Establishment techniques affect productivity,nutritive value and atmospheric N2 fixation of two sunn hemp cultivars     

David M. Jaramillo  José C. B. Dubeux Jr  Joao M. B. Vendramini  Luana M. D. Queiroz  Erick R. S. Santos  Martin Ruiz-Moreno  Liza Garcia  Daciele Sousa de Abreu  Lucas Ramos de Miranda  Michelle Cristina Fernando de Siqueira 《Grass and Forage Science》2020,75(2):153-158

Nitrogen fertilization is a common practice for sustaining forage production in forage systems in southeastern United States. Warm-season annual legumes may be an alternative forage to warm-season perennial grasses that do not require N fertilization. Sunn hemp (Crotalaria juncea L.) is a fast-growing, warm-season annual legume native to India and Pakistan. The objective of this 2-year study was to assess the herbage accumulation (HA), atmospheric N₂ fixation (ANF) and nutritive value of sunn hemp. Treatments were the factorial arrangement of two sunn hemp cultivars (“Crescent Sun” and “Blue Leaf”), three seeding rates (17, 28 and 39 kg seed/ha) and seed inoculation (inoculated or non-inoculated seeds), distributed in a randomized complete block design with four replicates. Crescent sun had greater HA (3,218 vs. 1764 kg DM/ha) and ANF (41 vs. 25 kg N/ha). Blue leaf had greater crude protein (CP) (188 vs. 176 g/kg) and in vitro digestible organic matter (IVDOM) concentrations (564 vs. 531 g/kg) than crescent sun. Non-inoculated seed had greater CP than inoculated seed, 188 and 177 g/kg, respectively, and inoculation did not affect HA. Intermediate seeding rate (28 kg/ha) decreased HA (2002 kg DM/ha), while HA from high and low seeding rates (17 and 39 kg/ha, respectively) did not differ (2,863 and 2,615 kg DM/ha respectively). Planting non-inoculated crescent sun at 17 kg/ha seeding rate is a feasible management practice to produce sunn hemp in subtropical regions; however, inoculation should always be recommended for proper establishment.  相似文献   

Soil CO2 emission in sugarcane management systems     

Rose Luiza Moraes Tavares  Zigomar Menezes de Souza  Diego Silva Siqueira  Newton La Scala Júnior  Alan Rodrigo Panosso 《Acta Agriculturae Scandinavica, Section B - Plant Soil Science》2013,63(8):755-762

Sugarcane management systems affect soil attributes such as the carbon cycle. This fact has stimulated the sugar and alcohol industry to refine the sugarcane production systems by replacing the pre-harvest burning (PB) and manual harvest with mechanized harvesting followed by residue deposition. The aim of this study was to evaluate different management systems with respect to C cycling carbon dioxide and soil parameters (chemical, physical and biological) which were determined over the season. Three sugarcane cultivation systems were evaluated at the following periods: (a) PB, (b) 5-year green harvest and (c) 10-year green harvest. The results indicated that CO₂ emission was 36% greater in the 10-year sugarcane green harvest system than in the PB system. The bulk density and macroporosity were the factors that were most affected by the different sugarcane management systems and that significantly influenced soil CO₂ emissions. The principal component analysis showed that soil CO₂ emission was 18% influenced by base saturation (V%) and 14% by pH, especially in the PB area. Additionally, 19% was affected by carbon and macroporosity in the 5- and 10-year green harvest areas, respectively. From our results, it can be concluded that the most CO₂ emissions are in the areas of sugarcane green, this is due to the higher carbon concentration when compared with the area of burning sugarcane. The parameters that most influenced the CO₂ emissions were bulk density, porosity, macroporosity, pH and V%.  相似文献   

Continuous infusion of propofol in calves: bispectral index and hemodynamic effects          下载免费PDF全文

Mauricio Deschk  Juliana T Wagatsuma  Marcelo A Araújo  Guilherme GF Santos  Sergio SR Júnior  Caio JX Abimussi  Carlos E Siqueira  Jéssica CL Motta  Silvia HV Perri  Paulo SP Santos 《Veterinary anaesthesia and analgesia》2016,43(3):309-315

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Effect of supplementation of beef cattle with different protein levels and degradation rates during transition from the dry to rainy season     

Rodolfo Maciel Fernandes  Chafic Mustafé de Almeida  Bruna Caldas Carvalho  João Alexandrino Alves Neto  Verônica Aparecida Costa Mota  Flávio Dutra de Resende  Gustavo Rezende Siqueira 《Tropical animal health and production》2016,48(1):95-101

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Effects of deficit irrigation strategies on cluster microclimate for improving fruit composition of Moscatel field-grown grapevines   总被引：1，自引：0，他引：1  

