全文获取类型
收费全文 | 207篇 |
免费 | 12篇 |
专业分类
林业 | 25篇 |
农学 | 11篇 |
基础科学 | 1篇 |
41篇 | |
综合类 | 14篇 |
农作物 | 18篇 |
水产渔业 | 6篇 |
畜牧兽医 | 70篇 |
园艺 | 12篇 |
植物保护 | 21篇 |
出版年
2023年 | 2篇 |
2022年 | 7篇 |
2021年 | 7篇 |
2019年 | 7篇 |
2018年 | 11篇 |
2017年 | 7篇 |
2016年 | 6篇 |
2015年 | 4篇 |
2014年 | 6篇 |
2013年 | 11篇 |
2012年 | 11篇 |
2011年 | 18篇 |
2010年 | 13篇 |
2009年 | 18篇 |
2008年 | 18篇 |
2007年 | 10篇 |
2006年 | 6篇 |
2005年 | 8篇 |
2004年 | 7篇 |
2003年 | 4篇 |
2002年 | 8篇 |
2001年 | 3篇 |
2000年 | 1篇 |
1999年 | 2篇 |
1997年 | 2篇 |
1996年 | 2篇 |
1993年 | 1篇 |
1991年 | 3篇 |
1990年 | 3篇 |
1987年 | 1篇 |
1984年 | 3篇 |
1983年 | 2篇 |
1955年 | 2篇 |
1953年 | 1篇 |
1951年 | 1篇 |
1947年 | 1篇 |
1935年 | 1篇 |
1929年 | 1篇 |
排序方式: 共有219条查询结果,搜索用时 0 毫秒
1.
2.
3.
4.
Jennifer A Berry Lewis J Bartlett Selina Bruckner Christian Baker S Kris Braman Keith S Delaplane Geoffrey R Williams 《Journal of insect science (Online)》2022,22(1)
The American beekeeping industry continually experiences colony mortality with annual losses as high as 43%. A leading cause of this is the exotic, ectoparasitic mite, Varroa destructor Anderson & Trueman (Mesostigmata: Varroidae). Integrated Pest Management (IPM) options are used to keep mite populations from reaching lethal levels, however, due to resistance and/or the lack of suitable treatment options, novel controls for reducing mites are warranted. Oxalic acid for controlling V. destructor has become a popular treatment regimen among commercial and backyard beekeepers. Applying vaporized oxalic acid inside a honey bee hive is a legal application method in the U.S., and results in the death of exposed mites. However, if mites are in the reproductive stage and therefore under the protective wax capping, oxalic acid is ineffective. One popular method of applying oxalic is vaporizing multiple times over several weeks to try and circumvent the problem of mites hiding in brood cells. By comparing against control colonies, we tested oxalic acid vaporization in colonies treated with seven applications separated by 5 d (35 d total). We tested in apiaries in Georgia and Alabama during 2019 and 2020, totaling 99 colonies. We found that adult honey bees Linnaeus (Hymenoptera: Apidae), and developing brood experienced no adverse impacts from the oxalic vaporization regime. However, we did not find evidence that frequent periodic application of oxalic during brood-rearing periods is capable of bringing V. destructor populations below treatment thresholds. 相似文献
5.
Larval diet affects development and reproduction of East Asian strain of the fall armyworm,Spodoptera frugiperda
下载免费PDF全文
![点击此处可从《农业科学学报》网站下载免费的PDF全文](/ch/ext_images/free.gif)
Li-mei HE Teng-li WANG Yu-chao CHEN Shi-shuai GE Kris A.G. WYCKHUYS Kong-ming WU 《农业科学学报》2021,20(3):736-744
In December 11, 2018, the fall armyworm(FAW), Spodoptera frugiperda invaded China and has since impacted local maize, sorghum and other crops. Here, we draw on laboratory experiments to show how different host crops(i.e., maize, sorghum, wheat and rice) and artificial diet affect larval growth and adult reproduction of one local FAW strain. Larval diet affected development duration, pupation rate, survival and emergence rate of pupae, and S. frugiperda adult fecundity. FAW attained the slowest larval development(19.4 days) on sorghum and the fastest(14.1 days) on artificial diet, with larvae attaining 99.6% survival on the latter food item. On rice, FAW larvae attained survival rate of 0.4% and were unable to pupate successfully. Pupation rate and pupal survival varied substantially between artificial diet and live plantlets at different phenological stages. Pupal weight was the highest(0.26 g) on artificial diet and the lowest(0.14 g) on sorghum, while FAW females reached the highest fecundity(699.7 eggs/female) on 2-leaf stage maize. Egg hatching rate equaled 93.6% on 4-or 5-leaf stage maize and 36.6% on artificial diet. FAW intrinsic rate of natural increase and the finite rate of increase varied between larval diets, reflecting how young maize leaves are the most suitable diet. Our findings can help to refine laboratory rearing protocols, devise population forecasting models or guide the deployment of ‘area-wide' integrated pest management(IPM) modules in FAW-invaded areas of China and other Asian countries. 相似文献
6.
7.
Thibaut Olivier Vaidevutis Šveikauskas Elisabeth Demonty Kris De Jonghe Pascal Gentit Mojca Viršček-Marn Sabine Grausgruber-Gröger Sébastien Morio Francesco Faggioli Michèle Visage Frédéric Fauche Maria Gusina Marta Luigi Helena Lasner Irena Mavrič-Pleško 《European journal of plant pathology / European Foundation for Plant Pathology》2016,144(3):645-654
8.
