Manejo de azevém (Lolium multiflorum Lam.) resistente ao glyphosate com o uso de diferentes herbicidas

Pós-graduação em Agronomia (Proteção de Plantas) - FCA

Avaliação de modelos empíricos para determinação da taxa de passagem de caprinos em crescimento

Pós-graduação em Zootecnia - FCAV

Seasons of desiccant application in the soybean crop: water content and productivity

The herbicides glyphosate and paraquat have been used by Brazilian soybean producers to obtain crop desiccation and to anticipate and uniformity at harvest. However, improper use of herbicides can to occasion problems in agronomic and physiologic characteristics of crop. This study aimed to evaluate the use of the glyphosate and paraquat herbicides as a desiccant for growing soybeans. The experiment was conducted in 2005/06 crop year, in an experimental design of randomized blocks with four replications. Treatments were arranged in two factorial design, 3x3x5x2 and 3x2x5x2: two desiccants (glyphosate and paraquat) and control (without drying), three and two growth stages (R6, R7 and R8) and (R7 and R8) for varieties MSOY 6101 of superprecocious cycle, and MG / BR 46 (Conquista) of precocious cycle, respectively, five sampling times (2, 4, 6, 8 and 10 days after application) and two positions in the plants on the ground assessment (apex and base). Was evaluated for seed Production, mass and water content of 100 seeds. Desiccants tested were effective in reducing the water content of seeds, without affecting productivity and mass of 100 seeds.

Assessing biophysical variable parameters of bean crop with hyperspectral measurements

Recently high spectral resolution sensors have been developed, which allow new and more advanced applications in agriculture. Motivated by the increasing importance of hyperspectral remote sensing data, the need for research is important to define optimal wavebands to estimate biophysical parameters of crop. The use of narrow band vegetation indices (VI) derived from hyperspectral measurements acquired by a field spectrometer was evaluated to estimate bean (Phaseolus vulgaris L.) grain yield, plant height and leaf area index (LAI). Field canopy reflectance measurements were acquired at six bean growth stages over 48 plots with four water levels (179.5; 256.5; 357.5 and 406.2 mm) and tree nitrogen rates (0; 80 and 160 kg ha-1) and four replicates. The following VI was analyzed: OSNBR (optimum simple narrow-band reflectivity); NB_NDVI (narrow-band normalized difference vegetation index) and NDVI (normalized difference index). The vegetation indices investigated (OSNBR, NB_NDVI and NDVI) were efficient to estimate LAI, plant height and grain yield. During all crop development, the best correlations between biophysical variables and spectral variables were observed on V4 (the third trifoliolate leaves were unfolded in 50 % of plants) and R6 (plants developed first flowers in 50 % of plants) stages, according to the variable analyzed.

Informationsgehalt von ERS-1/-2 SAR-Daten zur Erfassung der Arteninventare und des Zustandes landwirtschaftlich genutzter Böden und Vegetation

Auf einer drei Anbauperioden umfassenden Ground Truth Datenbasis wird der Informationsgehalt multitemporaler ERS-1/-2 Synthetic Aperture Radar (SAR) Daten zur Erfassung der Arteninventare und des Zustandes landwirtschaftlich genutzter Böden und Vegetation in Agrarregionen Bayerns evaluiert.Dazu wird ein für Radardaten angepaßtes, multitemporales, auf landwirtschaftlichen Schlägen beruhendes Klassifizierungsverfahren ausgearbeitet, das auf bildstatistischen Parametern der ERS-Zeitreihen beruht. Als überwachte Klassifizierungsverfahren wird vergleichend der Maximum-Likelihood-Klassifikator und ein Neuronales-Backpropagation-Netz eingesetzt. Die auf Radarbildkanälen beruhenden Gesamtgenauigkeiten variieren zwischen 75 und 85%. Darüber hinaus wird gezeigt, daß die interferometrische Kohärenz und die Kombination mit Bildkanälen optischer Sensoren (Landsat-TM, SPOT-PAN und IRS-1C-PAN) zur Verbesserung der Klassifizierung beitragen. Gleichermaßen können die Klassifizierungsergebnisse durch eine vorgeschaltete Grobsegmentierung des Untersuchungsgebietes in naturräumlich homogene Raumeinheiten verbessert werden. Über die Landnutzungsklassifizierung hinaus, werden weitere bio- und bodenphysikalische Parameter aus den SAR-Daten anhand von Regressionsmodellen abgeleitet. Im Mittelpunkt stehen die Paramter oberflächennahen Bodenfeuchte vegetationsfreier/-armer Flächen sowie die Biomasse landwirtschaftlicher Kulturen. Die Ergebnisse zeigen, daß mit ERS-1/-2 SAR-Daten eine Messung der Bodenfeuchte möglich ist, wenn Informationen zur Bodenrauhigkeit vorliegen. Hinsichtlich der biophysikalischen Parameter sind signifikante Zusammenhänge zwischen der Frisch- bzw. Trockenmasse des Vegetationsbestandes verschiedener Getreide und dem Radarsignal nachweisbar. Die Biomasse-Informationen können zur Korrektur von Wachstumsmodellen genutzt werden und dazu beitragen, die Genauigkeit von Ertragsschätzungen zu steigern.

