Search

[EN] In this work, the evolution of six irrigation quality indexes was studied using treated wastewater, according to the treatment applied, the type of emitter, its hydraulic behavior and its insertion form. A total of 20 emitters from 10 different manufacturers and flow rates between 2.0 and 4.0 l/h were analyzed. There were three irrigation treatments: AR (regenerated water), AR-FR (regenerated water + fertilization with standard ionic solution) and AR-FR-M (regenerated water + standard ionic fertilization + maintenance). The results show a better performance of the AR-FR-M treatment, with no relationship between quality indexes and type of emitter, although there is a relationship with the way of insertion. The compensating drippers show a better performance. In conclusion, fertigation without maintenance is not recommended, under any of the conditions, since it affects the clogging of the emitters and, therefore, the uniformity of the installation., [ES] En este trabajo se ha estudiado la evolución de seis índices de calidad del riego usando aguas residuales depuradas, según el tratamiento aplicado, el tipo de emisor, su comportamiento hidráulico y su forma de inserción. Los emisores analizados fueron un total de 20 de 10 fabricantes distintos y caudales comprendidos entre 2.0 y 4.0 l/h. Los tratamientos de riego fueron tres: AR (Agua Regenerada), AR-FR (Agua regenerada + fertilización con solución iónica estándar) y AR-FR-M (Agua regenerada + fertilización iónica estándar + mantenimiento). Los resultados muestran un mejor comportamiento del tratamiento AR-FR-M, no existiendo relación entre índices de calidad y tipo de emisor, aunque si con su forma de inserción. Los goteros compensantes muestran un mejor desempeño. Como conclusión, no se recomienda, en ninguna de las condiciones, fertirrigar sin mantenimiento, ya que, afecta al atascamiento de los emisores y, por tanto, a la uniformidad de la instalación.

[EN] Ammonia and carbon dioxide are the most relevant among the harmful gases present in broiler houses and their effects on animal health depend on concentration and exposure time. Inside these houses, increasing ventilation is the most common strategy adopted to control the concentration of these gases. This strategy is effective but increases electrical energy consumption (for fan operation) and thermal energy consumption (for inlet air heating). In this work, the variations of energy consumption due to the increase of ventilation to maintain ammonia and carbon dioxide concentrations below established thresholds were evaluated. To carry out this analysis, various parameters (e.g. indoor air temperature and gas concentrations) of a broiler house located in the Mediterranean area were monitored during a production cycle in the cool (winter) season in which outdoor air temperature varied between 2 and 25 °C. The assessment of the increase in the energy consumption for climate control was carried out using the Specific Fan Performance and a customised building energy simulation model. The analysis showed that during the monitored period, the established thresholds of gas concentrations were exceeded approximately 60% of the time. To maintain the desired gas concentrations, the ventilation flow rate should be increased by 9%. This variation in the ventilation flow rate entailed a rise in the energy consumption by about 10% for electrical energy and by about 14% for thermal energy. Maintaining the gas concentration below the established thresholds entails an extra cost of around 0.02 € per harvested broiler.

[EN] Different polyvinyl alcohol (PVA) coating formulations incorporating starch (S) and carvacrol (C) as the active agent were applied to Golden Delicious apples to evaluate their effectiveness at controlling weight loss, respiration rate, fruit firmness, and fungal decay against B. cinerea and P. expansum throughout storage time. Moreover, the impact of these coatings on the sensory attributes of the fruit was also analyzed. The application of the coatings did not notably affect the weight loss, firmness changes, or respiration pathway of apples, probably due to the low solid surface density of the coatings. Nevertheless, they exhibited a highly efficient disease control against both black and green mold growths, as a function of the carvacrol content and distribution in the films. The sensory analysis revealed the great persistence of the carvacrol aroma and flavor in the coated samples, which negatively impact the acceptability of the coated products.

