Tratamentos pré-germinativos e substratos na emergência de sementes e qualidade de mudas de pinhão manso (Jatropha curcas L.)

The physic nut can be propagated asexually or sexually. Using cuttings have been earlier yield and more fidelity characteristics of the parent plant. However, there is less initial vegetative growth. The seeds from the plants have increased genetic variability, are more vigorous and begin production later. To get quality changes, the substrate is an important factor. With that the objective was to taste pre-germinated treatments and different substrate on seeds emergence and quality physic nut seedlings. The experimental design was completely randomized, in factorial scheme 6 x 3 (pre-germinated treatments x substrate), 18 treatments and 4 repetition, 8 seeds to each repetition. It was evaluated six pre-germination treatments: T1: witness (without treatments); T2: water immersion for 12 hours; T3: water immersion for 24 hours; T4: mechanical scarification; T5: mechanical scarification + water immersion for 12 hours; T6: mechanical scarification + water immersion for 24 hours, using as substrate: commercial, expanded vermiculite and sand washed. The mechanical scarification was realized opposite the micropyle using sandpaper n. 60. After the pre-germination treatments, the seeds were emergence in plastic cups (200mL) with substrates. We evaluated the characteristics: percentage, beginning and emergence speed index, mean length of plant, diameter of plant stem, SPAD index, fresh and dry shoot and root. The results showed that in seeds of Jatropha do not need pre-germinative treatments; and the use of commercial substrate showed seedling development.

Efeitos de práticas de descompactação do solo em área sob sistema plantio direto

Soil compaction is one of the limiting factors in areas subjected to direct seeding. The method used to break up the compacted layer should disturb the soil as little as possible, as well as maintain the ground cover. The aim of this study was to evaluate the influence of subsoiling, scarification and use of shaft-type furrowing mechanisms when sowing, on preserving the ground cover, water content and soil density, as well as the effects on maize yield in a dystroferic Red Nitosol, cultivated under a system of direct seeding for ten years. The experimental design was of randomised blocks, with eight soil management treatments: subsoiling to a depth of 0.40 m before sowing the winter crop, subsoiling to 0.40 m before sowing the maize, scarification to 0.30 m before the winter crop, scarification to 0.30 m before the maize, scarification to 0.20 m before the winter crop, scarification to 0.20 m before the maize, direct seeding of the maize with a shaft-type furrowing mechanism and direct seeding of the maize using a double disc furrower. There were four replications. Subsoiling and scarification influenced the preservation of the ground cover, soil density and water content immediately after sowing, but did not interfere in plant development or grain yield in the maize crop. The use of shaft-type furrowing mechanisms in the sowing operation had no effect on any of the parameters under study.

Impactos do manejo de um sistema plantio direto no crescimento e produtividade do arroz de terras altas e feijão de inverno em sucessão e nos atributos do solo

Pós-graduação em Agronomia - FEIS

Germinação de sementes de maracujazeiros: água, luz, temperatura e reguladores vegetais

The production of seedlings of passion fruit is done mainly with the use of seeds by most producers. It can also be propagated by cuttings, layering and in vitro tissue culture. However, even when grafting is used, it is necessary to use seeds to produce the rootstock. Nevertheless, most Passifloracea species have germination problems, making it difficult to obtain seedlings. Although several studies have been developed in an attempt to increase seed germination of passion fruit there are still difficulties in understanding the germination process and also disagreement about seed dormancy. Thus, the present study aimed to review papers related to seed germination of passion fruit emphasizing aspects such as mechanical resistance to water ingress, the need for adequate light and temperature and the use of plant growth regulators in overcoming seed dormancy. It was noticed that, in general, the passion fruit seeds are photoblastic negative and exhibit physiological dormancy, being no need of seed scarification to stimulate its germination.

