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1.
Many public authorities rely on the use of non‐chemical weed control methods, due to stringent restrictions on herbicide use in urban areas. However, these methods usually require more repeated treatments than chemical weed management, resulting in increased costs of weed management. In order to investigate the efficacy of four non‐chemical weed control methods and glyphosate treatment, experiments were carried out on traffic islands in the growing seasons 2005 and 2006. Three trial sites were each divided into six treatment areas, which were either treated with glyphosate, flame, steam, hot air/flame, hot water or left untreated. The treatments were carried out at regular, predetermined intervals throughout the growing season in 2004, whereas in 2005 and 2006 how many treatments that were required to keep weed cover below a predetermined acceptance level of 2% were investigated. Percentage weed cover was measured every second week using a 75 cm × 75 cm quadrat divided into 100 squares. On the control areas, a rapid increase in weed cover was observed, whereas weed cover could be kept below 2% by 2–7 treatments per year, depending on control method. On average, the following numbers of treatments per year were required: glyphosate 2.5, hot water 3, flames 5, hot air/flames 5.5 and steam 5.5 treatments. The results demonstrate that the weed control should be adjusted to the prescribed quality for the traffic islands by regularly assessing the need for weed control. They also show that tailored treatments can reduce the number of required non‐chemical treatments per year. 相似文献
2.
Reduction in herbicide use in non‐agricultural areas is being imposed by a growing number of governments, triggering the development of alternative strategies for weed prevention and control. This study aimed to determine the weed preventive abilities of different paving types, the required treatment frequency of non‐chemical weed control scenarios on these pavements and the associated weed species composition. A test parking area, constructed with four concrete paving types, was sown with a mixture of dominant weed species. Six scenarios with repeated use of a single weed control method (brushing with waste removal, hot air, selective application of hot water and three scenarios with flaming) and two scenarios with alternating use of brushes and hot air were applied to control the weeds during two growing seasons. Treatments were applied at well‐defined intervention moments, based upon weed development. Over 2 years, the paving types differed in weed coverage (up to a fourfold difference) and required varying treatment frequency (up to a 11‐fold difference) with lowest values for pavings with porous pavers. Within most paving types, up to 28% lower treatment frequencies were found for selective application of hot water, as compared with all other single method scenarios. Shifts in weed composition occurred in plots treated repeatedly with the same technique. Paving type determined the chances for the establishment of different weed species and alternating non‐chemical control methods with different modes of action offered the best opportunity to keep weeds under control. 相似文献
3.
Non‐chemical weed control on pavements needs more frequently repeated treatments than the application of glyphosate and often uses large amounts of fuel. To obtain effective hot water control with minimum energy consumption, an in‐depth study of efficacy‐influencing factors was performed. Three dose–response pot experiments were conducted outdoors to investigate the impact of growth stage (39, 60 and 81 day old), water temperature (78, 88 and 98°C), time of the day (2, 7 and 12 h after sunrise) and treatment interval (2, 3, 4 and 6 week intervals) on hot water sensitivity of seven weed species that are hard to control on pavements. Responses to hot water were quantified by weed coverage and total dry biomass. In general, hot water sensitivity was highest for species with large planophile leaves and lowest for grasses with small erectophile leaves. Most species were twofold to sixfold more sensitive to water at 98°C than at 78 and 88°C, particularly when treated at early growth stages. Among treatment intervals, treating at 3‐week intervals was up to twofold more effective and energy efficient than treating at 6‐week intervals. Sensitivity was about twofold lower in the morning than in the afternoon. For effective control of weeds, while using less fuel, it is recommended to apply hot water in the late afternoon, to operate at high water temperature (98°C) and to treat plants as young as possible at 3‐week intervals. 相似文献
4.
The influence of rain and drought before, and air temperature during, weed control with hot water was studied in laboratory experiments on the test weed Sinapis alba (white mustard). The plants were grown in a greenhouse and treated outdoors. There was no difference in weed control effect when S. alba plants at the four‐leaf stage were treated at the air temperatures 7°C and 18°C. The effective energy dose for a 90% fresh weight reduction was 465 kJ m?2 for both air temperatures. Weed control of S. alba at the four‐ to six‐leaf stage in rainfall above the rainwater run‐off level increased the required effective energy dose by 20% (i.e. 120 kJ m?2) compared with dry plants. A short period of drought just before treatment on S. alba at the two‐ to four‐leaf stage increased the plant fresh weight reduction, which was 22% at low energy dose (190 kJ m?2) and 44% at high energy dose (360 kJ m?2). Hot water weed control should thus be carried out when the plants are drought stressed and avoided when the plants are wet. The air temperature seems to be of little importance in the range 7–18°C. 相似文献
5.
