131 research outputs found
Effect of Different Parameters (Treatment Administration Mode, Concentration and Phenological Weed Stage) on Thymbra capitata L. Essential Oil Herbicidal Activity
The essential oil (EO) of Thymbra capitata has been demonstrated to possess herbicidal activity and could be used as an alternative to synthetic herbicides with reduced persistence in soil and new mode of action. Nevertheless, it is necessary to determine the adequate doses for its use, the proper way for its application and the best phenological stage of weeds and crops in which the EO should be applied to obtain maximum efficacy against weeds without compromising crop production. In this work, T. capitata EO was tested at three different concentrations against weeds grown from a citrus orchard soil seedbank untreated with herbicides and against three important weed species grown in substrate to determine the efficacy of the concentrations on different weed species. All experiments were carried out under greenhouse conditions. To find out the best way for applying the EO, it was applied by irrigation and by spraying on the targeted weeds, and to verify the influence of timing, it was tested on Lolium rigidum at two different phenological stages and on wheat at a later phenological stage than weeds. The highest concentration tested (12 μL·mL−1) showed the best performance to control weeds. The more effective mode of application was by spraying on dicotyledons and by irrigation on monocotyledons at the earliest phenological stage. T. capitata EO was phytotoxic for wheat. More trials in different crops are needed to determine the best conditions for its use
Herbicidal activity of essential oils extracted from different Mediterranean species against Echinochloa crus galli
Weed infestation in agricultural fields can cause huge economic losses and low-quality crop yields. Echinochloa crus-galli (L.) P.Beauv. (barnyardgrass) is one of the greatest yields limiting weeds in rice cultivation systems. It is a cosmopolitan weed in both temperate and tropical regions and is reported as a weed in 36 different crops in 61 countries. The success of this weed may be attributed to the production of large numbers of small, easily dispersed seeds per plant, possession of seed dormancy, rapid development and ability to flower under a wide range of photoperiods, and relative resistance of mature plants to herbicide sprays. Thus, the best way to control barnyardgrass in an environmentally acceptable and sustainable approach is to develop eco-friendly and effective alternative means based on natural allelochemicals. Among the natural plant products, essential oils (EOs) constitute an important group. EOs may help reducing the use of synthetic herbicides and lead to less pollution and more safe agricultural products. Recently, the interest in exploring EOs with phytotoxic effects from aromatic plants for weed control has increased tremendously, because they do not persist in soil and do not leach into ground water. EOs extracted from Thymbra capitata (L.) Cav.; Mentha x piperita L.; and Santolina chamaecyparissus L. were reported to reduce the emergence and seedling growth of many weeds.
The present investigation allows for a more detailed insight into the herbicidal activity of the previously mentioned EOs during spray foliar and irrigation application in post-emergence on E. crus-galli plants.
T. capitata M. piperita and S. chamaecyparissus EOs were purchased from “Bordas Chinchurreta”, “Sigma-Aldrich” and and “Aromas de Ademuz”, respectively. Soil for the experiments was collected from the topsoil of a citrus field not treated with herbicides (Valencia, Spain), that was air-dried and sieved at 1 cm. E.crus-galli seeds were purchased from Herbiseed (England), and germinated in a germination-growth chamber at 30 ± 0.1 °C, 16 h in light and 20 ± 0.1 °C, 8 h in dark. Once the seedlings of E.crus-galli emerged, they were placed on pots (8x8x7 cm) filled with 2 cm of perlite at the bottom and 5 cm of the collected soil. Ten pots per treatment were prepared and placed in the greenhouse. In order to find the most effective dose of EOs and its adequate mode of application, different concentrations were used: 12, 16 and 20 µL/mL for Mentha and Santolina EOs and 4, 8 and 12 µL/mL for Thymbra EO. Fitoil was used as emulsifier at a concentration of 0.05% (v/v). Plants of barnyardgrass were treated at two-leaf stage by irrigating and spraying mode of application. To monitor the experiments, photos were taken after 24, 48 and 72 hours; and then once a week. The photos were processed with Digimizer software to obtain different data: efficacy of the treatment, level of damage, height of plants, weed plant fresh and dry weight
Adaptability of invasive plants to climate change
