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1.
Aimed at finding out natural compounds to kill weeds, a plant pathogenic fungus, Botrytis cinerea isolate BC4, was chosen as a source. A significantly polar metabolite, which was different in chromatographic behavior from ABAGE-like metabolite, was isolated from cultural filtrate of the fungus by column chromatography on silica gel, preparative LC, TLC and HPLC. The structure of the metabolite was determined by HPLC-ESI MS, g.l.c, IR, ^1H NMR and hydrolysis. The results showed that this metabolite was quite similar with ABAGS. The bioassay showed the metabolite had inhibition to seed germination of both broadleaf weeds [Amaranthus retroflerus L. and Chenopodium album L.] and gramineae weeds [Digitaria sanguinalis L. Scop and Echinochloa crusgalii L. Beauv]. It also had inhibitory activity to the seedling growth of broadleaf weeds. The bioassay, using Amaranthus retroflexus L. as an indicator, showed that the lowest concentration of the metabolite to inhibit root+sprout growth of A. retroflexus was 0.6 μM, and the concentration for 50% inhibition was 1.3μM.  相似文献   

2.
稻鸭共育对病虫草害及经济效益的影响(英文)   总被引:2,自引:0,他引:2  
[Objective] Study on the effects of rice-duck mutualism on weeds and insects pests and economic benefits of paddy field.[Method] Comparison of the incidence of weeds,sheath blight and insects pest under rice-duck mutualism,conventional cultivation and control treatment,the yield and economic benefits were analyzed under the 3 treatments.[Result] Average occurrence of weeds in rice-duck mutualism group decreased by 2.33 and 52.08 ind/m2 compared with that in conventional cultivation and control treatment;the control rate of mutualism was up to 75% against rice hopper,but just between 25%-60% against rice leaf roller and Chilo suppressalis.The rates of diseased plant and diseased holl against rice sheath blight were higher and disease indices were lower compared with control group.The yield of mutualism group was identical with conventional cultivation,which was greatly higher than that of control group.The results suggested an higher economic benefits and lower cost benefit ratio for rice-duck mutualism treatment.[Conclusion] Rice-duck mutualism gives birth to a positive effect to control the diseases,insect pests and weeds,as well as to economic benefits,providing basis on extension of rice-duck mutualism system.  相似文献   

3.
Tank-mix adjuvant has the potential to improve the weed control efficacy of post-emergence herbicides. In order to study the synergistic effect of adjuvant, the effects of different rates of fomesafen alone or applied methylated soybean oil adjuvant(MSO) were sprayed on redroot pigweed, abutilon and black nightshade under greenhouse condition. The results showed that fomesafen had different performance on the three weeds, and MSO adjuvant could effectively increase the control. The nightshade control was lower than other two weeds with all the fomesafen doses from 131.25 to 506.25 ga.i. · hm-2 with or without adjuvant. The control of abutilon was between the black nightshade and the redroot pigweed, and had better control at 375 ga.i. · hm-2 with adjuvant or 506.25 ga.i. · hm-2 alone or with adjuvant respectively. The results indicated that mixing adjuvant with fomesafen improved the control on weeds, especially at the low rate. Black nightshade was more difficult to control. The redroot pigweed had the most susceptibility to fomesafen alone or with adjuvant.  相似文献   

4.
High temperature stress (HT) is efficient in breaking endo-dormancy of perennial trees. The effects of HT (50°C) on the respiration of dormant nectarine (Prunus persica var. nectariana cv. Shuguang) vegetative buds were evaluated in the research. We found that bud respiration was transiently inhibited by HT and the pentose phosphate pathway (PPP) and the cytochrome C pathway (CYT) were significantly affected. On the substrate level, PPP was activated in the HT-treated buds compared with the control group. However, the activation did mot occur until hours after HT treatment. The tricarboxylic acid cycle (TCA) in both the HT-treated buds and in the control group proceeded at a low level most of the time compared with total respiration. On the electron transfer level, CYT was transiently inhibited by HT but became significantly active in the later stage. CYT operation in the control group exhibited an attenuation process. The alternative pathway (ALT) fluctuated both in the HT-treated samples and in the control. The results suggest that the temporary CYT inhibition and the following PPP activation may be involved in HT-induced bud dormancy release and budburst mechanisms.  相似文献   