Demanda energética de máquinas agrícolas na implantação da cultura do sorgo forrageiro

Forage sorghum can be grown in areas and environmental conditions dry and warm, where the productivity of other forage plants can often be uneconomical. The soil disturbance can be made only on the lines of planting (direct seeding) or entirely from the area for seeding (conventional tillage), as plowing, harrowing, subsoiling and chiseling (minimum tillage). The displacement speed ideal for planting is one in which the groove is opened and closed without removing the over-ground, allowing the distribution of seed spacing and depth constant. The experiment was conducted in a soil classified as Typic Oxisol at Lageado Experimental Farm, Faculty of Agronomic Sciences, UNESP, Botucatu campus. This study aimed to evaluate the response of sorghum in four forward speeds (3, 5, 6 and 9 km h-1) and four systems of soil management: SD (direct seeding), GP (harrow + sowing), LPG (disc harrow and two light disking + sowing) and CR (scarification and seeding). Data was subjected to analysis of variance in a factorial 4 x 4 and a randomized block design with split plots. The following parameters were determined: average speed, average strength of the drawbar, the average power drawbar, theoretical field capacity of the tractor-equipment, fuel consumption per hour. For the conditions under which the experiment was conducted, it was concluded that the hourly fuel consumption was not influenced by tillage systems and was inversely proportional to the increase of speed work, and that the change of speed in the sowing operation did not provide additional the values of average traction force on the bar of the tractor-planter.

Desempenho operacional de semeadora e produtividade do milho em plantio direto e cultivo mínimo

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Capacidade de suporte de carga e densidade do solo em áreas de plantio direto com e sem escarificação

No-till has been used in many different regions of Brazil. However, depending on the location and intensity of machinery traffic, this has caused the problem of soil compaction and many producers are scarification the land as a solution to break through the layer that is restricting plant growth. The objective of this study was to evaluate the influence of scarification (0.30 m) in the physical properties of a dystrophic Alfisol comparing the results with a non-scarified contiguous area; both were previously conducted using no-till. The density and pressure of pre-consolidation were sampled in two areas of non-tillage, one with chiseling (PDCE) and one without (PDSE) by using the UMAS -Mobile Soil Sampling Unit built by NEMPA – Agroforestry Machinery and Tire Testing Center/FCA / UNESP, Botucatu ,SP. The UMAS is equipped with GPS which allows the samples to be georeferenced. The samples were evaluated in the laboratory through the collection of standardized rings. Sampling was performed at a dimension of 15 x 50 m, with 160 rings being collected. The samples containing rings which were used in determining the density and also for testing the consolidometer, were collected from the layers of 0 to 0.10 m, 0.10 to 0.20 m, 0.20 to 0.30 0.30 to I 0.40 m. For the odometer test the undisturbed sample rings were used in obtaining the load bearing capacity of the soil. The soil management adopted provided a decrease in soil density using no-tillage with scarification depths from 0.0 to 0.10 0.10 to 0.20 m while the other depths did not show any decrease. The pre-consolidation pressure in combination with soil aggregate resistance identified that the management process PDCE within all layers was subjected to water content reliability regarding a greater load bearing capacity of the soil. For the PDSE that only was possible in the 0 to 0.10 m, showing greater consolidation of this layer.

Caracterização biométrica e superação de dormência em sementes de Chloroleucon foliolosum (Benth.) G. P. Lewis

The objectives of this work were performing the biometric characterization of seed Chloroleucon foliosolum (Benth) G. P. (Lewis) from the municipality Ituaçu - BA, and analyze methods of scarification and temperature on germination. The seeds were characterized according to measurements of length, width and thickness, weight of thousand seeds, and water content. Were employed methods of scarification with sandpaper and sulfuric acid for 15 and 30 minutes, and not scarified seeds, combined with germination temperatures of 20, 25, 30 and 35 °C. Percentage and germination speed index, and percentage of primary root protrusion, abnormal seedlings, hard seeds and dead seeds were evaluated. The means of length, width and thickness was 6.03, 4.30 and 3.47 mm, respectively. The weight of a thousand seeds was 67.3 g with water content of 6.1%. Whereas the percentage germination with normal seedling, the method of scarification with sulfuric acid for 15 or 30 minutes combined to germination temperatures of 25 or 30 °C were effective in overcoming dormancy of Chloroleucon foliolosum.

