Los objetivos de este estudio fueron determinar el efecto alelopático de extractos acuosos foliares de diez ecotipos de Triticum aestivum L. en dos concentraciones sobre la germinación y crecimiento de la maleza Rumex acetosella L. y clasificarlos según su efectividad.El diseño experimental fue completamente al azar con tres repeticiones.Se evaluó porcentaje de germinación, altura de plántula (cm), longitud de radícula (cm), peso fresco y peso seco de follaje y radical (g).Los resultados fueron evaluados a los 15 días postsiembra y sometidos a un Análisis de Varianza y la comparación de medias con la prueba de significancia mínima (LSD) (P ≤ 0,05).La maleza R. acetosella manifestó sensibilidad alelopática diferenciada para los diez ecotipos de trigo.Sin embargo, dicha sensibilidad no fue significativa en todos los parámetros evaluados.

E. Mariangel, M. Reyes-Diaz, W. Lobos, E. Bensch, H. Schalchli, and P. Ibarra. 2013. The antioxidant properties of calafate (Berberis microphylla) fruits from four different locations in southern Chile. Cien. Inv. Agr. 40(1):161-170. The antioxidant capacity (AC), total anthocyanins (TA) and total phenols (TP) of calafate fruit from four locations in southern Chile (El Blanco, Lonquimay, Manihuales and Temuco) were determined using both the free radical 2.2-diphenyl-1-picrylhydrazyl (DPPH) method and the linoleic acid oxidation inhibition method as well as the pH-differential and Folin-Ciocalteu methods. Phenolic compounds were also identified using HPLC-DAD (High Performance Liquid Chromatography-Diode-Array Detection). The results showed that TP varied significantly according to the location. Manihuales was noteworthy, with 34.9 mg of GAE g(-1) dried fruit. The measured AC level depended on the methodology used, varying significantly between locations according to the DPPH results. Manihuales was again noteworthy, with the highest AC values (9.4 mg of TE g(-1) dried fruit). The results based on the inhibition of linoleic acid oxidation showed no significant differences between Temuco and El Blanco, and the highest value was found for Manihuales (0.25 mg of TE g dried fruit). The TA showed significant differences among locations and was highest for El Blanco (0.64 mg of cyanidin g(-1) dried fruit). The phenolic acid compounds that were identified included gallic acid, chlorogenic acid, caffeic acid, coumaric acid, ferulic acid and flavonoids such as rutin, myricetin, quercetin and kaempferol. These compounds varied according to location. Temuco showed a higher content of coumaric acid; Lonquimay of chlorogenic acid, caffeic acid, coumaric acid and flavonoids such as rutin and quercetin; Manihuales of gallic acid, chlorogenic acid, caffeic acid, ferulic acid and flavonoids such as rutin and quercetin; and El Blanco of caffeic acid and flavonoids such as myricetin, quercetin and kaempferol. The AC was positively correlated with TP (DPPH r=1, linoleic acid r=0.84). In contrast, a low correlation was obtained between AC and TA (DPPH r=0.31; linoleic acid r=-0.28) and between TP and AT (r=0.27). It is concluded that calafate fruits from different geographical areas of southern Chile show statistically significant differences in antioxidant capacity, total phenols, anthocyanins and phenolic compounds, with Manihuales showing the highest values for these parameters. The chemical composition of the fruits also varies with the origin of the samples.

Wheat (Triticum aestivum L.) is known for its ability to produce and release allelopathic compounds, which have potential for controlling weeds and diseases. Previous reports have shown the fungitoxic effects of allelochemicals present in wheat. Thus, these compounds can be exuded by roots to protect the tissues directly affected by Gaeumannomyces graminis var. tritici (Ggt) fungus that causes wheat take-all disease. The aim of this research was to evaluate in vitro the allelopathic effect of root exudate extracts from four Chilean wheat cultivars on Ggt growth. Root exudates were released from wheat seedlings to a sterile culture medium without nutrients. Afterward, the exudates in the culture medium were separated by liquid-liquid extraction using ethyl acetate. Eight different concentrations were tested for each cultivar. The results showed that the degree to which the extracts strongly inhibit the phytopathogen growth is highly dependent on both the concentration and the cultivar. The root extract of the Domo cultivar was significantly active against Ggt (MIC=0.36 mg mL(-1)). IC50 and MIC values obtained for Dollinco and Domo root exudate extracts showed toxicity to Ggt. These findings may be considered in future studies related to the use of allelopathic potential as a selection factor in order to reduce the yield losses caused by various take-all diseases, as an alternative to chemical controls.