5.
Soil flame disinfestation(SFD) is a form of physical disinfestation that can be used both in greenhouses and on field crops. Its use for soil disinfestation in different crop growing conditions makes it increasingly attractive for controlling soilborne pathogens and weeds. But little is known about the effect on weeds and soilbrone diseases. This study reports on greenhouses and field crops in China that determined the efficacy of SFD to control weeds, nematodes and fungi. It also determined the impact of SFD on the soil physical and chemical properties(water content, bulk density, NO_3~–-N content, NH_4~+-N content, conductivity and organic matter) in three field trials. A second generation SFD machine was used in these trials. SFD treatment significantly reduced weeds(87.8%) and root-knot nematodes(Meloidogyne incognita)(98.1%). Plant height and crop yield was significantly increased with SFD treatment. NO_3~–-N and NH_4~+-N increased after the SFD treatment, and there was also an increase in soil conductivity. Water content, bulk density and organic matter decreased significantly in the soil after the SFD treatment compared to the control. Soil flame disinfestation is a potential technique for controlling weeds and diseases in greenhouses or in fields. SFD is a non-chemical, safe, environmentally-friendly soil disinfection method.  相似文献   

6.
7.
Methiopyrisulfuron is a novel sulfonylurea herbicide with good activity for annual broadleaf and gramineal weeds control. Present study was to investigate the effects of organic amendments (including peat (PE), sewage sludge (SS), and humic acid (HA)) on adsorption, desorption and leaching of methiopyrisulfuron in soils. The batch equilibration technique was applied for adsorption-desorption experiments and the leaching was tested through soil column simulated experiments under laboratory conditions. The Freundlich model may well describe adsorption-desorption of methiopyrisulfuron on organic amendments, the natural soil, and amended soils. Organic amendments could not only greatly increase the adsorption capacity of methiopyrisulfuron, but also significantly enhance the hysteresis of desorption of methiopyrisulfuron. The correlations between Kf-ads and organic matter content of amended soils were significant, and the correlations between H and soil organic matter in amended soils with PE, SS, and HA were significant too. The results of soil column experiments indicated that organic amendments greatly decreased leaching of methiopyrisulfuron. This study suggested that PE, SS, and HA could greatly influence environmental behavior of methiopyrisulfuron in soils. Use of organic amendments might be an effective management practice for controlling potential pollution of methiopyrisulfuron to environment.  相似文献   

8.
In order to understand the compsition and structure of herbicidal component of Pythium aphanidermatum,the isolation and structural indentification were researched.The culture filtrate was extracted by ethyl acetate,petroleum,and chloroform with the same volume respectively and the activity of the crude toxin was bioassayed.The toxin was separated by using the method of thin layer chromatography(TLC),then the main fraction was separated by HPLC,and the structure was analyzed by the sepctrum of IR,13C-NMR and 1HNMR.The results showed that the ethyl acetate extracts had the strongest herbicidal activity.Using the method of TLC,the bioassay results showed that the extracts with Rf 0.19 had the strongest effect on weeds and the inhibition to Digitaria sanguinalis and Amaranthus retroflexus reached five levels,and the component was proved to be dimethyl o-phthalate from the spectrum of IR,13C-NMR and 1HNMR,which was one of the components from the toxin,and it had herbicidal activity.  相似文献   

9.
[Objective] It was to study nitrogen use efficiency under the condition of deposition of perennial ryegrass (Lolium perenne L.) and barley (Hordeum vulgare L.), further revealing the difference in gene variation.[Method] A pot experiment was conducted under 3 treatments of rainwater, ammonium-N (aN) and nitrate-N (nN).[Result] In the treatments of aN and nN, the biomass and N contents in plants were obviously higher than those in rainwater treatment, while the largest biomass(36.116 g) was observed in nN treatment. The absorption to aN was best to perennial ryegrass while nN to barley. According to the differential analysis of N content, treatments of both aN and nN was nitrogen superfluous, which led to release excessive N to the atmosphere, and the rainwater treatment and the control were N deficient, the largest N absorption from atmosphere was 0.698 g in rainwater treatment.[Conclusion] Average N use efficiency contributed by atmosphere N deposition ranged from 1.321%-6.116%, while the control of barley had the highest of 6.116%.  相似文献   