Long-term decomposition of sugarcane harvest residues in Sao Paulo state, Brazil

Crop residues returned to the soil are important to preserve fertility and sustainability. This research addressed the long-term decomposition of sugarcane post-harvest residues (trash) under reduced tillage, therefore field renewal was performed with herbicide followed by subsoiling and ratoons were deprived of interrow scarification. The trial was conducted in the northern Sao Paulo State, Brazil during four consecutive crops (2005-2008) where litter bags containing N-15-labeled trash were disposed in the field attempting to simulate two distinct situations: the previous crop trash (PCT) or residues incorporated in the field after tillage, and post-harvest trash (PHT) or the remains of plant-cane harvest. Decomposition rates regarding dry matter (DM), carbon (C), root growth, plant nutrients (N, P, K, Ca, Mg and S), lignin (LIG) cellulose (CEL) and hemicellulose (HCEL) contents were assessed for PCT (2005 ndash;2008) and for PHT (2006-2008). There were significant reductions on DM and C:N ratio due to C losses and root growth within the litter bags over time. The DM from PCT and PHT decreased 96% and 73% after four and three crops, respectively, and the higher nutrients release were found for K, Ca and N. The LIG, CEL and HCEL concentrations in PCT decreased 60%, 29%, 70% after four crops and 47%, 35%, 70% from PHT after three crops, respectively. Trash decomposition was driven mainly by residues biochemical composition, root growth within the trash blanket and the climatic conditions during the crop cycles. (C) 2012 Elsevier Ltd. All rights reserved.

Revisiting a medical case of "stinging" in the human oral cavity caused by ingestion of raw squid (Cephalopoda: Teuthida): new data on the functioning of squid's spermatophores

Male squid produce intricate spermatophores that, when transferred to the female, undergo the spermatophoric reaction, a complex process of evagination that leads to the attachment of the spermatangium, that is, the everted spermatophore containing the sperm mass. While this process is still not completely understood, the medical literature includes several reports of "oral stinging" (i.e., punctured wounds in the human oral cavity) following consumption of raw male squid, which contains undischarged spermatophores able to inflict such wounds. Here, we revisit a recent medical report of oral stinging by Shiraki et al. (Pathol Int 61:749-751, 2011), providing an in-depth reanalysis of their histological biopsies and revealing vital information on the functioning of squid spermatophores. The morphology of the spermatangia attached within the oral cavity is similar to the condition found in spermatangia naturally attached to female squids. The spermatangia were able to superficially puncture the superficial layers of the oral stratified squamous epithelium, and numerous, minute stellate particles from the squid spermatophore were found adhered to the oral epithelium. These findings corroborate previous hypotheses on the functioning of squid spermatophores, namely that spermatophore attachment generally involves tissue scarification, and that stellate particles play a vital role in the attachment process. Moreover, spermatophore attachment is confirmed to be autonomous (i.e., performed by the spermatophore itself) in another squid species (possibly a loliginid), and the results strongly indicate that the attachment mechanism is not dependent upon a specialized epithelium, nor a mate's specific chemical stimulus. From the pathological point of view, the best prophylactic measure at present is the removal of the internal organs of the raw squid prior to its consumption.

SUPERAÇÃO DE DORMÊNCIA DAS SEMENTES E CONTROLE QUÍMICO DE Momordicacharantia L.