[EN] Climate change represents one of the greatest environmental challenges of the 21st century, accentuated by deforestation and the degradation of habitats. Changes in vital aspects such as temperature, the amount and distribution of rainfall or the frequency of extreme meteorological phenomena will probably negatively affect ecosystems. The possibilities of invasion will predictably increase, being endemic species especially vulnerable to the effects of climate change. Invasive species are extremely adaptable to climate variability, as evidenced by their current large latitudinal ranges. Generally, invasive plants also have rapid dispersal characteristics, allowing them to vary their ranges in response to changing climatic conditions rapidly. As a result, these species could become more dominant in many areas under changing climatic conditions. In many situations, the environmental stress generated by climate change and invasive plants are synergistic: invasive species can exacerbate the impacts of climate change on ecosystems, and in the same way, climate change can allow new invasions.S.G-O acknowledges a 'Margarita Salas' postdoctoral contract from Universitat Politècnica
de València and the Spanish Ministry of
Universities, supported by the European Union
- Next Generation fundsGonzález-Orenga, S.; Boscaiu, M.; Verdeguer Sancho, MM.; Sánchez-Moreiras, AM.; González, L.; Vicente, O. (2022). Adaptability of invasive plants to climate change. AgroLife Scientific Journal (Online). 11(2):58-65. https://doi.org/10.17930/AGL202227586511
Actas Portuguesas de Horticultura
La producción de estátice en el sur de la Comunidad
Valenciana es de gran relevancia en la floricultura. Se trata de una
especie halotolerante en la que, hoy por hoy, para el manejo de su
fertirrigación se utilizan aguas de baja salinidad en la que se
incorporan elevados contenidos de nutrientes. Tanto el hecho de que
se consigan elevados rendimientos de calidad como el coste menor
que suponen los fertilizantes respecto a los del resto de los insumos de
cultivo, explican que esta práctica se haya establecido. Se sabe, sin
embargo, que el estátice es una planta poco exigente en nutrientes
minerales, por lo que son de suponer elevadas pérdidas de los mismos
por lixiviación, que no son permisibles desde una perspectiva de
sostenibilidad. Minimizar los aportes minerales sin que se produzcan
mermas ni en el rendimiento ni en la calidad de la cosecha es un claro
objetivo a perseguir. El periodo de recolección se inicia a final de
octubre y es continuo hasta final de mayo con variaciones estacionales
de las tasas de producción. Este trabajo se plantea para conocer los
efectos de la reducción en un 50% de los aportes minerales sobre el
rendimiento y la calidad de la cosecha a lo largo del ciclo de cultivo.
Para ello, en un mismo invernadero y a lo largo de todo un ciclo de
cultivo, se ha llevado el seguimiento y comparación de la producción
de tallos florales de dos poblaciones de Limonium sinuatum cv. Duel
Violet, con la misma fecha de plantación. Para cada uno de los
tratamientos, se han determinado semanalmente tanto la cantidad
(número de tallos florales, pesos fresco y seco) como la calidad
(longitud de los tallos, de las panículas, relaciones peso seco vs peso
fresco) de los tallos florales cosechados. Paralelamente, se han
obtenido relaciones de la biomasa producida con respecto a la
radiación interceptada y la integral térmica. No se muestran
diferencias cualitativas entre ambos tratamientos en casi todo el
periodo de cultivo. Cuantitativamente, desde noviembre hasta marzo
las respuestas de los tratamientos son similares, dependiendo el
rendimiento tanto de la radiación interceptada como de la integral
térmica, sin embargo, en primavera, con temperaturas medias elevadas
y fotoperiodos más largos que revierten en mayores tasas de
producción, la menor aportación mineral resulta en un ligero descenso
del rendimiento en unidades totales al final del cultivo, que la planta
compensa aumentando el peso de los tallos florales, y la calidad de los
mismos
Herbicidal Potential of the Natural Compounds Carvacrol, Thymol, Eugenol, p-Cymene, Citral and Pelargonic Acid in Field Conditions: Indications for Better Performance
In recent years, interest in natural products with herbicidal activity as new tools for integrated weed management has increased. The European Union is demanding a reduction in the number of herbicides used, forbidding use of the most toxic ones, despite the problem of weed resistance increasing. Pelargonic acid (PA) is the only natural herbicide available in Spain. In this work, two field assays were performed with the natural compounds carvacrol (CAR), citral (CIT), eugenol (EUG), thymol (THY), p-cymene (P-CYM), (PA), and the combination of PA with CIT-all except P-CYM formulated by Seipasa-to test their herbicidal efficacy in real conditions. They were compared with commercial PA, glyphosate (GLY) and oxyfluorfen (OXY). In both experiments, GLY achieved the best weed control. Considering the natural herbicides, PA formulated by Seipasa and PA plus CIT were the most effective. From both experiments, some conclusions can be extracted for better herbicidal performance of natural products: (1) use products on sensitive weed species, (2) treat weeds at earlier phenological stages, (3) find the active doses in field conditions, (4) cover weeds well when treating, (5) ensure adequate formulation of products, and (6) develop a strategy for correct application