10.
The air temperature of Wuli,which is located in seasonal frozen ground zone,is rising by 13 ℃ yearly.This paper discusses the days that each ground layers' temperature lags behind the surface temperature in reaching extremum.The results were shown:The time of each ground layers' lagging days was increasing;the lagging day in warm season was longer than that in cold season;the growth rate of lagging days in warm season was 0.5 d/y,while the growth rate of lagging days in cold season was 0.7 d/y.  相似文献   

11.
本试验采用乙草胺与吡嘧磺隆混用防除稻田杂草,经过1994~1995年小区试验,筛选出防除稗草、野慈菇和萤蔺等一年生及多年生杂草的最佳配比;1996年进行了大区药效试验,防除效果达90%~95%。成本低于丁草胺与吡嘧磺隆混剂。  相似文献   

12.
中国境内外来杂草的特点危害及其综合治理对策   总被引:18,自引:0,他引:18  
中国有外来杂草23科、76属、108种。我国外来杂草的特点表现为来源广泛,以一年生种类为主,近年来入侵的种类较多。外来杂草入侵的原因主要与生境相似度、外来杂草的生态位宽度、繁殖能力以及遗传多样性的改变有关。外来杂草入侵已经对我国各种各样的生态系统和社会经济发展造成明显损害。针对我国外来杂草的危害现状,本文提出了有效治理外来杂草的策略。  相似文献   

13.
对河口低热河谷区辣木林四季杂草种类、群落组成进行调查。结果表明,该辣木林有杂草73种,隶属22科65属,其中外来入侵种19种,占杂草总数的26.0%。通过分析四季主要杂草的优势度得出,春、夏、秋季优势杂草主要是菊科的鬼针草(Bidens pilosa),禾本科的马唐(Digitaria sanguinalis)、十字马唐(Digitaria cruciata)、光头稗(Echinochloa colona)、牛筋草(Eleusine indica)等组成;冬季优势杂草主要有菊科的鬼针草、小飞蓬(Conyza canadensis)、鼠麴草(Gnaphalium affine)、野茼蒿(Gnaphalium affine)组成。其中,鬼针草为常年优势杂草,在四季杂草组成中外来入侵杂草优势明显。  相似文献   

14.
杂草是目前严重影响水稻生产的主要障碍。经田间药效试验确定了37.5%苯.二甲水剂的适用剂量为:防治扁秆藨草、日本藨草、藨草等恶性杂草为3000-3750 mL.hm^-2;防治鸭舌草、慈菇、泽泻、谷精草和狼巴草等一般阔叶杂草则为2250 mL.hm^-2,施药适期是在杂草出齐后开花前排水喷雾茎叶处理,对水稻安全。对扁秆藨草、日本藨草和藨草的防效达98%-100%。  相似文献   

15.
阴山北麓保护性耕作油菜田间杂草控制试验   总被引:2,自引:0,他引:2  
据调查,阴山北麓保护性耕作油菜田初期杂草密度增加,田间杂草发生时间提前,上下茬农田杂草重叠发生,多年生杂草为害加重。采用化学除草、机械除草、人工除草、农业轮作等单因素和多因素除草技术进行研究。结果表明,采用综合除草"深松+高特克+胺苯磺隆+龙拳"和"中耕+高特克+胺苯磺隆+龙拳"除草效果好,杂草株防除率和鲜质量防除率均达90%以上。  相似文献   

