HERBICIDES

Author: ALBARRÁN LISO ANGEL.
Year: 2003.
University: EXTREMADURA [www.unex.es].
Place of defense: ESCUELA DE INGENIERÍAS AGRARIAS BADAJOZ.
Place of preparation: FACULTAD DE CIENCIAS.

Summary: The increased use of pesticides, among others, imposes a culture of minimum tillage justifies that, in recent years, has been detected herbicide in the waters of abastecimíento of Extremadura, and at concentrations above ajas admissible by the European Union. The objective of this study is to determine the mechanism of evolution of simazine in olive grove floors of the Group of Municipalities of La Serena (Badajoz) and analyze the effects of waste mills (alperujo and pomace) on the behavior of this herbicide the system suelo-agua. To achieve the proposed targets have addressed the following activities: -Caracterizar as the basis Referral World Land Appeal (FAO) soils more representative incorporating triazinas in the study area. Analyzing processes adsorption, desorption and degradation of the herbicide simazine -Monitorización of residues of the herbicide and determination of its persistence in experimental plots of olive grove. - To quantify the presence of simazma water runoff as a basis for diagnosing the impact / contamination of surface water for human consumption. - To determine the effects that the use of mill residues as organic amendments currently in the process of adsorción - desorción, degradation, porosity and leaching simazma. Soils represent those receiving simazine in the study area belong according BRMRS (FAO) to four groups: Luvisoles, Leptosoles, Cambisoles and Vertisol. The results of this work show that the adsorption capacity of simazine in soils selected is linked to the proportion and type of clay present at the same and to a lesser extent on the concentration of organic matter. The evolution of the waste shows a very rapid disappearance of the same and with a deep mobility barely exceeds 10 cm, which implies little impact on groundwater. It confirms that the greatest source of contamination of drinking water stored in the swamps comes from water runoff that haul, with the first rains, part of herbicide applied. Adding alperujo and pomace produced an increase in adsorption and increased the persistence due to a large decrease in the mineralization process, which could be offset mobility and transport of simazine, lengthening his persistence. Keywords: Simazine; Soil Extremadura; Adsorption; Desorción; Degradation, Mobility; Porosity; Alperujo; Pomace; Runoff: Persistence.

Author: ALBARRÁN LISO ANGEL.
Year: 2003.
University: EXTREMADURA [www.unex.es].
Place of defense: ESCUELA DE INGENIERÍAS AGRARIAS.
Place of preparation: FACULTAD DE CIENCIAS.

Summary: The increased use of pesticides, among others, imposes a culture of minimum tillage justifies that, in recent years, has been detected herbicides in water supply Extremadura, and at concentrations higher than allowable by the EU. The objective of this study is to determine the mechanism of evolution of simazine in olive grove floors of the Group of Municipalities of Serena (Badajoz) and analyze the effects of waste mills (alperujo and pomace) on the behavior of this herbicide the system suelo-agua. To achieve the proposed targets have addressed the following: * To characterize as the basis Referral World Land Appeal (FAO) soils more representative incorporating triazinas in the study area. * Analyze the processes of adsorption, desorption and degradation of the herbicide simazine. * Monitor residues of the herbicide and determination of its persistence in experimental plots of olive grove. * To quantify the presence of simazine in water runoff as a basis for diagnosing the impact / contamination of surface water for human consumption. * To determine the impact that the use of mill residues as organic amendments currently in the process of adsorción - desorción, degradation, porosity and leaching of simazine. Soils represent those receiving simazine in the study area belong according BRMRS (FAO) to four groups: Luvisoles, Leptosoles, Cambisoles and Vertisol. The results of this work show that the adsorption capacity of simazine in soils selected is linked to the proportion and type of clay present at the same and to a lesser extent on the concentration of organic matter. The evolution of the waste meustra a very rapid disappearance of the same and with a deep mobility barely exceeds 10 cm, which implies little impact on groundwater. It confirms that the greatest source of contamination of drinking water stored in the swamps comes from water runoff that haul, with the first rains, part of herbicide applied. Adding alperujo and pomace produced an increase in adsorption and increased the persistence due to a large decrease in the process of mineralization with what might be offset mobility and transport of simazine, lengthening his persistence. KEYWORDS Simazine, Floors Extremadura, Adsorption, Desorción, Degradation, Mobility, Porosity, Alperujo, Pomace, Escorrentia and Persistence.