[ES] Este trabajo caracteriza desde el punto de vista productivo y socioeconómico las explotaciones con bovino en la Cornisa Cantábrica y España, además de analizar la evolución reciente de los principales indicadores de ajuste entre 2007 y el año 2016. Para lograr este objetivo se han utilizado las principales magnitudes agrarias, relativas al número de explotaciones, superficie, ganado, trabajo y valor económico de la producción. Los resultados obtenidos muestran una concentración territorial, especialización y concentración productiva del bovino, junto a un avance del proceso de ajuste estructural., [EN] This study characterizes, from a productive and socioeconomic point of view, the cattle farms in Cantabrian Cornice and Spain, besides analyzing recent evolution of the main adjustment indicators between 2007 and 2016. In doing so, we have analyzed the main agricultural magnitudes, relative to the number of farms, land, livestock, labor and economic value of production. The results obtained show a territorial concentration, specialization and productive concentration of the cattle, together with an advance of the structural adjustment process.

La poda manual de limoneros en el sureste de España supone aproximadamente el 39% del total de los costes de mano de obra del cultivo. La poda mecánica se puede integrar en una estrategia de gestión del cultivo para reducir los costes de poda; sin embargo, no es una técnica que está ampliamente aceptada entre los agricultores, entre otros motivos, por la falta de estudios rigurosos con variedades y formas de cultivo que justifiquen sus posibles ventajas. En este trabajo se exponen los resultados de una experiencia de tres años para evaluar el potencial de la poda mecánica combinada con poda manual en limoneros ‘Fino 95’. Los parámetros analizados han sido producción, calibre, calidad de la fruta, características de la biomasa podada y productividad de la labor. Se han realizado cinco tipos de tratamientos de poda: (1) poda manual (control) y cuatro intensidades de poda mecánica que tienen en común la poda de faldas y copa; y en las que la intensidad de poda mecánica se incrementó a medida que la intensidad de la poda manual se reducía; (2) poda mecánica de faldas y copa con repaso manual, (3) poda mecánica de faldas, copa y un lado del árbol; y poda manual del otro lado del árbol, (4) poda mecánica de faldas, copa y un lado del árbol, y (5) poda mecánica de faldas, copa y los dos lados del árbol. Estos tratamientos se han repetido durante tres años con alternancia de tipo de poda en el mismo bloque creando cinco tratamientos plurianuales. La principal conclusión del trabajo es que el tratamiento plurianual que alternó anualmente poda mecánica y manual, o bien el tratamiento de solo poda mecánica los tres años obtuvieron la mayor producción comercial acumulada. Por otro lado, los tratamientos con poda manual y mecánica el mismo año han obtenido la menor producción comercial acumulada.

[EN] Sour orange, Citrus aurantium, displays higher constitutive and earlier inducible direct defenses against the two-spotted spider mite, Tetranychus urticae, than Cleopatra mandarin, Citrus reshni. Moreover, herbivore-induced plant volatiles (HIPVs) produced by sour orange upon infestation can induce resistance in Cleopatra mandarin but not vice versa. Because the role of these HIPVs in indirect resistance remains ignored, we have carried out a series of behavioral assays with three predatory mites with different levels of specialization on this herbivore, from strict entomophagy to omnivory. We have further characterized the volatile blend associated with T. urticae, which interestingly includes the HIPV methyl salicylate, as well as that produced by induced Cleopatra mandarin plants. Although a preference for less defended plants with presumably higher prey densities (i.e., C. reshni) was expected, this was not always the case. Because predators' responses changed with diet width, with omnivore predators responding to both HIPVs and prey-related odors and specialized ones mostly to prey, our results reveal that these responses depend on plant genotype, prey presence and predator diet specialization. As the different volatile blends produced by infested sour orange, induced Cleopatra mandarin and T. urticae itself are attractive to T. urticae natural enemies but not to the herbivore, they may provide clues to develop new more sustainable tools to manipulate these agriculturally relevant species.