Tetti verdi: Analisi sperimentale e Modellazione numerica

I tetti verdi rappresentano, sempre più frequentemente, una tecnologia idonea alla mitigazione alle problematiche connesse all’ urbanizzazione, tuttavia la conoscenza delle prestazioni dei GR estensivi in clima sub-Mediterraneo è ancora limitata. La presente ricerca è supportata da 15 mesi di analisi sperimentali su due GR situati presso la Scuola di Ingegneria di Bologna. Inizialmente vengono comparate, tra loro e rispetto a una superficie di riferimento (RR), le prestazioni idrologiche ed energetiche dei due GR, caratterizzati da vegetazione a Sedum (SR) e a erbe native perenni (NR). Entrambi riducono i volumi defluiti e le temperature superficiali. Il NR si dimostra migliore del SR sia in campo idrologico che termico, la fisiologia della vegetazione del NR determina l'apertura diurna degli stomi e conseguentemente una maggiore evapotraspirazione (ET). Successivamente si sono studiate la variazioni giornaliere di umidità nel substrato del SR riscontrando che la loro ampiezza è influenzata dalla temperatura, dall’umidità iniziale e dalla fase vegetativa. Queste sono state simulate mediante un modello idrologico basato sull'equazione di bilancio idrico e su due modelli convenzionali per la stima della ET potenziale combinati con una funzione di estrazione dell’ umidità dal suolo. Sono stati proposti dei coefficienti di correzione, ottenuti per calibrazione, per considerare le differenze tra la coltura di riferimento e le colture nei GR durante le fasi di crescita. Infine, con l’ausilio di un modello implementato in SWMM 5.1. 007 utilizzando il modulo Low Impact Development (LID) durante simulazioni in continuo (12 mesi) si sono valutate le prestazioni in termini di ritenzione dei plot SR e RR. Il modello, calibrato e validato, mostra di essere in grado di riprodurre in modo soddisfacente i volumi defluiti dai due plot. Il modello, a seguito di una dettagliata calibrazione, potrebbe supportare Ingegneri e Amministrazioni nella valutazioni dei vantaggi derivanti dall'utilizzo dei GR.

Identification, quantification, spatiotemporal distribution and genetic variation of major latex secondary metabolites in the common dandelion (Taraxacum officinale agg.)

The secondary metabolites in the roots, leaves and flowers of the common dandelion (Taraxacum officinale agg.) have been studied in detail. However, little is known about the specific constituents of the plant’s highly specialized laticifer cells. Using a combination of liquid and gas chromatography, mass spectrometry and nuclear magnetic resonance spectrometry, we identified and quantified the major secondary metabolites in the latex of different organs across different growth stages in three genotypes, and tested the activity of the metabolites against the generalist root herbivore Diabrotica balteata. We found that common dandelion latex is dominated by three classes of secondary metabolites: phenolic inositol esters (PIEs), triterpene acetates (TritAc) and the sesquiterpene lactone taraxinic acid β-d-glucopyranosyl ester (TA-G). Purification and absolute quantification revealed concentrations in the upper mg g−1 range for all compound classes with up to 6% PIEs, 5% TritAc and 7% TA-G per gram latex fresh weight. Contrary to typical secondary metabolite patterns, concentrations of all three classes increased with plant age. The highest concentrations were measured in the main root. PIE profiles differed both quantitatively and qualitatively between plant genotypes, whereas TritAc and TA-G differed only quantitatively. Metabolite concentrations were positively correlated within and between the different compound classes, indicating tight biosynthetic co-regulation. Latex metabolite extracts strongly repelled D. balteata larvae, suggesting that the latex constituents are biologically active.

