首页 | 本学科首页   官方微博 | 高级检索  
相似文献
 共查询到20条相似文献,搜索用时 140 毫秒
1.
2.
This article explores the potential use of multi-spectral high-spatial resolution QuickBird imagery to detect cruciferous weed patches in winter wheat fields. In the present study, research was conducted on six individual naturally infested fields (field-scale study: field area ranging between 3 and 52 ha) and on a QuickBird-segmented winter wheat image (broad-scale study: area covering approximately 263 winter wheat fields, approximately 2 656 ha) located in the province of Córdoba (southern Spain). To evaluate the feasibility of mapping cruciferous weed patches in both the field-scale and broad-scale studies, two supervised classification methods were used: the Maximum likelihood classifier (MLC) and vegetation indices. Then, the best classification methods were selected to develop in-season site-specific cruciferous weed patch treatment maps. The analysis showed that cruciferous weed patches were accurately discriminated in both field-scale and broad-scale scenarios. Thus, considering the broad-scale study, classification accuracies of 91.3 and 89.45 % were obtained using the MLC and blue/green (B/G) vegetation indices, respectively. The site-specific treatment maps obtained from the best classifiers indicated that there is a great potential for reducing herbicide use through in-season, cruciferous weed patch site-specific control on both a field-scale and broad-scale. For example, it can be determined that by applying site-specific treatment maps on a broad-scale, herbicide savings of 61.31 % for the no-treatment areas and 13.02 % for the low-dose herbicide areas were obtained.  相似文献   

3.
Site-specific weed management is defined as the application of customised control treatments only where weeds are located within the crop-field by using adequate herbicide according to weed emergence. The aim of the study was to generate georeferenced weed seedling infestation maps in two sunflower fields by analysing overlapping aerial images of the visible and near-infrared spectrum (using visible or multi-spectral cameras) collected by an unmanned aerial vehicle (UAV) flying at 30 and 60 m altitudes. The main tasks focused on the configuration and evaluation of the UAV and its sensors for image acquisition and ortho-mosaicking, as well as the development of an automatic and robust image analysis procedure for weed seedling mapping used to design a site-specific weed management program. The control strategy was based on seven weed thresholds with 2.5 steps of increasing ratio from 0 % (herbicide must be applied just when there is presence or absence of weed) to 15 % (herbicide applied when weed coverage >15 %). As a first step of the imagery analysis, sunflower rows were correctly matched to the ortho-mosaicked imagery, which allowed accurate image analysis using object-based image analysis [object-based-image-analysis (OBIA) methods]. The OBIA algorithm developed for weed seedling mapping with ortho-mosaicked imagery successfully classified the sunflower-rows with 100 % accuracy in both fields for all flight altitudes and camera types, indicating the computational and analytical robustness of OBIA. Regarding weed discrimination, high accuracies were observed using the multi-spectral camera at any flight altitude, with the highest (approximately 100 %) being those recorded for the 15 % weed threshold, although satisfactory results from 2.5 to 5 % thresholds were also observed, with accuracies higher than 85 % for both field 1 and field 2. The lowest accuracies (ranging from 50 to 60 %) were achieved with the visible camera at all flight altitudes and 0 % weed threshold. Herbicide savings were relevant in both fields, although they were higher in field 2 due to less weed infestation. These herbicide savings varied according to the different scenarios studied. For example, in field 2 and at 30 m flight altitude and using the multi-spectral camera, a range of 23–3 % of the field (i.e., 77 and 97 % of area) could be treated for 0–15 % weed thresholds. The OBIA procedure computed multiple data which permitted calculation of herbicide requirements for timely and site-specific post-emergence weed seedling management.  相似文献   

4.
Field experiments were conducted to determine how a site-specific weed management practice in Zea mays L. influenced the numerical and spatial distribution of a naturally occurring weed infestation in Z. mays and the succeeding Beta vulgaris L. crop. Compared to conventional broadcast herbicide applications, site-specific herbicide applications reduced herbicide load by 11.5 and 98.0% in two separate Z. mays fields. The broad range in outcomes was attributed to the spatial aggregation and density of target weed populations. While herbicide use was successfully reduced at field locations with low weed density, most survivors of multiple control tactics were in locations with the highest initial density. A greater understanding of interactions between weed management and weed density would increase the likelihood that site-specific weed management offers long-term improvements over conventional approaches.  相似文献   