[EN] Traditionally persimmon cultivation has been considered a minor crop in Spain, but in recent years this crop has experienced an important increase in both cultivated area and production. This increase has been mainly attributed to the widespread adoption of a new postharvest treatment which considerably extends the fruit commercialization period. The sudden expansion of this crop has not allowed time to correctly develop an integrated pest management (IPM) program. Consequently, chemical treatments have become the main strategy to lessen the impact of pests. Given the importance of phytoseiids in other Mediterranean fruit crops, where they are the basis of IPM, we sought to determine whether they could be similarly employed in persimmon crops. For this, we studied the predatory mite complex, the phytoseiid population dynamics and the potential prey for them during three consecutive seasons in four persimmon orchards, two of which managed conventionally, and two organically. Phytoseiids were abundant throughout the season, found on average at a density of more than 1 predatory mite per leaf. The most abundant species was Euseius stipulatus (57.3%) followed by Typhlodromus phialatus (24.8%), Amblyseius andersoni (17.1%) and Paraseiulus talbii (0.8%). Persimmon leaves provided a diversity of prey for predatory mites throughout the year, the most abundant being mealybugs, coccids, whiteflies and thrips. The abundance of predatory mites was significantly correlated to the abundance of potential prey available. From our results we anticipate that phytoseiids will be key actors in the development of persimmon IPM. Their role in this crop is discussed, as well as how to conserve their populations.

[EN] Delottococcus aberiae De Lotto (Hemiptera: Pseudococcidae) is one of the latest invasive mealybugs in Europe. It causes severe fruit distortion and reduced fruit size leading into important economic losses in citrus. Cryptolaemus montrouzieri (Mulsant) (Coleoptera: Coccinellidae) is probably one of the most-used predators of mealybugs in biological control programs worldwide. However, its impact on D. aberiae is still unknown. Here, we conducted a two-year field study in nine citrus orchards located in eastern Spain in order to describe the population dynamics of D. aberiae and C. monirouzieri and evaluate the effect of the predator on D. aberiae using different approaches. Our results showed that C. monirouzieri and D. aberiae had two main synchronised population peaks per year: early spring and summer. Although D. aberiae and C. monirouzieri seasonal trends were synchronised, C. montrouzieri neither reduced mealybug density within the same year nor prevented fruit damage, which occurs early in the season. Moreover, D. aberiae population growth rates were not correlated with C. montrouzieri density. When two consecutive years were analyzed, the increase of D. aberiae in the second year was negatively correlated with the density of C. monirouzieri in summer of the previous year. Based on our two years of data, C. monirouzieri was not able to regulate D. aberiae on its own or prevent the damages produced by the mealybug but might become a valuable addition to the natural enemy guild when combined with other natural enemies and rational control measures.

This Document is Protected by copyright and was first published by Frontiers. All rights reserved. it is reproduced with permission., [EN] The microbiota colonizing the rhizosphere and the endorhizosphere contribute to plant growth, productivity, carbon sequestration, and phytoremediation. Several studies suggested that different plants types and even genotypes of the same plant species harbor partially different microbiomes. Here, we characterize the rhizosphere bacterial and fungal microbiota across five grapevine rootstock genotypes cultivated in the same soil at two vineyards and sampling dates over 2 years by 16S rRNA gene and ITS high-throughput amplicon sequencing. In addition, we use quantitative PCR (qPCR) approach to measure the relative abundance and dynamic changes of fungal pathogens associated with black-foot disease. The objectives were to (1) unravel the effects of rootstock genotype on microbial communities in the rhizosphere of grapevine and (2) to compare the relative abundances of sequence reads and DNA amount of black-foot disease pathogens. Host genetic control of the microbiome was evident in the rhizosphere of the mature vineyard. Microbiome composition also shifted as year of sampling, and fungal diversity varied with sampling moments. Linear discriminant analysis identified specific bacterial (i.e., Bacillus) and fungal (i.e., Glomus) taxa associated with grapevine rootstocks. Host genotype did not predict any summary metrics of rhizosphere alpha- and beta-diversity in the young vineyard. Regarding black-foot associated pathogens, a significant correlation between sequencing reads and qPCR was observed. In conclusion, grapevine rootstock genotypes in the mature vineyard were associated with different rhizosphere microbiomes. The latter could also have been affected by age of the vineyard, soil properties or field management practices. A more comprehensive study is needed to decipher the cause of the rootstock microbiome selection and the mechanisms by which grapevines are able to shape their associated microbial community. Understanding the vast diversity of bacteria and

