全文获取类型
收费全文 | 397篇 |
免费 | 21篇 |
国内免费 | 4篇 |
专业分类
林业 | 20篇 |
农学 | 44篇 |
基础科学 | 6篇 |
116篇 | |
综合类 | 34篇 |
农作物 | 30篇 |
水产渔业 | 21篇 |
畜牧兽医 | 94篇 |
园艺 | 11篇 |
植物保护 | 46篇 |
出版年
2023年 | 4篇 |
2022年 | 15篇 |
2021年 | 12篇 |
2020年 | 15篇 |
2019年 | 23篇 |
2018年 | 39篇 |
2017年 | 22篇 |
2016年 | 21篇 |
2015年 | 11篇 |
2014年 | 17篇 |
2013年 | 52篇 |
2012年 | 21篇 |
2011年 | 18篇 |
2010年 | 8篇 |
2009年 | 9篇 |
2008年 | 16篇 |
2007年 | 4篇 |
2006年 | 5篇 |
2005年 | 9篇 |
2004年 | 8篇 |
2003年 | 5篇 |
2002年 | 1篇 |
2001年 | 4篇 |
2000年 | 1篇 |
1999年 | 2篇 |
1998年 | 3篇 |
1997年 | 5篇 |
1996年 | 4篇 |
1995年 | 3篇 |
1994年 | 5篇 |
1993年 | 5篇 |
1992年 | 5篇 |
1991年 | 6篇 |
1990年 | 4篇 |
1989年 | 5篇 |
1988年 | 5篇 |
1987年 | 4篇 |
1986年 | 5篇 |
1985年 | 3篇 |
1984年 | 3篇 |
1983年 | 1篇 |
1982年 | 2篇 |
1980年 | 3篇 |
1978年 | 1篇 |
1975年 | 2篇 |
1974年 | 2篇 |
1971年 | 1篇 |
1970年 | 1篇 |
1967年 | 2篇 |
排序方式: 共有422条查询结果,搜索用时 15 毫秒
51.
Jasmonic and salicylic acid-induced resistance in sorghum against the stem borer Chilo partellus 总被引:1,自引:0,他引:1
Induced resistance was studied in three sorghum genotypes (IS2205, ICSV1 and ICSV700) against Chilo partellus (Swinhoe) (Lepidoptera; Pyralidae) infestation and jasmonic acid (JA) and salicylic acid (SA) application. The activity of plant defensive enzymes [peroxidase (POD), polyphenol oxidase (PPO), superoxide dismutase (SOD), and catalase (CAT)], and the amounts of total phenols, hydrogen peroxide (H2O2), malondialdehyde (MDA), and proteins were recorded at 6 days after infestation. The induction of enzyme activities and the amounts of secondary metabolites varied among the genotypes and treatments. The genotype IS2205 showed a stronger effect than that of ICSV1 or ICSV 700. Treatment with JA followed by insect infestation induced greater levels of enzymes and secondary metabolites. The results suggest that JA induces greater levels of resistance components in sorghum plants against insect pests. Thus, pretreatment of plants with elicitors including JA and SA could provide a greater opportunity for plant defense against herbivores. 相似文献
52.
Blackspot, caused by Didymella pinodes (Berk. & Blox.)Vestergr., is one of the most important diseases of field pea, causing significant reduction in seed yield and quality in southern Australia and in other parts of the world. Development of resistant germplasm has been slow because of the low level of resistance found in the available germplasm, poor reliability of screening methods and the polygenic nature of inheritance. Crosses were made between agronomically suitable lines and resistant germplasm from different sources. Their progeny were advanced through the single seed descent method and single plants were selected at F4/F5. The F4/F5 derived lines were screened against blackspot in the field under disease pressure and evaluated for grain yield at multilocations over 2 years. Despite the low level of resistance in the parental germplasm, the level of resistance has increased significantly in the new germplasm. Many of the resistant lines were late and low yielding, but lines with higher resistance and early flowering and high yield potential were also identified indicating that the disease resistance, adaptation and yield potential can be combined. However, the resistance identified in this study is only partial and suitable agronomic practices may need to be supplemented to minimise the yield loss and enhance the benefits of this partial resistance. 相似文献
53.
