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1.
The diversity and composition of floating weed seed communities were surveyed in 27 sites across the main rice-growing regions in China with the aim of better understanding weed seed dispersal via irrigation water. Seed of 74 species, belonging to 20 families, were identified from floating matter on the water surface in lowland rice fields. Thirty-five species from three families: Poaceae (15), Asteraceae (11), and Polygonaceae (9), accounted for 47% of all species identified. Species with seed maturing in the summer accounted for 64% of the weed seed and their mean relative abundance was 0.74. Species richness, Shannon–Wiener index and Pielou evenness index were significantly different among the floating weed seed communities. The diversity of weed seed communities in the Yangtze river valley was higher than that in other sites, and some sites were dominated by only a few weed species, such as Beckmannia syzigachne , Alopecurus aequalis , A. japonicus , and Polypogon fugax. At all sites, the dominant weed seeds reflected the dominant weed species in the previous crop. The 27 sample sites of weed seed communities can be clustered into two groups on the basis of previous crop, either lowland rice or sites with previous crops of winter fallow, winter wheat or oilseed rape. Canonical correspondence analysis (CCA) revealed that irrigation frequency, previous crop, and latitude, but not soil type or longitude, significantly affected species composition. The numbers of floating weed seed species were high in lowland rice fields; composition was affected by previous crops and irrigation frequency. Filtering irrigation water and collecting and removing floating weed seeds from the water surface could be integrated into weed management practices to control weeds in lowland rice fields. 相似文献
2.
ZE PU ZHANG 《Weed Biology and Management》2003,3(4):197-203
More than 200 species of weeds are infesting main crop fields in China, among which approximately 30 species are major weeds causing great crop yield losses. About 35.8 million hectares of crop fields are heavily infested by weeds and the annual reduction of crop yields is 12.3–16.5% (weighted average). Along with rural economic development, approximately 50% of the main crop fields undergo herbicide application. Chemical weed control has changed cultural practices to save weeding labor in rice, wheat, maize, soybeans and cotton. At the same time, continuous use of the same herbicides has caused weed shift problems and weed resistance to herbicides. Consequently, integrated weed management in main crops is being developed. 相似文献
3.
Rabiatuladawiyah Ruzmi Muhammad S. Ahmad‐Hamdani Baki B. Bakar 《Weed Biology and Management》2017,17(1):3-16
The management of weeds in Malaysian rice fields is very much herbicide‐based. The heavy reliance on herbicide for weed control by many rice‐growers arguably eventually has led to the development and evolution of herbicide‐resistant biotypes in Malaysian rice fields over the years. The continuous use of synthetic auxin (phenoxy group) herbicides and acetohydroxyacid synthase‐inhibiting herbicides to control rice weeds was consequential in leading to the emergence and prevalence of resistant weed biotypes. This review discusses the history and confirmed cases and incidence of herbicide‐resistant weeds in Malaysian rice fields. It also reviews the Clearfield Production System and its impact on the evolution of herbicide resistance among rice weed species and biotypes. This review also emphasizes the strategies and management options for herbicide‐resistant rice field weeds within the framework of herbicide‐based integrated weed management. These include the use of optimum tillage practices, certified clean seeds, increased crop competition through high seeding rates, crop rotation, the application of multiple modes of action of herbicides in annual rotations, tank mixtures and sequential applications to enable a broad spectrum of weed control, increase the selective control of noxious weed species in a field and help to delay the resistance evolution by reducing the selection pressure that is forced on those weed populations by a specific herbicidal mode of action. 相似文献
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5.
Hidejiro Shibayama 《Weed Biology and Management》2001,1(1):53-60
The area of paddy rice fields in Japan was 1.79 million ha in 1998 almost all of which was planted with young seedlings from nursery boxes by a mechanical rice transplanter. Japanese farmers controlled paddy weeds mainly by chemical herbicides, which were applied around 1.8 times in one growing season of rice by sequential treatment. The cost of herbicides was 35 320 ¥/ha on average, the main of which was ‘one‐shot’ herbicides, while weeding labor for the paddy field, including herbicide application, was 19.0 h/ha, or 29 976 ¥/ha in labor cost, in 1998. Under the Integrated Weed Management (IWM) for sustainable paddy rice production, other technologies for weed management are also recommended to paddy farmers, such as ecological or cultural, mechanical, biological methods and so on. 相似文献
6.