[EN] The effect of controlled deficit irrigation (CDI) on the accumulation of carotenoids, polyphenols and l-ascorbic acid was studied in conventional and high lycopene tomato cultivars. Plants were initially irrigated to cover 100%ETc and after the fruit set phase, the dose was reduced to 75% or 50% of ETc. CDI had no significant effect on the accumulation of carotenoids, while it increased the levels of the hydroxycinnamic acids chlorogenic and ferulic acids, the flavonoid rutin and l-ascorbic acid. Nevertheless, there were important interactions and this effect was highly dependent on the year and site of cultivation. Certain growing areas would be more favorable to supply high quality markets, and, fortunately, CDI would maximize polyphenol (100¿75%ETc) and l-ascorbic acid (100¿50%ETc) in these areas. A combination of the best genotype and growing area with CDI would offer high quality products, preserving a scarce resource: water.

[EN] Chemical sanitizers continue to be widely used by the food industry to disinfect food contact surfaces. However, as some chemical disinfectants have been reported to produce unhealthy by-products, alternative and natural compounds need to be investigated. To this end, nine essential oils (EOs) were screened to develop a natural sanitizing solution (SAN) for disinfecting food contact surfaces. Once extracted, their antimicrobial activity and chemical composition were determined. An exploratory multivariate approach was used to investigate the relationships between the chemical and microbiological data sets. Among the tested EOs, Thymbra capitata EO, containing up to 93.31% oxygenated monoterpenes (mainly carvacrol), showed the strongest antimicrobial activity and thus was assayed as a potential SAN for food contact surfaces. To this end, a SAN consisting of 1% T. capitata EO was first validated according to the AOAC standard, which showed about 8¿log reduction for Escherichia coli and Salmonella enterica after 30 and 60¿s of contact time, respectively. Then, the SAN was evaluated at various concentrations, cleanliness conditions, and contact times on stainless steel, glass, and polypropylene surfaces for sanitizing purposes. The results showed that the SAN containing 2.5% of T. capitata EO applied for 10¿min, reduced the levels of E. coli by >3¿log and S. enterica by 1¿log under clean working conditions on the three tested surfaces. These findings indicate that EOs can be used as natural disinfectants to decontaminate food contact surfaces, thus lowering the risk of the indirect transfer of bacterial pathogens to food or persons.

There is little information about the potential effects of compost and zeolite or zeolite with leonardite as soil amendments in barley cultivation. Thus in this study, the following objectives were proposed: i) to compare the effects of the addition of compost, alone or simultaneously with zeolite, and of the addition of leonarditeenriched zeolite with those of the conventional NPK fertilization used in barley cultivation, on the soil nutritional status, microbial community structure, and enzyme activity in different stages of barley cultivation; and ii) to establish relationships between the different soil parameter trends, soil microbial community structure, and barley crop yield. In the field experiment carried out with a barley crop, the alternative fertilization treatments tested had an overall positive effect, in comparison with conventional fertilization with a mineral NPK fertilizer, when soil quality parameters, the nutritional level and yield of the barley crop were analyzed. Zeolite with leonardite increased barley yield in comparison with the compost treatments, either with zeolite or without, but had an excessive contribution to the water soluble contents of Na and N in soil. So, using environmental and agronomic criteria, the most rational action would be the use of compost in agriculture.

[EN] DNA-binding with one finger (DOF)-type transcription factors are involved in many fundamental processes in higher plants, from responses to light and phytohormones to flowering time and seed maturation, but their relation with abiotic stress tolerance is largely unknown. Here, we identify the roles of CDF3, an Arabidopsis DOF gene in abiotic stress responses and developmental processes like flowering time. CDF3 is highly induced by drought, extreme temperatures and abscisic acid treatment. The CDF3 T-DNA insertion mutant cdf3-1 is much more sensitive to drought and low temperature stress, whereas CDF3 overexpression enhances the tolerance of transgenic plants to drought, cold and osmotic stress and promotes late flowering. Transcriptome analysis revealed that CDF3 regulates a set of genes involved in cellular osmoprotection and oxidative stress, including the stress tolerance transcription factors CBFs, DREB2A and ZAT12, which involve both gigantea-dependent and independent pathways. Consistently, metabolite profiling disclosed that the total amount of some protective metabolites including -aminobutyric acid, proline, glutamine and sucrose were higher in CDF3-overexpressing plants. Taken together, these results indicate that CDF3 plays a multifaceted role acting on both flowering time and abiotic stress tolerance, in part by controlling the CBF/DREB2A-CRT/DRE and ZAT10/12 modules.

