全文获取类型
收费全文 | 888篇 |
免费 | 298篇 |
国内免费 | 3篇 |
专业分类
林业 | 50篇 |
农学 | 38篇 |
基础科学 | 16篇 |
138篇 | |
综合类 | 465篇 |
农作物 | 57篇 |
水产渔业 | 23篇 |
畜牧兽医 | 41篇 |
园艺 | 36篇 |
植物保护 | 325篇 |
出版年
2025年 | 12篇 |
2024年 | 21篇 |
2023年 | 28篇 |
2022年 | 19篇 |
2021年 | 30篇 |
2020年 | 37篇 |
2019年 | 54篇 |
2018年 | 29篇 |
2017年 | 41篇 |
2016年 | 52篇 |
2015年 | 42篇 |
2014年 | 56篇 |
2013年 | 51篇 |
2012年 | 76篇 |
2011年 | 90篇 |
2010年 | 76篇 |
2009年 | 76篇 |
2008年 | 53篇 |
2007年 | 60篇 |
2006年 | 52篇 |
2005年 | 39篇 |
2004年 | 24篇 |
2003年 | 18篇 |
2002年 | 25篇 |
2001年 | 19篇 |
2000年 | 22篇 |
1999年 | 16篇 |
1998年 | 13篇 |
1997年 | 14篇 |
1996年 | 11篇 |
1995年 | 6篇 |
1994年 | 3篇 |
1993年 | 2篇 |
1992年 | 4篇 |
1991年 | 2篇 |
1990年 | 4篇 |
1989年 | 1篇 |
1988年 | 3篇 |
1987年 | 6篇 |
1985年 | 1篇 |
1980年 | 1篇 |
排序方式: 共有1189条查询结果,搜索用时 15 毫秒
1.
研究大蒜素对番茄生产上叶霉菌主流生理小种1.2.3.4以及2014年新发现生理小种2.5、2.4.5和1.2.3.4.9的抑制作用,为开发安全、高效的植物源农药奠定基础。首先制备大蒜素抽提母液,采用定硫法对其中的大蒜素进行定量测定,发现当溶液中滴加4 m L浓硝酸、溶液p H值为2.0时能够更为准确地测得大蒜素的含量,试验测得大蒜素含量为0.52%。在此基础上,进行了大蒜素对4个叶霉菌生理小种菌丝生长、孢子萌发的抑制试验,离体叶片上的病害预防试验以及苗期药效试验。结果表明,当大蒜素剂量25μL/m L时,其对叶霉菌生理小种菌丝生长的抑制活性较高,其中对1.2.3.4的抑制率最高,对1.2.3.4.9的抑制率最低,对其他2个生理小种的抑制率差异不显著。当大蒜素剂量7.5μL/m L时,其对4个生理小种孢子萌发的抑制效应存在差异,其中对1.2.3.4.9的孢子萌发抑制率最低,对1.2.3.4的孢子萌发抑制率最高。当大蒜素剂量为125μL/m L时,其对叶霉菌4个生理小种在离体叶片上的预防效果均超过95%。苗期药效试验表明,在相等剂量下,大蒜素对叶霉菌的防治效果高于多菌灵和甲基托布津,说明大蒜素是一种可以替代化学药剂防治叶霉病的有效抑菌物质。 相似文献
2.
3.
4.
苹果梨黑星病药剂筛选试验 总被引:2,自引:0,他引:2
试验筛选出防治苹果梨黑星病的理想药剂为20%苯醚甲环唑微乳剂、40%氟硅唑乳油和80%腈菌唑.锰锌可湿性粉剂等;确定三唑类杀菌剂为目前防治苹果梨黑星病的首选药剂,并可与其他类杀菌剂混合或轮换使用,以延缓其抗性的产生,为果农更好地防治该病害提供技术支持。 相似文献
5.
Martínez Vidal JL Egea González FJ Garrido Frenich A Martínez Galera M Aguilera PA López Carrique E 《Pest management science》2002,58(8):784-790
Principal component analysis (PCA) was applied to the gas chromatographic data obtained from 23 different greenhouse trials. This was used to establish which factors, including application technique (very small, small, medium and large drop-size), crop characteristics (short/tall, thin/dense) and pattern application of the operator (walking towards or away from the treated area) are relevant to the dermal exposure levels of greenhouse applicators. The results showed that the highest exposure by pesticides during field applications in greenhouses, in the climatic conditions and in the crop conditions typical of a southern European country, occurs on the lower legs and front thighs of the applicators. Similar results were obtained by hierarchical cluster analysis (HCA). Drop-size seems to be very important in determining total exposure, while height and density of crops have little influence on total exposure under the conditions of the present study. No pesticide type is a major factor in total exposure. The application of multiple regression analysis (MRA) allowed assessment of the relationships between the pesticide exposure of the less affected parts of the body with the most affected parts. 相似文献
6.
