扁穗牛鞭草人工草地中空心莲子草杂草防除效果研究   总被引：3，自引：0，他引：3  

徐胜  张新全  李建龙 《中国草地学报》2003,25(2):34-37

利用水花生净除莠剂可有效地防除扁穗牛鞭草人工草地中的杂草空心莲子草,平均株防效达26.7%～99.8%,并且在较高防效下药剂对扁穗牛鞭草较为安全。在空心莲子草杂草生长盛期,14%的水花生净乳油以浓度为675ml/hm2～900ml/hm2、各处理对水600ml的防除效果最佳,可达到100%。综合考虑,以525ml/hm2～675ml/hm2的浓度为宜。  相似文献   

蒜地杂草的化学防除（上）     

薛光 《长江蔬菜》1997,(10):1-4

论述了我国蒜地除草剂应用概况，华东地区蒜地杂草有２０科５４种，组成５种不同杂草种群生态区。蒜草醚、旱草灵、乙草胺、恶草灵等对不同品种大蒜的安全性测定结果，蒜草醚、恶草灵、旱草灵安全系数４，乙划是胺，大惠利安全系数为２，嘧黄隆不可在大蒜地应用。  相似文献   

萌前型除草剂对草坪草的影响和杂草防除研究     

王清奎  张志国  孟艳丽 《中国草地学报》2003,25(2):38-41

通过盆栽试验研究了4种萌前型除草剂(禾草净、农思它、施田补、乙草胺)对草坪草生长的影响和杂草防除效果。试验结果表明:除草剂对草坪草生长有不同程度的影响,其中乙草胺对草坪草影响最大,产生了伤害作用,不宜在草坪中使用;各种除草剂对杂草都有不同程度的防除效果,其中农思它和禾草净效果较好,乙草胺对杂草的防除效果最差。  相似文献   

肥胖基因研究进展     

郭晓红  韩晓鑫  周忠孝 《四川畜牧兽医》2003,30(5):35-37

与肥胖有关的基因已发现很多，但ob基因是研究的重点，其表达产物Leptin的作用机制已有较深入的了解。本文主要介绍了ob基因及其产物Leptin的作用机制、生物学效应、Leptin抵抗现象，以及其它与肥胖有关的基因和蛋白。  相似文献   

The rates of maize growth and lignin biosynthesis change after root-applied chalcone     

WEIJUN CHEN  MIN-SOO YUN  FAN DENG  YASUHIRO YOGO 《Weed Biology and Management》2005,5(3):118-122

The effects of root-applied chalcone at 0.15 mmol L⁻¹ on the growth and lignin biosynthesis in maize were investigated. The contents of 4-coumarate: CoA ligase (4CL, EC 6.2.1.12) substrates in maize shoots were increased more rapidly in the samples with chalcone application than in the control and the increase occurred at ≤ 3 h after the application (HAA). The lignin content was reduced by chalcone at ≤ 6 HAA. The shoot growth was suppressed by chalcone at ≤ 9 HAA. Consequently, the results suggest that chalcone suppressed maize growth by inhibiting monolignol biosynthesis.  相似文献   

苏南丘陵区秋播苜蓿适用伴生作物筛选试验   总被引：3，自引：0，他引：3  

戚志强胡跃高  曾昭海傅反生 储国良 《中国草地》2005,27(5):22-28

为解决苏南丘陵区苜蓿苗期的杂草问题,从保护播种入手,在多年生黑麦草、一年生黑麦草、黑麦、小黑麦四种作物共五个品种中寻找适宜的伴生作物.通过对产量、株高、杂草率等多个指标测定分析,筛选出中新830小黑麦、赣选一号黑麦草适于用作苜蓿播种的伴生作物,同时获得两个苜蓿存活率最高的处理：苜蓿（15kg/hm^2）＋中新830小黑麦（150kg/hm^2）撒播及苜蓿（18 kg/hm^2）＋中新830小黑麦（250kg/hm^2）30cm条播.试验还表明撒播方式下,苜蓿播量与其竞争力不成正比。  相似文献   

Effects of winter wheat cultivars and seed rate on the biological characteristics of naturally occurring weed flora   总被引：3，自引：0，他引：3  