Lim HS Ko TS Hobbs HA Lambert KN Yu JM McCoppin NK Korban SS Hartman GL Domier LL 《Phytopathology》2007,97(3):366-372
ABSTRACT Transgenic soybean (Glycine max) plants expressing Soybean mosaic virus (SMV) helper component-protease (HC-Pro) showed altered vegetative and reproductive phenotypes and responses to SMV infection. When inoculated with SMV, transgenic plants expressing the lowest level of HC-Pro mRNA and those transformed with the vector alone initially showed mild SMV symptoms. Plants that accumulated the highest level of SMV HC-Pro mRNA showed very severe SMV symptoms initially, but after 2 weeks symptoms disappeared, and SMV titers were greatly reduced. Analysis of SMV RNA abundance over time with region-specific probes showed that the HC-Pro region of the SMV genome was degraded before the coat protein region. Transgenic soybean plants that expressed SMV HC-Pro showed dose-dependent alterations in unifoliate leaf morphologies and seed production where plants expressing the highest levels of HC-Pro had the most deformed leaves and the lowest seed production. Accumulation of microRNAs (miRNAs) and mRNAs putatively targeted by miRNAs was analyzed in leaves and flowers of healthy, HC-Pro-transgenic, and SMV-infected plants. Neither expression of SMV HC-Pro nor SMV infection produced greater than twofold changes in accumulation of six miRNAs. In contrast, SMV infection was associated with twofold or greater increases in the accumulation of four of seven miRNA-targeted mRNAs tested. 相似文献
9.
Allan Fulton Larry Schwankl Kris Lynn Bruce Lampinen John Edstrom Terry Prichard 《Irrigation Science》2011,29(6):497-512
Orchard and vineyard producers conduct preplant site evaluations to help prevent planting permanent tree and vine crops on
lands where the crop will not perform to its highest potential or attain its full life expectancy. Physical soil characteristics
within specific soil profiles and spatially throughout an orchard influence decisions on land preparation, irrigation system
selection, horticultural choices, and nutrient management. Producers depend on soil surveys to help them understand the soil
characteristics of the land and may be interested in technology that provides additional information. Electromagnetic induction
(EM38) and four-probe soil resistance sensors (VERIS) are being used in combination with global positioning systems to map
spatial variability of soils using apparent soil electrical conductivity (ECa). The hypothesis evaluated in this study is
whether rapid, in situ, and relatively low-cost methods of measuring ECa (EM38 and VERIS) can effectively identify and map
physical soil variability in non-saline soils. The supposition is that in non-saline soils, ECa levels will relate well to
soil texture and water-holding capacity and can be used to map physical soil variability. In turn, the information can be
used to guide decisions on preplant tillage, irrigation system design, water and nutritional management, and other horticultural
considerations. Two sites in the Sacramento Valley were mapped each with EM38 and VERIS methods. Site-specific management
zones were identified by each provider on ECa maps for each site, and then soil samples were collected by University of California
researchers to verify these zones. Results showed that on non-saline soils, ECa measured with both EM38 and VERIS correlate
with physical soil properties such as gravel, sand, silt, and clay content but the relationship between conductivity and these
physical soil properties varied from moderately strong to weak. The strength of the correlation may be affected by several
factors including how dominant soil texture is on conductivity relative to other soil properties and on methods of equipment
operation, data analysis and interpretation. Overall, the commercial providers of ECa surveys in this study delivered reasonable
levels of accuracy that were consistent with results reported in previous studies. At one site, an ECa map developed with
VERIS provided more detail on physical soil variability to supplement published soil surveys and aided in the planning and
development of a walnut orchard. At a second site, almond yield appeared to correlate well with distinctly different soil
zones identified with EM38 mapping. 相似文献
10.
Sandy Adriaenssens Jeroen Staelens Karen Wuyts An de Schrijver Shari Van Wittenberghe Tatiana Wuytack Fatemeh Kardel Kris Verheyen Roeland Samson Pascal Boeckx 《Water, air, and soil pollution》2011,219(1-4):43-57
This study assessed the foliar uptake of 15N-labelled nitrogen (N) originating from wet deposition along with leaf surface conditions, measured by wettability and water storage capacity. Foliar 15N uptake was measured on saplings of silver birch, European beech, pedunculate oak and Scots pine and the effect of nitrogen form (NH 4 + or NO 3 ? ), NH 4 + to NO 3 ? ratio and leaf phenology on this N uptake was assessed. Next to this, leaf wettability and water storage capacity were determined for each tree species and phenological stage, and the relationship with 15NH 4 + and 15NO 3 ? uptake was examined. Uptake rates were on average five times higher (p?<?0.05) for NH 4 + than for NO 3 ? and four times higher for deciduous species than for Scots pine. Developing leaves showed lower uptake than fully developed and senescent leaves, but this effect was tree species dependent. The applied NH 4 + to NO 3 ? ratio did only affect the amount of N uptake by senescent leaves. The negative correlation between measured leaf contact angles and foliar N uptake demonstrates that the observed effects of tree species and phenological stage are related to differences in leaf wettability and not to water storage capacity. 相似文献