Tiago Pedreira dos Santos  Carlos M. Lopes  M. Lucília Rodrigues  Claudia R. de Souza  Jorge M. Ricardo-da-Silva  João P. Maroco  João S. Pereira  M. Manuela Chaves 《Scientia Horticulturae》2007

The grapevine plays a very important role in the economic, social and cultural sectors of many regions; however vineyards are often grown in regions under stressful conditions and thus they are vulnerable to climate change. The objective of this research was to investigate the effect of partial root-zone drying (PRD) irrigation on vine water relations, vegetative growth, plant microclimate, berry composition and yield components, compared to conventional deficit irrigation (DI, 50% ETc), full irrigation (FI, 100% of ETc) and non-irrigated vines (NI). The study was undertaken in mature ‘Moscatel’ grapevines (Vitis vinifera L.) grown in Pegões, South of Portugal. Compared to the other irrigated treatments, PRD vines showed a better microclimate at the cluster zone with higher incident photosynthetic photon flux density (PPFD). Within the more open canopies of NI and PRD treatments, berry temperatures were higher than those of denser ones (DI and FI). Compared to the conventional irrigation technique the better microclimate observed in PRD vines was a consequence of a reduction in vine growth, where lower values of leaf layer number, leaf area, canopy wideness, water shoots and shoot weight were observed. In PRD vines we observed a tendency to a development of a deeper root system, while DI and FI showed a more homogeneous root distribution throughout the different soil layers. PRD showed an improvement in berry quality with higher values of flavour precursors, and total phenols concentration without any significant yield reduction compared to DI and FI.  相似文献   

Cacao leaf procyanidins increase locally and systemically in response to infection by Moniliophthora perniciosa basidiospores     

Fabio C. Chaves  Thomas J. Gianfagna   《Physiological and Molecular Plant Pathology》2007,70(4-6):174-179

Flavan-3-ol monomers and oligomers from dimers to decamers were quantitatively determined by HPLC-FLD in leaves of four Theobroma cacao varieties. Cacao flush leaves had higher procyanidin content than mature leaves. Moniliophthora perniciosa basidiospore infection results in an increase in cacao leaf procyanidins in the inoculated leaves, as well as in the uninoculated, adjacent, older leaves on an actively growing branch, resulting in both a local and systemic increase in procyanidin content in response to infection. Procyanidin oligomers increased significantly in leaves of the less susceptible genotype Scavina 6 upon infection, and total procyanidin levels were higher than in Cacao Comum a more disease susceptible genotype. Selection of genotypes with high constitutive and/or inducible content of procyanidins in young flush leaves may be a strategy to develop witches’ broom disease resistant cultivars.  相似文献   

Combining endophytic fungi and bacteria for the biocontrol of Radopholus similis (Cobb) Thorne and for effects on plant growth     

Nancy P. Chaves  Luis E. Pocasangre  Fritz Elango  Franklin E. Rosales  Richard Sikora 《Scientia Horticulturae》2009,122(3):472-478

Eight endophytic fungal and bacterial isolates with antagonistic activity against Radopholus similis were evaluated in vivo for their individual and combined effects on biocontrol of R. similis and on the growth of “Grand Naine” cultivar banana plantlets in the greenhouse. Penetration efficiency (PE) of R. similis was between 3 and 21% in 29 biological agents (BAs) treatments, less than the 29% of the nematode-alone control (p ≤ 0.0001); 24 of the BAs treatments did not differ from the PE of 5% for a nematicide control. Twenty nine BAs treatments exhibited antagonistic activity against nematodes which reduced final population levels between 18 and 93%, relative to those on nematode-alone control plants (p ≤ 0.0001), and 14 BAs treatments were statistically similar to the nematicide treatment (88% reduction). Twenty four BAs treatments had increments of plant root biomass ranging from 20 to 58%, greater than the control plants; 37% of the treatments with single and combined BAs inoculations had root length increments ranging from 29 to 54% compared with control and chemical treatment. The nematicide, Terbufos 10GR, did not affect plant growth.  相似文献   

Cryopreservation of Piau‐Breed Wild Boar Sperm: Assessment of Cooling Curves and Centrifugation Regimes          下载免费PDF全文

HH Shiomi  RO Pinho  DMA Lima  JB Siqueira  MCR Santos  EV Costa  PS Lopes  SEF Guimarães  JD Guimarães 《Reproduction in domestic animals》2015,50(4):545-553