N E Korres  & R J Froud-Williams 《Weed Research》2002,42(6):417-428

Summary Differential competitive ability of six winter wheat cultivars and traits that confer such attributes were investigated for a range of seed rates in the presence or absence of weeds for a naturally occurring weed flora in two successive years in split-plot field experiments. Crop height and tillering capacity were considered suitable attributes for weed suppression, although competitiveness is a relative rather than an absolute characteristic. Maris Huntsman and Maris Widgeon were the most competitive cultivars whereas Fresco was the least competitive. Manipulation of seed rate was a more reliable factor than cultivar selection for enhancement of weed suppression, although competitiveness of cultivars Buster, Riband and Maris Widgeon was not enhanced by increased seed rate. Crop densities ranging between 125 and 270 plants m⁻² were found to offer adequate weed suppression. Linear relationships were observed between individual and total weed species dry weight and reproductive structures per unit area.  相似文献   

Effects of weed control practices on surface-dwelling arthropod predators in tomato agroecosystems     

Yardım  Erdal N.  Edwards  Clive A. 《Phytoparasitica》2002,30(4):379-386

Weed control, an important practice in agroecosystems to protect crop production, is usually achieved with herbicides. However, these pesticides are expensive, pose potential risks to the environment, may affect some beneficial organisms indirectly, and decrease overall arthropod biodiversity, including pests and their natural enemies, by removing weeds that might act as hosts or shelters for many organisms. The activity density response of important surface-dwelling arthropod predators (ground beetles [Coleoptera: Carabidae], ants [Hymenoptera: Formicidae] and spiders [Arachnida: Araneae]) to herbicides (trifluralin and paraquat), and to two alternative weed management practices (rye straw mulch and mechanical treatment to maintain weeds below threshold levels, in comparison with an untreated check), was assessed using pitfall traps. The mulch treatment had the greatest effect on activity density, reducing the number of predators trapped significantly (P<0.05). Herbicide use resulted in significant (P<0.05) reductions in the activity density of ground beetles. Most predators were trapped in the check plots — which had the highest weed biomass, followed in turn by numbers trapped in the threshold weed control treatment, the full herbicide application and the mulch treatment plots. http://www.phytoparasitica.org posting July 10, 2002.  相似文献   

Further suppression of<Emphasis Type="Italic">Botrytis cinerea</Emphasis> disease in cucumber seedlings by chitosan-copper complex as compared with chitosan alone     

N. Ben-Shalom  E. Fallik 《Phytoparasitica》2003,31(1):99-102

Chitosan-copper complex compared with chitosan alone enhanced suppression ofBotrytis cinerea rot development on four-true-leaf cucumber seedlings in controlled growth chambers. This paper constitutes the first report of such enhancement. The optimal concentrations for the most effective suppression ofBotrytis development were 0.2 gl ⁻¹ chitosan and 1.6 mmole copper. After 12 days’ incubation, marked and significantly better disease suppression was obtained with chitosan-copper complex (75% suppression) than with chitosan alone. The chitosan-copper complex could be a very promising decay control agent for use in both conventional and organic agriculture. http://www.phytoparasitica.org posting Dec. 18, 2002.  相似文献   

Reduced paraquat translocation in paraquat resistant Arctotheca calendula (L.) Levyns is a consequence of the primary resistance mechanism, not the cause     

C.J. Soar  J. KarotamC. Preston  S.B. Powles 《Pesticide biochemistry and physiology》2003,76(3):91-98

Resistance to paraquat has been studied in detail in many weed species for more than a decade, with the precise mechanism of resistance still unclear. Several studies have indicated that reduced movement of the herbicide to the site of action in the chloroplast is at least partly responsible for endowing resistance. Although paraquat translocation studies have been performed in the past it has been rare for these studies to have been conducted on whole plants in the light, despite early observations which clearly showed that paraquat translocation is minimal unless treated plants are exposed to light. This study has addressed this issue in Arctotheca calendula by tracing the movement of ¹⁴C-paraquat in resistant and susceptible plants in both the dark and light. Differences in paraquat translocation between the resistant and susceptible biotypes of A. calendula were only observed when treated plants were exposed to light. It was observed that paraquat translocation was significantly reduced in the resistant compared to the susceptible biotype when plants were exposed to light but not in the dark. It is postulated that paraquat translocation is dependent on light mediated damage. As paraquat-induced damage is less severe in paraquat resistant plants, overall paraquat translocation is reduced in the resistant biotype.  相似文献