Iqra Javid Mahroze Fatima Syed Zakir Hussain Shah Muhammad Afzal 《Aquaculture Nutrition》2021,27(1):217-224
The effect of organic acids (OA) and dicalcium phosphate (Pi) supplementation in the feed of Labeo rohita fingerlings was studied by formulating seven practical diets, designed as D1 with no feed additives {dicalcium phosphorus (Pi) and organic acid (OA) blend} while, D2, D3, D4 and D5 were supplemented with Pi at the graded levels of 5, 10, 15 and 20 g/kg, respectively, whereas D6 and D7 contained blend of OA at 15 and 30 g/kg, respectively. The diet supplemented with OA blend exhibited increase (p < .05) in growth of L. rohita fingerlings compared with the diet supplemented with Pi. The OA supplementation at both levels showed significant improvement in nutrients digestibility and minerals absorption in fingerlings. Moreover, in case of muscle proximate composition, crude fat (CF) and crude protein (CP) were increased (p < .05) with the inclusion of OA blend in the diet while crude ash (CA) was improved by Pi supplementation. Additionally, digestive enzyme activities were not affected (p ? .05) by OA blend supplementation while increased activities were observed in the fingerlings fed with Pi diet. Consequently, supplementation of OA blend in the diet improved the growth performance and nutrient status while Pi enhanced digestive enzyme activities of L. rohita fingerlings. 相似文献
54.
Shahid Iqbal Awan Muhammad Shahzad Ahmed Jehanzeb Farooq Syed Dilnawaz Ahmad Muhammad Ilyas Asad Hussain Shah Muhammad Fareed Khan Sardar Ali Lutful Hasan 《Frontiers of Agriculture in China》2011,5(4):486-496
An experiment was conducted to access the genetic variability among early vigour and quantitative traits under limited moisture
in F2 generation of a 5 × 5 diallel cross of bread wheat. The results indicated that there was significant genotypic variation
among the genotypes. Additive dominance model revealed full fitness of the data for RL, DSW, FRW, DRW, spike length, and 1000-grain
weight but was partially fit for SL, FSW, R/S, tillers per seedling, plant height, tillers per plant, spikelets per spike,
and grain yield per plant. The partially adequate models for these plant characters might be due to the presence of non-allelic
interaction, linkage, and non-independent distribution of the genes in the parents. Additive genes coupled with moderate to
high narrow sense heritability were involved in the heritage of all the traits, which indicated a higher scope of selection
in early generations. 相似文献
55.
56.
Ali Al Maliki Gary Owens Hussain M Hussain Saadi Al-Dahaan 《Communications in Soil Science and Plant Analysis》2018,49(11):1370-1383
A total of 73 soil samples were initially analyzed for lead (Pb) concentration as an indicator of the environment impact of smelter activity in the Port Pirie, South Australia. Chemometric techniques were used to assess the ability of near-infrared (NIR) reflectance spectroscopy to predict soil Pb using spectrally active soil characteristics such as soil carbon (C). The result indicated a strong linear relationship between log-transformed data of soil Pb and spectral reflectance in the range between 500 and 612 nm with R2 = 0.54 and a low root-mean-square error (RMSEv = 0.38) for the validation mode with an acceptable ratio of performance to deviation and ratio of error range (1.6 and 7.7, respectively). This study suggested that NIR spectroscopy based on auxiliary spectrally active components is a rapid and noninvasive assessment technique and has the ability to determine Pb contamination in urban soil to be useful in environmental health risk assessment. 相似文献
57.
Asia Nosheen Humaira Yasmin Rabia Naz Asghari Bano Rumana Keyani Ishtiaq Hussain 《Soil Science and Plant Nutrition》2018,64(4):520-525
Effective management of the nutrients and enzyme activity in the soil is necessary for maximum crop growth and productivity. However, the excessive use of chemical fertilizers (CFs) not only adversely affects the soil nutrient status and soil physicochemical properties but also aids pollution to the ecosystem. The objective of present study was to investigate the effect of single as well as combined applications of phosphate-solubilizing bacteria and agrochemicals on important soil enzyme activities and their impact on the growth of kasumbha (safflower). Pseudomonas putida (P. putida;106 cells/mL) was applied as seed inoculation prior to sowing, and CFs were applied as full, half, and quarter doses during sowing to modulate the growth of kasumbha host plants. P. putida in combination with half dose of CFs (PH) increased the soil urease and phosphatase activities, while P. putida combined with quarter dose of CFs (PQ) augmented the soil invertase activities. Moreover, the PQ treatment exhibited the maximum colony-forming units of P. putida. Leaf chlorophyll, carotenoids, protein contents, and root lengths were increased by PH treatment. Whereas, shoot length and leaf area were improved by PH and PQ treatments, respectively. Leaf protease activity was enhanced by P. putida in combination with full dose of CFs and PQ treatments, while leaf phosphate contents were significantly improved by PQ treatment. It can be concluded that P. putida in combination with half as well as quarter doses of CFs is a promising approach for the improvement of soil enzyme activities and growth of kasumbha and replacing 50% of the use of CFs. 相似文献
58.
