Field evaluation of a self-propelled sprayer and effects of the application rate on spray deposition and losses to the ground in greenhouse tomato crops     

Sánchez-Hermosilla J  Rincón VJ  Páez F  Agüera F  Carvajal F 《Pest management science》2011,67(8):942-947

BACKGROUND: In the greenhouses of south‐eastern Spain, plant protection products are applied using mainly sprayers at high pressures and high volumes. This results in major losses on the ground and less than uniform spray deposition on the canopy. Recently, self‐propelled vehicles equipped with vertical spray booms have appeared on the market. In this study, deposition on the canopy and the losses to the ground at different spray volumes have been compared, using a self‐propelled vehicle with vertical spray booms versus a gun sprayer. Three different spray volumes have been tested with a boom sprayer, and two with a spray gun. RESULTS: The vehicle with the vertical spray boom gave similar depositions to those made with the gun, but at lower application volumes. Also, the distribution of the vertical spray boom was more uniform, with lower losses to the ground. CONCLUSIONS: The vertical spray booms used in tomato crops improve the application of plant protection products with respect to the spray gun, reducing the application volumes and the environmental risks of soil pollution. Copyright © 2011 Society of Chemical Industry  相似文献   

Treatment of male goats with equine chorionic gonadotrophin during the non-breeding season does not affect their sperm characteristics during the subsequent breeding season     

Beracochea  Florencia  Viera  María Noel  Santiago-Moreno  Julián  Ungerfeld  Rodolfo 《Tropical animal health and production》2020,52(1):211-215

Tropical Animal Health and Production - Equine chorionic gonadotrophin (eCG) is a hormone having FSH/LH effects. It can be used to enhance sperm quality in male goats (bucks) during the...  相似文献   

Quantification of phenolic compounds in olive oil mill wastewater by artificial neural network/laccase biosensor   总被引：2，自引：0，他引：2  

Torrecilla JS  Mena ML  Yáñez-Sedeño P  García J 《Journal of agricultural and food chemistry》2007,55(18):7418-7426

In this paper is considered a new computerized approach to the determination of concentrations of phenolic compounds (caffeic acid and catechol). An integrated artificial neural network (ANN)/laccase biosensor is designed. The data collected (current signals) from amperometric detection of the laccase biosensor were transferred into an ANN trained computer for modeling and prediction of output. Such an integrated ANN/laccase biosensor system is capable of the prediction of caffeic acid and catechol concentrations of olive oil mill wastewater, based on the created models and patterns, without any previous knowledge of this phenomenon. The predicted results using the ANN were compared with the amperometric detection of phenolic compounds obtained at a laccase biosensor in olive oil wastewater of the 2004-2005 harvest season. The difference between the real and the predicted values was <0.5%. biosensor; olive oil mill wastewater; chemical analysis; phenolic compounds.  相似文献   

Fire severity as a key factor in post-fire regeneration of Pinus pinaster (Ait.) in Central Portugal     

Paula Maia  Juli G. Pausas  Ana Vasques  Jan Jacob Keizer 《Annals of Forest Science》2012,69(4):489-498

Context

Mediterranean pine woodlands are strongly affected by wildfires; however, there are knowledge gaps in the role of fire severity on Pinus pinaster Ait. regeneration.

Objectives

The principal questions were: (a) does post-fire regeneration of Maritime Pine differ where canopies were consumed to a low vs. high degree and (b) which factors, besides fire severity, could explain these differences.

Methods

Pine recruitment was monitored from 2 to 36?months after a summer wildfire in 18 25?m² plots, equally divided over two fire severity classes based on crown consumption. Besides the degree of crown consumption, three quantitative fire severity indices as well as post-fire site conditions, seed input and understory vegetation recovery were measured.

Results

Pine seedling densities were consistently higher in the plots with low than high crown consumption but due to marked spatial variability, they were only significantly different at two out of the eight sampling occasions. This variability could be explained by a quantitative index based on the diameter of twigs, as well as by seed input and post-fire site conditions (ash and litter cover).

