南京地区油菜田杂草群东特点及分布规律的研究

利用７级 法调查了南京地区油菜田３１例样点的杂草优势度级，并以其重要值为指标，对３１个样点的杂草群落进行模拟聚类分析。结果表明，受耕作措施，除草剂的施用等因素的影响，南京地区油菜田草群落类型多样化。     

江苏省长江以北地区麦田杂草群落的定量分析

用 7级目测法调查江苏省长江以北地区 6 9个样点的 6 38块麦田共计约 5 4 5hm2 的草害情况 ,数据转化成综合值后 ,进行主成分分析 ,并赋予生态学意义上的解释。研究结果表明 ,决定江苏长江以北地区麦田杂草发生、分布和危害的主要因素是土壤水分、土壤性质 地带性气候因素 ;主成分分析结果表明 ,生境相似 ,杂草群落有趋同性 ;可将 6 9个样点划分为 3个聚类群 ,即沿海旱茬麦类群、内陆旱茬麦类群和稻茬麦类群 ,各聚类群均有相应的优势杂草 ,粘毛卷耳、波斯婆婆纳、刺儿菜、猪殃殃等为沿海旱茬麦田优势杂草 ,内陆旱茬麦田的主要杂草是播娘蒿和麦家公 ,稻茬麦田的杂草优势种为硬草、棒头草 ,并就该地区杂草发生的特点提出了综合治理的建议     

合肥地区油菜田杂草种群分布及生态位特征的初步研究

运用七级目测法对合肥地区三县(肥东县、肥西县、长丰县)的油菜田样点进行了深入的调查,根据相对盖度、相对高度、相对多度等计测重要值、生态位宽度、生态相似系数,结果表明:合肥地区油菜田常见杂草有31种,隶属18个科,生态位宽度前10位的杂草分别是野老鹳草、日本看麦娘、粘毛卷耳、猪殃殃、一年蓬、看麦娘、酸膜叶蓼、罔草、大巢菜、抱茎苦苣菜.各样点间的相似系数较高,由于各杂草间普遍存在生态位的重叠,群落组成的稳定性是相对的.     

直播油菜田重在前期化除

直播油菜田杂草发生规律 稻茬免耕直播油菜田杂草主要有看麦娘、繁缕、碎米荠、雀舌草等杂草。旱茬（前茬为棉花、芝麻、花生等旱作物）免耕直播油菜田杂草主要有猪殃殃、婆婆纳、播娘蒿、小藜、荠菜、野燕麦、篇蓄、麦瓶草、刺儿菜、小旋花等杂草。     

不同调查方法对邗江区小麦田主要危害性杂草的研究分析

通过样方计数法和七级目测法两种方式对邗江区麦田杂草进行系统调查,以确定本地麦田主要危害性杂草,为农技部门科学指导农民开展防除,以及进行针对性的药剂筛选试验提供理论依据。调查结果表明,邗江区麦田主要危害性杂草有日本看麦娘、菵草、看麦娘、猪殃殃、牛繁缕、野老鹳、泥胡菜等,其中日本看麦娘和菵草危害最严重,为本地杂草群落的优势种,硬草已经由主要草害下降为本地麦田次要草害。     

无为市冬小麦田杂草调查及防治对策

为了明确无为市冬小麦田的杂草发生危害情况,指导农民科学防除,研究人员对该地区冬小麦田杂草进行了调查。结果表明,无为市冬小麦田主要危害性杂草有菵草、看麦娘、日本看麦娘、早熟禾、繁缕、阿拉伯婆婆纳、猪殃殃、野老鹳草等。其中,菵草、猪殃殃、繁缕为本地的优势杂草。最后提出防治对策,以期为科学防治杂草提供参考。     

油菜田化学除草剂的选择与应用

1.杂草的种类与现状水田油菜杂草以看麦娘发生危害最重,其次有猪殃殃、繁缕、稻槎菜和婆婆纳等.稻茬免耕直播油菜田主要有看麦娘、繁缕和碎米荠等杂草.旱茬(前作为棉花、芝麻、花生等旱作物)免耕直播油菜杂草主要有猪殃殃、婆婆纳、播娘蒿、荠菜、野燕麦、麦瓶草、刺儿菜和小旋花等杂草.第一出草盛期在9月下旬至11月中旬,第二出草盛期在翌春2月上旬至3月初.一般直播油菜在播后7天～20天达到第一出草高峰,而稻田或棉田移栽油菜,一般在栽后10天～25天达到第一出草高峰.而免耕地油菜出草早且发生量大.     