Objetivou-se com este estudo avaliar diferentes métodos para a superação da dormência das sementes e a eficiência de herbicidas no controle químico de plantas de Momordicacharantia L. no estádio reprodutivo. O primeiro experimento constituiu-seem esquema fatorial 2 x 8 (duas épocas de coleta das sementes (2006 e 2007) e oito métodos de quebra de dormência: escarificação mecânica; imersão em ácido sulfúrico concentrado e a 50%; imersão em nitrato de potássio a 2%por três e seis horas; calor seco a 60°C; água quente a 60°C e uma testemunha sem tratamento). No segundo ensaio avaliou-se o controle da Momordicacharantia L. por meio de seis herbicidas distintos: Imazapic, Metsulfuron-methyl, Metribuzin, 2,4-D, Amicarbazone, Paraquat e uma testemunha sem aplicação de herbicidas. Em ambos os ensaios, o delineamento experimental utilizado foi o inteiramente casualizados, com quatro repetições. Após a aplicação dos tratamentos,pode-se concluir que a imersão das sementes em ácido sulfúrico concentrado por 3 minutos proporcionou uma maior porcentagem e velocidade de germinação e que o herbicida Metribuzin alcançou, embora tardiamente, um controle total das plantas de melão de São-Caetano.

Efecto de la temperatura, escarificación y concentraciones de calcio en la germinación de Gymnocalycium schickendantzii (F.A.C. Weber) Britton & Rose (Cactaceae)

Gymnocalycium schickendantzii (F.A.C. Weber) Britton & Rose (Cactaceae) es una especie endémica de Argentina. En la provincia de Mendoza las poblaciones de este cactus todavía no están siendo afectadas por las urbanizaciones y cultivos que ponen en peligro su supervivencia. Conocer aspectos sobre su germinación podría ayudar a explicar el porqué de la presencia de esta especie en su hábitat natural. El objetivo del presente trabajo fue determinar en un ensayo de germinación de G. schickendantzii el efecto de tratamientos de temperaturas de 20 y 30°C durante 25 días en laboratorio usando 3 concentraciones de calcio (1, 10 y 20 meq/l Ca), y agua como testigo con y sin escarificación, y bajo condiciones de luz blanca. Se observó que a 30°C los porcentajes de germinación, con o sin escarificación, fueron significativamente mayores que a 20°C. El efecto de la escarificación sólo ayudó a incrementar los valores de germinación cuando fueron tratadas a 20°C. Las concentraciones de calcio tienen un débil efecto en la germinación de las semillas en las mismas condiciones. El tiempo de inicio de germinación (IG) y para obtener el 50% de ella (T50) fueron mayores a 30°C tanto en las semillas escarificadas como sin escarificar.

Census, reproductive biology, and germination of Astragalus gines-lopezii (Fabaceae), a narrow and endangered endemic species of SW Spain

Astragalus gines-lopezii Talavera, Podlech, Devesa & F.M.Vázquez (Fabaceae) is a threatened endemic species with a distribution restricted to a very small area in Badajoz Province (Extremadura Region, SW Spain) and only 2 populations are known. This species was catalogued in the ?Endangered? category in the 2008 Red List and the 2010 Threatened Spanish Vascular Flora List. Despite its status as an endangered species, at present very little is known about the distribution, census, and reproductive biology of this species. In this study we have carried out an exhaustive census of A. gines-lopezii , and we have evaluated the production of flowers, fruits, and seeds and the existence or not of intra- and interpopulation variability in seed germination. Results have highlighted the high reproductive capacity of this species on the basis of a high production of flowers, fruits, and seeds. Mechanical scarification of seeds was effective for increasing germination. Thus, initial germination (22%?60%) was increased to 97%?99% when seeds were rubbed with sandpapers. A high intra- and interpopulation variability in seed germination was found in this species. A. gines-lopezii produces seeds with different degrees of physical dormancy, varying this grade among different individuals within a population.

Census, reproductive biology, and germination of Astragalus gines-lopezii (Fabaceae),a narrow and endangered endemic species of SW Spain.