Maize Domestication and Anti-Herbivore Defences: Leaf-Specific Dynamics during Early Ontogeny of Maize and Its Wild Ancestors

As a consequence of artificial selection for specific traits, crop plants underwent considerable genotypic and phenotypic changes during the process of domestication. These changes may have led to reduced resistance in the cultivated plant due to shifts in resource allocation from defensive traits to increased growth rates and yield. Modern maize (Zea mays ssp. mays) was domesticated from its ancestor Balsas teosinte (Z. mays ssp. parviglumis) approximately 9000 years ago. Although maize displays a high genetic overlap with its direct ancestor and other annual teosintes, several studies show that maize and its ancestors differ in their resistance phenotypes with teosintes being less susceptible to herbivore damage. However, the underlying mechanisms are poorly understood. Here we addressed the question to what extent maize domestication has affected two crucial chemical and one physical defence traits and whether differences in their expression may explain the differences in herbivore resistance levels. The ontogenetic trajectories of 1,4-benzoxazin-3-ones, maysin and leaf toughness were monitored for different leaf types across several maize cultivars and teosinte accessions during early vegetative growth stages. We found significant quantitative and qualitative differences in 1,4-benzoxazin-3-one accumulation in an initial pairwise comparison, but we did not find consistent differences between wild and cultivated genotypes during a more thorough examination employing several cultivars/accessions. Yet, 1,4-benzoxazin-3-one levels tended to decline more rapidly with plant age in the modern maize cultivars. Foliar maysin levels and leaf toughness increased with plant age in a leaf-specific manner, but were also unaffected by domestication. Based on our findings we suggest that defence traits other than the ones that were investigated are responsible for the observed differences in herbivore resistance between teosinte and maize. Furthermore, our results indicate that single pairwise comparisons may lead to false conclusions regarding the effects of domestication on defensive and possibly other traits.

Polar Nature of Biomimetic Fluorapatite/Gelatin Composites: A Comparison of Bipolar Objects and the Polar State of Natural Tissue

The correspondence of the state of alignment of macromolecules in biomimetic materials and natural tissues is demonstrated by investigating a mechanism of electrical polarity formation: An in vitro grown biomimetic FAp/gelatin composite is investigated for its polar properties by second harmonic (SHGM) and scanning pyroelectric microscopy (SPEM). Hexagonal prismatic seed crystals formed in gelatin gels represent a monodomain polar state, due to aligned mineralized gelatin molecules. Later growth stages, showing dumbbell morphologies, develop into a bipolar state because of surface recognition by gelatin functionality: A reversal of the polar alignment of macromolecules, thus, takes place close to that basal plane of the seed. In natural hard tissues (teeth and bone investigated by SPEM) and the biomimetic FAp/gelatin composite, we find a surprising analogy in view of growth-induced states of polarity: The development of polarity in vivo and in vitro can be explained by a Markov-type mechanism of molecular recognition during the attachment of macromolecules.

Trace Elements in the Statoliths of Jumbo Flying Squid Off the Exclusive Economic Zones of Chile and Peru

Ontogenetic variation in 4 trace element ((88)Sr, (137)Ba, (24)Mg, (23)Na) concentrations and their ratios to Ca were measured in statoliths of the jumbo flying squid Dosidicus gigas off the Exclusive Economic Zone of Chilean and Peruvian waters using laser ablation inductively coupled plasma mass spectrometry (LA-ICP-MS). The element compositions of statoliths showed no significant differences between females and males. All of the elements in different growth zones showed significant variations, except for Mg. Sr:Ca and Mg:Ca were good indicators for distinguishing squid from autumn and winter spawning seasons. Sr:Ca and Ba:Ca distribution patterns in statoliths confirmed that paralarvae and juvenile squid inhabit surface waters, while subadult squid migrate into deeper waters. An increasing Sr: Ca ratio of subadult squid could be explained by declining temperature gradients from northern to southern sampling locations, although no significant Sr: Ca differences were observed (p > 0.05). Mg:Ca ratios decreased progressively from the nucleus to the peripheral zone, which might be correlated with statolith growth rates. Na:Ca ratios slightly declined from paralarvae to the subadult phase. Quantitative relationships between statolith trace elements and environmental conditions under different growth stages are needed to improve our understanding of life history of D. gigas.