我国农田杂草治理技术的发展 总被引：36，自引：0，他引：36
我国稻、麦、玉米、大豆及棉花等主要农作物农田杂草有580种,属于危害重而又难于防除的有17种,受杂草危害较重的农田有3 580万hm2,年平均受草害减产12.3％～16.5％(加权平均)。自1980年以来,全国化学除草面积以年增200万hm2的速度扩大,农田化学除草面积从20世纪70年代早期不到100万hm2扩大到近年来6 000万hm2。本文概述了我国农田主要作物杂草的发生危害、化学除草剂应用现状及其综合防治进展,并提出今后杂草防除的设想与建议。 相似文献
7.
Nooshin Shahbazi Ken C. Flower J. Nikolaus Callow Ajmal Mian Michael B. Ashworth Hugh J. Beckie 《Weed Research》2021,61(1):25-34
Weeds and weed control are major production costs in global agriculture, with increasing challenges associated with herbicide‐based management because of concerns with chemical residue and herbicide resistance. Non‐chemical weed management may address these challenges but requires the ability to differentiate weeds from crops. Harvest is an ideal opportunity for the differentiation of weeds that grow taller than the crop, however, the ability to differentiate late‐season weeds from the crop is unknown. Weed mapping enables farmers to locate weed patches, evaluate the success of previous weed management strategies, and assist with planning for future herbicide applications. The aim of this study was to determine whether weed patches could be differentiated from the crop plants, based on height differences. Field surveys were carried out before crop harvest in 2018 and 2019, where a total of 86 and 105 weedy patches were manually assessed respectively. The results of this study demonstrated that across the 191 assessed weedy patches, in 97% of patches with Avena fatua (wild oat) plants, 86% with Raphanus raphanistrum (wild radish) plants and 92% with Sonchus oleraceus L. (sow thistles) plants it was possible to distinguish the weeds taller than the 95% of the crop plants. Future work should be dedicated to the assessment of the ability of remote sensing methods such as Light Detection and Ranging to detect and map late‐season weed species based on the results from this study on crop and weed height differences. 相似文献
8.
Rice–duck farming is one of the traditional, but current and gradually popularized, ecological farming techniques for paddy rice production in China. In comparison to rice monoculture farming, we investigated a weed community and weed infestation in a transplanted rice–duck farming system and examined the effects of duck activities on the weeds. Three treatments were imposed in the experiment: a rice–duck coculture with duck grazing and disturbance effects, a rice–duck coculture with duck disturbance effects only, and a control (rice monoculture, no duck effects). Rice seedlings were nursed and transplanted in this experiment. The total number of weed species was significantly lower in the treatment with both duck grazing and disturbance and in the treatment with duck disturbance only than in the monoculture rice treatment (control). The Shannon‐Wiener Biodiversity Index of the weed species decreased but the Pielou Evenness Index increased in both treatments with ducks compared to the monoculture control. Sorensen's coefficient of similarity of the weed communities was low between the treatments with ducks and the monoculture control, implying that the weed communities diverged. The total density and biomass of the weed community in both the treatments with ducks were significantly lower compared to the monoculture control. However, compared to the rice monoculture control, the weed biomass was reduced by 98% in the treatment with duck grazing and disturbance and by 84% in the treatment with duck disturbance only, implying that only 14% of the weeds were controlled by duck grazing and that 84% of the weed biomass was inhibited by duck activities in the rice field with ducks. The rice grain yield increased in the treatments with ducks compared to the control. The results suggested that duck activities, like grazing weeds and disturbance of the soil and water, had a significant effect on the weed community structure and that weeds could be well controlled without herbicide application under a rice–duck farming system. 相似文献
9.
