Effectiveness of Combined Use of Mineral Oil and Insecticide Spray in Reducing <Emphasis Type="Italic">Potato Virus Y</Emphasis> (PVY) Spread under Field Conditions in New Brunswick,Canada     

Tyler D. B. MacKenzie  Jacques Lavoie  Xianzhou Nie  Mathuresh Singh 《American Journal of Potato Research》2017,94(1):70-80

In the 2014 and 2015 crop seasons, the efficacies of different types, rates and combinations of mineral oil and insecticide foliar sprays for reducing Potato virus Y (PVY) spread were tested in controlled field trials in New Brunswick (NB), Canada. Experimental plots were planted with certified PVY-free Goldrush, supplemented with known virus-infected seed to raise PVY inoculum to 2.3% and 3% at the beginning of the 2014 and 2015 seasons, respectively. Treatments consisted of mineral oil-only sprays at different application rates, insecticide-only sprays of differing numbers, and several combined mineral oil and insecticide spray regimes, all compared to a no-spray control treatment. PVY spread to 18% (2014) and 22% (2015) of initially virus-free plants in no-spray control plots, with significant reductions observed in PVY spread in several treatments. Greatest PVY reductions, as low as 4% (2014) and 12% (2015), were in combined mineral oil and insecticide spray treatments, followed by oil-only sprays; while insecticide-only sprays did not significantly reduce PVY spread. As well as measuring PVY spread to marked test plants and randomly collected post-harvest tuber sample from the plots, exhibited similar treatment pattern for PVY incidence. Multiple logistic regression modeling confirmed the relative efficacy of combined oil and insecticide sprays for reducing PVY spread, while accounting for variable inoculum and aphid factors. Modeling also highlighted the importance of planting low-PVY seed initially, and of early application of foliar sprays. Local best management practice recommendations for reduction of in-field PVY spread were discussed.  相似文献   

Nano-calcium carbonate reinforced polypropylene and propylene-ethylene copolymer nanocomposites: Tensile vs. impact behavior     

Mangala Joshi  Satyajit Brahma  Anasuya Roy  S. Wazed Ali 《Fibers and Polymers》2017,18(11):2161-2169

Improvement of both the tensile and impact strength of the same polymeric material has always been a great challenge for the plastic industry. The study focuses on the effect of incorporation of calcium carbonate nanoparticles (0.3 wt% to 15 wt%) into three polypropylene (PP) based matrices viz. PP homopolymer, propylene-ethylene (PP-PE) copolymer and the blend of PP:PP-PE (30:70) to improve their impact behavior without hampering the tensile strength much. A loss in both the tensile and impact properties was observed in PP based nanocomposite. However, PP-PE based nanocomposites showed a significant improvement in impact strength (47 %) at 10 wt% loading with a loss of tensile strength by 22 %. To minimize this loss a blend of PP:PP-PE (30:70) was explored as a matrix. At 10 wt% loading, this matrix showed an improvement of 30 % in impact strength whereas the tensile loss was minimized to 10 %. Further, silane coupling agent which promoted good interfacial adhesion was used for best compositions. The variation of crystalline morphology of the nanocomposites with various formulations was analyzed using differential scanning calorimetry and X-ray diffraction.  相似文献   

Degradation and kinetic modeling of polyvinyl alcohol in aqueous solutions by a H<Subscript>2</Subscript>O<Subscript>2</Subscript>/Mn(II) system     

Yangfan Su  Mengjuan Li  Qiang Gao  Xiaoqiang Li  Anqi Ju  Yang Lu  Mingqiao Ge 《Fibers and Polymers》2017,18(12):2269-2277

This paper is about the degradation of polyvinyl alcohol (PVA) in aqueous solutions using a H2O2/Mn(II) system. Fourier transform infrared spectroscopy (FTIR) and gel permeation chromatography (GPC) were applied to analyze the degradation products of PVA, and the results revealed that the backbone chain of PVA could be effectively broken and oxidized. Several unsaturated degradation products, including carboxylic acids, ketones, aldehydes, olefins, and alkynes were also detected and identified by gas chromatography-mass spectrometry (GC-MS), which indicated that higher treatment temperatures would considerably promote the generation of lower molecular weight degradation products. According to the work presented in this paper, the degradation efficiency of PVA increased from 55 % at 60 oC to 99 % at 90 oC after treatment when the initial PVA concentration was 5 %, at pH=3 with a H2O2 and Mn(II) dose of 100 ml/l and 0.6 mol/l, respectively. In addition, kinetic modeling indicated that the experimental results were best fitted by the Page-modified model with an activation energy of 48.78 kJ/mol.  相似文献   

Dyeing performance of the azo dyes containing trifluoromethyl group for polyester fabrics and its single crystal structure     