PPARγ contributes to PKM2 and HK2 expression in fatty liver
Rapidly proliferating cells promote glycolysis in aerobic conditions, to increase growth rate. Expression of specific glycolytic enzymes, namely pyruvate kinase M2 and hexokinase 2, concurs to this metabolic adaptation, as their kinetics and intracellular localization favour biosynthetic processes required for cell proliferation. Intracellular factors regulating their selective expression remain largely unknown. Here we show that the peroxisome proliferator-activated receptor gamma transcription factor and nuclear hormone receptor contributes to selective pyruvate kinase M2 and hexokinase 2 gene expression in PTEN-null fatty liver. Peroxisome proliferator-activated receptor gamma expression, liver steatosis, shift to aerobic glycolysis and tumorigenesis are under the control of the Akt2 kinase in PTEN-null mouse livers. Peroxisome proliferator-activated receptor gamma binds to hexokinase 2 and pyruvate kinase M promoters to activate transcription. In vivo rescue of peroxisome proliferator-activated receptor gamma activity causes liver steatosis, hypertrophy and hyperplasia. Our data suggest that therapies with the insulin-sensitizing agents and peroxisome proliferator-activated receptor gamma agonists, thiazolidinediones, may have opposite outcomes depending on the nutritional or genetic origins of liver steatosis
Inhibitor of apoptosis proteins, NAIP, cIAP1 and cIAP2 expression during macrophage differentiation and M1/M2 polarization
Monocytes and macrophages constitute the first line of defense of the immune system
against external pathogens. Macrophages have a highly plastic phenotype depending on
environmental conditions; the extremes of this phenotypic spectrum are a pro-inflammatory
defensive role (M1 phenotype) and an anti-inflammatory tissue-repair one (M2 phenotype).
The Inhibitor of Apoptosis (IAP) proteins have important roles in the regulation of several cellular
processes, including innate and adaptive immunity. In this study we have analyzed the
differential expression of the IAPs, NAIP, cIAP1 and cIAP2, during macrophage differentiation
and polarization into M1 or M2. In polarized THP-1 cells and primary human macrophages,
NAIP is abundantly expressed in M2 macrophages, while cIAP1 and cIAP2 show
an inverse pattern of expression in polarized macrophages, with elevated expression levels
of cIAP1 in M2 and cIAP2 preferentially expressed in M1. Interestingly, treatment with the
IAP antagonist SMC-LCL161, induced the upregulation of NAIP in M2, the downregulation
of cIAP1 in M1 and M2 and an induction of cIAP2 in M1 macrophages.This work was supported by Universidad
de Granada, Plan Propio 2015;#P3B: FAM, VMC
(http://investigacion.ugr.es/pages/planpropio/2015/
resoluciones/p3b_def_28072015); Universidad
de Granada CEI BioTic;#CAEP2-84: VMC (http://
biotic.ugr.es/pages/resolucionprovisional
enseaanzapractica22demayo/!); and Canadian nstitutes of Health Research;#231421, #318176,
#361847: STB, ECL, RK (http://www.cihr-irsc.gc.
ca/e/193.html). The funders had no role in study
design, data collection and analysis, decision to
publish, or preparation of the manuscript
Renal malformations associated with mutations of developmental genes: messages from the clinic
Renal tract malformations (RTMs) account for about 40% of children with end-stage renal failure. RTMs can be caused by mutations of genes normally active in the developing kidney and lower renal tract. Moreover, some RTMs occur in the context of multi-organ malformation syndromes. For these reasons, and because genetic testing is becoming more widely available, pediatric nephrologists should work closely with clinical geneticists to make genetic diagnoses in children with RTMs, followed by appropriate family counseling. Here we highlight families with renal cysts and diabetes, renal coloboma and Fraser syndromes, and a child with microdeletion of chromosome 19q who had a rare combination of malformations. Such diagnoses provide families with often long-sought answers to the question “why was our child born with kidney disease”. Precise genetic diagnoses will also help to define cohorts of children with RTMs for long-term clinical outcome studies
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