Conclusion

Fire severity was found to strongly affect the pine recruitment following wildfire, using both a qualitative visual severity index and a quantitative, more labour-intensive one.  相似文献   

环境中有机农药吸附热力学模型及吸附影响因素   总被引：1，自引：0，他引：1  

柯常亮  林钦  甘居利  李刘冬  陈洁文  王增焕  黄珂 《南方水产》2013,(1):68-73

有机农药的生态风险决定于其在环境中迁移、转化和归宿等环境行为,研究有机农药在环境中的吸附机制对评估有机农药的使用效率和生态风险具有重要意义。文章综述了有机农药吸附研究的主要热力学理论模型,对模型成立的理论基础、应用范围和局限性进行探讨;还就有机农药吸附过程与pH、离子强度、有机质和温度等环境因子之间的相互关系展开讨论。不仅为有机农药吸附机制的深入研究和实际应用提供借鉴,亦可为渔业生产合理用药提供科学依据。  相似文献   

Flagellar Sensillar Equipment of Two Morphologically Closely Related Aphid Hyperparasitoids (Hymenoptera: Figitidae: Alloxysta)     

Carlo Polidori  Amanda Freitas-Cerqueira  Juli Pujade-Villar  Francesc Oliva  Mar Ferrer-Suay 《Journal of insect science (Online)》2016,16(1)

The antennal sensillar equipment in the parasitic wasp family Figitidae was analyzed to date only in few species, despite some are associated with crop pests and can have an economic importance. It is the case of the genus Alloxysta, which includes hyperparasitoids of aphids which can potentially reduce effectiveness of primary pest parasitoids. Here we analyzed, through scanning electron microscopy, the diversity, morphology, and distribution of the antennal sensilla in males and females of Alloxysta consobrina (Zetterstedt) and Alloxysta victrix (Westwood), two species with overall very similar morphology. In both species, antennae are filiform and cylindrical, and flagellum was longer in A. victrix. Eight sensillar types have been recognized: four types of sensilla trichoidea (ST-A, ST-B, ST-C, ST-D), sensilla coeloconica, sensilla placoidea, sensilla campaniformia, and sensilla basiconica. ST-A, ST-B, ST-C, and sensilla placoidea were the most abundant types on the antennae and often increased in number and decreased in size toward the tip of antenna. The two species seem to have several differences in their sensillar equipment, possibly in accordance with the different degree of host range. On the other hand, sexual dimorphism is probably due to the different stimuli that have to be correctly processed. The comparison with the other species of Figitidae studied by far showed, at subfamily-level, that variability in sensillar equipment and phylogeny do not agree. This suggests a complex series of morphological changes during evolution of this group. The taxonomic sample should be thus substantially enlarged to disclose possible trends in sensillar equipment evolution in the family.  相似文献   

Experimental test of the impacts of feral hogs on forest dynamics and processes in the southeastern US     

Evan Siemann  Juli A. Carrillo  Christopher A. Gabler  Roy Zipp  William E. Rogers 《Forest Ecology and Management》2009

The foraging activities of nonindigenous feral hogs (Sus scrofa) create widespread, conspicuous soil disturbances. Hogs may impact forest regeneration dynamics through both direct effects, such as consumption of seeds, or indirectly via changes in disturbance frequency or intensity. Because they incorporate litter and live plant material into the soil, hogs may also influence ground cover and soil nutrient concentrations. We investigated the impacts of exotic feral hogs in a mixed pine-hardwood forest in the Big Thicket National Preserve (Texas, USA) where they are abundant. We established sixteen 10 m × 10 m plots and fenced eight of them to exclude feral hogs for 7 years. Excluding hogs increased the diversity of woody plants in the understory. Large seeded (>250 mg) species known to be preferred forage of feral hogs all responded positively to hog exclusion, thus consumption of Carya (hickory nuts), Quercus (acorns), and Nyssa seeds (tupelo) by hogs may be causing this pattern. The only exotic woody species, Sapium sebiferum (Chinese tallow tree), was more than twice as abundant with hogs present, perhaps as a response to increased disturbance. Hogs increased the amount of bare soil by decreasing the amounts of plant cover and surface litter. Plots with hogs present had lower soil C:N, possibly due to accelerated rates of nitrogen mineralization. These results demonstrate that hogs may influence future overstory composition and reduce tree diversity in this forest. Management of hogs may be desirable in this and other forests where large-seeded species are an important component of the ecosystem. Further, by accelerating litter breakdown and elevating nitrogen in the soil, hogs have the potential to impact local vegetation composition via nitrogen inputs as well.  相似文献   