Hongwei Shen  Liu Hu  Kongliang Xie  Aiqin Gao 《Fibers and Polymers》2017,18(12):2322-2327

The structures of disperse dyes and their intermolecular interactions have important impacts on dyeing and printing performances for polyester fabrics. The fluorine dyes show some unique molecular stability and photochemical properties. The dyeing property of the azo dye containing trifluoromethyl group for polyester fabrics, 4'-(N-acetoxyethyl-Nethyl)- amino-2-bromine-4-nitro-6-trifluoromethylazo- benzene (D1), was investigated and compared with the similar structure disperse dye. The results show that the high color yield and good exhaustion of the dyed PET fabrics could be obtained. The polyester fabrics dyed with D1 had excellent light fastness. Its single crystal was prepared and the supramolecular interactions were solved by X-ray diffraction. Dye D1 formed triclinic crystals in a trimeric packing mode. The C-F bond distances of CF3 are 1.2730 Å, 1.2240 Å and 1.2900 Å, respectively. The two benzene rings linked azo unit (-N=N-) are obviously twist. The dihedral angle of the two benzene rings is 50.23 o. There are six weak hydrogen bonds around trifluoromethyl group in the intramolecule and intermolecule. The excellent light stability of the dye should be attributed to its unique supramolecular structure.  相似文献   

Structural and optical properties of cellulose nanocrystals isolated from the fruit shell of <Emphasis Type="Italic">Camellia oleifera</Emphasis> Abel     

Jin Yao  Haibo Huang  Long Mao  Zhihan Li  Heping Zhu  Yuejun Liu 《Fibers and Polymers》2017,18(11):2118-2124

Cellulose nanocrystals (CNC) with high aspect ratio of 80 have been readily prepared from the inexpensive fruit shell of Camellia oleifera Abel (SCOA) for the first time. In this study, SOCA was consecutively subjected to alkali extraction, hydrogen peroxide bleaching and acid hydrolysis to remove non-cellulosic components and release CNC. The derived CNC possesses a needle-shaped structure that in average diameter and length of 6±2 nm and 500±100 nm, respectively. The crystallinity index of CNC increased to 72 % and the initial decomposition temperature raised to 230 oC. The obtained CNC was formed to nanopaper by vacuum filtration showing high visible light transmittance over 90 %. Thus SOCA derived CNC is of great practical potential to apply in the field of biomedicine, energy, packing, etc. Overall, this study is anticipated to offer new possibility for the CNC production from the inexpensive but abundant agricultural wastes.  相似文献   

Water and dye-free coloration of wool     

Guangming Cai  Zhenglin Xu  Bin Tang  Xungai Wang 《Fibers and Polymers》2017,18(1):102-109

A water and dye-free heat treatment method was used to color wool fibers. The heat effect changed wool fibers to different colors from white in a nitrogen atmosphere. The influences of heating temperature and time on the colors of wool were investigated and the mechanical property of colored wool fibers was evaluated. The color strength of wool fibers increased as heat treatment temperature and time increased. The tensile strength retention rate of wool fiber was relatively high (≥90 %) when the heat temperature was below 200 °C. The surface morphologies of wool fibers scarcely changed during the heat treatment. The carbon content of fibers was found to reduce by heat treatment, indicating oxidization of components in the wool fibers in the process of coloration. Heat treatment may provide a water and dye-free approach to color wool and other textile fibers, albeit within a limited color range.  相似文献   

Optimization of curing process for polymer-matrix composites based on orthogonal experimental method     

Tengfei Chang  Lihua Zhan  Wei Tan  Shujian Li 《Fibers and Polymers》2017,18(1):148-154

In this paper, the orthogonal experimental method was carried out to optimize the curing process of aeronautical composite X850/T800 in autoclave process. Four important curing parameters including curing pressure, heating rate, curing temperature and heat preservation time were taken into account, and sixteen samples were fabricated to study the effects of the four parameters mentioned above on the curing quality by interlaminar properties test and microstructure analysis. The interlaminar properties and the interfacial bonding quality of these samples were studied by the short-beam three points bending test and scanning electron microscopy, respectively. Results revealed that the optimal curing process of X850/T800 composite laminate should be as follows: curing pressure of 0.6 MPa, heating rate of 1.5 °C/min, curing temperature of 160 °C, and heat preservation time of 120 min.  相似文献   

Effect of hybrid post treatments on the structural property and water flux of polysulfone hollow fiber membrane     

