全文获取类型
收费全文 | 153篇 |
免费 | 3篇 |
国内免费 | 8篇 |
专业分类
林业 | 10篇 |
农学 | 12篇 |
20篇 | |
综合类 | 53篇 |
农作物 | 38篇 |
畜牧兽医 | 7篇 |
园艺 | 1篇 |
植物保护 | 23篇 |
出版年
2024年 | 2篇 |
2023年 | 2篇 |
2022年 | 2篇 |
2021年 | 4篇 |
2020年 | 1篇 |
2018年 | 1篇 |
2017年 | 3篇 |
2016年 | 6篇 |
2015年 | 5篇 |
2014年 | 5篇 |
2013年 | 10篇 |
2012年 | 11篇 |
2011年 | 20篇 |
2010年 | 15篇 |
2009年 | 11篇 |
2008年 | 9篇 |
2007年 | 8篇 |
2006年 | 13篇 |
2005年 | 7篇 |
2004年 | 3篇 |
2003年 | 5篇 |
2002年 | 3篇 |
2001年 | 4篇 |
2000年 | 2篇 |
1999年 | 2篇 |
1995年 | 1篇 |
1994年 | 1篇 |
1993年 | 2篇 |
1987年 | 6篇 |
排序方式: 共有164条查询结果,搜索用时 15 毫秒
31.
The role of common milkweed in the lifecycle of the monarch butterfly has increased interest in the presence of this weed in the north central United States. An initial survey conducted in 1999 found that low densities of common milkweed occurred in approximately 50% of Iowa corn and soybean fields. In 2009, common milkweed was present in only 8% of surveyed fields, and the area within infested fields occupied by common milkweed was reduced by approximately 90% compared to 1999. The widespread adoption of glyphosate resistant corn and soybean cultivars and the reliance on post-emergence applications of glyphosate for weed control in crop fields likely has contributed to the decline in common milkweed in agricultural fields. 相似文献
32.
33.
油菜抗除草剂不育系的抗性效应研究 总被引:1,自引:0,他引:1
为探明转育获得的抗除草剂不育系的抗性效应,苗期用不同浓度草甘膦处理抗草甘膦油菜不育系TA6,TA7。结果表明:随着喷药浓度增加,对叶片、茎秆和根的生长表现为不同程度的抑制作用,其中对叶片生长的影响较早且最严重,对茎秆生长的影响较迟,程度相对较轻,对根部生长的抑制作用最小,表现为先抑后扬,但随着时间推移,影响程度逐渐减轻,至喷药60 d后,油菜苗生长基本恢复正常。花期育性调查和套袋自交结果表明,抗性不育系喷施草甘膦除草剂后,育性未受任何影响,TA6,TA7的不育率和不育度均表现正常。 相似文献
34.
为探讨除草剂施用对柑橘园土壤氮转化及温室气体排放的影响,在实验室培养条件下,研究了0年(林地)、种植10年和30年的柑橘园土壤中分别添加除草剂草甘膦和丁草胺后,尿素态氮含量、硝化和反硝化作用以及温室气体排放的变化。研究结果表明,橘园土壤中尿素第1 d的水解率、氮肥硝化率、反硝化作用损失总量以及N_2O和CO_2排放量显著高于林地土壤(P0.05)。与10年橘园土壤相比,30年橘园土壤显著增加了尿素的水解速率、氮肥硝化率和CO_2排放量(P0.05),但二者的反硝化损失量没有显著差异。施用草甘膦和丁草胺都显著促进了林地土壤的尿素水解(P0.05),第1 d尿素态氮含量分别降低11.20%和12.43%;但对3种土壤氮肥的硝化率均没有明显影响。施用丁草胺显著降低了林地土壤的CO_2排放量(P0.05),对两种橘园土壤的CO_2排放没有明显影响,但明显增加了两种橘园土壤的N_2O排放总量(P0.05),分别比不施除草剂增加56.27%和85.41%;施用草甘膦对3种土壤的N_2O和CO_2排放均没有明显影响。可见,草甘膦和丁草胺的施用不会对柑橘园土壤的氮转化过程产生影响,但丁草胺显著增加了柑橘园土壤的N_2O排放。 相似文献
36.
[目的]明确33%草甘膦·精喹禾灵·乙羧氟草醚可分散油悬浮剂对非耕地杂草的最佳使用剂量.[方法]采用田间药效试验研究33%草甘膦·精喹禾灵·乙羧氟草醚可分散油悬浮剂对非耕地杂草的防除效果.[结果]33%草甘膦·精喹禾灵·乙羧氟草醚可分散油悬浮剂200.0~400.0 g/hm2对非耕地杂草有明显的防除效果,茎叶喷雾处理15 d后对试验地杂草的株防效达87.53% ~92.92%,35 d后平均鲜重防效达88.37%~93.89%.[结论]在单子叶杂草大部分6~8叶、阔叶杂草10~ 12叶时采用该制剂进行茎叶喷雾,用量为有效成分990.0~1 980.0 g/hm2(制剂量3 000.0~6 000.0 g/hm2). 相似文献
37.
Luiz H.S. Zobiole Robert J. KremerRubem S. Oliveira Jr. Jamil Constantin 《Pesticide biochemistry and physiology》2011,99(1):53-60
The recently developed “second generation” of Roundup Ready® soybean (RR2) cultivars commercially available for farmers in 2008 were promoted as higher yielding relative to the “first generation” RR cultivars (RR1). Previous studies showed that glyphosate reduced such yield components as photosynthesis, water absorption, nutrient uptake and symbiotic N2 fixation in RR soybean cultivars; however, no data are available regarding the glyphosate effects on these physiological factors in RR2 soybean. Thus, the objective of this research was to evaluate the nutrient accumulation and nodulation of both generations of RR soybeans at different rates of glyphosate applied at various growth stages. In general, increased glyphosate rates and late applications decreased the nutrient accumulation, nodulation, and shoot and root biomass in both RR1 and RR2. All macro- and micronutrients, with exception of N and K, accumulated more in RR1 than RR2. Although this result may be an individual cultivar characteristic, it suggests that the RR2 cultivar was also inefficient in nutrient uptake and translocation or was unable to rapidly recover from potential chelating effects of glyphosate. These studies suggest that applying glyphosate at early growth stages using the lowest glyphosate rate might have less damage on growth and productivity of RR soybeans. 相似文献
38.
39.
In perennial crops like coffee, glyphosate drift exposure can occur multiple times during its commercial life span. Due to limited glyphosate degradation in higher plants, a potential accumulation of glyphosate could lead to increased biological effects with increased exposure frequency. In this study, we investigated glyphosate translocation over time, and its concentration and biological effects after single and multiple simulated spray-drift exposures. Additionally, shikimic acid/glyphosate ratios were used as biomarkers for glyphosate binding to its target enzyme.Four weeks after the exposure, glyphosate was continuously translocated. Shikimic acid levels were linear correlated with glyphosate levels. After two months, however, glyphosate appeared to have reduced activity. In the greenhouse, multiple applications resulted in higher internal glyphosate concentrations. The time of application, however, was more important regarding biological effects than the number of applications both in the greenhouse and in the field. In the field, berry yield, the most important biological response variable, was reduced 26% by the first out of four sequential applications of glyphosate at 64 g a.e. ha−1 each. The three subsequent applications did not reduce yield any further. 相似文献
40.