首页 | 本学科首页   官方微博 | 高级检索  
文章检索
  按 检索   检索词:      
出版年份:   被引次数:   他引次数: 提示:输入*表示无穷大
  收费全文   118篇
  免费   9篇
  国内免费   3篇
林业   4篇
农学   11篇
综合类   43篇
农作物   2篇
水产渔业   39篇
畜牧兽医   1篇
植物保护   30篇
  2024年   3篇
  2023年   1篇
  2022年   4篇
  2021年   6篇
  2020年   5篇
  2019年   6篇
  2018年   3篇
  2017年   6篇
  2016年   10篇
  2015年   3篇
  2014年   3篇
  2013年   11篇
  2012年   3篇
  2011年   5篇
  2010年   8篇
  2009年   3篇
  2008年   5篇
  2007年   6篇
  2006年   10篇
  2005年   4篇
  2004年   4篇
  2003年   1篇
  2002年   2篇
  2001年   5篇
  2000年   2篇
  1998年   1篇
  1994年   1篇
  1993年   1篇
  1992年   2篇
  1991年   1篇
  1990年   2篇
  1989年   2篇
  1988年   1篇
排序方式: 共有130条查询结果,搜索用时 204 毫秒
41.
Fumigant activity of essential oil vapors distilled from Carum copticum C. B. Clarke and Vitex pseudo-negundo Hand I. MZT. was tested against eggs, larvae and adults of Callosobruchus maculatus (F.). Fumigant toxicity was assessed at 27 ± 1°C and 60 ± 5% RH, in dark condition. The influence of different concentrations of the essential oil vapors on egg hatchability, larval and adult mortality was significant. Data probit analysis showed that lethal concentration of the essential oil to kill 50% of the population (LC50) for egg, larvae and adult were found to be 1.01, 2.50 and 0.90 μl/l air of C. copticum oil, followed by 2.20, 8.42 and 9.39 μl/l air essential oil of V. pseudo-negundo, respectively. Between these essential oils, C. copticum was almost more toxic than V. pseudo-negundo on all growth stages of C. maculatus. The present study suggests that essential oils from these medicinal plants may be potential grain protectants as botanical alternative fumigants and could be used in the management of various life stages of C. maculatus.  相似文献   
42.
结合聚合酶链反应(polymerase chain reaction,PCR)和酶切方法,对鹰嘴豆象Callosobruchus analis(Fabricius)和四纹豆象Callosobruchus maculatus(Fabricius)的分子检测技术进行了研究。根据两种豆象m tDNACOⅠ基因序列的比对结果设计了2对特异性PCR引物,并筛选到2个特异性内切酶SnaⅠ和MboⅠ,通过PCR反应(最适退火温度为55℃)和PCR产物的酶切反应检测2个近缘种。可靠性检测表明,2对引物针对不同地理种群和个体以及不同DNA浓度的鹰嘴豆象和四纹豆象均能扩增出相应的目的条带。限制性内切酶验证结果表明,PCR技术具有较高的准确性和灵敏度,弥补了形态鉴定的不足。  相似文献   
43.
通过绿豆象自由选择和无选择大豆种子两组试验,研究了绿豆象产卵量、羽化数量及羽化率等生物学特性与大豆种子含水量的关系。在自由选择试验中,大豆含水量从6.5%上升到12.5%,绿豆象在大豆上的产卵量从85.00粒增加到352.75粒,羽化成虫数从14.75头增加到230.00头,羽化率从17.34%上升到65.15%;在无选择试验中,大豆含水量从6.5%到12.5%,绿豆象在大豆上的产卵量从117.50粒增加到到310.00粒,羽化成虫数从19.50头增加到198.00头,羽化率从16.78%上升到63.83%。试验数据显示随着大豆种子含水量的增加,绿豆象产卵量、成虫羽化的数量以及羽化率都在增加,绿豆象更喜欢在含水量大的大豆种子上产卵。  相似文献   
44.
对25对池塘回养花(Hemibarbus maculatus Bleeker)(雄鱼平均体长25cm,平均体重247.9g;雌鱼平均体长25.8cm,平均体重278.8g)繁殖前后体成份的变化进行了测定,并确定了其产卵类型。结果显示,繁殖后亲鱼的粗脂肪含量比繁殖前低了32.14%;粗蛋白含量则升高13.19%;灰分变化不大,水分略呈下降趋势。卵径分布频率结果显示,花属于一次分批产卵类型。  相似文献   
45.
为探明中草药提取物对仓储害虫绿豆象的生物活性,为其植物源农药的开发利用提供依据,通过点滴、熏蒸等方法测定络石、苣荬菜、土牛膝和马松子等4种中草药正己烷提取物对绿豆象的触杀、熏蒸和趋避等活性.结果表明:马松子的触杀活性最高,达83%;其次是土牛膝和苣荬菜,分别为63%和57%.4种中草药均没有明显的熏蒸活性,苣荬菜和土牛膝的趋避活性分别为Ⅲ级和Ⅱ级.中草药不同部位提取物的杀虫效果存在差异,络石的触杀效果叶优于藤(56.7%>13.3%),苣荬菜的触杀活性茎优于叶(60%>53.3%),但是,其趋避活性叶优于茎(56.7%>16.7%).  相似文献   
46.