5.
An essential part of the wild blueberry cropping system is the proper management of agrochemical inputs including herbicides, fungicides and insecticides. A machine vision system was developed and mounted on the rear sprayer boom 0.18 m in front of the sprayer nozzles capable of targeting the agrochemical application on an as-needed basis. The three-point hitch mounted sprayer featured 27 nozzles over a 13.7 m boom width and a storage tank capacity of 1135 l. Nine digital color cameras continually take images in real-time while computer software processes the images in 0.15 s to determine the target locations where the nozzles open and spray at speeds up to 1.77 m s?1. Two wild blueberry fields in central Nova Scotia were selected for smart sprayer performance testing with spot-application (SA) of agrochemical as compared to control and uniform application techniques. Chateau® herbicide was applied in a field with an infestation of hair cap moss. Spray droplet comparison showed moss patches were properly targeted using the smart sprayer. SA provided the same coverage performance as compared to uniform on the moss targets with herbicide application savings of 78.5% using the smart sprayer. Harvestable yield results were similar for all application tracks. TruPhos Magnesium and ZincMax foliar fertilizers were tank mixed with Bravo® and Proline® fungicides and applied to compare the difference of SA, control and uniform application. Results showed SA of foliar fertilizer and fungicide led to less premature leaf drop and increased the blueberry stem height, number of branches, stem diameter and fruit buds. SA of foliar fertilizer and fungicide also increased the percent of healthy wild blueberry plants by 57.8% and the harvestable yield by 137.8%. Fungicide application savings using the smart sprayer for SA were 11.6%.  相似文献   

6.
In sugar beet, maize and soybean, weeds are usually controlled by herbicides uniformly applied across the whole field. Due to restrictions in herbicide use and negative side effects, mechanical weeding plays a major role in integrated weed management (IWM). In 2015 and 2016, eight field experiments were conducted to test the efficacy of an OEM Claas 3-D stereo camera® in combination with an Einböck Row-Guard® hoe for controlling weeds. Ducks-foot blades in the inter-row were combined with four different mechanical intra-row weeding elements in sugar beet, maize and soybean and a band sprayer in sugar beet. Average weed densities in the untreated control plots were from 12 to 153 plants m?2 with Chenopodium album, Polygonum convolvulus, Thlapsi arvense being the most abundant weed species. Camera steered hoeing resulted in 78% weed control efficacy compared to 65% using machine hoeing with manual guidance. Mechanical intra-row elements controlled up to 79% of the weeds in the crop rows. Those elements did not cause significant crop damage except for the treatment with a rotary harrow in maize in 2016. Weed control efficacy was highest in the herbicide treatments with almost 100% followed by herbicide band-applications combined with inter-row hoeing. Mechanical weed control treatments increased white sugar yield by 39%, maize biomass yield by 43% and soybean grain yield by 58% compared to the untreated control in both years. However, yield increase was again higher with chemical weed control. In conclusion, camera guided weed hoeing has improved efficacy and selectivity of mechanical weed control in sugar beet, maize and soybean.  相似文献   

7.
江苏省长江以北地区麦田杂草群落的定量分析   总被引:12,自引:0,他引:12  
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  相似文献   

8.
天津麦田杂草化学防除现状和问题   总被引:1,自引:0,他引:1  
介绍了天津麦田杂草发生与危害的现状,总结了麦田杂草化学防除的特点及除草剂的应用现状,并针对其存在的问题提出相应建议,以期对麦田化学除草技术的推广及避免麦田化学除草中出现的问题有所帮助。  相似文献   

9.
通过对天津地区麦田杂草发生现状的调查 ,阐述麦田杂草的危害及优势杂草产生变化的原因 ;结合麦田除草剂应用情况及杂草防除试验 ,探讨以药剂防除为主的防除对策。  相似文献   