Reza Saghafi 《Fibers and Polymers》2017,18(1):41-49

The application of post treatments in preparation of high flux membranes is expanding rapidly. In this work, several hybrid post treatments have been introduced and used for change in the water flux of polysulfone (PSf) hollow fiber membranes. Dry wet spinning method was employed for fabrication of PSf hollow fiber membrane from spinning dope in mass ratio of 15:5:80 of PSf/PVP-K90/NMP. The simultaneous effects of single and hybrid post treatments containing traditional hypochlorite; high pressure injection technique (HPI) of hypochlorite, hot air and hot water treatments on the morphology and water flux of fabricated hollow fibers has been investigated. AFM analysis and image processing of SEM microphotographs of hollow fibers were used for structural studies. The mechanical properties of hollow fibers as well as strain at break and strength also were studied. It was found that the pores size and surface roughness parameter of hollow fiber membranes have been increased after traditional hypochlorite, HPI technique and hot water treatments while decreased when heat treated in air. In general all the employed hybrid post treatments caused to increase in the pores size of hollow fibers although the pores size increase rate in the membranes treated by the hybrid post treatments involving hot air was much lower than the others. The mechanical properties of hollow fibers have been decreased after hybrid and single post treatments containing traditional hypochlorite, HPI technique and hot water treatment while slightly increased after post treatments containing hot air. It was stated that the fabricated PSf hollow fibers were considerably affected by the employed hybrid post treatments. This can be attributed to the combine effects of used post treatments.  相似文献   

Effect of nitrogen root zone fertilization on rice yield,uptake and utilization of macronutrient in lower reaches of Yangtze River,China   总被引：1，自引：0，他引：1  

Xiaowei Liu  Huoyan Wang  Jianmin Zhou  Zhaoming Chen  Dianjun Lu  Dejin Zhu  Pingliang Deng 《Paddy and Water Environment》2017,15(3):625-638

Improper application of nitrogen (N) has led to high N losses and low N use efficiency in the lower reaches of Yangtze River in China. An effective method to solve such problems is the deep fertilized N in root zone (RZF). Limited information is available on the effect of RZF on the uptake of macronutrients (N, P and K) and rice yield. Field experiments, conducted from 2014 to 2015, compared the farmer fertilizer practice (FFP, with 225 kg ha^?1 of N, split into three doses) and RZF using the same rate but placing N 5 cm away from rice roots in holes 10 cm deep (RZF10) or 5 cm deep (RZF5) as a single application. The highest mean yield (10.0 t ha^?1) was obtained in RZF10, which was 19.5% more than that in FFP. Root zone fertilization of urea (whether 10 cm deep or 5 cm deep) resulted in greater accumulation of N, P and K in stem, leaf sheaths, leaf blades and grains compared to that in FFP in sandy and in loam soils. The uptake of N, P and K was the highest in RZF10 (average at 176.7, 66.2 and 179.1 kg ha^?1, respectively), higher than that in FFP by 45.0, 17.0 and 22.6%, respectively. N apparent recovery efficiency was markedly higher in RZF10 (53.1%) than in FFP (27.5%). RZF10 significantly increased the N, P, K uptake compared with FFP under different N rates in both sandy and loam soils. These results suggest that the N, P and K input amount should be re-determined under RZF.  相似文献   

Drainage and irrigation performance of hybrid ditches in converted paddy fields under winter wheat cultivation in Hokkaido     

Yasutaka Tsukamoto  Iwao Kitagawa  Ryuuich Nakamura 《Paddy and Water Environment》2017,15(3):681-691

Paddy fields converted into winter wheat fields in Hokkaido, Japan, receive extremely high snowfall, creating a risk of flood damage to crops in spring due to waterlogging of snowmelt runoff and poor drainage. Meanwhile, in June there is relatively little rainfall, and a lack of moisture inhibits winter wheat growth. Therefore, we developed a method involving a series of 30-cm-deep ditches in agricultural fields to be used for drainage during the flood-prone period and for furrow irrigation during the dry period using water drawn from the canals that feed the paddy fields. The ditches are called ‘hybrid ditches’ as they are able to perform both drainage and irrigation functions. In this study, we investigated the optimal construction timing and spacing for hybrid ditches. We also evaluated their ability to improve the drainage and irrigation of winter wheat. We found that the optimal timing for digging hybrid ditches is immediately after sowing, and the inter-ditch spacing for irrigation should be 15 m or less. The hybrid ditches promoted increased soil temperature and healthy development of wheat plants by improving drainage during the flood-prone period. In addition, water was successfully supplied via the hybrid ditches to irrigate the fields in June. Under experimental conditions in which rainfall was excluded, grain yield was 10% higher and percent protein content was more than 1% point greater in the irrigated plot compared with the non-irrigated plot. Grain yield was also observed to increase by 3–29% in demonstration tests conducted at local farms. From these results, we conclude that hybrid ditches are capable of improving the growth and yield of winter wheat by improving drainage and providing irrigation in converted paddy fields in Hokkaido.  相似文献