全文获取类型
收费全文 | 7944篇 |
免费 | 85篇 |
国内免费 | 14篇 |
专业分类
林业 | 777篇 |
农学 | 246篇 |
基础科学 | 49篇 |
989篇 | |
综合类 | 379篇 |
农作物 | 513篇 |
水产渔业 | 477篇 |
畜牧兽医 | 3855篇 |
园艺 | 216篇 |
植物保护 | 542篇 |
出版年
2022年 | 14篇 |
2020年 | 14篇 |
2018年 | 133篇 |
2017年 | 203篇 |
2016年 | 181篇 |
2015年 | 245篇 |
2014年 | 213篇 |
2013年 | 173篇 |
2012年 | 468篇 |
2011年 | 332篇 |
2010年 | 120篇 |
2009年 | 80篇 |
2008年 | 78篇 |
2007年 | 55篇 |
2006年 | 70篇 |
2005年 | 795篇 |
2004年 | 668篇 |
2003年 | 475篇 |
2002年 | 127篇 |
2001年 | 141篇 |
2000年 | 47篇 |
1999年 | 157篇 |
1992年 | 122篇 |
1991年 | 154篇 |
1990年 | 177篇 |
1989年 | 154篇 |
1988年 | 175篇 |
1987年 | 120篇 |
1986年 | 149篇 |
1985年 | 122篇 |
1984年 | 96篇 |
1983年 | 83篇 |
1982年 | 34篇 |
1981年 | 17篇 |
1980年 | 24篇 |
1979年 | 140篇 |
1978年 | 100篇 |
1977年 | 95篇 |
1976年 | 81篇 |
1975年 | 140篇 |
1974年 | 131篇 |
1973年 | 125篇 |
1972年 | 139篇 |
1971年 | 119篇 |
1970年 | 90篇 |
1969年 | 105篇 |
1968年 | 118篇 |
1967年 | 132篇 |
1966年 | 107篇 |
1965年 | 75篇 |
排序方式: 共有8043条查询结果,搜索用时 15 毫秒
81.
Twenty-nine new records are reported from Turkey. The fungi species, including their macro-and microscopic features and distributions,
are described.
http://www.phytoparasitica.org posting July 14, 2004. 相似文献
82.
Guido?MarchiEmail author Carlo?Viti Luciana?Giovannetti Giuseppe?Surico 《European journal of plant pathology / European Foundation for Plant Pathology》2005,112(2):101-112
Mixtures of wet vegetable wastes (Brassica, carrot or onion) and dry onion waste were composted at 50 °C for 7 days. The incorporation of the raw or composted vegetable waste mixtures into sandy loam, silt and peat soils reduced the viability of sclerotia of S. cepivorum in glasshouse pot bioassays. The reduction in viability was dependent on waste type, rate of incorporation, duration of exposure and soil type. Onion waste was the most effective waste type in reducing sclerotia viability in all three soils. The Brassica and carrot wastes were as effective as the onion waste in silt soil but less effective in sandy loam and peat soil. A 50% w/w incorporation rate of the wastes gave the largest reduction in viability, with an increase in reduction over time. Composted onion waste reduced sclerotia viability under glasshouse and field conditions although the effect was smaller in the field. Composted onion waste incorporated into soil at 50% w/w reduced the incidence of Allium white rot on onion seedlings in glasshouse pot tests. Incidence and control of the disease differed with soil type. The most consistent control was achieved in peat soil whereas no control was observed in silt soil. Incorporation of the waste 2 months prior to sowing or transplanting reduced seedling emergence in sandy loam soil and growth in all three soil types. The potential for field application of composted vegetable wastes as a sustainable method for control of Allium white rot and waste disposal is discussed. 相似文献
83.
