全文获取类型
收费全文 | 350篇 |
免费 | 6篇 |
国内免费 | 17篇 |
专业分类
林业 | 39篇 |
农学 | 20篇 |
基础科学 | 2篇 |
27篇 | |
综合类 | 117篇 |
农作物 | 49篇 |
水产渔业 | 3篇 |
畜牧兽医 | 52篇 |
园艺 | 18篇 |
植物保护 | 46篇 |
出版年
2023年 | 1篇 |
2022年 | 2篇 |
2021年 | 7篇 |
2020年 | 7篇 |
2019年 | 7篇 |
2018年 | 7篇 |
2017年 | 2篇 |
2016年 | 15篇 |
2015年 | 11篇 |
2014年 | 9篇 |
2013年 | 10篇 |
2012年 | 19篇 |
2011年 | 25篇 |
2010年 | 27篇 |
2009年 | 25篇 |
2008年 | 30篇 |
2007年 | 33篇 |
2006年 | 22篇 |
2005年 | 15篇 |
2004年 | 10篇 |
2003年 | 11篇 |
2002年 | 11篇 |
2001年 | 3篇 |
2000年 | 7篇 |
1999年 | 6篇 |
1998年 | 3篇 |
1997年 | 8篇 |
1996年 | 6篇 |
1995年 | 8篇 |
1994年 | 4篇 |
1993年 | 1篇 |
1992年 | 4篇 |
1991年 | 5篇 |
1990年 | 1篇 |
1989年 | 5篇 |
1988年 | 2篇 |
1987年 | 4篇 |
排序方式: 共有373条查询结果,搜索用时 15 毫秒
61.
南方根结线虫对不同寄主植物侵染能力的比较 总被引:1,自引:0,他引:1
[目的]筛选南方根结线虫的易感寄主。[方法]通过接种试验比较了南方根结线虫对5种寄主植物(黄瓜、番茄、茄子、菠菜及辣椒)的侵染能力。[结果]南方根结线虫对不同寄主植物的侵染能力存在显著差异。黄瓜和番茄的根结百分率显著高于菠菜、茄子和辣椒,黄瓜和番茄根际土壤中2龄幼虫数、雌成虫数及卵块数都显著高于菠菜、茄子和辣椒。[结论]南方根结线虫对黄瓜和番茄的侵染能力显著强于菠菜、茄子和辣椒,为南方根结线虫的易感寄主植物。 相似文献
62.
63.
64.
Yingfang Xiao Lance S. Osborne Jianjun Chen Cindy Mckenzie Katherine Houben Fabieli Irizarry 《Crop Protection》2011,30(12):1635-1642
The twospotted spider mite, Tetranychus urticae Koch (Acari: Tetranychidae), is one of the most important and highly polyphagous pests of vegetables and other crops worldwide. Experiments were conducted in the laboratory and greenhouse to evaluate corn (Zea mays L.) as a banker plant for the predatory gall midge, Feltiella acarisuga (Vallot) (Diptera: Cecidomyiidae) to potentially control T. urticae. Choice and no-choice experiments were carried out to determine the host plant preference of an alternative prey, Oligonychus pratensis (Banks)(Acari: Tetranychidae) to corn and green bean (Phaseolus vulgaris L.). Results showed that O. pratensis adults strongly preferred corn as a host plant and posed no risk to green bean. F. acarisuga was found to fly at least 7.0 m to search for new preys on green bean plants, and over 176 F. acarisuga larvae per leaf were recorded at 14 d after dispersal. F. acarisuga proved to be an excellent predator of both T. urticae and O. pratensis. The predation by F. acarisuga to T. urticae and O. pratensis ranged from 43.7 to 67.9% and 59.2 to 90.3%, respectively, under laboratory conditions. In a non-cage study, 81.2% of T. urticae population was suppressed by F. acarisuga in reference to the control (cage treatment). The results showed that this banker plant system has potential for controlling T. urticae in greenhouse vegetable production. 相似文献
65.
为了研究香蕉根颈象甲在海南香蕉上的产卵特性,指导田间防控技术,室内研究了香蕉根颈象甲成虫对寄主植物、叶鞘部位的产卵选择性及不同饲养方式下的产卵率。结果表明,在巴西蕉和泰国蕉上,香蕉根颈象甲的产卵率分别为32.87%和30.93%,均显著高于台蕉、大蕉、皇帝蕉和粉蕉;香蕉根颈甲成虫嗜好在香蕉假茎中部叶鞘产卵,在第2层叶鞘的选择性最高,选择系数为45.78%,显著高于其它几层叶鞘的选择系数;分别提供腐烂和新鲜的香蕉假茎让香蕉根颈象甲产卵,周平均产卵量分别为4粒和2粒,可见,香蕉根颈象甲喜欢在腐烂的假茎上产卵。 相似文献
66.