R. U. Khan M. Z. Khan A. Khan S. Saba F. Hussain I. U. Jan 《Journal of plant nutrition》2018,41(4):453-460
The effect of plant-derived humic acid (PDHA) and coal-derived humic acid (CDHA) on wheat growth was tested on two alkaline calcareous soils in pots. Humic acid derived from plant and coal materials was applied at the rate 0 (control), 50 and 100 kg/ha to wheat in pots carrying two soils viz. clayey loam soil and sandy loam soil separately. Data was collected on plant growth parameters such as spike weight, grain and straw weight, and plant nutrients (macronutrients and micronutrients). Results showed that spike weight increased by 19%, 15%, and 26%, and 11% with application of PDHA at the rate of 50 and 100 mg/kg in clayey loam and sandy loam soil, respectively. Grain yield show an increase of 21% and 11% over control with application of PDHA and CDHA at the rate of 50 mg/kg on both soils, respectively, and 10% and 22% with application of PDHA and CDHA at the rate of 100 mg/kg on both soils. 相似文献
59.
Azhar Mehmood Asif Tanveer Muhammad Mansoor Javed Muhammad Ather Nadeem Muhammad Naeem 《Archives of Agronomy and Soil Science》2018,64(2):208-218
Alligator weed (Alternanthera philoxeroides) is the most troublesome invasive weed in transplanted rice ecosystems worldwide. A two-year field study was conducted to estimate economic threshold levels and the season long competitive effect of six alligator weed densities (0, 2, 4, 8, 16, and 32 plants m?2) on yield and quality traits of transplanted rice. A gradual linear incline in dry weight of alligator weed was observed with an increase in its density from 2 to 32 plants m?2. Maximum N (15.93–18.26 kg ha?1), P (15.10–16.46 kg ha?1) and K (16.34–17.81 kg ha?1) uptake by alligator weed was recorded at its density of 32 plants m?2. More micronutrient loss to the tune of 6.53, 47.92, 19.99, and 38.42 mg kg?1 for Cu, Fe, Zn, and Mn, respectively was observed at the same density. Increasing density of alligator weed caused more losses in paddy yield (up to 21.37–23.78%), amylose and rice grain protein contents. According to a nonlinear hyperbolic regression model, maximum paddy yield loss of rice at asymptotic value of alligator weed density was 38.8% during 2011 and 42.4% during 2012. Economic threshold value of alligator weed was estimated 1.5 and 1.3 plants per m2 during 2011 and 2012, respectively. 相似文献
60.
Maria Khan Hassan Munir Maria Kausar Muhammad Mubashar Hussain Ejaz Ashraf 《Archives of Agronomy and Soil Science》2017,63(4):525-535
Sunflower is an important oilseed crop, which shows susceptibility to heat stress. In this study, 63 single cross hybrids were evaluated under heat stress condition for 2 years and compared with the two commercial hybrids. Genotype and genotype × environment (GGE) was used to differentiate single cross hybrids on the basis of multiple traits. GGE biplot showed that several single cross hybrids had higher seed yield potential than standard check. Moreover, seed yield per plant (SYP) was related to pollen viability percentage, showing that achene yield was the product of high gametophytic fertility under heat stress. Hybrids having high seed yield potential under heat stress had lower cell membrane injury. GGE biplot for SYP and its components showed that single cross hybrids were characterized into two major groups. Group I was further characterized into two sub group. Group Ia included hybrids with high 100-SW, while group Ib had the hybrids with high number of seeds per head and head diameter. Group II had the hybrids with high kernel weight and kernel to seed ratio. The hybrids could be recommended according to their potential utilization in the seed industry. 相似文献