Summary The influence of plant developmental stage in hot water weed control was studied on the test weed Sinapis alba in field experiments. The dose was measured as thermal energy in the hot water (kJ m−2 ) and the response as reduction in plant weight. The energy dose for a 90% reduction in plant weight was 340 kJ m−2 at the two-leaf stage, which is one-third of the energy required for the same reduction at the six-leaf stage. Treatment at an early stage saves energy, increases the driving speed and lowers the costs. Hard surface areas with naturally developed weeds were used to study the required treatment interval and the influence of time of assessment on the reduction in weed cover. The required treatment interval was 25 d on average, which is similar to that of flame weeding. A longer lasting effect requires a higher energy dose. A 50% higher energy dose was needed to obtain a 90% reduction in weed cover that lasted for 15 d instead of 7 d. After 3–4 weeks, hardly any reduction could be recorded because of regrowth of perennial weeds. However, hot water weed control has a potential on urban hard surfaces and railroad embankments, especially where the use of herbicides is restricted. 相似文献
6.
Weed competition and nutrient scarcity often restrict organic cereal production, especially where the availability of livestock manure is limited. While harrowing of annual weeds and legume cover crops can be used, these methods are both executed in early spring and may hinder each other. Two cycles of a 2‐year crop rotation were carried out in south‐east Norway (60°42′N, 10°51′E, altitude 250 m) with weed harrowing and undersown cover crops (WHCC) at two fertiliser rates (40 and 100 kg nitrogen ha?1). The effect of the WHCC treatments was measured by weed density and species, weed biomass, changes in weed seedbank and grain yield. The weed density depended on the interaction between WHCC, fertiliser and year. On average, pre‐emergence weed harrowing reduced weed density by 32% and weed biomass by 49%, while pre‐ and post‐emergence weed harrowing reduced weed density by 59% and weed biomass by 67% compared with the untreated control. Spergula arvensis became more abundant at low rather than at high fertiliser rates. On average, white clover cover crop sown after pre‐emergence weed harrowing resulted in the highest yields for both oat (+12.1%) and wheat (+16.4%) compared with the untreated control. Despite differences in weed population density and biomass among WHCC treatments within years, the weed biomass, weed density and seedbank increased for all WHCC treatments over the 4‐year period. More research is required into improving the efficacy of mechanical and cultural weed suppression methods that organic systems rely on. 相似文献
7.
We evaluated whether new information could be drawn from additional data collection and unconventional statistical analyses of an on-farm trial. First, we compared a conventional sampling method using a biomass estimate of weed abundance to repeated visual assessment of the percentage ground cover of weeds. The biomass was sampled once after the treatment, whereas the ground cover was repeatedly sampled once before weed control plus several occasions after weed control. Second, we contrasted the outcomes from analysis of variance ( anova ), taking samples from a single point in time with repeated measures (rm) anova and a multivariate method. As the outcomes and conclusions drawn were relatively similar, we conclude that the ground cover estimate of weed abundance was as reliable as the biomass estimate. The rm anova enabled us to follow the temporal trend in response to treatments in the most abundant species, including possible initial differences. Multivariate analysis went even further, by clearly displaying species-wise responses and treatment selectivity. 相似文献
8.
Agronomic evaluation of precise mechanical hoeing and chemical weed control in sugar beet 总被引：1，自引：0，他引：1
Most herbicide applications to sugar beet (Beta vulgaris L.) are made to the whole crop area, but there is the opportunity to restrict applications to the crop row, decreasing the usage of herbicide by up to 70%. However, this would require greater use of mechanical weed control between rows. Experiments were performed in two seasons to evaluate the weed control performance of a novel, vision‐guided, inter‐row hoe in sugar beet crops grown on a peat fen soil. Hoe lateral placement was within ±30 mm. A precise hoeing and band spraying treatment was compared with overall herbicide use, and with treatments in which the herbicide applications were replaced by hand weeding to minimize competition between crop and weeds. Two hoe passes were made in each season, at crop growth stages of two and 10–12 true leaves in the first season and four and eight true leaves in the second season. Plant population density was not affected by treatment, indicating that none of the treatments caused crop plant loss. Use of the guided hoe controlled weeds better than overall spraying. Crop yields were not significantly different between treatments, indicating that weed control prevented competition with the crop in all treatments. 相似文献
9.
10.