Essential oil(EO) of Nigeria-grown Lippia adoensis leaf was analyzed using gas chromatography mass spectrometry(GCMS) and its fumigant and repellent properties against Callosobruchus maculatus were evaluated. Sixteen compounds predominated by monoterpenes were identified. The major compounds were Eucalyptol(28.36%), α-Terpineol(25.99%), γ-Terpinene(15.24%), α-Pinene(5.08%), 1H-Cyclopropa[a]naphthalene(4.25%) and 1, 3, 6, 10-Dodecatetraene(3.74%). Percentage mortality due to fumigant toxicity was dose- and exposure period-dependent. One hour after treatment(HAT), application of L. adoensis leaf EO at 107 μL· L~(-1) air caused significantly(p?0.05) higher mortality(50.00%) than 0.00% mortality observed at 0-53 μL· L~(-1) air, but not significantly(p?0.05) different from 22.50% observed in 80 μL· L~(-1) air. At 3 HAT, application of L. adoensis EO at 80 μL· L~(-1)air caused significantly higher mortality(90.00 %) than mortality observed at 0 μL· L~(-1) air. At 6 HAT, application of L. adoensis EO at 53-107 μL· L~(-1) air caused significantly higher mortality(100.00 %) than that was observed in the control. The same trend was observed at 12 HAT where 100 % mortality observed in 27-107 μL· L~(-1) air was significantly greater than 13.33 % observed in the control. At 3 HAT, percentage repellence was significantly(p0.05) affected by doses. Application of EO at 10-30 μL· cm~(-2) caused class V repellence(86.67%-100%) compared with the control which caused class I repellence(0-20%).  相似文献   
47.

Extracts from nine plant materials were tested in choice and no-choice tests as oviposition deterrents for cowpea bruchid, Callosobruchus maculatus (F.) on chickpea, Cicer arietinum L. Seed treatment with 0.1% crude extract of materials resulted in a significant reduction in ovipositional preference of the bruchid. The highest repellency was found in Rhazya stricta leaves (82%), Azadirachta indica seeds (76.8%), Heliotropium bacciferum aerial parts (59.2%) and citrus peels (58.6%). Progeny production was significantly reduced: only 11.5, 11.9, 12.4, 13.4 and 14.8% of the eggs deposited reached adulthood in R. stricta, neem seeds, Piper nigrum, citrus peels and H. bacciferum, respectively. F1 females laid significantly fewer eggs in response to R. stricta, neem seeds, Eugenia caryophyllata cloves, H. bacciferum, citrus peels and P. nigrum. Percentage reduction in F2 progeny ranged between 71.4% with R. stricta-treated seeds and 24.5% in the P. nigrum treatment.  相似文献   
48.
四纹豆象与绿豆象种群竞争的研究   总被引:4,自引:0,他引:4  
本研究通过混合竞争实验、互相产卵实验和不同着卵量下的成虫卵巢可见卵量观察实验,得出在四纹豆象与绿豆象种群竞争中四纹豆象占优势的结论。混合竞争实验,虽然在绿豆象发育最适温度30℃条件下进行,但绿豆象在竞争中仍处于劣势。由此充分说明四纹豆象是一种危害性害虫,应加强对该虫的检疫。  相似文献   
49.
花(鱼骨)耗氧率和窒息点的初步研究   总被引:1,自引:0,他引:1  
实验测定了花的耗氧率和窒息点,并对耗氧率的昼夜变化规律以及体重对其窒息点的影响进行了研究。结果表明,在实验温度(10~25℃)条件下,花的耗氧率随温度的升高而增大,随体重的增加而降低;耗氧率(R0)与温度(T)和体重(W)的二元线形回归方程是:R0=0.022T-0.001W-0.05,复相关系数为0.926,F检验表明,花的耗氧率与温度和体重之间有极显著复相关关系;花的耗氧率具有昼夜节律性,耗氧高峰出现在凌晨3:00,低谷是在上午11:00;花的窒息点与体重显著相关,窒息点A(mg/L)与体重W(g)的相关关系表示为:A=0.2671W0.2801,随体重的增加而升高。  相似文献   
50.
Abstract

The efficacy of two application rates of powdered fruits of four types of peppers (Capsicum spp.) was evaluated for the control of Callosobruchus maculatus (F). The various pepper powders at 2.5 g‐5.0 g per 250 g of seed were effective in reducing oviposition and damage to cowpea seeds. The pepper type Capsicum frutescens var. yarmunchi was the most effective in discouraging oviposition and minimizing damage to the seed, as indicated by the significantly lower number of emergence holes. The seed quality and viability were not affected by the powdered pepper fruit treatment. The result is indicative of the potential for the use of powdered fruits of some peppertypes in protecting stored cowpea seeds against C. maculatus.  相似文献   
设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号