3种除草剂对水稻旱直播阔叶杂草防效及安全性研究 总被引：1，自引：0，他引：1
为明确不同除草剂茎叶处理对旱直播水稻田旱生阔叶杂草防除及安全性的影响,采用随机区组试验设计,选用30% 2,4-滴丁酸钠盐AS、84%氯酯磺草胺WG、480 g/L灭草松AS 3种除草剂在水稻4叶期、5叶期施用,施药后每间隔7 d测定杂草株防效、鲜重防效和水稻目测药害,同步测定水稻生长指标和抗逆酶活性。结果表明:30% 2,4-滴丁酸钠盐AS 900.0 g/hm2在水稻4叶期的杂草防效最佳,第28天杂草株防效及鲜重防效仍可达93.55%和96.42%,且对大龄鸭跖草防效显著,施药后水稻生长与人工除草相比无显著差异。叶片SOD、POD活性和MDA含量均先升后降,至施药后28 d恢复正常。30% 2,4-滴丁酸钠盐AS 900.0 g/hm2可高效防除阔叶杂草,该药剂在水稻4叶期和5叶期施用对旱直播水稻安全。 相似文献
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Akihiko Kamoshita Hiroyuki Ikeda Junko Yamagishi Bunna Lor Makara Ouk 《Weed Biology and Management》2016,16(3):93-107
The effects of the planting method (transplanting vs. direct seeding), rice cultivar (Sen Pidao vs. Phka Rumduol), and herbicide application (admixture of bentazone and cyhalofop‐butyl) on weeds and weed seed banks were quantified in unflooded, shallowly flooded, and deeply flooded paddy fields in Cambodia in 2005 and 2006. Broad‐leaved weeds infested more toward maturity in 2006 than in 2005, particularly in directly seeded plots. Weed dry weights at pre‐heading and/or maturity were consistently reduced by herbicide application and Phka Rumduol cultivar, while weed numbers increased under unflooded condition. The proportion of sedges was consistently larger in directly seeded and non‐herbicide plots at pre‐heading. Larger numbers and dry weights of sedges and total weeds in 2005 caused larger seed bank sizes of sedges and total weeds in 2006, which further caused their infestation in 2006. A greater weed dry weight at 62 days after sowing in 2005 resulted in larger seed banks of Cyperus iria and Fimbristylis miliacea, which were most severe under non‐herbicide, direct‐seeded treatment, while that at rice maturity resulted in larger seed banks of Cyperus difformis, Scirpus juncoides, and Lindernia antipoda. Overall, sedges shared the majority of the total weed seed bank, followed by broad‐leaved weeds and then grasses. A lower yield in 2005 led to significantly larger seed bank sizes of sedges, but not of grasses or broad‐leaved weeds. Rice yield reduction was consistently related to larger numbers of sedges by heading and those of grasses at maturity. 相似文献
12.
Competition between weeds and wet season transplanted paddy rice for nitrogen use, growth and yield in the central and northern regions of Laos 总被引：2，自引：0，他引：2
TATSUYA INAMURA SHUICHI MIYAGAWA OLAYVANH SINGVILAY NIVONG SIPASEAUTH YASUYUKI KONO 《Weed Biology and Management》2003,3(4):213-221
To quantify the effect of weeds on the nitrogen (N) use, growth and yield of wet season paddy rice in the central and northern regions of Laos, we surveyed the paddy fields in these regions in October 1999 and November 2000. We found 13 weed species in total, but there were few major weeds abundant at the survey sites. In the infertile soils under rainfed conditions, weed growth was poor. Rough rice yield, the number of panicles, the number of seeds per square meter, the above-ground biomass of paddy rice and the amount of N accumulated in the above-ground biomass of paddy rice (amount of N in rice) were suppressed by competition with weeds. However, harvest index (HI) and nitrogen use efficiency (NUE) of paddy rice were not suppressed by competition with weeds. The amount of N in rice was suppressed by competition with weeds, the number of panicles decreased as the amount of N in rice decreased, and the number of seeds per square meter decreased as the number of panicles decreased. As a result, rough rice yield was suppressed by competition with weeds. The weeds competed with paddy rice for N uptake during the productive tillering stage. However, the ability of paddy rice to compete for N uptake with weeds was not reduced under rainfed lowland conditions. When the weeds were completely removed, the amount of N in rice increased. Rough rice yield may be increased by 10% under rainfed lowland conditions and by 17–19% under irrigated conditions. 相似文献
13.
Micheal DK Owen Hugh J Beckie Julia Y Leeson Jason K Norsworthy Larry E Steckel 《Pest management science》2015,71(3):357-376
There is interest in more diverse weed management tactics because of evolved herbicide resistance in important weeds in many US and Canadian crop systems. While herbicide resistance in weeds is not new, the issue has become critical because of the adoption of simple, convenient and inexpensive crop systems based on genetically engineered glyphosate‐tolerant crop cultivars. Importantly, genetic engineering has not been a factor in rice and wheat, two globally important food crops. There are many tactics that help to mitigate herbicide resistance in weeds and should be widely adopted. Evolved herbicide resistance in key weeds has influenced a limited number of growers to include a more diverse suite of tactics to supplement existing herbicidal tactics. Most growers still emphasize herbicides, often to the exclusion of alternative tactics. Application of integrated pest management for weeds is better characterized as integrated weed management, and more typically integrated herbicide management. However, adoption of diverse weed management tactics is limited. Modifying herbicide use will not solve herbicide resistance in weeds, and the relief provided by different herbicide use practices is generally short‐lived at best. More diversity of tactics for weed management must be incorporated in crop systems. © 2014 Society of Chemical Industry 相似文献
14.