[EN] Background: Apricot (Prunus armeniaca L.) exhibits a gametophytic self-incompatibility (GSI) system and it is mostly considered as a self-incompatible species though numerous self-compatible exceptions occur. These are mainly linked to the mutated SC-haplotype carrying an insertion in the S-locus F-box gene that leads to a truncated protein. However, two S-locus unlinked pollen-part mutations (PPMs) termed m and m¿ have also been reported to confer self-compatibility (SC) in the apricot cultivars `Canino¿ and `Katy¿, respectively. This work was aimed to explore whether other additional mutations might explain SC in apricot as well. Results: A set of 67 cultivars/accessions with different geographic origins were analyzed by PCR-screening of the S- and M-loci genotypes, contrasting results with the available phenotype data. Up to 20 S-alleles, including 3 new ones, were detected and sequence analysis revealed interesting synonymies and homonymies in particular with S-alleles found in Chinese cultivars. Haplotype analysis performed by genotyping and determining linkagephases of 7 SSR markers, showed that the m and m¿ PPMs are linked to the same m0¿haplotype. Results indicate that m0-haplotype is tightly associated with SC in apricot germplasm being quite frequent in Europe and North-America. However, its prevalence is lower than that for SC in terms of frequency and geographic distribution. Structures of 34 additional M-haplotypes were inferred and analyzed to depict phylogenetic relationships and M1¿2 was found to be the closest haplotype to m0. Genotyping results showed that four cultivars classified as self-compatible do not have neither the SC- nor the m0-haplotype. Conclusions: According to apricot germplasm S-genotyping, a loss of genetic diversity affecting the S-locus has been produced probably due to crop dissemination. Genotyping and phenotyping data support that self-(in)compatibility in apricot relies mainly on the S- but also on the M-locus. Regarding

[EN] A methodology for the determination of tomato phenolic acids and flavonoids has been developed combining MEKC and DAD detection. The influence on polyphenol separation of pH and background electrolyte, BGE (borax, acetonitrile, methanol and SDS concentrations), was studied and optimized using response surface methodology and weighted desirability function. Separation of polyphenols was achieved within 20 min at 15 degrees C using 11.3 mM borax and 11.2 mM SDS adjusted to pH 8.5 as BGE. Validation was performed using standards and tomato extracts. Recoveries ranged from 77 to 106%. Acceptable repeatabilities were obtained for peak area (% RSD <3.1% and <3.7%) and migration times (% RSD <0.2% and <1.4%) for intra-and inter-day respectively. Detection limits ranged between 0.8 and 3.8 mg kg (1). Five and seven of these polyphenols were determined in samples of tomato and related species. This methodology will be valuable tool in breeding programs, analyzing a large number of samples. (C) 2016 Elsevier Ltd. All rights reserved.

[EN] Abscission is a cell separation process by which plants can shed organs such as fruits, leaves, or flowers. The process takes place in specific locations termed abscission zones. In fruit crops like citrus, fruit abscission represents a high percentage of annual yield losses. Thus, understanding the molecular regulation of abscission is of capital relevance to control production. To identify genes preferentially expressed within the citrus fruit abscission zone (AZ-C), we performed a comparative transcriptomics assay at the cell type resolution level between the AZ-C and adjacent fruit rind cells (non-abscising tissue) during ethylene-promoted abscission. Our strategy combined laser microdissection with microarray analysis. Cell wall modification-related gene families displayed prominent representation in the AZ-C. Phylogenetic analyses of such gene families revealed a link between phylogenetic proximity and expression pattern during abscission suggesting highly conserved roles for specific members of these families in abscission. Our transcriptomic data was validated with (and strongly supported by) a parallel approach consisting on anatomical, histochemical and biochemical analyses on the AZ-C during fruit abscission. Our work identifies genes potentially involved in organ abscission and provides relevant data for future biotechnology approaches aimed at controlling such crucial process for citrus yield.

