共查询到20条相似文献，搜索用时 890 毫秒
1.
2.
假眼小绿叶蝉（Empoasca vitis Gothe）,属同翅目（Homoptera）叶蝉科（Cicadellidae）,是茶树的主要害虫之一。若虫、成虫刺吸嫩梢芽叶汁液,雌成虫且在嫩梢内产卵,导致输导组织受损,养分丧失,水分供应不足。芽叶受害后表现凋萎、叶脉变红、叶尖叶缘红变以至枯焦,节间短缩、质地变脆,严重影响茶叶产量和品质。是茶叶高产、优质、高效的重要制约因素之一。由于假眼小绿叶蝉为害的严重性,在上个世纪50～60年代起国内就对假眼小绿叶蝉进行研究,提出了各种控制措施。本文就假眼小绿叶蝉在农业、生物防治等方面的研究进行概括论述。 相似文献
3.
假眼小绿叶蝉为茶树重要害虫，以成、若虫剌吸茶树新梢汁液，被害嫩叶失绿，芽梢枯焦萎缩，质地变脆，严重影响茶叶的产量及品质。为探讨不同农药对假眼小绿叶蝉的防治效果，我站在茶园中进行药效试验。 相似文献
4.
茶树害虫假眼小绿叶蝉无公害防治技术 总被引：3，自引：0，他引：3
假眼小绿叶蝉（Empoasca vitis Gothe）是我国茶区分布最广、为害最重的一种茶树害虫。该虫以成虫和若虫吸取茶树汁液为害,干扰茶树营养物质的正常输送,导致茶树芽叶失水、生长迟缓、焦边、焦叶,造成茶叶减产。全年以夏秋茶受害最重,一般受假眼小绿叶蝉为害可使夏秋茶减产10％～15％,为害严重年份减产可高达50％以上。此外,假眼小绿叶蝉为害后的芽叶,在加工过程中易断碎,易产生烟焦味,对茶叶品质亦有严重的影响。 相似文献
5.
6.
小绿叶蝉 [Empoasca flauescens(Fabricius) ]属同翅目 ,叶蝉科 ,俗名浮尘子、叶跳虫。是我国茶区的主要害虫。成、若虫集中刺吸茶树嫩梢汁液 ,受害芽叶卷缩、硬化 ,叶尖和叶缘红褐枯焦 ,芽梢生长缓慢或停止 ,新芽减少 ,甚至不发芽。为害严重时 ,常使夏、秋茶严重减产 ,甚至绝收。小绿叶蝉在四川、重庆一带年发生 1 0代左右 ,由于常规农药在茶园中长时期使用而导致害虫产生抗药性 ,影响防治效果。为寻求适合茶园使用的新农药 ,我们引进年丰对小绿叶蝉进行了药效试验。现将结果报导如下。1 材料与方法1 .1 供试材料(1 )供试农药 :年丰为四… 相似文献
7.
8.
9.
棕管巢蛛对假眼小绿叶蝉的捕食密度反应 总被引：1，自引：1，他引：0
在茶园害虫的生态控制中,充分了解和利用优势种天敌在茶树害虫中的捕食控制作用,是其中重要的一环,经我所的多年系统调查和观察表明,茶园蜘蛛是假眼小绿叶蝉(Emposca Pirisuga)的重要天敌类群,棕管巢蛛(Clubiona japonicola Boeset Str.)则是茶园蜘蛛的优势种群之一.为了进一步探讨棕管巢蛛对假眼小绿叶蝉的捕食控制潜能,我们做了不同叶蝉密度的实验,现将初步结果整理如下: 相似文献
10.
假眼小绿叶蝉是泰顺县茶区主要害虫之一，突出危害夏秋茶。受害茶树芽叶卷缩、硬化、叶尖和叶缘红褐枯焦，芽梢生长缓慢，对茶叶产量和质量有很大影响。为了进一步提高假眼茶小绿叶蝉的防治效果，选择高效、低毒的农药，是茶树假眼茶小绿叶蝉防治中必须解决的问题。2004年我们在产茶乡、镇、茶场以及茶叶专业户茶园，应用安纳进行对假眼小绿叶蝉防治试验。 相似文献
11.
Composite films based on EVA with CMF were prepared and characterized for their solvent transport nature. CMF were derived from Hibiscus sabdariffa by steam explosion technique and incorporated in the EVA matrix by extrusion. Solvent transport by the composites was analyzed using hexane, heptane and octane as penetrant molecules. The solvent uptake behavior of EVA/CMF composites is explained on the basis of the penetrant size, temperature and the filler loading. The composite had improved barrier property compared with unfilled EVA. This in turn is an indication of good fiber-matrix interaction in the composite system. Diffusion parameters such as diffusion coefficient, permeation coefficient and Arrhenius activation parameters and thermodynamic parameters such as enthalpy and entropy were evaluated in detail. The mode of transport was found to be Fickian. 相似文献
12.