Change in weed control studies of rice paddy fields in Korea 总被引：1，自引：0，他引：1
This paper was reviewed on the research status of weed control according to cultivating patterns of rice in Korea. Weed control study in a nursery bed was chiefly carried out to control the species of barnyardgrass at the times of machine transplanting. Propanil and nitrofen were applied successfully in wet-nursery beds, and chlornitrofen and pyrazolate/butachlor were also successfully applied in protected semi-irrigated rice nursery beds in the 1970s. Sequential application of herbicides in the mid-1980s has resulted in the end of hand weeding. In machine transplanting, basic research such as the selection of herbicides was conducted in the early 1970s, and its related research including crop injury, seedling age, and reaction of cultivars were done in the late 1970s to early 1980s. Effects of the continuous application of herbicides and its methods of labor saving for rice cultivation were studied in the mid to late 1980s. When the rice planting methods were newly established, such as transplanting when seedlings were 10-days-old and direct seeding from the early 1990s, weed control research relating to herbicides was carried out (e.g. herbicide registration, crop injury, water management, appropriate application time, and neighboring application with insecticide). Weed control for the dill seeding of fields in wetted and reclaimed saline land have been experimented with, particularly in terms of the physio-ecological characteristics and the control of problematic weeds, and the resistance of weeds to herbicides was also investigated systematically. 相似文献
15.
SOPHEA PHENG MARIA OLOFSDOTTER GARY JAHN STEVE ADKINS 《Weed Biology and Management》2010,10(3):176-184
There is a general perception among Cambodian rice (Oryza sativa) farmers that, after harvesting, rice crop residues that are incorporated into the field benefit the growth of the subsequent rice crop. However, the effect of this action upon weed establishment and growth has not yet been considered. A series of pot and field trials were conducted to determine whether such action could inhibit weed establishment and/or growth. The pot studies first evaluated the response of the test plant (rice line ST‐3) and three weed species, barnyardgrass (Echinochloa crus‐galli), small umbrella sedge (Cyperus difformis), and water primrose (Ludwigia octovalves), to the residue of 16 rice lines and the field trials were later conducted to evaluate the response of the same test plants to the residue of seven putatively allelopathic rice lines and one non‐allelopathic rice line. The residue of all the studied rice lines, depending on how long they had been incorporated into the soil, reduced the establishment and growth of all three weed species, as well as the rice crop. However, if the residue's incorporation was delayed by 2 weeks or only a proportion of the residue was incorporated, the rice crop could withstand the growth‐inhibiting effect, while the inhibition of the establishment and growth of the three weed species was retained. These responses of rice and the weeds to rice crop residues might provide a basis for a weed management strategy, particularly in the resource‐poor rice‐production systems of Cambodia. 相似文献
16.
Belz RG 《Pest management science》2007,63(4):308-326
Since varietal differences in allelopathy of crops against weeds were discovered in the 1970s, much research has documented the potential that allelopathic crops offer for integrated weed management with substantially reduced herbicide rates. Research groups worldwide have identified several crop species possessing potent allelopathic interference mediated by root exudation of allelochemicals. Rice, wheat, barley and sorghum have attracted most attention. Past research focused on germplasm screening for elite allelopathic cultivars and the identification of the allelochemicals involved. Based on this, traditional breeding efforts were initiated in rice and wheat to breed agronomically acceptable, weed-suppressive cultivars with improved allelopathic interference. Promising suppressive crosses are under investigation. Molecular approaches have elucidated the genetics of allelopathy by QTL mapping which associated the trait in rice and wheat with several chromosomes and suggested the involvement of several allelochemicals. Potentially important compounds that are constitutively secreted from roots have been identified in all crop species under investigation. Biosynthesis and exudation of these metabolites follow a distinct temporal pattern and can be induced by biotic and abiotic factors. The current state of knowledge suggests that allelopathy involves fluctuating mixtures of allelochemicals and their metabolites as regulated by genotype and developmental stage of the producing plant, environment, cultivation and signalling effects, as well as the chemical or microbial turnover of compounds in the rhizosphere. Functional genomics is being applied to identify genes involved in biosynthesis of several identified allelochemicals, providing the potential to improve allelopathy by molecular breeding. The dynamics of crop allelopathy, inducible processes and plant signalling is gaining growing attention; however, future research should also consider allelochemical release mechanisms, persistence, selectivity and modes of action, as well as consequences of improved crop allelopathy on plant physiology, the environment and management strategies. Creation of weed-suppressive cultivars with improved allelopathic interference is still a challenge, but traditional breeding or biotechnology should pave the way. 相似文献
17.