Los objetivos de este estudio fueron: evaluar el efecto del momento de cosecha y la permanencia en huerto sobre el deterioro de arandano cultivares Berkeley, Brigitta y Elliott durante la temporada 2006; identificar hongos de poscosecha segun tratamientos, cultivares y periodo de almacenaje en frio y laboratorio y cuantificar la incidencia de hongos de poscosecha y su relacion con los tratamientos, cultivares y periodo de almacenaje en frio y laboratorio y evaluar deshidratacion en funcion de los tratamientos, cultivares y periodo de almacenaje en frio y laboratorio. El estudio se realizo durante los meses de enero y febrero de 2006 en la localidad de Freire, region de La Araucania. Para la realizacion de este estudio se usaron frutos de maduracion temprana (Berkeley), media (Brigitta) y tardia (Elliott), cosechando la fruta por la manana entre las 9 y las 11 horas; y por la tarde entre las 13 y las 16 horas, para luego de 2 y 4 horas de permanencia en huerto ser depositada en cestillos de exportacion e ingresar la fruta a camara de frio durante 14 dias, para realizar las evaluaciones en laboratorio luego de 7 y 14 dias. Los datos obtenidos fueron sometidos aanalisis de contrastes ortogonales, y las medias de los tratamientos y subtratamientos se compararon a traves de pruebas de significancia minima (LSD) (p ≤ 0,05). Durante la poscosecha del arandano, se identifico a Botrytis cinerea, Cladosporium herbarum, Alternaria alternata, Colletotrichum gloeosporioides, Pestalotia guepini y Penicillium sp. El patogeno de mayor incidencia fue Cladosporium herbarum (1,6 %), seguido en orden decreciente por Botrytis cinerea (1,4 %), Penicillium spp. (0,5 %), Alternaria alternata (0,4 %), Colletotrichum gloeosporioides (0,1 %) y Pestalotiaguepini (0,05 %). El cultivar Berkeley presento la mayor incidencia, seguido de Brigitta y Elliott en orden decreciente en ambas localidades. Al cosechar la fruta por la tarde se observo un aumento en la incidencia de hongos de poscosecha, no registrandose un efecto significativo sobre la incidencia de hongos al prolongar el periodo de permanencia en huerto.

Esta investigacion se realizo con el proposito de evaluar el efecto de extractos acuosos de ecotipos de trigo (Triticum aestivum L.) sobre el crecimiento micelial in vitro de Gaeumannomyces graminis var. tritici. Se utilizaron 17 extractos obtenidos de raices y hojas de los ecotipos de trigo Castano, Cebada, Diente de perro, G8, Grano de oro, Cain, Linaza I, Linaza II, NN1, NN17, NN24, NN31, NN35, Pulil, R3, Rachel y Varon, y cultivares comerciales de avena cv. Urano, trigo cv. Kumpa y Otto a las concentraciones 1 y 5% p/v. Se evaluo el radio promedio del crecimiento micelial ( mm) desde el centro de la placa petri contenida con APD y el extracto respectivo, siempre en el mismo sentido y lugar, a partir de las 24 horas postsiembra y cada 24 horas hasta completar la placa control. Se utilizo un diseno experimental completamente al azar. Los datos fueron analizados mediante ANDEVA y comparacion de medias por las pruebas LSD y Tukey (p < 0,05). Todos los extractos acuosos de ecotipos de trigo ejercieron efecto inhibitorio del crecimiento micelial de G. graminis var. tritici. Este efecto fue superior al de cultivares comerciales de avena cv. Urano y trigo cvs. Kumpa y Otto. La secuencia de mayor a menor efecto inhibitorio del crecimiento micelial fue la siguiente: extracto radical al 1% (ecotipos Varon, NN1 y Pulil); al 5% (ecotipos Linaza I, Cain, Varon, Grano de oro y NN1). Extracto foliar al 1% (ecotipos Castano y Grano de oro); al 5% (ecotipos NN17, NN24, NN31, Cain y Varon).