Author: LOUREIRO BELDARRAIN IÑIGO.
Year: 2004.
University: COMPLUTENSE DE MADRID [www.ucm.es].
Place of defense: FACULTAD DE CIENCIAS BIOLÓGICAS.
Place of preparation: FACULTAD DE CIENCIAS BIOLÓGICAS.

Summary: Faced with the possibility of setting up fields of transgenic wheat in the not too distant future it is necessary to have experimental data to evaluate the potential risks that exist in our conditions. The aim of the thesis is the study of the main agronomic and environmental risks associated with the introduction of transgenic wheat tolerantea herbicides. There has been studying a direct risk, the transfer of resistance genes to other crops and related species by hybridization, which has been addressed by studying the potential for hybridization and the fertility of hfbridos obtained, as well as a study of the dispersion of pollen wheat under conditions similar to the field in order to evaluate the possibility that takes place gene flow. It has also studied a risk indirectly, of the possible emergence of resistance in weeds associated with the cultivation due to the continued use of a single herbicide, which has studied the response of different populations of weeds cereal Bromus diandrus and Lolium rígidum to the herbicide dalapon, in order to know the state of these over the application of a "new" herbicide, meaning a new herbicide that has not been previously used in cereals. The availability of data will allow the adoption of appropriate management actions to avoid contamination between crops and the escape of transgenes. It will be necessary prior studies of the response of the populations of weeds growing in front associated with the application of the herbicide and control measures will prevent the development of populations of herbicide resistant weeds.

Author: CUEVAS SÁNCHEZ M. VICTORIA.
Year: 2004.
University: SEVILLA [www.us.es].
Place of defense: INSTITUTO DE RECURSOS NATURALES Y AGROBIOLOGÍA DE SEVILLA-CSIC.
Place of preparation: INSTITUTO DE RECURSOS NATURALES Y AGROBIOLOGÍA DE SEVILLA-CSIC.

Summary: This work is part of the Spanish contribution to the project APECOP (Ref. QLK4-CT-1999-01238) designed to evaluate the risk of contamination of soil and groundwater by the use of herbicides. The objectives were: 1-To determine the persistence and mobility of cloridazona and lenacilo in a clay soil in irrigated conditions. 2-To determine the persistence and mobility of dicamba on surfaces franco-arcillo-arenoso in rainfed and under two different tillage systems, and traditional conservation. 3-Calibrate and validate the new version 5.0 of MACRO model for predicting the risk of contamination by the use of herbicides on crops irrigated considered in this study, and compare its performance with that of the latest version, 4.3. The field work was carried out on two farms in Valle del Guadalquivir typical agricultural systems considered. Efforts were also complementary laboratory, in order to better understand the processes involved in the mobility and persistence of herbicides. This work consisted of experiments mobility and persistence in soil columns altered and unaltered, and incubation experiments and adsorption and desorption. The results obtained allowed, finally, calibrate and validate the new version 5.0 of the model MACRO, and compare it with version 4.3. The risk of contamination of groundwater by cloridazona and lenacilo is limited to the conditions studied. This is mainly due to low porosity soil pilot who, along with the characteristics of solubility of herbicides (average for cloridazona and low for lenacilo) brings the mobility of both is low, and to stagnate in the small pores, , which favors adsorption and degradation, thereby reducing the persistence of both products. The degradation cloridazona appears to be more dependent than biotic abiotic processes, while the lenacilo opposite happens. By contrast, the risk of contamination is high dicamba, especially when water significant contributions occur shortly after the application of the herbicide. This is due to the high mobility of the product, due to its nature and form acid anion. The risk of contamination is higher than with traditional tillage with conservation tillage, as the former leads to on the ground there is a greater volume of larger pores, which facilitates the mobility of the herbicide. Both versions of the model reasonably well MACRO simulate the evolution of the moisture and waste cloridazona and lenacilo, on the ground studied. While no differences were observed between the simulated values for both versions, the 5.0 has the advantage of greater discretization of the layers of soil, and a more perfect simulation of the effect of tillage on the soil hydraulic properties .-

Author: MICHITTE PAOLA CARLA.
Year: 2005.
University: CÓRDOBA [www.uco.es].
Place of defense: E.T.S.I. AGRONOMOS Y MONTES.
Place of preparation: E.T.S.I. AGRONOMOS Y MONTES.

