查询词典 weed-cutting

Chenopodium album,Solanum nigrum, and Amaranthus retroflexus were very susceptible to the herbicides. Polygonum persicaria and Abutilon theophrasti were relatively less susceptible to the herbicides, and Lycopersicon esculentum was not susceptible to it. The relationship between reduction rates of weed biomass and PPM values of weed leaves 2,4, and 6 days after treatment was established.

供试的6种杂草对该混剂的敏感性存在显著差异：红心藜Chenopodium album、龙葵Solanum nigrum和反枝苋Amaranthus retroflexus对该混剂最敏感，ED90值分别为47.65、71.67和29.17g/hm2；春蓼Polygonum persicaria和苘麻Abutilon theophrasti敏感，ED90值分别为96.91、114.20g/hm2；而番茄不敏感。

The present study investigatated the effect on the diversification of weed community, including weed abundance, dominance, evenness, biomass, and mean height after mulching straw and intercropping white clover in the tea plantation from 2005 to 2006. The results were as follows: 16 families and 31 species were found in total. In April, the dominant species characterized with slow growth, lower biomass, and less than 30 cm height; in July those who grow faster with higher biomass and height became dominant; In September, these malignant communities reduced, while the oxalis and diffusa characterized with lower biomass and low height gradually increased. In the three seasons, the weed abundance, community diversity and evenness increased, and the dominance, the biomass and average height of weeds remarkably reduced after intercropping white clover and muching straw.

结果表明：茶园共有杂草16科31属31种，春季（4月）以生长速度较慢、生物量小、株高在30 cm以下的杂草为主，夏季（7月）以生长快、植株高和生物量大恶性杂草为主，秋季（9月）恶性杂草开始减少，酢浆草、白花蛇舌草等生物量小、株高矮的杂草逐渐增多；稻草覆盖处理茶园春、夏和秋季3个观测时期杂草物种丰富度、多样性、均匀度等指数均高于清耕对照，优势集中性指数低于清耕对照；间种白三叶草处理春、夏和秋季3个观测时期杂草总数量和生物量均显著低于清耕对照，夏、秋季杂草平均株高显著低于清耕对照；稻草覆盖和间种白三叶草处理春季茶芽重和产量显著高于清耕对照，鲜叶中游离氨基酸含量高于清耕对照，茶叶感官评审得分高于清耕对照处理。

The spraying control system aiming at weed based on machine vision was designed and developed. The index of 2G-R-B is used for segmentation and the method of improved pixel lateral histogram is used for extracting the center of crop row,the method of threthold is also used for identificating between-row weed and BP ANN based on fratal and texture is used for identificating in-row weed. PLC correspondence and performing procedure is desi -gned and developed.

设计和开发了基于机器视觉的麦田除草剂对准喷药控制系统，该系统的视觉子系统首先用过绿的2G-R-B进行植物与土壤背景的分割，其次用改进像素直方图法识别作物中心行，用阈值法识别行间杂草区域，用BP神经网络基于分形和纹理的共同特征识别行内杂草区域，设计并开发了计算机与PLC的通信程序，设计了PLC的运行程序。

The color component of ir was the best for close operation while the other two color component (r+g and r+g+ir) would do a better performance on open operation. Finally, the results of these 3 color components for recognizing weed showed that ir was the best. So, as a conclusion, the color component of ir is best for recognizing weed based on computer vision. Also the operation process for recognizing weed was proposed.6. Supposed an idea on the variable spray mechanism of weedicide.

借助Matlab7.0.1软件对数值量ir和数值组合r+g、r+g+ir进行进一步的分析，在对ir、r+g、r+g+ir图像完成为了去除图像噪声而进行的中值滤波和二值化背景分割后，为消除特定图像细节进行二值形态学操作，通过分别对三个数值量和数值组合的开启和闭合操作结果的比较，发现处理后的数值量ir适合进行闭合操

This weed population had a wider niche breadth, the second widest among 12 major weed populations in weed community, and had bigger niche overlap with Stellaria alsine, Alopecurus acquallis, Malachium aquaticum, Poa annua, Polygonum persicaria and Lapsana apogonoides. In rape, wheat or fallow, B.