10.
11.
Site-specific weed management can include both limiting herbicide application to areas of the field where weed pressure is above the economic threshold (patch spraying) and varying the choice of herbicide for most cost-effective weed control of local populations. The benefits of patch spraying with several, postemergence herbicides in irrigated corn were evaluated in simulation studies using weed counts from 16 fields. Patch spraying with one, two or the number of herbicides that maximized net return for a field was simulated. With patch spraying of one herbicide, the average area of a field left untreated is 34.5%. Net return increases by $3.09 ha−1 compared to a uniform application without decreasing crop yield. Additional herbicides increase the average benefits with just 4% more of the field treated. With two herbicides, the increase in net return is almost tripled and herbicide use is reduced nearly 10-fold compared to patch spraying with one herbicide, and weed control is better than the uniform application in 10 fields. Using more than two herbicides for patch spraying further reduces weed escapes, but herbicide use is greater than a uniform application in 10 fields. Growers might be more willing to adopt patch spraying if more than one herbicide is used in a field.  相似文献   

12.
Young  Douglas L.  Kwon  T. J.  Smith  E. G.  Young  F. L. 《Precision Agriculture》2003,4(2):227-238
A user-friendly computerized agricultural herbicide decision model has been developed for selecting profitable site-specific herbicide applications in winter wheat. The model is based on 6 years of field research in southeastern Washington State, USA. The model calibrates herbicide applications to management unit weed densities, soil organic matter, soil moisture, and preceding management, as well as to expected input and output prices. The model increased broadleaf herbicide rates by an average 0.65 of label rates compared to the recommendations by farmers and weed science professionals, but cut the more expensive grass herbicides by an average 0.56 of label rates. The model increased average projected profitability, excluding model application costs, by 65% compared to four other criteria for determining application rates. The profitability increase relative to local farmers was 19%. Both the model and the cooperating farmers properly chose to use no grass herbicides on the study sites, but the weed science experts chose to use up to 1.0 of label rates. The estimated payoff from using the model substantially exceeded the cost of weed scouting and other information collection. Determining economically optimal sampling and management units is an important challenge for the adoption of precision agriculture models like the one developed in this study.  相似文献   

13.
14.
刘苏闽  王奎萍 《安徽农业科学》2010,38(35):20078-20080
[目的]采用超高茬麦田套稻技术田间杂草危害严重,是其大面积推广应用的主要障碍之一,通过不同药剂的防效试验筛选最佳除草剂。[方法]选用35.5%丁.恶乳油等除草剂在水稻套播后和小麦收割后,用毒土法先后2次处理麦田套播水稻田,调查防效。[结果]除草效果以35.5%丁.恶乳油2 250 ml/hm2最佳,其后依次为30%丁.苄1 500 ml/hm2、50%杀草丹3 000 ml/hm2+10%苄磺隆225 ml/hm2、50%苯噻草胺750 ml/hm2+10%苄磺隆225 ml/hm2,而36%二氯.苄750 ml/hm2效果最差;用药时间越早,对禾本科杂草防效越好,供试药剂持效期均为45 d左右;中、后期可根据田间杂草发生情况辅以茎叶处理,效果更佳。[结论]以稗草和阔叶杂草为主的田块,5种药剂均可使用;以千金子和阔叶杂草为主的田块,除36%二氯.苄750 ml/hm2外,其他4种药剂均可使用;以莎草科和阔叶杂草为主的田块,可用含有苄磺隆的复配除草剂,或单用10%苄磺隆225~300 ml/hm2进行防除。供试药剂均对水稻安全。  相似文献   

15.
除草药肥对麦田杂草防效及小麦生长的影响   总被引:2,自引:1,他引:2  
通过盆钵栽培和田间小区试验 ,研究新型高效复配小麦专用除草药肥对麦田杂草防效和小麦生长发育的影响。结果表明 ,除草药肥对麦田杂草有很好的防除效果 ,并对小麦有较高的安全性。杂草株总防效为 6 5 .3 %~ 92 .7% ,鲜重防效为89.0 %~ 93.5 %。除草药肥能促进小麦生长发育 ,改善经济性状 ,提高产量。盆栽试验增产 9.15 %~ 14 .5 % ,田间试验平均增产率为 9.15 %~ 14 .5 %。  相似文献   

