprayer on seedlings of the aforementioned species. Total polyphenols were determined using the Folin-Ciocalteu method. Under control conditions, the polyphenol concentration in C. annuum was lower in laboratory than in greenhouse conditions (P&lt;0.05). Conversely, L. sativa had a higher polyphenol concentration in the laboratory than in the greenhouse (P&lt;0.05). Also, under laboratory conditions the polyphenol content rose with increasing extract doses in both species, but this tendency was not observed in the greenhouse. Finally, different doses of extracts of U. europaeus L. affect total polyphenol content in both species. This effect is clear under laboratory conditions, but not in greenhouse experiments. These findings open up the possibility of cultivating species with higher antioxidant contents using natural products. <![CDATA[Phosphorus efficiency modulates phenol metabolism in wheat genotypes]]> Abstract: The effect of phosphorus (P) supply on P uptake, plant growth, and phenols production with either antioxidant or structural function was investigated in wheat. Ten wheat cultivars were grown hydroponically at 0, 0.01, 0.1, 0.4 mM P. After harvest, P concentration, plant growth, lipid peroxidation and total phenols concentration were determined. Chloroplasts hydrogen peroxide (H2O2) production and lignin distribution were also analyzed. According to the nutritional requirements of wheat, the application of both 0.1 mM P and 0.4 mM P provided sufficient P levels. However, P concentration in wheat cultivars treated with either 0 or 0.01 mM P reached a P deficient state. Almost all cultivars reduced shoot biomass under P shortage, which in turn led to increase root growth and root/shoot ratio. Consequently, genotypes with contrasting P efficiency were defined. The oxidative damage, chloroplast H2O2 production, total phenols and lignin accumulation augmented in wheat cultivars as P supply decreased. Moreover, P-inefficient genotypes accumulated more total phenols in their tissues than P-efficient genotypes under P-deficient conditions. In fact, a clear relationship between P efficiency and phenol metabolism was found. Additionally, based on our results, we ranked wheat cultivars according to their susceptibly to P deficiency.