在杂草群落中，草的生态位宽度居第2位，说明其有潜在的较强的适应环境的能力；草与雀舌草、看麦娘、牛繁缕、早熟禾、春蓼和稻搓菜等杂草种群的生态位重叠较大，与它们的生态要求比较接近。

The main achievements of the project are as follows: 1 the hypothesis that a decrease in seed mass causes an increase in mean dispersal distance has been tested based on the experiments of weed dispersal by wind. The experimental results partly support the hypothesis. The results will help farmers to make an optimal strategy of weed control; 2 a statistic method for inferring probabilistic distribution function of a random variable has been developed, by which probabilistic distribution functions of weed species dispersal have been determined; 3 the reproduction structure of Bromus sterilis has been studied; 4 a more complex CA model with 25 neighborhood cells were built, which can simulate spread of a weed population. This work promotes developments in both theory and application of CA models; 5 the "mean law" in weed control has been proposed. Accordingly, the algorism of patch spring may be calibrated; 6 the "patch" and "true patch" have been mathematically defined so that herbicide can be efficiently applied; 7 simulation validates that initial configurations of weed will affect dispersal of its population and strategies of controlling it, or its distribution patterns affect its dispersal progresses.

主要完成的工作和取得的成果有：1）用实验证实了重量较轻的杂草种子并不一定飞得比较重的远，其结果有助于农民制订杂草的优化控制策略；2）发展了一种推断随机变量分布函数的统计方法并用它来获得了几个杂草种的扩散分布函数；3）对杂草Bromus sterilis的繁殖结构进行了研究；4）建立了一个具有25邻的较复杂的能模拟杂草扩散的CA模型，并在理论和应用方面促进了CA模型的发展；5）在杂草控制方面提出了&平均法则&，据此可对按块施药方法进行校正；6）精确地定义了&块&和&真块&以便在杂草控制中能更有效地使用除草剂；7）模拟证实杂草种群的初始配置影响其扩散和控制策略，或者格局影响过程。

Using nuclear DNA C-values for 539 angiosperms in China, we examined the variation of these values among growth forms and taxonomic groups and the relationship of these values with invasiveness. Mean DNA C-value of the 539 angiosperm species was 4.06 pg. Mean DNA C-value was(1) significantly lower for woody species (1.84 pg) than for herbaceous species(5.02 pg);(2) significantly lower for 360 dicots (2.20 pg) than for 179 monocots (7.80 pg);(3) significantly lower for annuals (2.78 pg) than for perennials(6.65 pg);(4) significantly lower for 134 weed species (1.93 pg) than for herbaceous non-weeds (6.75 pg) and for several families that have an unusually high proportion of weed species;(5) significantly lower for 47 exotic weed species (1.76 pg) than for 134 native weeds (1.93 pg), but significantly lower than that of "non-weedy" herbaceous species (6.75 pg);(6) lower for weeds than for "non-weedy" species in same genus or family; and (7) in herbaceous species, generally lower for weedy compared to "non-weedy" species, with some exceptions such as Avena fatua, whose DNA C-value is as high as 14.15 pg, contrarily, and some "non-weedy" herbaceous species in Cruciferae and Cucurbitaceae with very low values.