16.
阔叶杂草的危害是显著降低高羊茅(Festuca arundinace)种子产量的主要因子之一,有必要研制对高羊茅种子生产安全和高效的除草剂复配制剂。根据2014-2015年的田间试验结果配制了6种芽前与芽后除草剂的混合制剂。于2015-2016年在上海闵行地区高羊茅种子生产田,以不除草、手工除草、7个单体药剂和1个常用药剂组合共10个处理为对照,对包含6个药剂组合在内的共计16个处理进行了田间试验,鉴定和比较了其治除杂草的功效和对高羊茅种子生产的安全性。试验结果表明,组合4药剂处理的高羊茅籽粒产量最高(604kg/hm~2),显著高于不除草对照(456kg/hm~2)的32%,比手工除草对照(499kg/hm~2)高出21%。其对杂草的治除效果处于中等水平,具有相对株数防效为83%~90%,杀草谱为6种,杂草伤害率为85%。与组合4功效相当值得推广应用的药剂还有组合5和苯磺隆。组合4、组合5和苯磺隆的推广应用将有利于降低高羊茅种子生产的田间杂草管理成本。  相似文献   

17.
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.  相似文献   

18.
在半湿润地区中等肥力土垫旱耕人为土上进行田间试验,通过对冬小麦不同生育期杂草和作物样品的采集与分析,研究不同施肥及杂草处理对氮肥肥效的影响。结果表明:作物吸氮量随施氮量增加而增加,杂草吸氮量随吸氮量增加而降低;在不同杂草处理全生育期不清除杂草(A)、越冬前清除杂草(B)、返青期清除杂草(C)和拔节期清除杂草(D)的各个处理中,A、B、C和D杂草吸氮量分别占农田植物(作物 杂草)地上部分总吸氮量的1.98%、1.39%、3.99%和3.82%。籽粒产量随施氮量增加而增加,施氮量为135 kg N.hm-2时产量最高,达5 645.1 kg.hm-2,施氮量高于135 kg N.hm-2时,产量趋于稳定。氮肥利用率、氮肥利用效率、氮肥农学效率和氮肥生理效率均随施氮量增加而降低;从不同杂草处理看,以全生育期不清除杂草处理氮肥利用率最高,达到43.8%,返青期清除杂草处理氮肥利用率最低,为26.3%,二者间差异达显著水平;氮肥利用效率以越冬期清除杂草处理最高,为42.8 kg.kg-1N,全生育期不清除杂草处理最低,为40.6kg.kg-1N;氮肥生理效率以返青期清除杂草处理最高,为57.5 kg.kg-1N,显著高于其他杂草处理。综合氮效率及产量效率,小麦农田杂草处理时间应该相对较早,以越冬期和返青期清除杂草较好。  相似文献   

19.
探讨除草剂减施对麦田杂草的防治效果,以及对小麦生长过程中叶绿素SPAD值变化的影响。结果表明,药后45 d,10%苯磺隆WP 9.00 g/hm~2处理(减施60.00%)、10%苯磺隆WP 9.00 g/hm~2+5%(唑啉草酯+炔草酯)EC 30.00 g/hm~2处理(减施60.00%)、7%双氟·炔草酯OD 63.00 g/hm~2处理(减施25.00%)和28%唑草·苯磺隆WP 16.80 g/hm~2处理(减施33.33%)对麦田阔叶杂草的鲜质量防效分别为98.64%、98.99%、98.54%和98.68%,表明除草剂减量施用对麦田杂草仍具有较好的防效。施用除草剂后,小麦叶片叶绿素SPAD值呈现先下降再上升的趋势。药后3 d、5 d、7 d,28%唑草·苯磺隆WP 33.60 g/hm~2处理(增施33.33%)小麦叶片叶绿素SPAD值显著低于7%双氟·炔草酯OD 63.00 g/hm~2处理(减施25.00%)、10%苯磺隆WP 9.00 g/hm~2处理(减施60.00%)和空白对照(CK)的叶绿素SPAD值,低于其他处理的叶绿素SPAD值。  相似文献   

20.
设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号