我国水稻田杂草抗药性研究进展 总被引：13，自引：0，他引：13
水稻是我国最主要的粮食作物之一,杂草的危害严重影响了水稻的产量与品质。化学防除仍然是治理水稻田杂草最有效的途径。目前我国水稻田稗属杂草、千金子、马唐、雨久花、野慈姑、异型莎草、耳叶水苋、眼子菜、节节菜、萤蔺等多种杂草对二氯喹啉酸、五氟磺草胺、氰氟草酯、噁唑酰草胺、苄嘧磺隆、吡嘧磺隆、双草醚、噁草酮、乙氧氟草醚等多种常用除草剂产生了抗药性。面对日趋严重的水稻田抗药性杂草的危害,对抗药性杂草进行深入系统的研究以达到科学防治的目的显得尤为重要。本文总结了我国水稻田抗药性杂草的抗药性水平、靶标酶抗药性机理、代谢酶抗药性机理和其他抗药性机理,归纳了抗药性杂草的交互抗性、多抗性发生情况以及抗药性治理现状,分析了我们在杂草抗药性研究与治理方面面临的问题。 相似文献
18.
不同除草剂对稻田杂草群落演替的影响 总被引：7，自引：1，他引：7
为了明确除草剂对稻田杂草群落演替的影响,2001～2004年,连续4年施用7种稻田除草剂控制移栽稻田杂草,每年调查稻田杂草的种类、密度和鲜重,分析稻田杂草种群的变化.结果表明：连续使用同一除草剂对稻田杂草群落演替影响显著,靶标杂草的优势度值与药剂使用年限存在显著的线性或非线性关系：Y=a＋bx或Y=ax^2＋bx＋c;非靶标杂草优势度值与药剂使用年限呈极显著正相关线性关系.不同药剂处理的杂草群落有一定的差异,连续使用二元复配除草剂,杂草群落的均匀度和多样性指数分别为0.40～0.43和1.57～1.84,明显低于单剂处理和对照区,田间主要杂草是陌上菜、水苋、千金子和水莎草,其杂草的鲜重显著低于其它处理. 相似文献
19.
AKIHIKO KAMOSHITA HIROYUKI IKEDA JUNKO YAMAGISHI MAKARA OUK 《Weed Biology and Management》2010,10(4):261-272
Weed infestations are a major cause of yield reduction in rice (Oryza sativa) cultivation, particularly with direct‐seeding methods, but the relationship between weed dynamics and water availability in Cambodian paddy fields has not been documented previously. We surveyed the weed abundance and weed seed banks in the soil of paddy fields with inferred differences in their water regime in 22 farm fields in three provinces of Cambodia in the 2005 and 2006 rainy seasons. We studied rain‐fed lowland fields in upslope and downslope topographic positions and fields at different distances from the irrigation water source inside an irrigation rehabilitation area. The weed seed banks were estimated by seedling emergence in small containers and weed abundance and vigor were estimated by a simple scoring system. The estimated weed seed bank in the top 5 cm of soil ranged from 52.1 to 167 × 103 seeds m?2 (overall mean of 8.5 × 103 seeds m?2) and contained a high proportion (86%) of sedge species, such as Fimbristylis miliacea L. and Cyperus difformis. Several fields had particularly large seed banks, including one near the reservoir. No clear difference was found in the weed seed banks between the irrigated fields that were located close to (upstream) and distant from (downstream) the water source or between the irrigated and rain‐fed lowland fields, but the weed scores were larger in the rain‐fed fields and the downstream fields within the irrigated area. A water shortage during the late growing season in 2005 led to a proliferation of weeds in some fields and an associated increase in weed seedbank size in 2006. However, the weed scores in 2006 were more strongly associated with that year's water conditions than with the weed seedbank size. 相似文献
20.
为明确新型水直播稻田除草剂精噁唑甘草胺以及对照药剂对于直播稻田禾本科杂草的防除效果以及对于水稻及后茬作物的安全性, 于2019年在江西宜春市上高县水稻田进行了大田杂草防效试验以及后茬作物安全性研究。结果表明:8%精噁唑甘草胺OD对于直播水稻田的禾本科杂草具有良好的防除效果, 120 g/hm2 以及200 g/hm2 剂量处理对于禾本科杂草的防效均在88%以上。而且所有处理对于水稻均无药害产生, 实现增产, 并对后茬作物生长安全。综上所述, 新型直播稻田除草剂精噁唑甘草胺对直播水稻田禾本科杂草有良好防除效果, 可以在市场上推广应用。 相似文献