统计了中国境内有分布的539种被子植物的DNA C-值，分析了它们在不同分类群、生活型、倍性、生活史类型以及在杂草和非杂草类群中的分布情况，主要结果如下：(1)539种被子植物DNA C-值平均为4.06 pg，其中木本植物的DNA C-值平均为1.84 pg，低于草本植物的平均值(5.02 pg)；(2)双子叶植物(360种)的DNA C-值平均为2.20 pg，极明显地小于单子叶植物(179种)的平均值(7.80 pg)；(3)1年生植物的DNA C-值平均为2.78 pg，明显小于多年植物的平均DNA C-值(6.65 pg)；(4)134种杂草的DNA C-值平均为1.93 pg，明显小于非杂草草本植物的平均值(6.75 pg)，含杂草较多的科，平均DNA C-值相对较小；(5)统计的47种入侵杂草的DNA C-值平均为1.76 pg，略小于134种杂草的平均DNA C-值(1.93 pg)，极显著地小于非杂草性草本植物(6.75 pg)；(6)以科为单位，不同科的DNA C-值存在着极大的差异；(7)DNA C-值与染色体倍性的关系并不明显，但是，随着倍性的增加，基因组变小；(8)在同一科、属中，与非杂草相比，典型杂草的DNA C-值往往偏小；(9)总体上杂草或杂草性强的植物，它们的DNA C-值比非杂草性植物的要小。

Variation of important value of dominant weed is that in spring and fall the dominant weed is Viola prionantha while in summer it is Digitaria ischaemum. In general management lawn community it is Leymus secalinus that is the dominant weed in spring and fall and Digitaria ischaemum in summer.

管理水平较差的草坪群落中，春季和秋季是早开堇菜占优势，夏季是止血马唐占优势；管理水平一般的草坪群落中春、秋季节是赖草占优势，夏季也是止血马唐占优势；管理水平较好的草坪群落中整个生长季是鼠掌老鹳草、鹅绒委陵菜、赖草占优势，且以鼠掌老鹳草的优势度最大。

When the mevinphos was utilized for a long time in highland barley field, the young-root of next-season cole shortened 1.9~2.0cm and fresh weight decreased 0.13~0.14g per individual plant compared with the control. Low-tillage in time after autumn-harvest showed that the weed seeds in the ground surface were harrowed into the tilth of 0~10cm. Early-low-tillage in spring-sow of the next year induced weed seeds of soil surface to germinate and come out ahead. After 10 days, tillage-sow can decrease about 40% weeds. Compared to the normal plough-row, direct late-tillage-row was postponed 10 days, and can decrease about 30% weeds. In the seedling period or later, rudimental weed seeds were handled with a hoe, which led to better cure and control effects and had more benefits to the young seedling growth and yield of the next-season crop.

研究结果表明：氟乐灵在油菜田长期使用时，土壤残留农药抑制下茬青稞幼根生长，幼根较对照株缩短3.0~3.1cm/株，鲜重量减少0.19~0.20g/株；甲磺隆在青稞田长期使用时，下茬油菜幼根较对照株缩短1.9~2.0cm/株，鲜重量减少0.13~0.14g/株；秋收后及时浅耕可将落入地表的杂草种子全耙入0~10cm耕层内；翌年春播早浅耕可诱发土壤表层的杂草种子提前萌发出苗，10d后耕种，能防除40%左右的杂草株数；较正常播种期推迟10d后直接晚耕播种，可防除30%左右杂草株数；苗期或后期拔出残余杂草种子时，除草效果理想，对下茬作物幼苗生长发育及产量无任何不良影响。

As one kind of the extensive weed killer, Glyphosate is one of the biggest global output agricultural chemical original drug weed killer. It occupies the entire weed killer market 30 % and the first world pesticide sales in continuously many years.

中文摘要嘉磷塞是目前全球产量与使用量最大之杀草剂农药，嘉磷塞作为一种广谱灭生性杀草剂，占整个杀草剂市场总量的30%，连续多年占据世界农药销售额首位。

According to the clear water experiment, aeration performance of the new equipment is good with high total oxygen transfer coefficient and oxygen utilization ratio.

曝气设备的动力效率在叶轮转速为120rpm～150rpm时取得最大值，此时氧利用率和充氧能力也具有较高值。

The environmental stability of that world - including its crushing pressures and icy darkness - means that some of its most famous inhabitants have survived for eons as evolutionary throwbacks, their bodies undergoing little change.

稳定的海底环境─包括能把人压扁的压力和冰冷的黑暗─意谓海底某些最知名的栖居生物已以演化返祖的样态活了万世，形体几无变化。