Summary: As a result of selection pressure that the application of herbicides imposes on agricultural systems, there is the emergence of resistant weed populations. Glyphosate action is not selective and systematically applied in a post from weeds. Serves alternating biosynthesis of aromatic amino acids essential by inhibiting the enzyme EPSP synthase (Steinrucken, 1980). Diclofop-metil a ariloxifenoxipropionato, is a graminicida whose primary mode of action is inhibition of ACCasa, and as a result, the synthesis of fatty acids (Burton et al., 1989). Glyphosate and diclofop-metil are two of the most commonly used herbicides in direct sowing, where the use of herbicides to control bad hiertas is essential. This practice is very common in Chile. Glofosto is used successfully for over 15 years in presiembra and post and diclofop-metil applies during cultivation. However, recently in the Region IX, a population of Lolium multiflorum (vile-1), is being poorly controlled with both herbicides. As a result of its competition with the cultivation, production losses and costs related to its control have increased, as required higher doses and greater number of treatments per year. The objectives of this study were to confirm the resistance of Vil-1 to glofosato and diclofop-metil and determine the extent of the same; find the causes -bioquímicas and / or fisiológicas- of both resistance and find alternatives for the control of this biotype. The dose response curves confirmed the resistance of Vil-1 on both herbicides, both the state as a seedling at the stadium from 3 to 4 leaves. The decline in basorciónde glyphosate by delbiotipo resistant, along with a change in the pattern of translocation of the herbicide, which migrates toward areas that do not affect the survival of the plant, seem to explain the resistance of Vil-1 to this herbicide. The analysis of the cuticle suggest that this may play a role in reducing penetration. There already by its membership, but by its morphology, studied by electronic microscope. There is no evidence that resistance diclofop-metil gave any change in the absorption, metabolism or translocation of the herbicide by the resistant biotype. Nor differences were found when studying in vitro affinity of the ACCasa of resistant and susceptible biotypes by diclofop-metil. Therefore it is suspected that another mechanism, sequestration, is responsible for the resistance to this herbicide. In the field, the herbicide cletodím is presented as a good alternative to diclofop-metil, according to the results of the tests conducted. Before or after ciclom cultivation can be used to control Vil-1 therefore to aminotriazol (a systemic action at all), as the herbicide preemergencia evaluated in the field.

Author: MARTINEZ CORDON MARIA JOSE.
Year: 2005.
University: CÓRDOBA [www.uco.es].
Place of defense: FACULTAD DE CIENCIAS.
Place of preparation: FACULTAD DE CIENCIAS.

Summary: In this case, besides the problem of whether soil erosion, we take into account the negative effects that herbicides could cause on the environment and health. In the fight against erosion have been observed using covers (live or inert) protects the soil from erosion. The objective of this study is to evaluate and compare the behavior in soil and the consequences of the use of simazine and terbutilazina in an area representing Andalusian olive grove moderate slope. They have done several tests of mobility, adsorption and degradation using soils from different management systems in the regime of non-tillage: bare soil by applying herbicides, NL; bare soil covered more chemically harvested vegetables, NLCQ and bare soil most roofing plant harvested mechanically, NLCM. Also examined were the incidences positive and / or negative that the use of these herbicides or ground cover may pose to the culture itself and the quality of the oil. The test results show that terbutilazina presents leaching greater adsorption capacity that simazine. In incubaciones suelo-herbicida in laboratory conditions identical and there was a rapid degradation of both molecules, not eñcontrándose no difference between soil from the different management systems. But in field conditions terbutilazina is more persistent than simazine. A larger volumes of precipitation were found higher rates of dissipation of herbicides, and in the case of simazine, the results showed that their average life times decrease with the number of applications. Moreover, the presence of ground cover lowers rates of dissipation of herbicides. These results are consistent with those found in studies show that runoff as covers not only reduce the flow of runoff, but also the quantities of herbicides transported in them. In evaluating the effect of management systems on the olive groves are both herbicides were effective in controlling weeds during the harvest season, ensuring good returns on crops, although the effectiveness of terbutilazina was slightly higher . The nutritional status of trees and production were not affected by the different soil management systems or herbicides. The quantification of residual levels of both molecules in oil shows higher levels in olive oil from the ground, which should take special care.

Author: GARCIA ANGULO PENELOPE.
Year: 2005.
University: LEÓN [www.unileon.es].
Place of defense: FACULTAD DE CIENCIAS BIOLÓGICAS Y AMBIENTALES.
Place of preparation: FACULTAD DE CIENCIAS BIOLOGICAS Y AMBIENTES.