16.
紫花苜蓿苗期田间杂草化学防治的研究   总被引:4,自引:0,他引:4  
紫花苜蓿为豆科多年生优质牧草,常常因为苗期杂草危害造成严重减产,甚至导致种植失败。在日光温室、塑料大棚、土坡荒地和基本农田条件下,应用化学除草剂进行防治试验。结果表明,使用化学除草剂播前进行土壤处理、播后苗前进行地表封闭和出苗后进行茎叶处理,均可有效控制紫花苜蓿苗期田间杂草危害。  相似文献   

17.
为了了解青岛地区秋季为害苜蓿生产的主要杂草种类及其发生动态,作者于2012年8~10月在青岛畜牧科技示范园牧草试验基地的人工苜蓿田,采用普查与样线法相结合的方法,调查了主要杂草的发生种类及其生长动态。结果表明:在青岛地区紫花苜蓿田秋季发生的杂草种类有16种(隶属11科),多为夏季1 a生和多年生杂草。出现数量较多、为害较大的杂草种类是以马唐、稗草和狗尾草为主的禾本科,以苍耳为主的菊科,以反枝苋和刺菜为主的苋科,以绿藜为主的藜科和以龙葵为主的茄科,其中优势种为禾本科。自8月开始,禾本科和藜科杂草已经开始结实,基本不再生长;其他科杂草处于苗期、营养期或花期,仍在生长。  相似文献   

18.
江苏金坛茶园春季主要杂草发生危害调查研究   总被引:2,自引:1,他引:1  
采用"M"形9点取样法定块调查,结果表明,金坛茶园春季杂草有40种。其中:禾本科杂草4种,占10.00%;阔叶杂草31种,占77.50%;莎草科杂草1种,占2.50%;其他杂草4种,占10.00%。多年生杂草14种,占35.00%。阔叶杂草中藤本杂草3种,占阔叶杂草的9.68%。分析比较了新、老茶园春季优势杂草的种群种类、数量区别,明确了茶园春季杂草群落组成。春季杂草相对多度大于5%的优势杂草有菵草、一年蓬、猪殃殃、繁缕、野老鹳草、酢浆草、婆婆纳、荠菜、卷耳、泥湖菜、巢菜、小飞蓬、飞廉、鼠麹、早熟禾、碎米荠、附地菜。  相似文献   

19.
3种除草剂对旱地杂草的防效及对烤烟生长的影响   总被引:1,自引:0,他引:1  
为解决杂草严重危害烤烟生产以及人工除草效率低的问题,对湘西州烤烟田间杂草群落进行调查,选择二甲戊灵、砜嘧磺隆、精喹禾灵3种除草剂进行杂草防控试验。结果表明,烤烟旱地杂草以艾蒿、鳢肠、苍耳、双模叶蓼、心叶黄花稔、光头稗、千金子等7种为优势种群,是主要防除对象。烟苗移栽前使用33%二甲戊灵EC1500~3000 mL/hm2,对一年生单、双子叶杂草具有较好的防除效果,但对多年生杂草防效不理想,且对烤烟幼苗有药害并抑制其生长发育,作为芽前除草剂在烤烟生产上应谨慎施用。在烤烟揭膜后定向喷施25%砜嘧磺隆52.5 g/hm2于垄面垄沟,一次施用,能有效防除除香附子外的单、双子叶杂草,且对烤烟的生长发育影响小,可在旱地选择施用。在烤烟揭膜后使用8.8%精喹禾灵525 mL/hm2,对单子叶杂草防效好且持效期长,而对双子叶杂草基本无防效,烤烟生长发育安全,可选择在以禾本科杂草为主的水稻烟田施用。砜嘧磺隆与精喹禾灵混合使用,增效作用不突出。在烟苗移栽后至缓苗期内一旦发现有除草剂危害,通过换苗可缓解或解除药害的影响。  相似文献   

20.
选用50%莠去津WP 4个不同施用浓度,对玉米地一年生杂草和多年生杂草进行药效试验,探索不同浓度的防除效果。结果表明:4种不同浓度对玉米地杂草的防除效果以250 g/667m2防效最佳,其次是200 g/667m2。化学除草取代人工除草,可减轻农民的劳动强度,提高劳动生产率,在农业生产中具有推广价值。  相似文献   

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