油菜草害发生特点及防除方法

一、主要杂草种类 江苏省油菜主要是冬播油菜．春播油菜极少．冬播油菜田杂草的发生种类与麦田基本相同．其前茬有旱地茬和稻板茬两种。旱茬油菜主要杂草有：猪殃殃、麦仁珠、婆婆纳、小藜、播娘蒿、荠菜、遏兰菜、离蕊荠、早熟禾、野燕麦、扁蓄、麦瓶草、刺儿菜、小旋花等．部分地区野燕麦危害严重。     

油菜田杂草化学防除技术

一、油菜田杂草种类我国油菜种植分春油菜和冬油菜，冬油菜田分布于长江、黄河流域的四川、贵州、湖南、湖北、浙江、江苏、河南、山东等省，播种面积近500万公顷，约占全国油菜种植面积的90％，是我国主要油菜产区。杂草主要有看麦娘、日本看麦娘、棒头草、稗草、千金子、野燕麦、早熟禾、硬草等禾本科杂草和繁缕、牛繁缕、猪殃殃、雀舌草、碎米荠、播娘蒿、荠菜、大巢菜、通泉草、藜、毛莨、王不留行、麦瓶草等阔叶杂草。稻茬油菜田以看麦娘、日本看麦娘和硬草为主，早作油菜田以野燕麦、猪殃殃、荠菜为主；     

油菜田化学除草方法

一、杂草分布和发生特点1.油菜田杂草分布移栽油菜由于株行间空隙大,前期杂草危害严重;直播油菜容易发生草盖苗,免耕直播油菜田杂草更多。我国油菜杂草可划分为三大区系:(1)稻茬冬油菜田,主要杂草以看麦娘、日本看麦娘为主,其他有猪殃殃、牛繁缕、雀舌草、大巢菜、碎米荠、婆婆纳、棒头草、稻茬菜等。以看麦娘发生危害最为严重。(2)旱作冬油菜田,与棉花、芝麻、     

稻茬油菜田杂草的发生规律及防除

采用拔除法调查稻茬油菜田杂草种类及其出苗动态和发生规律,以人工除草和不除草作对照,考察3种除草剂13.5%草铵膦、油力1+1、10.8%高效氟吡甲禾灵对杂草的田间控制效果。结果表明：在稻茬油菜田中共发现杂草16种,分属10个科,优势种群为早熟禾,亚优势种群为看麦娘、繁缕;杂草于油菜播种后开始出苗,有冬前出苗最高峰和春季出苗次高峰2个出苗高峰;施用草铵膦第8 天后,对总杂草、禾本科杂草、阔叶类杂草等的防效达90%以上,第16、32、64 天后的防效仍可高达90%以上;与不除草相比,施用草铵膦,可使油菜增产约8%。     

农作措施对油菜田杂草的生态控制作用

研究了稻草覆盖、增加作物种植密度及开沟深度等农作措施对油菜田杂草的控制作用。结果表明。稻草覆盖总体控草效果可达85％以以上，使油菜株间光照强度显著上升。增加油菜种植密度，可以增强植株整体竞争能力，对田间杂草的控制效果也逐步提高。油菜田开沟改变了田间的水湿条件，能显著降低田间恶性杂草牛繁缕、看麦娘及茼草的发生数量。农作措施在有效控制田间杂草危害的同时，使油菜产量显著提高。     

广灭灵防除移栽油菜田杂草研究

1998～2000年，广灭灵36CS对油菜田杂草效果及油菜安全性室内盆栽和田间小区试验研究表明：广灭灵是防除猪殃殃、牛繁缕、婆婆纳等油菜田主要阔叶杂草的有效药剂，对油菜较安全。虽易引起油菜白化，但可通过选用耐药力较强的秦油2号、蓉油4号等品种，培育壮秧，大苗移栽，适当延长施药到移栽间隔期等措施来解决；若在油菜移栽前，用广灭灵81～108g/hm^2与乙草胺337.5～450g/hm^2混用，不仅可降低广灭灵用量，而且能明显降低油菜白化率，并能扩大杀草谱，提高防效，促使油菜籽增产。     

Patchy weed distribution and site-specific weed control in winter cereals

Site-specific weed control in winter cereals was performed on the same fields every year over a 5-year period (1999–2003). The most common weeds (Apera spica-venti, Galium aparine, Veronica hederifolia, Viola arvensis) were counted by species, at grid points which were georeferenced and the data were analysed spatially. For weed control, weeds were grouped into three classes: grass, broad-leaved weeds (without Galium aparine), and Galium aparine. Based on weed distribution maps generated by the spatial analyses, herbicide application maps were created and site-specific herbicide application was carried out for grouped and or single weed species. This resulted in a significant reduction in herbicide use. Averaging the results for all fields and years, the total field area treated with herbicides was 39% for grass weeds, 44% for broad-leaved weeds (without Galium aparine) and 49% for Galium aparine. Therefore, site-specific weed control has the potential to reduce herbicide use compared to broadcast application, thus giving environmental and economic benefits.     