桑褐刺蛾的生物学特性及防治 总被引:5,自引:0,他引:5
通过野外观察及室内饲养相结合的方法,进行桑褐刺蛾的生物学习性及防治研究。研究发现桑褐刺蛾在浙江莫干山1a发生2代,以老熟幼虫在树下土壤内做茧越冬,翌年5月初化蛹,成虫于5月末始见羽化,6月中旬始见初孵幼虫。幼虫有8个龄期。以树干柱枝打孔注射农药方法,对桑褐制蛾进行防治研究。在幼虫出现前2周在悬铃木主枝上按1cm胸径打孔注射2mL50%甲胺磷乳油、40%氧化乐果乳油和50%久效磷水剂,平均校正死亡率分别为85.8%,84.8%和82.6%,图1表4参8 相似文献
7.
The purpose of this study was to evaluate oxidative stress and neurotoxic potential of organophosphorus (OP) insecticide diazinon in the sentinel freshwater fish, Oreochromis niloticus. Antioxidant and acetylcholinesterase (AChE) enzyme activities and malondialdehyde (MDA) and protein levels were measured spectrophotometrically in gill, kidney, alimentary tract, and muscle tissues of fish treated with sub-lethal diazinon concentrations for 1, 7, 15, and 30 days. Dose-dependent inhibitions of AChE were observed in all the experimental fish. On the contrary of alimentary tract, MDA levels were elevated in kidney and muscle and gill was not affected. AChE and MDA levels intercorrelated in kidney and muscle tissues. Diazinon had increased superoxide dismutase (SOD) activities in all the tissues, while kidney was the most affected tissue. Tissue-specific alterations were observed on catalase (CAT) and glutathione peroxidase (GPx) activities; however, the activities were not changed in gill and muscle tissues for GPx and in gill, muscle, and kidney tissues for CAT. Protein levels decreased in kidney, muscle, and alimentary tract, while increased in gill and alimentary tract in 15 days. With respect to these results, diazinon has oxidative and neurotoxic potentials in O. niloticus. Observed changes with diazinon treatment were generally tissue-specific and dose-dependent. 相似文献
8.
Mariyono J 《Pest management science》2008,64(10):1069-1073
BACKGROUND: Integrated pest management (IPM) technology has been disseminated since 1989 in Indonesia to cut down pesticide use, but the adoption and diffusion of the technology are still debated. This study aims to estimate the models of demand for pesticides and to analyse the impact of IPM technology on pesticide use. Aggregate cross-section time series data from 1990-1998 are used.RESULTS: The results show that IPM technology reduces the use of pesticides by improving the process of rice production, such that pesticides are more efficiently used. In this case, the IPM technology is not a pest control technique.CONCLUSION There is an indication that IPM technology has been adopted by farmers. This is evidence that the IPM programme in Indonesia was successful in this area. Copyright (c) 2008 Society of Chemical Industry. 相似文献
9.
The contact toxicity of indoxacarb, abamectin, endosulfan, insecticide soap, S-kinoprene and dimethoate to Orius insidiosus (Say) and Aphidius colemani Viereck were studied in the laboratory. These beneficials are often used in the greenhouses to manage various insect pests. Indoxacarb is slow acting and therefore, to estimate lethal dosages, observations should be continued for several days until data stabilize. Seven days after treatment, the LC50 was 0.119 g AI litre(-1) for O insidiosus adults and 0.019 g AI litre(-1) for A colemani. At that time, the recommended field concentration was 0.479 times the LC50 for O insidiosus adults and three times the LC50 for A colemani. In contrast, indoxacarb had no adverse effect on the reproductive capacity of wasps surviving a treatment or the developing wasps in the aphid mummy. Among the other insecticides S-kinoprene was the most innocuous while dimethoate was the most toxic to the two beneficials. The other insecticides had overlapping toxicities. 相似文献
10.
Paul A. Umina Aston L. Arthur Stuart A. McColl Ary A. Hoffmann John M.K. Roberts 《Crop Protection》2010
Control of invertebrate pests in broad-acre agriculture largely relies on the application of broad-spectrum pesticides, however resistance problems and environmental concerns are driving a search for alternatives including more selective products. Here we explore the feasibility of using novel chemical groupings in the control of problematic pests that attack germinating pastures and grain crops in Australia. A modified laboratory bioassay is described for testing the response of several invertebrate pests to pesticides that have contact and systemic/translaminar properties. Two contact pesticides (fenitrothion and gamma-cyhalothrin) and three pesticides with strong systemic/translaminar properties (lambda-cyhalothrin, abamectin and diafenthiuron) showed promise for control of the collembolan Sminthurus viridis and four mite pests (Halotydeus destructor, Balaustium medicagoense, Penthaleus falcatus and Bryobia sp.). No single pesticide emerged as the most efficacious against all these pests, highlighting the need for correct pest identification before making control recommendations. Incorporating these new chemical options into pest control programs may help to control emerging pests and counter pesticide resistance issues. Selective pesticides in particular are likely to be compatible with integrated control programs that promote the establishment and maintenance of beneficial natural enemies. 相似文献