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991.
山西杉苞蚧的研究(同翅目:蚧总科:蚧科)   总被引:4,自引:1,他引:3  
武三安  尉万葱 《林业科学》2000,36(2):98-102
山西杉苞蚧PhysokermesshanxiensisTang是一种新发现的园林害虫。在山西中部严重危害白PiceameyeriRehd .etWils.为害轻者树势衰弱 ,重者整株枯死。本文首次描述和图示了各幼虫期虫态和雄成虫的形态特征 ,重描了雌成虫的形态。同时也观察了其生物学特性 ,结果表明 :该虫在山西中部 1年发生 1代 ,以2龄若虫在 1年生枝条和针叶上越冬 ;取食为害高峰在 4月上旬至 5月中旬 ;行两性生殖 ,每雌产卵 1 5~ 1 1 4 3粒 ,平均 6 0 2 3粒 ;天敌主要有异色瓢虫Harmoniaoxyridis(Pallas)的十八斑变型和二星瓢虫Adaliabipunctata(Linnaeus)。此外 ,本文还提出了有效的防治措施  相似文献   
992.
检疫有害生物治理软件的开发与应用   总被引:2,自引:0,他引:2  
检疫性有害生物治理(QPM)软件是由三个系统集成,即基础知识、LucID和测验。基础知识系统提供用户学习检疫法律法规、有害生物基础知识和检疫操作技术。LucID系统是通过多途径检索表让用户鉴定有害生物分类单元。LucID系统是由两个了系统构成,即Builer子系统是用于建立多途径检索表,而Player子系统是显示多途径检索表。在QPM中,LucID检索表是昆虫目检索表、植物检疫性病害检索表、植物检疫性昆虫检索表和植物检疫性杂草检索表。测验系统是考察用户对于检疫知识掌握的程度。QPM软件测试表明:运行稳定,结果可靠,系统各功能符合设计要求。它适合于我国国内检疫人员对检疫性有害生物快速鉴定及培训和自学提高,也可用于相关的检疫机构和教学领域。  相似文献   
993.
应用斯氏线虫防治桑皱鞘叶甲   总被引:4,自引:1,他引:4  
应用斯氏属小卷蛾线虫Steinernema carpocapsae(A24品系)对桑皱鞘叶甲Abirus fortunei(Baly)进行了室内和田间感染试验。在25~30℃的室内条件下,1500~2000条线虫/ml的处理使桑皱鞘叶甲幼虫感染率达86%~100%。在9~10月份,先清除田间杂草,然后在桑园开沟,按45~75万条线虫/m^2的剂量施用小卷蛾线虫,对幼虫的防治效果可达88.3%~96.2%,并使次年成虫的出土数量减少46.2%~86.7%。此种防治方法,避免了在春蚕期间摘叶饲蚕与桑皱鞘叶甲化学防治的矛盾,显示出应用昆虫病原线虫防治桑皱鞘叶甲的良好前景。  相似文献   
994.
氟虫腈对水稻害虫的作用特点及应用   总被引:10,自引:0,他引:10  
通过室内生物测定和田间试验,明确了氟虫腈(商品名为锐劲特Regent)对三化暝的内吸杀虫活性、杀卵活性、持效期和对褐飞虱的杀虫活性以及对水稻主要害虫的田间防治效果,同时评价了其对天敌的安全性。结果表明:(1)氟虫腈由水稻根和茎叶内吸传导对三化暝的杀虫活性高,根和茎叶的内吸对初孵蚁暝的LC50值分别为29.12和13.07mg/L;(2)持效期长,50mg/L氟虫腈药后10d和15d对接三化暝初孵蚁暝的防效仍达92.1%和87.2%,而甲胺磷1000mg/L药后3d的防效即降为0;(3)对三化暝的杀卵效果较差,100mg/L的杀卵效果仅为30.3%,极显著低于500mg/L三唑磷的杀卵效果(95.26%);(4)对褐飞虱的综合活性高,对3龄若虫的LC50值为10.52mg/L;(5)在江苏高淳、丹阳等地的田间试验表明,5%氟虫腈悬浮剂0.3、0.45、0.75L/hm^2可分别有效控制白背飞虱、三化暝枯心、稻纵卷叶暝、三化暝白穗和褐飞虱;(6)氟虫腈对以狼蛛为代表的稻田蜘蛛杀伤力大,但对暝卵内赤眼蜂幼期较安全。  相似文献   
995.
A multidisciplinary study was undertaken on the bionomics of the African armyworm in eastern Africa as a basis for the development of control strategies for this important pest of cereal crops and pastures. Relevant findings from studies on seasonal distribution, migration, field infestations and population cycles are reviewed in relation to understanding the causes for the onset and spread of armyworm outbreaks. It is concluded that the onset of the first outbreaks of an armyworm epidemic is caused by oviposition at high density by moths concentrated by wind convergence at storm outflows. The sources of these moths seem to be low-density populations which survive from one season to the next at sites receiving unseasonable rainfall. Some areas in Tanzania and Kenya are particularly prone to early outbreaks which are potentially critical for the initiation of a subsequent spread of outbreaks downwind throughout eastern Africa. These areas have low and erratic rainfall, and are near the first rising land inland from the coast. Below average rainfall prior to the development of outbreaks increases the probability of their occurrence. Their subsequent spread is enhanced by storms downwind which concentrate moths in flight and by sunshine during caterpillar development. Persistent wet weather reduces the spread of outbreaks. This study demonstrates the importance and value of developing and implementing a long-term monitoring system over a large region, in this case in Africa, not only for the generation of data used by the forecasters for the prediction and location of possible outbreaks, but also for obtaining a clearer understanding of the epidemiology of a highly mobile pest.  相似文献   
996.
