全文获取类型
收费全文 | 298篇 |
免费 | 14篇 |
国内免费 | 1篇 |
学科分类
农业科学 | 313篇 |
出版年
2023年 | 5篇 |
2022年 | 9篇 |
2021年 | 6篇 |
2020年 | 9篇 |
2019年 | 8篇 |
2018年 | 12篇 |
2017年 | 7篇 |
2016年 | 9篇 |
2015年 | 9篇 |
2014年 | 11篇 |
2013年 | 29篇 |
2012年 | 18篇 |
2011年 | 20篇 |
2010年 | 11篇 |
2009年 | 10篇 |
2008年 | 17篇 |
2007年 | 8篇 |
2006年 | 12篇 |
2005年 | 13篇 |
2004年 | 9篇 |
2003年 | 6篇 |
2002年 | 5篇 |
2001年 | 3篇 |
2000年 | 7篇 |
1998年 | 5篇 |
1997年 | 4篇 |
1996年 | 3篇 |
1995年 | 5篇 |
1994年 | 5篇 |
1993年 | 2篇 |
1991年 | 3篇 |
1990年 | 3篇 |
1989年 | 2篇 |
1988年 | 2篇 |
1987年 | 4篇 |
1986年 | 3篇 |
1985年 | 2篇 |
1982年 | 2篇 |
1981年 | 1篇 |
1979年 | 3篇 |
1977年 | 2篇 |
1973年 | 1篇 |
1968年 | 1篇 |
1966年 | 2篇 |
1964年 | 1篇 |
1963年 | 1篇 |
1961年 | 1篇 |
1959年 | 1篇 |
1948年 | 1篇 |
排序方式: 共有313条查询结果,搜索用时 31 毫秒
31.
M. Masidur Alam M. Naeem M. Idrees M. Masroor A. Khan Moinuddin 《Journal of Crop Science and Biotechnology》2012,15(2):117-129
Exogenous application of plant growth regulators (PGRs) has vital impact on the growth and productivity of plants. Foliar application of selected PGRs, viz. indole-3-acetic acid (IAA), indole-3-butyric acid (IBA), naphthalene acetic acid (NAA), 6-benzylaminopurine (BAP), kinetin (KIN), thidiazuron (TDZ), gibberellic acid (GA3), salicylic acid (SA), homobrassinosteroids (HBR), and triacontanol (TRIA), were carried out in order to assess the effects on growth of two cultivars (Rosea and Alba) of Catharanthus roseus L. G. Don. The Rosea and Alba plants were sprayed with PGRs (10−7 M) at 60 days after planting (DAP). Shoot and root lengths, plant fresh and dry weights, leaf-area index, total chlorophyll and carotenoids content, net photosynthetic rate, nitrate reductase and carbonic anhydrase activities, and leaf essential nutrients (N, P, and K) were analyzed at 150 DAP while yield attributes and total alkaloids of leaves and roots, contents of vincristine and vinblastine alkaloids were measured at 210 DAP. The results showed that HBR significantly improved most of the growth attributes. Application of HBR, KIN, and GA3 resulted in the ameliorative effects on plant productivity, physiological and biochemical parameters as compared to the unsprayed (control) plants. The effect of TDZ was not significantly different than the control plants. GA3 application significantly increased the vincristine content (7.3%) while TDZ exhibited reduced vincristine content. The effect of other PGR was insignificant towards vincristine and vinblastine contents. The response of Rosea toward exogenous PGRs application was better than Alba in terms of crop productivity, physiological and biochemical parameters, and alkaloid production. 相似文献
32.
Ruenphet S Jahangir A Shoham D Takehara K 《The Journal of veterinary medical science / the Japanese Society of Veterinary Science》2012,74(4):477-480
A total of 516 slaughter-age ostrich sera were collected in Japan during 2006-2009. Sixty-one of five hundred and sixteen were positive by virus neutralization (VN) test and the titer of most positive samples was low level. Within the 61 positive sera, 35 sera were collected from unvaccinated ostriches. This result implies that these ostriches might have been infected naturally with low-virulent Newcastle disease virus (NDV). Within the 455 negative samples, 125 samples were from vaccinated ostriches. Since ostrich farmers use live attenuated vaccines, it is reasonable that the titer decreased to below detection level by 1 or 1.5 year-old. The above data indicate that NDV has infiltrated into ostrich farms in Japan, and that the efficacy of ostrich ND vaccination is often time-limited. 相似文献
33.