Summary: The cell wall is a dynamic structure whose structural plasticity determined, at least in part, the acquisition of tolerance diclobenil. The use of herbicides, inhibitors of cell wall biosynthesis represents an excellent working strategy for the study of various aspects of the composition, structure and dynamics of the cell wall. The main objective of this work is the analysis of the changes taking place within the walls of cell cultures of bean used to diclobenil, as well as the stability of these changes, and its involvement in the crusade to other stress tolerance. For addressed uses a set of techniques such as optical microscopy and electronics, immunoassay, FTIR spectroscopy, incorporation of (14C) Gic in fractions of the cell wall, and so on. The room in this entails three major inhibitory effects on cell wall: training aposiciones, variation dela proportion among major components (pectins, hemicelulosas, cellulose and proteins) and establishing new partnerships between polymers. The aposiciones consist of a mixture of polysaccharides of the cell wall, including B-1 ,4-glucano, homogalacturonano very metilesterificado, remnogalacturnano I xiloglucano. It is likely that the presence of a B-1 ,4-glucano not cellulosic in aposiciones of lapared is a direct consequence of the action of diclobenil that, rather than prevent the incorporation of glucose cellulose inhibit your organization microfibrilar. The decrease in the cellulose content is causing diclobenil is offset by an increase in the deposition of polysaccharides pécticos little methyl esterification. However, although the time in the presence of inhibitory cells recover levels of cellulose content pectins not declining. The plasticity of the cell wall was also evident in the ability of interaction of the three networks that initially were considered independientementes. We noticed a greater degree of unity among and hemicelulosas between pectins and cellulose and between pectins and proteins. The cells revert gradually accustomed morphology and the overall composition of the cell wall to eliminate diclobenil of culture medium, but other changes persist and may be responsible for the high tolerance diclobenil, and other inhibitors of the cell wall, which holds deshabituadas still retain.

Author: DELGADO MORENO LAURA ISABEL.
Year: 2006.
University: GRANADA [www.ugr.es].
Place of defense: ESTACIÓN EXPERI. DEL ZAIDIN, CSIC.
Place of preparation: ESTACIÓN EXPERIMENTAL DEL ZAIDÍN. CONSEJO SUPERIOR DE INVESTIGACIONES CIENTÍFICAS (C.S.I.C).

Summary: As a result of the high consumption of pesticides, there are currently numerous soil and water contaminated by pesticides. These findings show that the purification capacity of the soil is finite. Moreover, the problem is exacerbated in areas of the Mediterranean region, since as a result of the current drought is becoming increasingly necessary to use groundwater for consumption. Therefore, the search for techniques designed to prevent or correct the contamination by pesticides has taken in recent times especially relevant. One of these techniques involves the application of agricultural soils amendments, as organic waste can be of a different nature contributing to their revaluation. For the realization of this study have found two families of herbicides, triazinas and sulfonylureas, which are widely used in agriculture, particularly in Vega of Granada, use eminent agricultural area that is located on one of the most important aquifers in Andalusia. On the other hand, amendments have been used as a functional alperujo, the residue obtained from the agribusiness of olive oil, of which Spain is the largest producer worldwide, and its products biotransformados, compost and vermicompost of alperujo. The behavior of herbicides triazínicos and sulfonilureicos on two floors of Granada province and the possibility of changing that behavior by adding alperujo, compost and vermicompost of alperujo is the main aim of this work. It conducted studies of adsorption and desorption of herbicides studied in unamended soil and amended with alperujo, compost and vermicompost of alperujo. Appreciative of the effect of dose amendment applied, the composition of the organic matter and soil amendments and the time of incubation of soil and amendments. In addition, it was determined the effect of adding alperujo, compost and vermicompost of alperujo in the degradation of herbicides studied. Finally, we conducted a field test with the herbicide sulfonilureico bensulfurón methyl to determine their mobility. The resultaros showed: On the one hand that the implementation of alperujo, compost and vermicompost of alperujo an agricultural dose had no effect on the adsorption of herbicides studied. However, the addition of amendments to a dose matter remediador favor adsorption triazinas and sulfonylureas primarily in the case of soil amended with alperujo mainly due to their higher content in the water-soluble fraction of organic compounds and aliphatic character, in the case of herbicides triazínicos and the resulting decrease in soil pH, in the case of sulfonilureicos. The incubation time of soil and amendments does not alter or diminish the adsorption capacity of the soil but favors the desorption of pesticides consistent with the environmental implications. Of the degradation studies reveal that the addition of amendments not passed so important in the degradation of herbicides studied, but we must point out that the results expressed different processes degradativos depending on the nature of the substrate. In this regard, the addition of compost and soil vermicompost favored biological degradation of pesticides. Finally highlight the importance of the strength of irrigation water applied to the field and the flow phenomena preferential mobility herbicide bensulfurón methyl into groundwater.