泰山1号昆虫病原线虫对棉铃虫幼虫和蛹的致死效果   总被引:10,自引:0,他引:10  
作者报道了昆虫病原线虫对棉铃虫室内测试的致死效果。试验采用人工饲养的棉铃虫1-5龄幼虫和蛹。当益害比为80:1时,1-5龄幼虫2天的校正死亡率分别是6.779%、70.968%、96.610%、93.750%和100%;益害比为40:1时,3天的校死亡率分别是21.818%、87.931%、98.333%、96.667%和96.667%。在含水量为6。591%,深度为5cm的沙中,益害比为200:  相似文献   
997.
The methods used to evaluate and categorise the effects of pesticides on beneficial arthropods are reviewed, including the potential significance of indirect, ‘sub-lethal’ activity and the importance of bioavailability of pesticides under semi-field or field conditions. Interspecific and intraspecific differences in the susceptibility of natural enemies (parasitoids and predators) to pesticides are considered, including the use of resistant strains in Integrated Pest Management (IPM) systems. The potential impact of pesticide resistance in the target pest on its natural enemies is also discussed. The need to assess the influence of the host plant/cultivar on the efficacy of pesticides for use in integrated control programmes (ditrophic effects) and of the possible effects of such chemicals on host plant/cultivar-pest-parasitoid systems (tritrophic effects) are then described with specific reference to the diamondback moth and key endolarval parasitoids. Finally, the potential for manipulation of tritrophic interactions to enhance parasitism by application of low doses of toxicants is demonstrated.  相似文献   
998.
Bemisia tabaci (Gennadius), the sweetpotato whitefly, has only one known entomophthoralean pathogen,Erynia radicans (Entomophthoraceae). Two new pathogens have been isolated recently from a glasshouse population of this pest:Conidiobolus coronatus and another, undescribed species ofConidiobolus (Entomophthorales: Ancylistaceae). Artificial inoculation experiments revealed that eggs ofB. tabaci are practically immune to infection by either species. Second-instar larvae are highly resistant, only high doses of conidia causing between <1% and 4.6% mortality. Adults were found to be much more susceptible. Doses of 60 conidia/mm2 ofC. coronatus caused average mortalities ofca 95%. The maximum mortality of adults caused byConidiobolus sp. was much lower,ca 30%, at a dose of 210 conidia/mm2. The incubation period (inoculation to death) for both species, under our experimental conditions, is very short: 18–24 h forC. coronatus and 30 h forConidiobolus sp. Both fungi produced loricoconidia (conidia metamorphosed into resting spores) on cotton leaves and other dry surfaces. This ability allowedConidiobolus sp. to remain viable for 17–21 days on cotton leaves, in glasshouse conditions and in the absence of hosts, whileC. coronatus persisted for 10–14 days.  相似文献   
999.
稻鸭共育对稻田杂草和病虫害的生物防治效应   总被引:29,自引:0,他引:29  
本文研究稻田全天放鸭对水稻病、虫、杂草的防治效果。试验结果表明,稻鸭共育后12和42d,共育田水稻基部飞虱、叶蝉的总量比不养鸭稻田平均减少63.8%和77.3%;稻鸭共育后10和40d,共育田杂草比不养鸭稻田平均减少50.6%和94.2%;分蘖高峰期和齐穗期的纹枯病病情指数,稻鸭共育田比不养鸭稻田分别低67.1%和52.5%。另外,稻鸭共育田的害虫天敌蜘蛛数量明显增加,比常规种稻田多1.66~2.61倍,这也显著改善了稻田的生态环境,抑制了水稻害虫的危害。  相似文献   
1000.
A droplet feeding technique was used to feed known amounts of Vairimorpha necatrix (Kramer) spores to larvae of the tomato moth, Lacanobia oleracea (L) in order to assess the susceptibility of this lepidopteran pest to the pathogen. All first- to fourth-instar larvae died as a result of ingesting 1000 or more V necatrix spores. Two forms of death were observed, which were dependent on the dose and the age of the insect when treated. For first-instar larvae, rapid death (within 6days of dosing) occurred after ingestion of 2000 spores, whereas lower doses resulted in a proportion of larvae dying from chronic infection (microsporidiosis). For more advanced stages, increasing spore doses were required to give rapid death, such that a dose of 200,000 spores was needed to give 80% mortality within 6 days for third-instar larvae. Rapid death was not observed in fourth- to sixth-instar larvae. In all cases successful pupation and adult emergence were much reduced compared with non-infected larvae. Suspensions of V necatrix were sprayed on to tomato (Lycopersicon esculentum Mill) plants maintained in small glasshouses prior to infestation of the plants with L oleracea larvae. The numbers and biomass of pest larvae retrieved from the plants sprayed with V necatrix were significantly reduced by up to 40% and 70%, respectively, compared with plants sprayed with water (control). Similarly, plants sprayed with V necatrix showed a reduction in damage of up to 45% compared with the control plants.  相似文献   
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