Ashraful Alam Antti Kilpeläinen Seppo Kellomäki 《European Journal of Forest Research》2012,131(3):655-667
An ecosystem model (Sima) was utilised to investigate the impact of forest management (by changing both the initial stand
density and basal area thinning thresholds from current recommendations) on energy wood production (at energy wood thinning
and final felling) and management-related carbon dioxide (CO2) emissions for the energy wood production in Finnish boreal conditions (62°39′ N, 29°37′ E). The simultaneous effects of
energy wood, timber and C stocks in the forest ecosystem (live and dead biomass) were also assessed. The analyses were carried
out at stand level during a rotation period of 80 years for Scots pine (Pinus sylvestris L.) and Norway spruce (Picea abies L. Karst.) growing in different fertility sites. Generally, the results showed that decreased basal area thinning thresholds,
compared with current thinning, reduced energy wood (logging residues) and timber production, as well as carbon stocks in
the forest ecosystem. Conversely, increased thinning thresholds increased energy wood production (ca. 1–27%) at both energy
wood thinning and final felling and reduced CO2 emissions (ca. 2–6%) related to the production chain (e.g. management operations), depending on the thinning threshold levels,
initial stand density, species and site. Increased thinning thresholds also enhanced timber production and carbon stocks in
the forest ecosystem. Additionally, increased initial stand density enhanced energy wood production for energy wood thinning
for both species, but this reduced energy wood production at final felling for Scots pine and Norway spruce. This study concluded
that increases in both initial stand density and thinning thresholds, compared with the current level, could be useful in
energy wood, timber and carbon stocks enhancement, as well as reducing management-related CO2 emissions for energy wood production. Only 2.4–3.3% of input of the produced energy (energy wood) was required during the
whole production chain, depending on the management regime, species and sites. However, a comprehensive substitution analysis
of wood-based energy, in respect to environmental benefits, would also require the inclusion of CO2 emissions related to ecosystem processes (e.g. decomposition). 相似文献
34.
Muhammad MUSHTAQ Iftikhar HUSSAIN Afsar MIAN Shahid MUNIR Irfan AHMED Abdul Aziz KHAN 《Integrative zoology》2013,8(3):285-292
This research study evaluated the effect of different additives on the bait consumption by Indian crested porcupine, a serious forest and agricultural pest, under field conditions. Different additives (saccharin, common salt, bone meal, fish meal, peanut butter, egg yolk, egg shell powder, yeast powder, mineral oil and coconut oil) at 2 and 5% each were tested for their relative preference, using groundnut–maize (1:1) as basic bait. All the additives were tested under a no‐choice test pattern. For control tests, no additive was mixed with the basic bait. Saccharin at 5% concentration significantly enhanced the consumption of bait over the basic bait, while 2% saccharin supplemented bait resulted in a non‐significant bait consumption. All other additives did not enhance the consumption of the bait material; rather, these worked as repellents. However, the repellency was lowest with the common salt, followed by egg yolk, egg shell powder, bone meal, peanut butter, mineral oil, fish meal and yeast powder, while coconut remained the most repellent compound. The present study suggested that groundnut–maize (1:1) supplemented with 5% saccharin was the preferred bait combination, and can be used with different rodenticides for the management of Indian crested porcupine. 相似文献
35.
Md. Samim Hossain Molla Sutkhet Nakasathien Md. Akkas Ali ASMMR Khan Md. Robiul Alam 《Archives of Agronomy and Soil Science》2019,65(7):928-944
Plants have evolved different mechanisms to survive under stress conditions. This field study was conducted to evaluate the influence of nitrogen (N) application on dry biomass allocation and translocation in two maize varieties under short pre-anthesis and prolonged bracketing flowering period of drought. Two maize varieties, ‘Pioneer 30B80? and ‘Suwan 4452? receiving N at 0 (control), 160 (optimal) and 320 (supra-optimal) kg ha?1 were subjected to short pre-anthesis and prolonged bracketing flowering periods of drought. Prolonged bracketing flowering period of drought had more suppressive effect on anthesis-silking interval, dry matter allocation and translocation, leaf greenness, contribution of current assimilates to grain (CCAG), kernel number, kernel weight and kernel yield of two maize varieties than a short pre-anthesis drought. Nitrogen application at optimal level was the best for all traits, except CCAG. The maize variety ‘Pioneer 30B80? performed better under both drought types due to more root xylem vessels of large size and more accumulation of dry matter in leaves and roots than the variety ‘Suwan 4452?. Therefore, the variety ‘Pioneer 30B80? may be planted in drought prone environments and may be used in breeding program aimed at developing drought-tolerant cultivars. 相似文献
36.
37.