This study aimed to assess the effects of different cooling curves and centrifugation regimes used in cryopreservation protocols on the post‐thaw viability of Piau‐breed wild boar (Sus scrofa) sperm using in vitro assessment tests. Two centrifugations (800  g for 10 min and 2400  g for 3 min) and two cooling curves (conventional cooling using nitrogen vapour – freezing 1 and automated cooling using a programmed freezing machine – freezing 2) were tested. Therefore, the treatments were divided into M3 – centrifugation at 2400  g for 3 min and freezing 2; M10 – centrifugation at 800  g for 10 min and freezing 2; R3 – centrifugation at 2400  g for 3 min and freezing 1; and R10 – centrifugation at 800  g for 10 min and freezing 1. No significant differences (p > 0.05) between treatments occurred post‐thawing regarding the total sperm motility means recorded. The mean values of the different treatments were not different from each other regarding the supravital staining (SV), hypo‐osmotic test (HO), sperm–egg binding assay or sperm morphology. This study showed that both the cooling curve and the centrifugation regime affected the quality of post‐thaw sperm, and centrifugation for shorter times and cooling curves using automated cooling are the most suitable for minimizing sperm injury.  相似文献   

Basis and monitoring of methoxyfenozide resistance in the South American tomato pinworm Tuta absoluta     

Langa  Teófilo P.  Dantas  Kayo C. T.  Pereira  Daniel L.  de Oliveira  Marcos  Ribeiro  Lílian M. S.  Siqueira  Herbert A. A. 《Journal of pest science》2022,95(1):351-364

The South American tomato pinworm, Tuta absoluta (Meyrick, 1917) (Lepidoptera: Gelechiidae), is heavily targeted by insecticide applications. Methoxyfenozide is highly effective against T. absoluta with reduced side effects to natural enemies. This work aimed to (1) genetically and biochemically characterize resistance of the T. absoluta GBN population to methoxyfenozide, (2) establish cross resistance profiles with other insecticide groups and (3) monitor resistance in populations with the goal of improving T. absoluta insecticide resistance management (IRM). Methoxyfenozide resistance was completely recessive, polyfactorial and autosomal. Effective dominance revealed that 10 mg methoxyfenozide/L would be enough to eliminate susceptible homozygotes and heterozygotes, thus used to diagnose resistance in field populations. The synergism of methoxyfenozide toxicity in the resistant population for PBO (SR?=?95×), DEF (SR?=?51×) and DEM (SR?=?45×), suggested monooxygenases, esterases and glutathione S-transferases as resistance mechanisms. However, only monooxygenase activity appeared to be involved in methoxyfenozide resistance. Resistance ratio for methoxyfenozide (2352-fold) after selection and cross-resistance ratios of a lab-selected GBN strain (“GBN-Sel”) were significant relative to a susceptible strain “JDR1-Sus” for tebufenozide (656-fold), cartap hydrochloride (10.68-fold), deltamethrin (4.70-fold), abamectin (2.65-fold), lufenuron (2.22-fold) and indoxacarb (1.92-fold), with negative cross-resistance to spinetoram (0.32-fold). Evidence of control failures was observed in 10 field populations of T. absoluta (mortalities between 13 and 76%), and all populations showed frequencies of resistant phenotypes (percentage survivorship ranging between 4 and 96%). A rational basis for managing resistance to bisacylhydrazines is discussed, along with details of recommended T. absoluta resistance management tactics.

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Short-term baths with essential oils of Lippia sidoides,Ocimum gratissimum and Zingiber officinale influence blood parameters and survival of tambaqui (Colossoma macropomum) after infection with Aeromonas hydrophila     

Patrícia Castro Monteiro  Maria Inês Braga de Oliveira  Franmir Rodrigues Brando  Caio Francisco Santana Farias  Cludia Majolo  Francisco Clio Maia Chaves  Humberto Ribeiro Bizzo  Fernanda Loureiro de Almeida O&#x;Sullivan  Maurício Latera Martins  Edsandra Campos Chagas 《Aquaculture Research》2022,53(1):265-275

This study evaluated the effect of short-term baths with the essential oils (EOs) of Lippia sidoides, Ocimum gratissimum and Zingiber officinale on the survival, haematological, biochemical and histopathological parameters of native fish tambaqui (Colossoma macropomum), challenged with Aeromonas hydrophila. After challenge, the fish infected with A. hydrophila received therapeutic baths of 60 min, for five consecutive days. Treatments were as follows: challenged and not treated; challenged and treated with 10 mg L^?1 of gentamicin; challenged and treated with EO of L. sidoides (2.5 and 5.0 mg L^?1); challenged and treated with EO of O. gratissimum (5.0 and 10.0 mg L^?1); challenged and treated with Z. officinale EO (5.0 and 10.0 mg L^?1). The highest survival rates were 89.5% (fish treated with 5.0 mg L^?1 of O. gratissimum EO) and 75.0% (fish treated with 5.0 mg L^?1 of L. sidoides EO). Reductions in the haematocrit percentage, haemoglobin and erythrocyte number were observed in fish treated with L. sidoides and Z. officinale EOs compared with control fish. Mild to moderate damage to the liver tissue of fish after challenge and EO treatments were observed. It is suggested that baths containing O. gratissimum and L. sidoides EOs consist in a viable treatment to increase survival rates of C. macropomum infected with A. hydrophila.  相似文献