Dirk?Jan?van?der? GaagEmail author Gerrit?Wever 《European journal of plant pathology / European Foundation for Plant Pathology》2005,112(1):31-41
Substrates made from rockwool, coir dust, pumice and perlite were compared for conduciveness to Pythium root and crown rot in cucumber under near-commercial conditions. Rockwool slabs of 7 cm height were more conducive to the Pythium disease than coir dust slabs, pumice or perlite under these conditions. Temperature, oxygen concentration and water content were determined in the substrates to explain differences in conduciveness between the inorganic substrates rockwool, pumice and perlite by differences in the physical conditions. Temperature and oxygen concentration could not explain the differences but the higher disease level on rockwool was associated with a much higher water content of this substrate as compared to coir dust, pumice and perlite. Increasing the height of the substrate from 7 to 14 cm greatly decreased the percentage of diseased plants due to the Pythium disease on rockwool but had no effect on the level of disease on perlite when the substrate had been infested 4 cm below the planting hole. This difference in response in substrate height between rockwool and perlite could be explained by a much larger decrease in water content with substrate height in the rockwool than in the perlite substrate. Temperature in the substrates were above 30 °C for more than 6 h on sunny days in June and reached maximum values of 35 °C or more. These temperatures are highly favourable for the pathogen P. aphanidermatum but will have adverse effects on most biocontrol strains. 相似文献
84.
Monika Go?mann Alexandra Scholz Frank Hennig Susanne von Bargen Carmen B��ttner 《Gesunde Pflanzen》2011,63(4):175-182
Fusarium oxysporum and Fusarium proliferatum are important causal agents of crown and root rot of asparagus. In order to detect differences in pathogenicity and aggressiveness, two F. proliferatum and five F. oxysporum single spore isolates from asparagus spears from plantings in Austria and Germany, 55 pure cultures of F. oxysporum from asparagus roots from a planting in Hesse, Germany, and a single F. oxysporum isolate from an asparagus shoot collected in Austria were evaluated in a 28-day quick test on Hoagland??s agar in glass culture tubes. Plantlets were inoculated with spore suspensions from each respective isolate after 14 days of growth under sterile, controlled conditions in a growth chamber. A severity scale was used to assess symptoms on roots two weeks after inoculation. The effects of the single-spore isolates on root and shoot fresh weights of the plantlets were also determined. The pathogenicity of the majority of the F. proliferatum and F. oxysporum isolates included in this study was confirmed. Inoculation with pure and single-spore cultures resulted in elevated disease severity in comparison to non-inoculated controls. In particular, the two F. proliferatum isolates were found to be more aggressive than the F. oxysporum isolates. Moreover, all single spore isolates caused a reduction in fresh weight of roots and shoots in comparison to the controls. With respect to differences among asparagus cultivars, ??Ramos??, was found to be more susceptible than ??Ravel??. Overall, the quick test method was found to be capable of evaluating the pathogenicity and aggressiveness of the tested F. oxysporum and F. proliferatum isolates towards asparagus within 28 days. 相似文献
85.
Persistent BVDV infection in mousedeer infects calves. Do we know the reservoirs for BVDV? 总被引:1,自引:0,他引:1
Uttenthal A Grøndahl C Hoyer MJ Houe H van Maanen C Rasmussen TB Larsen LE 《Preventive veterinary medicine》2005,72(1-2):87-91; discussion 215-9
Bovine virus diarrhoea virus (BVDV)-1f was isolated from a Lesser Malayan Mousedeer in Copenhagen Zoo during a routine screening. Analysis of animals related to the Copenhagen mousedeer revealed that its mother and all siblings were virus positive, a pattern also seen for persistently infected (PI) cattle. BVDV could be transmitted from the PI mousedeer to a calf after indirect contact. The host spectrum for BVDV seems to be even wider than expected; the implications for BVDV control are discussed. 相似文献
86.
John?W.?HornbuckleEmail author Evan?W.?Christen James?E.?Ayars Richard?D.?Faulkner 《Irrigation and Drainage Systems》2005,19(2):145-159
Recent community based actions to ensure the sustainability of irrigation and protection of associated ecosystems in the Murrumbidgee Irrigation Area (MIA) of Australia has seen the implementation of a regional Land and Water Management Plan. This aims to improve land and water management within the irrigation area and minimise downstream impacts associated with irrigation. One of the plan objectives is to decrease current salt loads generated from subsurface drainage in perennial horticulture within the area from 20 000 tonnes/year to 17 000 tonnes/year. In order to meet such objectives Controlled Water table Management (CWM) is being investigated as a possible ‘Best Management Practice’, to reduce drainage volumes and salt loads.During 2000–2002 a trial was conducted on a 15 ha subsurface drained vineyard. This compared a traditional unmanaged subsurface drainage system with a controlled drainage system utilizing weirs to maintain water tables and changes in irrigation scheduling to maximize the potential crop use of a shallow water table. Drainage volumes, salt loads and water table elevations throughout the field were monitored to investigate the effects of controlled drainage on drain flows and salt loads.Results from the experiment showed that controlled drainage significantly reduced drainage volumes and salt loads compared to unmanaged systems. However, there were marked increases in soil salinity which will need to be carefully monitored and managed. 相似文献
87.