[EN] Delottococcus aberiae De Lotto (Hemiptera: Pseudococcidae) is the latest exotic mealybug species introduced in citrus in the Mediterranean basin. It causes severe distortion and size reduction on developing fruits. Due to its first interaction with citrus, D. aberiae economic thresholds are still unknown for this crop and the current Integrated Pest Management programs have been disrupted. The objectives of this study were to determine the aggregation patterns of D. aberiae in citrus, develop an efficient sampling plan to assess its population density, and calculate its Economic and Economic Environmental Injury Levels (EIL and EEIL, respectively). Twelve and 19 orchards were sampled in 2014 and 2015, respectively. At each orchard, population densities were monitored fortnightly in leaves, twigs, and fruit, and fruit damage was determined at harvest. Our results showed a clumped aggregation of D. aberiae in all organs with no significant differences between generations on fruit. Fruit damage at harvest was strongly correlated with fruit occupation in spring. Based on these results and using chlorpyrifos as the insecticide of reference, the EIL and EEIL were calculated as 7.1 and 12.1% of occupied fruit in spring, respectively. With all this, we recommend sampling 275 fruits using a binomial sampling method or alternatively, 140 fruits with an enumerative method bimonthly between petal fall and July.

[EN] Nowadays, the detection, localization, and quantification of different kinds of features in an RGB image (segmentation) is extremely helpful for, e.g., process monitoring or customer product acceptance. In this article, some of the most commonly used RGB image segmentation approaches are compared in an orange quality control case study. Analysis of variance and correspondence analysis are combined for determining their most relevant differences and highlighting their pros and cons.

[EN] BACKGROUND: Berry weight, berry number and cluster weight are key parameters for yield estimation for wine and tablegrape industry. Current yield prediction methods are destructive, labour-demanding and time-consuming. In this work, a new methodology, based on image analysis was developed to determine cluster yield components in a fast and inexpensive way. RESULTS: Clusters of seven different red varieties of grapevine (Vitis vinifera L.) were photographed under laboratory conditions and their cluster yield components manually determined after image acquisition. Two algorithms based on the Canny and the logarithmic image processing approaches were tested to find the contours of the berries in the images prior to berry detection performed bymeans of the Hough Transform. Results were obtained in two ways: by analysing either a single image of the cluster or using four images per cluster from different orientations. The best results (R2 between 69% and 95% in berry detection and between 65% and 97% in cluster weight estimation) were achieved using four images and the Canny algorithm. The model¿s capability based on image analysis to predict berry weight was 84%. CONCLUSION: The new and low-cost methodology presented here enabled the assessment of cluster yield components, saving time and providing inexpensive information in comparison with current manual methods. © 2014 Society of Chemical Industry

Aim of study: We aim at (i) developing a reference definition of mixed forests in order to harmonize comparative research in mixed forests and (ii) briefly review the research perspectives in mixed forests. Area of study: The definition is developed in Europe but can be tested worldwide. Material and methods: Review of existent definitions of mixed forests based and literature review encompassing dynamics, management and economic valuation of mixed forests. Main results: A mixed forest is defined as a forest unit, excluding linear formations, where at least two tree species coexist at any developmental stage, sharing common resources (light, water, and/or soil nutrients). The presence of each of the component species is normally quantified as a proportion of the number of stems or of basal area, although volume, biomass or canopy cover as well as proportions by occupied stand area may be used for specific objectives. A variety of structures and patterns of mixtures can occur, and the interactions between the component species and their relative proportions may change over time. The research perspectives identified are (i) species interactions and responses to hazards, (ii) the concept of maximum density in mixed forests, (iii) conversion of monocultures to mixed-species forest and (iv) economic valuation of ecosystem services provided by mixed forests. Research highlights: The definition is considered a high-level one which encompasses previous attempts to define mixed forests. Current fields of research indicate that gradient studies, experimental design approaches, and model simulations are key topics providing new research opportunities. Key words: COST Action; EuMIXFOR; mixed-species forests; admixtures of species., Instituto Universitario de Gestión Forestal Sostenible

[EN] Green mold (Penicillium digitatum) and blue mold (Penicillium italicum) are important sources of postharvest decay affecting the commercialization of mandarins. These fungi infections produce enormous economic losses in mandarin production if early detection is not carried out. Nowadays, this detection is performed manually in dark chambers, where the fruit is illuminated by ultraviolet light to produce fluorescence, which is potentially dangerous for humans. This paper documents a new methodology based on hyperspectral imaging and advanced machine-learning techniques (artificial neural networks and classification and regression trees) for the segmentation and classification of images of citrus free of damage and affected by green mold and blue mold. Feature selection methods are used in order to reduce the dimensionality of the hyperspectral images and determine the 10 most relevant. Neural Networks were used to segment the hyperspectral images. Result's achieved using classifiers based on decision trees show an accuracy of around 93% in the problem of decay classification.