Impacto de mancha ojo de rana (Cercospora sojina k. Hara) sobre rendimiento y componentes industriales del grano de soja: aceite y proteína

La mezcla de fungicidas estrobilurina y triazol (E+T) se aplicó a 2 cultivares contrastantes en susceptibilidad a mancha ojo de rana (MOR) (DM3700 y DM3810) en los estadíos R3 o R3+R5; se incluyeron además 2 controles: enfermo y sano. Se avaluó incidencia y severidad de MOR, rendimiento, número de granos (NG), peso de granos (PG), aceite y proteína del grano. Se observaron distintos niveles de severidad entre tratamientos de DM3700 y ausencia de MOR en los tratamientos de DM3810. Se encontró correlación negativa entre severidad y rendimiento. En DM3700 los valores más elevados de severidad se correspondieron con rendimientos más bajos (2117 kg/ha). DM3810 exhibió rendimientos elevados y sin diferencias estadísticas entre tratamientos (3478 kg/ha). Aunque NG y PG disminuyeron en el testigo enfermo DM3700, las reducciones del NG fueron más pronunciadas. No hubo incrementos de rendimiento, NG y/o PG atribuidos a E+T en DM3810. La severidad máxima en el cultivar más susceptible no fue suficiente para disminuir significativamente aceite y proteína. MOR pudo ser controlada en el cultivar susceptible con una única aplicación de E+T en R3. El uso del cultivar resistente a MOR resultó efectivo para controlar la enfermedad y no manifestó beneficios adicionales en rendimiento debido a la aplicación de fungicidas. En este trabajo se concluyó que MOR no afectó la calidad industrial del grano.

Turbidite sedimentology and history at DSDP Site 89-585

At Site 585 in the East Mariana Basin, a 900-m section of Aptian-Albian to Recent sediments was recovered. The upper 590 m are pelagic components (carbonate, siliceous, and clay); small-scale graded sequences and laminations are common. The underlying sediments are volcaniclastic sandstones with a large proportion of shallow-water carbonate debris; sedimentary structures including complete Bouma sequences, cross-laminae, and scouring are common. These structures indicate that the entire section was deposited by turbidity currents. The change in lithology upward in the section reflects the evolution of the surrounding seamounts, from their growth stages during the middle of the Cretaceous to the later subsidence phases. Several black layers containing pyritized organic debris and associated turbidite structures were cored near the Cenomanian/Turonian boundary; this material has been transported from the flanks of the seamounts where it was deposited within a shallow anoxic zone. Seismic data extends the stratigraphy across the entire Basin, showing the reflectors onlapping the seamounts, and indicating at least 1200 m of sediment at Site 585. The crust is placed at 6900 m after correcting for sediment loading, and the subsidence curve indicates that the Basin has been deeper than 5500 m since before the Aptian.

Stable isotope ratios in shells of marine organisms

Oxygen and carbon isotope analyses have been carried out on calcareous skeletons of important recent groups of organisms. Annual temperature ranges and distinct developmental stages can be reconstructed from single shells with the aid of the micro-sampling technique made possible by modern mass-spectrometers. This is in contrast to the results of earlier studies which used bulk sampIes. The skeletons analysed are from Bermuda, the Philippines, the Persian Gulf and the continental margin off Peru. In these environments, seasonal salinity ranges and thus annual variations in the isotopic composition of the water are small. In addition, environmental parameters are weIl documented in these areas. The recognition of seasonal isotopic variations is dependant on the type of calcification. Shells built up by carbonate deposition at the margin, such as molluscs, are suitable for isotopic studies. Analysis is more difficult where chambers are added at the margin of the shell but where older chambers are simultaneously covered by a thin veneer of carbonate e. g. in rotaliid foraminifera. Organisms such as calcareous algae or echinoderms that thicken existing calcareous parts as weIl as growing in length and breadth are the most difficult to analyse. All organisms analysed show temperature related oxygen-isotope fractionation. The most recent groups fractionate oxygen isotopes in accordance with established d18O temperature relationships (Tab. 18, Fig. 42). These groups are deep-sea foraminifera, planktonic foraminifera, serpulids, brachiopods, bryozoa, almost all molluscs, sea urchins, and fish (otoliths). A second group of organisms including the calcareous algae Padina, Acetabularia, and Penicillus, as weIl as barnacles, cause enrichment of the heavy isotope 18O. Finally, the calcareous algae Amphiroa, Cymopolia and Halimeda, the larger foraminifera, corals, starfish, and holothurians cause enrichment of the lighter isotope 16O. Organisms causing non-equilibrium fractionation also record seasonal temperature variations within their skeletons which are reflected in stable-oxygen-isotope patterns. With the exception of the green algae Halimeda and Penicillus, all organisms analysed show lower d13C values than calculated equilibrium values (Tab. 18, Fig. 42). Especially enriched with the lighter isotope 12C are animals such as hermatypic corals and larger foraminifera which exist in symbiosis with other organisms, but also ahermatypic corals, starfish, and holothurians. With increasing age of the organisms, seven different d13C trends were observed within the skeletons. 1) No d13C variations are observed in deep-sea foraminifera presumably due to relatively stable environmental conditions. 2) Lower d13C values occur in miliolid larger foraminifera and are possibly related to increased growth with increasing age of the foraminifera. 3) Higher values are found in planktonic foraminifera and rotaliid larger foraminifera and can be explained by a slowing down of growth with increasing age. 4) A sudden change to lower d13C values at a distinct shell size occurs in molluscs and is possibly caused by the first reproductive event. 5) A low-high-Iow cycle in calcareous algae is possibly caused by variations in the stage of calcification or growth. 6) A positive correlation between d18O and d13C values is found in some hermatypic corals, all ahermatypic corals, in the septa of Nautilus and in the otoliths of fish. In hermatypic corals from tropical areas, this correlation is the result of the inverse relationship between temperature and light caused by summer cloud cover; in other groups it is inferred to be due to metabolic processes. 7) A negative correlation between d18O and d13C values found in hermatypic corals from the subtropics is explained by the sympathetic relationship between temperature and light in these latitudes. These trends show that the carbon isotope fractionation is controlled by the biology of the respective carbonate producing organisms. Thus, the carbon isotope distribution can provide information on the symbiont-host relationship, on metabolic processes and calcification and growth stages during ontogenesis of calcareous marine organisms.