Molecular characterization of Pseudomonas syringae isolates from fruit trees and raspberry in Serbia
?arko Ivanovi? Slavi?a Stankovi? Svetlana ?ivkovi? Veljko Gavrilovi? Milan Koji? Djordje Fira 《European journal of plant pathology / European Foundation for Plant Pathology》2012,134(1):191-203
Infection of fruit trees by Pseudomonas syringae is a potentially serious problem that may limit the establishment and sustained productivity of pome and stone fruit orchards in Serbia. To estimate possible diversity of Pseudomonas syringae fruit trees strains, we collected a set of strains in several areas of Serbia. The samples were taken from infected orchards with raspberry, plum, cherry, sour cherry, peach, pear and apple trees. Genetic diversity of P. syringae strains isolated from fruit trees was determined by using SpeI macrorestriction analysis of genomic DNAs by pulsed-field gel electrophoresis (PFGE) and REP-PCR. Molecular analysis showed that most of isolates had unique profiles, with the exception of isolates from plum and cherry that displayed profiles identical to each other and similar to P. syringae pv. morsprunorum. The study presented here clearly demonstrates the discriminative power of molecular techniques in enabling a detailed analysis of the genetic variations between strains of P. syringae from different pome and stone fruit hosts in Serbia. 相似文献
88.
89.
Ying-Hong?Lin Po-Jung?Lai Tao-Ho?Chang Yu-Ling?Wan Jenn-Wen?Huang Jin-Hsing?Huang Pi-Fang?Linda?ChangEmail author 《European journal of plant pathology / European Foundation for Plant Pathology》2014,139(4):721-733
Sorghum is an important drought tolerant crop cultivated for food and fodder purposes. Anthracnose disease caused by Colletotrichum graminicola is a major constraint in sorghum productivity in India. Certain antagonistic fungi, that were isolated in the previous study from the rhizosphere and rhizoplane of perennial grasses in India, were studied for their antagonism in vitro to C. graminicola, root colonization ability and rhizosphere competence. Out of 138 isolates tested, 89 were antagonistic. Fifteen fungal isolates with greater than 70 % in vitro inhibition zone to the pathogen tested positive for root and rhizosphere colonization abilities. Three isolates – Chaetomium globosum isolate 57, Trichoderma harzianum isolate 184 and Fusarium oxysporum (NSF isolate 9) with prominent biocontrol potentials were tested for the control of sorghum anthracnose in greenhouse and field. Chaetomium globosum, Trichoderma harzianum and Fusarium oxysporum isolates decreased seedling mortality, and incidence and severity of disease at different growing stages. They promoted plant growth (dry biomass- 45.3, 40.0 and 46.7 %) and increased yield (grain biomass- 33.3, 23.8 and 49.2 %) respectively, over control in field. The population of the above fungi in soil was moderately high at harvest stage. The present investigation revealed that fungal isolates from rhizosphere and rhizoplane of perennial grasses could be employed to manage anthracnose and enhance plant growth and yield potentialities in sorghum, at the same time. 相似文献
90.
The distribution of olive fruit fly captures with McPhail traps within an olive orchard 总被引:1,自引:0,他引:1
Ioannis?DimouEmail author Constantin?Koutsikopoulos Aristidis?Economopoulos Josef?Lykakis 《Phytoparasitica》2003,31(2):124-131
The spatial distribution of olive fruit flyBactrocera (Dacus) oleae (Gmelin) (Diptera: Tephritidae) field captures with McPhail traps within an experimental orchard was evaluated. Contour maps
were constructed to examine the patterns in the 3-year trapping data. Captures varied widely inside the olive orchard, with
traps suspended on wild olive trees exhibiting the poorest performance. Favorable microclimate, created by a standing water
pool, appeared to be responsible for increased trap captures during the hot summer months. The positive role of the olive
tree fruit load is also discussed.
http://www.phytoparasitica.org posting Feb. 2, 2003. 相似文献