[EN] Lufenuron is a chitin synthesis inhibitor, which is able to impede Mediterranean fruit fly, Ceratitis capitata (Wiedemann), reproduction. In laboratory trials, following ingestion of lufenuron, the eggs laid by female Ceratitis capitata were prevented from hatching. In field trials in Valencia, Spain, lufenuron showed its effectiveness by reducing C. capitata wild populations and its continuous application to several generations of fruit fly resulted in increased pest control. This field trial was conducted in an isolated valley some 80ha in size, over a continuous four-year period. In order to maintain the sterilizing effect in the field throughout the whole year, a new lufenuron bait gel was developed. This bait gel was introduced in to delta traps suspended in trees at a density of 24 traps ha 1, and these traps were replaced once a year during the field trial. Monitoring of the adult C. capitata population was conducted to assess the effects of the chemosterilant treatment. In the first year of treatment with sterilizing traps, a reduction of the C. capitata population was observed, indicating that the traps reduce the population right from the first generation. In the second, third and fourth years, a continuous and progressive reduction of the adult Mediterranean fruit fly population was observed. Therefore, the successive application of chemosterilization treatment has a cumulative effect on reducing the fly population year after year. Aerial treatment using malathion does not produce this cumulative effect, and consequently every year it is necessary to start again with the same number of flies as the year before. The possibility of using the chemosterilant method alone or combined with the sterile insect technique is discussed.

[ES] Se han medido los cambios temporales producidos en la cabecera y en el área de cinco sistemas de cárcavas en la zona de Guadix usando series de fotografías aéreas de 1956 y 1994. Para estimar el avance y la expansión de las mismas se han utilizado Sistemas de Información Geográfica (SIG) (ER-Mapper, ARC/INFO y ARC/View). Algunas de las cárcavas estudiadas no han tenido avance por cabecera en estos 38 años y las que han modificado su longitud lo han hecho entre 0.21 y 1.71 m/año. En estos ambientes mediterráneos los procesos naturales asociados a fluctuaciones climáticas son probablemente causas insuficientes para iniciar una cárcava pero sí pueden contribuir a su expansión.

[EN] A very intensive crop rotation, with three to four crops per year, typical in Valencia, frequently includes the earth almond Cyperus sculentus (Xufa) that acts as a real weed for the next crop. Methyl bromide (MB) is the preferred fumigant to control both diseases and weeds in this kind of rotation. The crop rotation begun by an escarole crop (September to January), followed by potato (February to May) and watermelon (May to August). Disinfestation treatments to compare were: 1) Non fumigated control; 2) Standard MB polyethylene (PE) 60g/ m2 ; 3) MB VIF 30g/ m2; 4) Solarization + Manure 5Kg/ m2; 5) Solarization + MS (N-Methyl Dithiocarbamate Sodic 40% p/v) 36g/ m2; 6) Telone C35 Mechanical application 40g/ m2; 7) Telone II (1,3-Dichloropropene 93%p/p)18g/ m2 + MS 108g/m2 All treatments are rather effective in controlling weeds when compared to the non treated control, the increase in cost of removing weeds is particularly high if none treatment is applied. Only the escarole crop suffered the attack of Scleotinia minar and treatments 2 and 7 gave a very good protection as is revealed by a low percent of debris. No specific pathogens were found in potato and watermelon crops, nevertheless grafting is confirmed as a very good technique that increases the yield of watermelon. Solarization treatments did not differ significantly from control in this experiment. Treatment 7 is as good as MB in sorne of the instances, but disinfestation with MB is absolutely necessary if non grafted plants of watermelon are employed.