对青海省7个地区24个县(市)小麦禾谷孢囊线虫病的发生分布进行了调查。调查结果表明,青海省不同海拔、不同生态区均有小麦禾谷孢囊线虫病的发生分布,平均孢囊样品发生率为72.67%。海拔3501~3900m的青稞种植区孢囊样品发生率最高,达到了100%,2501~3500m海拔区段单位孢囊数最高,200g土样内平均孢囊数达到36.11~35.07个。不同生态区调查显示浅山地区单位孢囊数较高,脑山次之,浅、脑山地区单位孢囊数均明显大于川水地区。小麦禾谷孢囊线虫的主要危害寄主为小麦和青稞。 相似文献
67.
Aleurotrachelus socialis is one of the most important pests of cassava (Manihot esculenta Crantz) in the Neotropics. In Colombia, high whitefly populations can reduce crop yields by 79%; and although the farmers intensify the use of insecticides, this practice is highly contaminating, costly and leads to the development of resistance in the insect. An alternative for managing whitefly populations is to develop genetically resistant varieties. Wild parents of Manihot are a useful source of genes against pests for the cultivated species of cassava. Based on prior research that showed the existence of moderate-to-high levels of resistance to A. socialis in Manihot flabellifolia, a wild species of cassava, this study was proposed to characterize this new source of resistance, evaluating the biology and demographics of A. socialis on eight accessions of M. flabellifolia, a susceptible check (CMC-40) and a resistant (MEcu72) check. The averages of A. socialis longevity and fecundity on the accessions were not significantly different to MEcu72, but different from CMC-40 (P < 0.05). Development time was not significantly different, ranging from 35–40 days on accessions and MEcu72 and 33.5 days on CMC-40 (P < 0.05). In contrast, the population growth rate (rm) was significantly lower on the M. flabellifolia accessions, with Fla 61 standing out with a growth rate 98 and 99% less than that obtained on MEcu72 and CMC-40, respectively. Once the resistant levels have been identified to A. socialis on the M. flabellifolia accessions, interspecific crosses of M. esculenta subsp. M. flabellifolia and backcross programs could be developed to incorporate the desirable characteristics from the wild relatives into elite progenitors of M. esculenta. 相似文献
68.
N.P. Castilla L. Willocquet S. Suwarno S. Santoso A. Nasution Y. Sulaeman S. Savary C.M. Vera Cruz 《Crop Protection》2010
Blast has become a major problem in the upland rice of Indonesia, as the improved resistant varieties with high yield performances released in the 90's became susceptible only a few years after their release. The present study investigated the efficiency of association of susceptible and resistant varieties in reducing leaf and neck blast and increasing yield. Two sets of experiments were conducted in fields with associations through using different proportions of resistant variety, and two types of susceptible variety (moderately and very susceptible) in the association. The efficiency of the association was measured by comparing disease intensity and yield in the variety when grown in association and when grown as a pure stand. ANOVAs and logistic regressions indicated that resistant-susceptible variety association was more efficient in reducing neck blast than leaf blast. Associations were more efficient (1) when the proportion of resistant variety was increased, (2) when a moderately susceptible variety was used instead of a very susceptible variety, and (3) when disease level in the pure stand was higher. Associations did not penalize the performances of the resistant variety, neither in terms of disease intensity, nor yield. Logistic regressions allowed to estimate the probability of a given association to reduce disease (or to increase yield) above a preset threshold, according to the proportion of resistant variety and to the type of susceptible variety. 相似文献
69.
中国柞树主要害虫名录(Ⅱ) 总被引:3,自引:3,他引:0
记述了我国有关鳞翅目(Lepidoptera)钩蛾科(Drepanidae)、尺蛾科(Geometridae)、蓑蛾科(Psychidae)、鹿蛾科(Amati-dae)、枯叶蛾科(Lasiocampidae)、家蚕蛾科(Bombycidae)、大蚕蛾科(Saturniidae)、天蛾科(Sphingoidae)共8个科的柞树主要害虫80种,分别介绍了害虫的中文名称、学名、寄主种类及主要分布区域,为有效控制尺蛾类、枯叶蛾类等柞树主要害虫的发生与危害提供相关的基础信息。 相似文献
70.