Astragalus gines-lopezii Talavera, Podlech, Devesa & F.M.Vazquez (Fabaceae) is a threatened endemic species with a distribution restricted to a very small area in Badajoz Province (Extremadura Region, SW Spain) and only 2 populations are known.This species was catalogued in the "Endangered" category in the 2008 Red List and the 2010 Threatened Spanish Vascular Flora List. Despite its status as an endangered species, at present very little is known about the distribution, census, and reproductive biology of this species. In this study we have carried out anexhaustive census of A. gines-lopezii, and we have evaluated the production of flowers, fruits, and seeds and the existence or not of intra- and interpopulation variability in seed germination. Results have highlighted the high reproductive capacity of this species on the basis of a high production of flowers, fruits, and seeds. Mechanical scarification of seeds was effective for increasing germination. Thus, initial germination (22%-60%) was increased to 97%-99% when seeds were rubbed with sandpapers. A high intra- and interpopulation variability in seed germination was found in this species. A. gines-lopezii produces seeds with different degrees of physical dormancy, varying this grade among different individuals within a population.

La regeneración natural del pino silvestre (Pinus sylvestris L.) en el Valle del Lozoya (Madrid): germinación y supervivencia inicial

La fase de establecimiento del regenerado es un proceso crítico para el desarrollo posterior de la masa tanto por las elevadas tasas de mortalidad que habitualmente lleva asociadas, como por proporcionar el material de partida del que van a disponer las fases subsiguientes. Las restricciones a la germinación y establecimiento de la regeneración del pino silvestre varían enormemente entre las distintas regiones de su extensa área de distribución geográfica. La región Mediterránea constituye un hábitat marginal de la especie en el que las condiciones ecológicas son muy diferentes a las del grueso de su área de distribución. Frente a otras limitaciones (frío, luz, encharcamiento…), en el entorno mediterráneo la tasa de mortalidad parece estar asociada a las condiciones micrometeorológicas del período estival - particularmente, a la sequía -, así como a la presencia excesiva de ganado o ungulados silvestres. No obstante, la mayoría de la información disponible sobre el proceso de regeneración de la especie procede del centro y norte de Europa, por lo que no es de aplicación directa en nuestra región, en la que los estudios de este tipo son mucho más escasos. El presente trabajo pretende contribuir a paliar esta relativa escasez a través del estudio del proceso de regeneración natural en el monte “Cabeza de Hierro”, masa irregular por bosquetes de pino silvestre, paradigma de gestión sostenible y uso múltiple. En este entorno, se pretende caracterizar y cuantificar tanto el proceso de germinación y supervivencia de la especie como la influencia de la cobertura vegetal (estratos arbóreo, arbustivo y herbáceo, y capa de restos vegetales) en su desarrollo. Se persigue así mismo analizar el efecto de la compactación del suelo sobre la persistencia de la masa y contrastar y comparar la eficacia de dos tratamientos edáficos de ayuda a la regeneración: escarificado y decapado+acaballonado. Con este fin se han planteado dos diseños experimentales consistentes en sendas redes de muestreo (Red de Muestreo I o RM I y Red de Muestreo II o RM II) integradas, respectivamente, por 192 y 24 parcelas de 1,5x1,5 m ubicadas bajo distintas condiciones de cobertura vegetal. Sobre una parte de estas parcelas (1/4 en la Red de Muestreo I; 1/2 en la Red de Muestreo II) se han aplicado tratamientos de ayuda a la regeneración (RM I: escarificado; RM II: decapado+acaballonado) y, tras llevar a cabo siembras controladas al inicio del período vegetativo, se han practicado controles periódicos de germinación y supervivencia durante uno (RM II) y tres años consecutivos (RM I). Se han realizado así mismo mediciones complementarias de variables micrometeorológicas, espesura, recubrimiento superficial del suelo y compactación. Los resultados obtenidos a partir de las experiencias realizadas en el monte objeto de estudio permiten concluir que, en relación con el proceso de regeneración natural de la especie en este tipo masa y entorno: 1) la regeneración del pino silvestre durante el primer período vegetativo presenta una tasa de éxito muy baja (1,4% de los sembrados), provocada por una elevada mortalidad durante el primer período estival (>92%) subsiguiente a una germinación de en torno al 17% de las semillas viables que llegan al suelo; 2) la mortalidad sigue siendo elevada hasta el tercer período vegetativo, en que comienza a reducirse significativamente hasta alcanzar el 45%; 3) la cobertura vegetal influye significativamente tanto en el proceso de germinación como en el de supervivencia, aunque ambos procesos presentan una baja correlación linear que pone de manifiesto que los lugares idóneos para la germinación no siempre son los más adecuados para la supervivencia; 4) la escarificación del suelo mejora las tasas iniciales de germinación y supervivencia, pero empeora la tasa de supervivencia posterior (años 2 y 3), por lo que su efecto a medio plazo no resulta significativo; 5) el decapado+acaballonado presenta mejores resultados que el escarificado durante el primer verano, aunque sólo resulta efectivo en condiciones intermedias de espesura de masa; 6) la compactación edáfica no resulta limitante para la productividad ni la persistencia de la masa considerada. ABSTRACT Seedling establishment is critical for later stand progress because it involves high mortality rates and the surviving saplings constitute the starting material for all the subsequent stages. Restrictions for Scots pine germination and seedling survival may vary greatly across its geographical range, as it is widely distributed within north latitudes. Mediterranean region is a marginal sector within this species range and its ecological conditions differ greatly from those of the bulk of the area. Mortality rates in Mediterranean environments seem to be related to summer weather (mainly drought) and high livestock stocking rather than to cold, light or flooding. Most available information on scots pine regeneration process comes from north European experiences and is not transferable to Spanish forests, whereas studies on Mediterranean region are much scarcer. The present work aims at broadening Scots pine regeneration knowledge within Mediterranean region by analyzing its establishment process in the “Cabeza de Hierro” forest: a Scots pine uneven-aged forest at blocklevel scale, exemplary managed for multi-services purpose. Germination and surviving processes are to be characterized and quantified as to vegetation cover both in trees, shrubs, grass and litter strata. Soil compaction effects on forest sustainability are also assessed and the efficacy of some site preparation techniques on regeneration success is tested and compared (scarification vs. scalping+mounding). Two sampling networks comprising respectively 198 (SN I) and 24 plots (SN II) of 1.5x1.5m have been established over a wide range of vegetal cover conditions within the forest. Soil preparation techniques have been applied only to some of the sampling points; namely, 1 out of 4 plots have been scarified within Sampling Network I , while 1 out of 2 plots have been object of scalping & mounding within Sampling Network II. After localized sowing prior to growing season, germination and surviving have been periodically sampled for either one (SN II) or three years (SN I). Supplementary measures for micrometeorological variables, stand density, ground vegetal cover and compaction have also been carried out. Results obtained for the studied forest lead to the following insights regarding Scots pine natural regeneration process within this sort of forest and environment: 1) seedling establishment success rate is quite low (0,15% of sowing seeds), due to high mortality during the first summer (>92%), following a prior 17% rate of germination over viable seeds reaching the soil; 2) mortality rate remains high until the third year after emergence and then decreases to the 50% of surviving; 3) although vegetal cover significantly affects both seedling germination and survival, lineal correlation between those two processes is rather low, which may indicate that places fit for emergence are not necessarily suitable for summer surviving; 4) soil scarification improves both germination and survival during the first growing season, but it is associated to higher mortality rates during the next two years; hence it has no significant medium term effect; 5) scalping & mounding treatment is more effective than scarification concerning establishment improving during the first summer; but its effects are only significant under intermediate stand density levels; 6) soil compaction does not restrict either forest productivity or persistence, despite the area’s long history of high livestock stocking rates and mechanized logging.