It is possible to incorporate a lot of natural antioxidants into the human organism by consuming berries which can prevent diseases generated by the action of free radicals. Antioxidants neutralize free radicals and thus protect the organism from the oxidative damage of lipids, proteins, and nucleic acids. Berries stand out as one of the richest sources of antioxidant phytonutrients among various fruits and vegetables. The objective of this research was to determine antioxidant capacity (AC), total anthocyanins (TA), and total phenols (TP) of wild and cultivated berries in different localities of La Araucan a and Los R os Regions in Chile. These parameters were analyzed by using the free radical 2,2-diphenyl-1-picrylhydrazyl hydrate (DPPH) method, pH-differential, and Folin-Ciocalteu method. Percentages of DPPH discoloration of different berries studied were between 67.8% and 95.3% for red sarsaparilla and rosehip, respectively. Maqui berries showed a significantly higher TA content (2240.2 and 1445.3 mg L-1 cyanidin 3-glucoside) than other berries, and a mean for all berries of 335.5 mg L-1. Higher phenol content levels were obtained in two cultivars of saskatoon (773.9 and 1001.9 mg L-1 gallic acid) and wild rosehip (1457.0 and 1140.4 mg L-1 gallic acid). We conclude that there are significant differences in antioxidant capacity of wild and cultivated Chilean berries in this study which show a strong correlation between AC and TP content.

espanolEl objetivo de esta investigacion fue evaluar el potencial alelopatico de cincuenta cultivares de trigo sobre cuatro especies de malezas frecuentes en el cultivo en la zona sur de Chile. El diseno experimental fue en bloques al azar con cuatro repeticiones. Se evaluo largo radical mayor de la especie receptora (maleza) a los 18 dias de establecida esta. Los datos transformados a porcentaje de inhibicion del largo radical de la especie receptora en relacion al testigo fueron sometidos a ANDEVA, Analisis Cluster y Tukey (P ? 0.05). Se constato que el efecto alelopatico de los cultivares sobre las especies de malezas evaluadas en la mayoria de los casos fue inhibitorio y ocasionalmente potenciador sobre algunas de estas malezas. Los cultivares mas inhibitorios fueron Perquenco, Metrenco, Aztec y Baroudeur (rango: 57-65%) y los con menor inhibicion Dollinco, Tilburi, Tukan y Bingo (rango: 20-29%). Los otros cultivares se ubicaron en un rango intermedio de inhibicion. La interaccion alelopatica entre los cultivares de trigo y las malezas evaluadas difirio significativamente. En aquellas de mayor sensibilidad la secuencia fue la siguiente: Spergula arvensis (+10 a 88%), Rumex acetosella (+8 a 70%), Avena fatua (+36 a 74%) y Vulpia bromoides (+11 a 68%). Englishhe objective was: to evaluate the allelopatic potential of 50 wheat cultivars on four weed species associated with this culture in south Chile. The experimental design was in blocks with four repetitions. The longest main root of the receptive species (weed) was evaluated eighteen days after the establishment of the last one. The transformed data into percentage of inhibition of root length of the receptive species in relation to the control was analyzed using ANDEVA, cluster analysis and Turkey (P

Los objetivos de esta investigación fueron: validar el método ECAM (Wu et al., 2000a) y determinar el potencial alelopático de cincuenta cvs.de trigo cultivados en Chile sobre ballica anual (Lolium rigidum) var.Wimmera.El diseño experimental fue completamente al azar y en bloque con cuatro repeticiones.Se evaluó largo radical mayor de la especie receptora (ballica) a los diez días de establecida.Los datos transformados a porcentaje de inhibición del largo radical de la especie receptora en relación al testigo fueron sometidos a ANDEVA, Análisis Cluster y Duncan o Tukey (P<0.05).El método ECAM modificado fue eficaz para evaluar el potencial alelopático de los cincuenta cultivares de trigo y, en general, se produjo inhibición del crecimiento radical de ballica con un rango de inhibición de 20 a 80%.Los cultivares más alelopáticos fueron Tukan, Oracle

It was determined the phenological stage of higher susceptibility, incidence and control of Botrytis cinerea and Alternaria alternata in three year old plants of highbush Blueberry cv. Blejay. The fungicides benomyl+captan (45g+144g i.a/HL) and BC1000 (150 c.c. i.a./HL) were evaluated. The treatments consisted of 1, 2, 3 and 4 aplications of BC1000 between the beginniug of flowering and maturity; and a comparative experiment between benomyl+captan and BC1000 with 1, 2, 3 aplications in differents phenological stage between full flowering and maturity. The fruits were mantained in a cold chamber (0°; 95% H.R) for a period of 14 days and in laboratory conditions (average of 18°; 60% H.R), for 7 days. The incidence of fungi was evaluated to the harvested crop and until the end of the storage period. Phenological stages of more susceptibiliiy to B.cinerea were flower-clot and maturity, while no such stages were accurately established for A.alternata. BC1000 had a more effcctive control over B.cinerea aplicated in flower-clot and maturity, while flowering aplications were no effective. BC1000 in field conditions did not control A.alternata significatively. Benomyl+captan was more effective than BC1000 over B.cinerea with three aplications from full flowering to maturity, and there were no differences between fungicides with two aplications (flower-clot and maturity) and one in maturity.