全文获取类型
收费全文 | 347篇 |
免费 | 22篇 |
国内免费 | 23篇 |
专业分类
林业 | 25篇 |
农学 | 33篇 |
基础科学 | 2篇 |
20篇 | |
综合类 | 134篇 |
农作物 | 23篇 |
水产渔业 | 1篇 |
畜牧兽医 | 43篇 |
园艺 | 15篇 |
植物保护 | 96篇 |
出版年
2023年 | 6篇 |
2022年 | 5篇 |
2021年 | 12篇 |
2020年 | 12篇 |
2019年 | 13篇 |
2018年 | 7篇 |
2017年 | 7篇 |
2016年 | 5篇 |
2015年 | 9篇 |
2014年 | 16篇 |
2013年 | 19篇 |
2012年 | 16篇 |
2011年 | 19篇 |
2010年 | 22篇 |
2009年 | 16篇 |
2008年 | 14篇 |
2007年 | 17篇 |
2006年 | 11篇 |
2005年 | 12篇 |
2004年 | 8篇 |
2003年 | 6篇 |
2002年 | 8篇 |
2001年 | 14篇 |
2000年 | 12篇 |
1999年 | 8篇 |
1998年 | 8篇 |
1997年 | 9篇 |
1996年 | 12篇 |
1995年 | 6篇 |
1994年 | 10篇 |
1993年 | 8篇 |
1992年 | 2篇 |
1991年 | 8篇 |
1990年 | 7篇 |
1989年 | 2篇 |
1988年 | 10篇 |
1987年 | 3篇 |
1986年 | 3篇 |
1985年 | 3篇 |
1980年 | 2篇 |
1979年 | 1篇 |
1978年 | 2篇 |
1977年 | 2篇 |
排序方式: 共有392条查询结果,搜索用时 15 毫秒
31.
A leaf disc bioassay was employed to investigate the influence of host species of deciduous fruit trees, like apple, peach,
plum, cherry and apricot, on the development and reproduction of the hawthorn spider mite Tetranychus viennensis Zacher in the laboratory under conditions of 25±1°C, 60±10% RH and a photoperiod of 16 h: 8 h light: dark. This was done
by determining the duration of each life stage of the mites, the intrinsic rate of population increase (r
m
), mean generation time (T) and net reproductive rate (R
0) of the spider mites on each of the host plant species. Differences in life table parameters of the spider mite among host
plants were analyzed with the jack-knife method. The results indicated that plum might be the best suitable plant for the
spider mite among the plants tested due to shorter developmental period and higher intrinsic rate of increase, whereas cherry
and apricot were least suitable due to their long developmental duration and low intrinsic rates of increase. When the spider
mites were transferred from apple to other fruit trees, negative effects on developmental duration, fecundity and life table
parameters were found in the first generation, but the effects faded out in succeeding generations. When transferred onto
plum and peach, the spider mite adapted to the new hosts in the second generation; however, on cherry and apricot, it adapted
in the third generation.
__________
Translated from Acta Ecologica Sinica, 2005, 27(7) [译自: 生态学报, 2005, 27(7)] 相似文献
32.
为测定应用人工饲养的蜘蛛防治稻飞虱的防治效果及实施该技术的可行性,项目组连续3 a人工饲养并释放蜘蛛,测定了蛛虱比、稻株的被害情况等指标,结果表明,以5 m2为单位,放蛛50、80、150三个不同密度的粽管巢蛛,10 d后防效均可达到84%以上,效果显著。 相似文献
33.
从植物组成抗性与诱导抗性两个方面,回顾了植物抗瘿螨的研究进展。其中,组成抗性研究已较为透彻,本文从遗传、组织结构与形态、代谢产物3个方面进行综述;而诱导抗性从诱导抗性方式论述,主要有瘿螨取食、化学物质诱导和机械损伤3个方面。诱导抗性还有待进一步的深入研究,仍有很大的研究空间。 相似文献
34.
35.
36.
福建省毛竹害螨暴发成因与防治管理对策 总被引:7,自引:0,他引:7
通过对福州市毛竹害螨危害与毛竹产值损失关系的调查 ,推算出福建省毛竹害螨危害造成的经济损失。在全省范围内对毛竹害螨暴发成灾原因进行调查、分析的基础上 ,制定了综合防治措施 ,并针对害螨防治工作中存在的问题 ,提出防治管理对策 相似文献
37.
O. M. B. De Ponti 《Euphytica》1978,27(2):435-439
Summary For several generations subpopulations of the twospotted spider mite were reared on cucumber varieties previously selected as partially resistant. Subsequently resistance tests were carried out in the laboratory and the glasshouse with mites from these subpopulations and concurrently with mites from a basic population reared on a susceptible cucumber line. In these tests neither acceptance nor net reproduction or damage index on the partially resistant varieties depended on the kind of mite populations used as inoculum. Therefore it is concluded that the resistance is genuine. The stability of the resistance is discussed. 相似文献
38.
O. M. B. de Ponti 《Euphytica》1977,26(3):641-654
Summary The relationship between the twospotted spider mite and cucumber has been studied on plants and on leaf disks of a number of varieties with different levels of resistance. Existing laboratory tests are critically discussed and it appears that they are only reliable if many factors are taken into account. A new, more efficient laboratory test for resistance, measuring acceptance and reproduction is described. 相似文献
39.
Elizabeth Keep 《Euphytica》1985,34(2):509-519
Summary In black currant (Ribes nigrum) backcross progenies segregating for resistance to the gall mite, Cecidophyopsis ribis
Westw. (gene Ce from Ribes grossularia L.), and to American gooseberry mildew, Sphaerotheca mors-uvae (Schw.) Berk. (gene Sph
3from R. glutinosum), significant differences in season of leafing out occurred between the resistant and susceptible classes. The data are consistent with the hypothesis that two additive genes, Lf
1and Lf
2, controlled season of leafing out and that Ce and Sph
3 were linked with Lf
1. 相似文献
40.
Summary The inheritance of resistance to the twospotted spider mite and of bitterness in cucumber has been studied in three sets of P1, P2, F1, F2, B11 and B12 of crosses between three bitter, resistant lines and one non-bitter, susceptible line. Resistance to the twospotted spider mite as measured by acceptance and oviposition appeared to be determined by several to many genes, which are inherited mainly in an additive fashion. Bitterness is basically governed by the gene Bi, which, contrary to earlier reports, is inherited in an intermediary way, while the expression of Bi is influenced by additively inherited intensifier genes. Whereas Bi and the bitterness intensifier genes are not related to the resistance factors acceptance and oviposition, they are related to resistance or tolerance as measured by the damage index. This relation is explained by linkage rather than by identity of the genes concerned. Changes in the test methods and breeding consequences are discussed. 相似文献