Xiansheng Zhang Xiaoning Tang Ran Wang Rui Wang Xiong Yan Meiwu Shi 《Fibers and Polymers》2017,18(8):1421-1430
Thermal degradation behaviors and fire retardant properties of poly(1,3,4-oxadiazole)s (POD) and poly(m-phenylene isophthalamide) (PMIA) fibers were investigated. The thermal gravimetric analysis (TGA) demonstrated that POD exhibited higher onset thermal degradation temperature (Tonset) than PMIA, exceeding nearly 80 °C. The thermal degradation kinetics, evaluated by the modified Coats-Redfern method, displayed that the apparent activation energy (Ea) of POD and PMIA fibers was similar when the conversion rate (α) ranges from 0.2 to 0.5, while with the α from 0.6 to 0.8, the Ea of POD was significantly lower than that of PMIA. The fire retardant performance of POD and PMIA fibers were evaluated by cone calorimeter under heat fluxes of 35, 50 and 75 kW/m2, during which the temperature of the fibers were monitored by a thermocouple. Surprisingly, POD fibers showed inferior fire retardant performance in comparison with PMIA, with lower time to ignition (TTI) and higher peak heat release rate (PHRR). The origin of the different fire retardant properties of both fibers was revealed by analyzing the residual chars and gaseous products during thermal pyrolysis. The morphology confirmed that stable and compact chars can be formed in PMIA. In addition, the Fourier Transform Infrared Spectroscopy (FTIR) characterization of the residual char revealed that POD can form carbonaceous chars at the heat flux of 50 kW/m2, while the heat flux of PMIA was 75 kW/m2. The pyrolysis products characterized by pyrolysis-gas chromatography-mass spectrometry (Py-GC-MS) indicated that POD can be pyrolyzed completely at 600 °C, while the temperature of PMIA was 700 °C. 相似文献
13.
14.
15.
《Journal of Crop Improvement》2013,27(2):287-298
Summary It is well known that C4 crops have a lower water requirement than C3 crops. Reasons for the difference are not well understood. Therefore, hydraulic resistance of sorghum [Sorghum bicolor (L.) Moench] (C4) and sunflower (Helianthus annuus L.) (C3) was determined to see if it might be one explanation for the lower water use of crops with the C4 photosynthetic pathway. Plants were grown under greenhouse conditions in pots with soil, which was well watered (soil matric potential of ～0 MPa) or allowed to dry (soil matric potential of ?0.038 MPa and ?0.065 MPa for sorghum and sunflower, respectively). Hydraulic resistance was calculated in two ways: (1) using the classic Ohm's law analogue, which assumes that the relation between flux (transpiration) and difference in water potentials of the soil and plant is linear and (2) using an equation that considers diurnal changes in leaf water content along with transpiration and difference in water potentials. Because change in leaf-water content during a day was small, hydraulic resistances calculated by the two methods resulted in similar values. Sorghum had a linear relationship between flux and difference in potentials (constant hydraulic resistance), but sunflower had a nonlinear one (variable hydraulic resistance). The hydraulic resistance of watered sunflower increased only slightly during a day and averaged about 40 MPa m2 s mol?1, which was 3.5 times less than that of watered or water-stressed sorghum (-140 MPa m2 s mol?1). The hydraulic resistance of water-stressed sunflower increased steeply during a day and by the end of the day it had a hydraulic resistance that approached that of sorghum. 相似文献
16.
The population density of Closterotomus trivialis (Costa) and its damage potential were studied in citrus and olive orchards of Crete. C. trivialis was found to be most abundant in wild radish Raphanus raphanistrum L., annual mercury Mercurialis annua L., Urtica sp. and upright pellitory Parietaria officinalis L. compared to mallow Malva sylvestris L., prickly goldenfleece Uropermum picroides (L.), sowthistle Sonchus oleraceus L., citrus or olive trees. Its damage potential on the setting of olive fruit was investigated at the early inflorescence stage. When 1, 5 or 10 adults of C. trivialis were enclosed with stems at the 55th and 57th phenological growth stages, the number of fruits was significantly reduced compared to controls.The developmental biology of individuals of C. trivialis was studied on R. raphanistrum at seven constant temperatures 15, 20, 25, 30, 32.5, 35 and 37 °C, under laboratory conditions. No nymphs survived above 35 °C. The highest nymph to adult survival (89.6%) was found at 20 °C and the lowest (40.6%) at 32.5 °C. Mean developmental time as well as adult longevity decreased with increasing temperature. The developmental time from 1st nymphal instar to adult ranged from at least 9.0 at 32.5 °C to 27.8 days at 15 °C. The adults lived from 2.9 days at 32.5 °C to 45.3 days at 15 °C. It required 212.7 degree-days to complete development above a minimum threshold of 7.72 °C as estimated by linear regression and 8 °C as estimated by nonlinear model. The importance of these findings in the management of this species through the prediction of its seasonal appearance is discussed. 相似文献
17.
野生大豆(G.Soja)、半野生大豆(G.Gracilis)和栽培大豆(G.max)的核型分析 总被引：2，自引：0，他引：2
本文应用数量统计的方法,分析野生大豆16份,半野生大豆5份和栽培大豆2份的核型。结果表明、野生大豆、半野生大豆和栽培大豆染色体数目为2n=40,核型为2n=24m+14sm+2st(SAT)。虽然三者的核型相似,但单倍染色体组长是有差别的,经X~2测定表明,这种差异是由于种间差异引起。因此,大豆核型的研究,对探讨大豆的进化具有重要意义。 在野生大豆中观察到一具有四随体类型,从进化观点看,具四随体类型较具二随体类型物种原始,同时为确定大豆是二倍体还是多倍体植物、提供有价值的材料。 野生大豆、半野生大豆和栽培大豆的Giemsa—C带分析表明,三种大豆的带型极其相似,基本带型为:第一组12条染色体有一条着丝点带;第二组12条染色体有一条中间带;第三组12条染色体有一条端带;第四组4条染色体有二条带。 相似文献
18.
本文记述桔狭胸天牛Philus antennatus(Gyllenhal)幼虫形态特征及发生、为害情况。 相似文献