Nitrogen management improves lodging resistance and production in maize (Zea mays L.) at a high plant density 下载免费PDF全文
Irshad AHMAD Maksat BATYRBEK Khushnuma IKRAM Shakeel AHMAD Muhammad KAMRAN Misbah Raham Sher KHAN HOU Fu-jiang HAN Qing-fang 《农业科学学报》2023,22(2):417-433
Lodging in maize leads to yield losses worldwide. In this study, we determined the effects of traditional and optimized nitrogen management strategies on culm morphological characteristics, culm mechanical strength, lignin content, root growth, lodging percentage and production in maize at a high plant density. We compared a traditional nitrogen (N) application rate of 300 kg ha–1 (R) and an optimized N application rate of 225 kg ha–1 (O) under four N application modes: 50% of N applied at sowing and 50% at the 10th-leaf stage (N1); 100% of N applied at sowing (N2); 40% of N applied at sowing, 40% at the 10th-leaf stage and 20% at tasseling stage (N3); and 30% of N applied at sowing, 30% at the 10th-leaf stage, 20% at the tasseling stage, and 20% at the silking stage (N4). The optimized N rate (225 kg ha–1) significantly reduced internode lengths, plant height, ear height, center of gravity height and lodging percentage. The optimized N rate significantly increased internode diameters, filling degrees, culm mechanical strength, root growth and lignin content. The application of N in four split doses (N4) significantly improved culm morphological characteristics, culm mechanical strength, lignin content, and root growth, while it reduced internode lengths, plant height, ear height, center of gravity height and lodging percentage. Internode diameters, filling degrees, culm mechanical strength, lignin content, number and diameter of brace roots, root volume, root dry weight, bleeding safe and grain yield were significantly negatively correlated with plant height, ear height, center of gravity height, internode lengths and lodging percentage. In conclusion, treatment ON4 significantly reduced the lodging percentage by improving the culm morphological characteristics, culm mechanical strength, lignin content, and root growth, so it improved the production of the maize crop at a high plant density. 相似文献
38.
Arsenic (As), one of the most harmful toxicant at the global level, severely affects plant metabolism when taken up. Interestingly, the presence of silicon (Si) as a fertilizer in As-contaminated soil is an effective strategy to decrease As accumulation in plants. Brassica juncea (var. Varuna) were grown hydroponically to investigate the role of Si at biochemical and molecular levels under arsenite (As3+) stress. Seedlings of B. juncea were exposed to As3+, Si, and a combination of both elements. Our data demonstrated that seedlings exposed to As3+ showed an inhibition in shoot length, chlorophyll, carotenoid, and protein, while co-application of Si improved these growth parameters. Silicon supplementation reduced As accumulation in shoot. Increase/decrease was observed in stress-related parameters (cysteine and proline), antioxidant enzymes (superoxide dismutase, ascorbate peroxidase, and catalase), and oxidative stress markers (malondialdehyde and H2O2), which were improved upon co-application of Si as compared to As3+ alone treatment. Random amplified polymorphic DNA (RAPD) is a suitable biomarker assay for plants for assessing the genotoxicity. Seven RAPD primers produced a total of 39 and 48 bands in the leaves of the untreated and treated seedlings, respectively. The RAPD band-profiles and genomic template stability were consistent with other growth and physiological parameters. In conclusion, the genotoxic alterations along with the biochemical parameters indicate that the exposure to Si mitigates As3+-induced oxidative stress by improving the stress-related parameters and antioxidant system in B. juncea. 相似文献
39.
Genome-wide association analysis for stripe rust resistance in spring wheat(Triticum aestivum L.) germplasm 下载免费PDF全文
Sher MUHAMMAD Muhammad SAJJAD Sultan Habibullah KHAN Muhammad SHAHID Muhammad ZUBAIR Faisal Saeed AWAN Azeem Iqbal KHAN Muhammad Salman MUBARAK Ayesha TAHIR Muhammad Umer Rumana KEYANI Muhammad Inam AFZAL Irfan MANZOOR Javed Iqbal WATTOO Aziz-ur REHMAN 《农业科学学报》2020,19(8):2035-2043
Stripe rust is a continuous threat to wheat crop all over the world. It causes considerable yield losses in wheat crop every year. Continuous deployment of adult plant resistance(APR) genes in newly developing wheat cultivars is the most judicious strategy to combat this disease. Herein, we dissected the genetics underpinning stripe rust resistance in Pakistani wheat germplasm. An association panel of 94 spring wheat genotypes was phenotyped for two years to score the infestation of stripe rust on each accession and was scanned with 203 polymorphic SSRs. Based on D' measure, linkage disequilibrium(LD) exhibited between loci distant up to 45 c M. Marker-trait associations(MTAs) were determined using mixed linear model(MLM). Total 31 quantitative trait loci(QTLs) were observed on all 21 wheat chromosomes. Twelve QTLs were newly discovered as well as 19 QTLs and 35 previously reported Yr genes were validated in Pakistani wheat germplasm. The major QTLs were QYr.uaf.2 AL and QYr.uaf.3 BS(PVE, 11.9%). Dissection of genes from the newly observed QTLs can provide new APR genes to improve genetic resources for APR resistance in wheat crop. 相似文献
40.
Yatoo Mohd. Iqbal Parray Oveas Raffiq Mir Muheet Bhat Riyaz Ahmed Malik Hamid Ullah Fazili Mujeeb ur Rehman Qureshi Sabia Mir Masood Salim Yousuf Raja Wasim Tufani Noor Alam Dhama Kuldeep Bashir Shah Tauseef 《Tropical animal health and production》2019,51(8):2127-2137
Tropical Animal Health and Production - Therapeutic management of contagious caprine pleuroneumonia (CCPP) involves mostly the use of oxytetracycline followed by enrofloxacin and rarely tylosin. In... 相似文献