Flavanol content and antioxidant activity in winery byproducts     

González-Paramás AM  Esteban-Ruano S  Santos-Buelga C  de Pascual-Teresa S  Rivas-Gonzalo JC 《Journal of agricultural and food chemistry》2004,52(2):234-238

Proanthocyanidins, particularly those coming from wine and grape products, have became of interest to nutritionists. Particular attention is currently being paid to the exploitation of this kind of grape byproducts for obtaining bio-active phenolic compounds with potential application as food antioxidants and preventive agents against cancer and other diseases. In this work, the flavanol composition of various winery byproducts submitted to different degrees of industrial exploitation has been studied and their antioxidant activity determined using two different methods (TBARS and TEAC) to evaluate their interest as suitable sources for the preparation of flavanol-rich antioxidant extracts. All the byproducts studied were still good flavanol sources no matter their exploitation degree. An important conclusion was that dried grape seeds, obtained as an end byproduct after the color extraction and alcohol distillation of the wine pomace, still kept important flavanol concentrations and significant antioxidant activity, even if they were submitted to high temperatures. These byproducts can be considered a cheap source for the extraction of antioxidant flavanols, which can be used as dietary supplements or in the production of phytochemicals.  相似文献   

Treatment of metastatic melanoma B16F10 by the flavonoids tangeretin, rutin, and diosmin     

Martínez Conesa C  Vicente Ortega V  Yáñez Gascón MJ  Alcaraz Baños M  Canteras Jordana M  Benavente-García O  Castillo J 《Journal of agricultural and food chemistry》2005,53(17):6791-6797

Melanoma is one of the most frequently metastasizing malignant neoplasias. This study examines an experimental model of pulmonary metastasis and the B16F10 cell subline, highly metastatic in the lung. Antimetastatic effects of the flavonoids tangeretin, rutin, and diosmin were analyzed, and at the same time an analysis of the metastatic activity of ethanol was performed, considered to be necessary because it is used as a vehicle for administering the flavonoids. Lentini's model, which complements the macroscopic evaluation of nodule numbers by using a stereoscopic microscope and image analysis at the microscopic level, was used. The greatest reduction in the number of metastatic nodules (52%) was obtained with diosmin; similarly, the percentages of implantation, growth index, and invasion index (79.40, 67.44, and 45.23%, respectively), were all compared with those of the ethanol group, considered to be an effective control group. Rutin- and tangeretin-treated groups also showed reductions of the same index compared with the ethanol group. It would seem that structural factors would better explain these results and the antimetastatic activity of each flavonoid and the respective metabolites.  相似文献   

Flavonoid distribution during the development of leaves, flowers, stems, and roots of Rosmarinus officinalis. postulation of a biosynthetic pathway     

del Baño MJ  Lorente J  Castillo J  Benavente-García O  Marín MP  Del Río JA  Ortuño A  Ibarra I 《Journal of agricultural and food chemistry》2004,52(16):4987-4992

The distribution of seven flavonoids, eriocitrin, luteolin 3'-O-beta-d-glucuronide, hesperidin, diosmin, isoscutellarein 7-O-glucoside, hispidulin 7-O-glucoside, and genkwanin, has been studied in Rosmarinus officinalis leaves, flowers, stems, and roots during plant growth. The maximum level reached by luteolin 3'-O-beta-d-glucuronide in leaves during June-August suggests the existence of a delay between the activation of the enzymes involved in the flavanone and flavone biosynthesis. The presence of hesperidin and diosmin in the vascular system is significant, and hesperidin shows even higher levels than the phenolic diterpenes and rosmarinic acid. The distribution of flavonoids observed in R. officinalis suggests a functional and structural relationship between phytoregulators and flavonoids, where flavonoids would be "protectors" of the activity of phytoregulators. A hypothesis for the general pathway of biosynthesis of these compounds in plants of the family Labiatae is proposed.  相似文献