Rare earth elements of ROV sample GeoB12338-2 from the Makran accretionary complex

Authigenic carbonates forming at an active methane-seep on the Makran accretionary prism mainly consist of aragonite in the form of microcrystalline, cryptocrystalline, and botryoidal phases. The d13Ccarbonate values are very negative (-49.0 to -44.0 per mill V-PDB), agreeing with microbial methane as dominant carbon source. The d18Ocarbonate values are exclusively positive (+ 3.0 to + 4.5 per mill V-PDB) and indicate precipitation in equilibrium with seawater at bottom water temperatures. The content of rare earth elements and yttrium (REE + Y) determined by laser ablation-inductively coupled plasma-mass spectrometry (LA-ICP-MS) and solution ICP-MS varies for each aragonite variety, with early microcrystalline aragonite yielding the highest, cryptocrystalline aragonite intermediate, and later botryoidal aragonite the lowest REE + Y concentrations. Shale-normalised REE + Y patterns of different types of authigenic carbonate reflect distinct pore fluid compositions during precipitation: Microcrystalline aragonite shows high contents of middle rare earth elements (MREE), reflecting REE patterns ascribed to anoxic pore water. Cryptocrystalline aragonite exhibits a seawater-like REE + Y pattern at elevated total REE + Y concentrations, indicating higher concentrations of REEs in pore waters, which were influenced by seawater. Botryoidal aragonite is characterised by seawater-like REE + Y patterns at initial growth stages followed by an increase of light rare earth elements (LREE) with advancing crystal growth, reflecting changing pore fluid composition during precipitation of this cement. Conventional sample preparation involving micro-drilling of carbonate phases and subsequent solution ICP-MS does not allow to recognise such subtle changes in the REE + Y composition of individual carbonate phases. To be able to reconstruct the evolution of pore water composition during early diagenesis, an analytical approach is required that allows to track the changing elemental composition in a paragenetic sequence as well as in individual phases. High-resolution analysis of seep carbonates from the Makran accretionary prism by LA-ICP-MS reveals that pore fluid composition not only evolved in the course of the formation of different phases, but also changed during the precipitation of individual phases.

The role of cover crops in irrigated systems: water balance, nitrate leaching and soil mineral nitrogen accumulation

Soil salinity and salt leaching are a risk for sustainable agricultural production in many irrigated areas. This study was conducted over 3.5 years to determine how replacing the usual winter fallow with a cover crop (CC) affects soil salt accumulation and salt leaching in irrigated systems. Treatments studied during the period between summer crops were: barley (Hordeum vulgare L.), vetch (Vicia villosa L.) and fallow. Soil water content was monitored daily to a depth of 1.3 m and used with the numerical model WAVE to calculate drainage. Electrical conductivity (EC) was measured in soil solutions periodically, and in the soil saturated paste extracts before sowing CC and maize. Salt leaching was calculated multiplying drainage by total dissolved salts in the soil solution, and use to obtain a salt balance. Total salt leaching over the four winter fallow periods was 26 Mg ha−1, whereas less than 18 Mg ha−1 in the presence of a CC. Periods of salt gain occurred more often in the CC than in the fallow. By the end of the experiment, net salt losses occurred in all treatments, owing to occasional periods of heavy rainfall. The CC were more prone than the fallow to reduce soil salt accumulation during the early growth stages of the subsequent cash crop.