Weed growth,herbicide efficacy,and rice productivity in dry seeded paddy field under different wheat stubble management methods

To ascertain the influence of wheat stubble management options and chemical weed control methods on weed growth and productivity of dry direct-seeded fine rice, a two years' field study was undertaken at the Agronomic Research Farm, University of Agriculture, Faisalabad, Pakistan in 2013 and 2014. Different wheat stubble management methods, viz., incorporation, burning and retention were executed during seed-bed preparation. While, herbicide treatments comprised of a weed check, weed free, pendimethalin followed by tank mixture of fenoxaprop p-ethyl+ethoxysulfuron ethyl, and bispyribac sodium followed by tank mixture of fenoxaprop p-ethyl+ethoxysulfuron ethyl. Results revealed that weed control efficacy of both herbicide treatments ranged from 84 to 94%. Herbicide treatments significantly reduced weed density(88–90%) and dry weight(86–88%), while improved the rice growth attributes compared with weed check. Application of bispyribac sodium followed by tank mixture of fenoxaprop p-ethyl+ethoxysulfuron ethyl in stubble retention recorded 226 and 273% increase in kernel yield over weedy check in 2013 and 2014, respectively. In stubble incorporation, pendimethalin followed by tank mixture of fenoxaprop p-ethyl+ethoxysulfuron ethyl was more effective in increasing(256–293%) rice yields over weedy check. Among different treatment combinations, the maximum net benefits(1 397.49~(–1) 472.22 USD ha~(–1)), net returns(636–700 USD ha~(–1)), benefit cost ratio(1.77~(–1).83) and marginal rate of return(2 187–2 330%) were recorded with the application of bispyribac sodium followed by fenoxaprop p-ethyl+ethoxysulfuron ethyl in stubble retention. In crux, application of bispyribac sodium followed by tank mixture of fenoxaprop p-ethyl+ethoxysulfuron ethyl in stubble retention is efficient approach to control weeds, and get maximum rice productivity and net economic returns under dry seeded system.     

上海市郊早春杂草的生态位计测

野外调查了上海市郊261个样地早春杂草的生态重要值,共计出现106种杂草,计测了其中84种主要杂草的生态位宽度和生态位重叠值。以生态位重叠值为指标,采用主坐标排序法(principal axis analysis,PAA)对84种主要杂草的生态位重叠关系进行了二维排序,并分析了主要杂草与伴生种的生态位重叠关系。结果表明:1)生态位最宽的前10种杂草分别为猪殃殃Galium aparine(0.442)、加拿大一枝黄花Solidago Canadensis(0.341)、刺果毛茛Ranunculus muricatus(0.336)、野胡萝卜Daucus carota(0.300)、大巢菜Vicia sativa(0.297)、泽漆Euphorbia beliocopia(0.297)、荠菜Capsella bursa-pastoris(0.292)、野塘蒿Conyza bonarinisis(0.278)、波斯婆婆纳Veronica persica(0.256)、葎草Humulus scandens(0.236);2)与主要杂草猪殃殃生态需求相似的种类主要有波斯婆婆纳、葎草、加拿大一枝黄花、刺果毛茛等,与重要外来杂草加拿大一枝黄花生态相似的主要有春一年蓬、葎草、猪殃殃等,刺果毛茛的主要伴生杂草有野老鹳草、棒头草Polypogon fugax、泥胡菜Hemistepta lyrata等;3)根据生态位重叠关系,84种主要杂草大致可以分为湿生、旱生和草坪杂草3种生态类型。     

油菜茬中稻免耕直播田杂草控制试验与示范简报

对油菜收获后的水稻免耕直播田使用不同除草剂控制杂草的发生,示范试验结果表明:对稗草、异型莎草、陌上菜、节节菜、千金子等杂草的总体株防效和总体鲜重防效分别达到85.05%以上和95.17%以上.每hm2节约成本1500元以上,每hm2产量两优培九除草处理较不除草处理高51.2%.该技术省工省时、节约成本,是一项可行的、值得推广的轻简栽培技术.     

Effect of Bt traits on transgenic rice’s growth and weed competitiveness

Transgene escape could lead to genetically modified rice establishing wild populations in the natural environment and competing for survival space with weeds. However, whether the expression of the Bacillus thuringiensis (Bt) gene in rice will alter the relationship between transgene plants and weeds and induce undesirable environmental consequences are poorly understood. Thus, field experiments were conducted to investigate the weed competitiveness and assess the ecological risk of transgenic Bt rice under herbicide-free and lepidopterous pest-controlled environments. Results showed that weed–rice competition in the direct-sowing (DS) field was earlier and more severe than that in the transplanting (TP) field, which resulted in a significant decrease in biomass and yield in DS. However, conventional Bt and non-Bt rice yield was not significantly different. The weed number, weed coverage ratio, and weed diversity of conventional Bt rice were significantly higher than those of non-Bt rice at the early growth and mature stages, especially in DS plots, suggesting that Bt traits did not increase the weed competitiveness of transgenic rice and had no negative effect on weed diversity. Grain yield and weed number varied between different hybrid rice lines, but those differences were insignificant between Bt and non-Bt rice. The number of insects increased with the increase of weeds in hybrid rice plots, whereas the insect number and diversity did not display a significant difference between Bt and non-Bt rice. Therefore, the ecological risk of transgenic Bt rice is comparable to non-Bt rice.