B Bukun 《Weed Research》2004,44(5):404-412
Field studies were conducted over 4 years in south‐eastern Turkey in 1999–2002 to establish the critical period for weed control (CPWC). This is the period in the crop growth cycle during which weeds must be controlled to prevent unacceptable yield losses. A quantitative series of treatments of both increasing duration of weed interference and of the weed‐free period were applied. The beginning and end of CPWC were based on 5% acceptable yield loss levels which were determined by fitting logistic and Gompertz equations to relative yield data representing increasing duration of weed interference and weed‐free period, estimated as growing degree days (GDD). Total weed dry weight increased with increasing time prior to weed removal. Cotton heights were reduced by prolonged delays in weed removal in all treatments in all 4 years. The beginning of CPWC ranged from 100 to 159 GDD, and the end from 1006 to 1174 GDD, depending on the weed species present and their densities. Practical implications of this study are that herbicides (pre‐emergence residual or post‐emergence), or other weed control methods should be used in Turkey to eliminate weeds from 1–2 weeks post‐crop emergence up to 11–12 weeks. Such an approach would keep yield loss levels below 5%. 相似文献
11.
Planning effective weed control in cropping systems requires exact appraisal of the weed intensity and duration of their competition with the crops. This 2‐year study was carried out in order to determine the critical weed control period in sesame fields. Related and relative crop yields were monitored and analyzed using a four‐parametric log‐logistic model. We recorded data from weed‐free plots and compared these with data from different periods of weed interference. In both the study years, the longer period of weed interference decreased the relative yield of sesame, whereas the yield was increased with increasing duration of the weed‐free period. A 51–78.7% decline in sesame yield was noted if the weeds were allowed to compete with the crop from planting to harvest. In the first year, the duration of the critical period for weed control (CPWC) was 177–820 growing degree days (GDD), which corresponded to 14–64 days after crop emergence (DAE), and between 170 and 837 GDD (13–64 DAE) in the second year; this was based on a 5% acceptable yield loss. The results of this study clearly elaborated that maintaining weed‐free conditions is compulsory from as early as the second week after the emergence of sesame plants, and this should be maintained at least until the ninth week to avoid sesame yield losses by more than 5%. These findings show that growers can benefit from CPWC to improve weed control in sesame production, including the efficacy of a weed control program and its cost. 相似文献
12.
S CHRISTENSEN H T SØGAARD† P KUDSK‡ M NØRREMARK§ I LUND¶ E S NADIMI¶ & R JØRGENSEN¶ 《Weed Research》2009,49(3):233-241
Site-specific weed control technologies are defined as machinery or equipment embedded with technologies that detect weeds growing in a crop and, taking into account predefined factors such as economics, take action to maximise the chances of successfully controlling them. In this study, we describe the basic parts of site-specific weed control technologies, comprising weed sensing systems, weed management models and precision weed control implements. A review of state-of-the-art technologies shows that several weed sensing systems and precision implements have been developed over the last two decades, although barriers prevent their breakthrough. Most important among these is the lack of a truly robust weed recognition method, owing to mutual shading among plants and limitations in the capacity of highly accurate spraying and weeding apparatus. Another barrier is the lack of knowledge about the economic and environmental potential for increasing the resolution of weed control. The integration of site-specific information on weed distribution, weed species composition and density and the effect on crop yield, is decisive for successful site-specific weed management. 相似文献
13.
Evyatar Asaf Gal Rozenberg Itai Shulner Hanan Eizenberg Ran Nisim Lati 《Weed Research》2023,63(2):102-114
Increased demand for pesticide-free food and the development of herbicide-resistant weed populations have created a need for non-chemical weed-control tools. A candidate mechanical tool for controlling weeds in the seeding line (intra-row zone) is the finger weeder. This study thus aimed to evaluate the safety and weed-control efficacy of the finger weeder in various irrigated field crops. Eight field trials were conducted in processing tomato, sweet corn, sunflower, cotton, and beetroot over 2 years. The finger weeder treatments were applied as the sole weed-control method (single or double treatments) and in combination with herbicides. A mini meta-analysis was used to evaluate the overall effect of the finger weeder treatments on crop stand and yield and on weed control efficacy. Weed density in the control not treated with herbicides nor a finger weeder ranged between 2 and 62 weeds m−2. The finger weeder treatments resulted in a significant reduction in weed density, which ranged between 40% and 90%. The weed density following the double finger weeder treatment was not significantly different from that for the conventional herbicide-based treatment (p = 0.32) and could therefore be considered as an effective environmentally friendly alternative. Furthermore, a single FW treatment integrated with herbicide application gave better weed control than the conventional herbicide treatment (p = 0.04). This treatment was safe for the crops with no significant stand (p = 0.19) or yield (p = 0.29) reductions compared to commercial treatment. The results of this study demonstrate the promise of the finger weeder as an effective tool within integrated weed management systems for conventional agro-systems. The tool offers a rational weed-control solution for sustainable systems under irrigation. 相似文献
14.
K Rasmussen 《Weed Research》2002,42(4):287-298
Summary Injection of liquid manure (slurry) into the soil is an alternative to the traditional surface application. By the injection method, it is possible to place nutrients closer to the crop sown, thus offering the crop a competitive advantage over weeds. This study compares the response in crop yield, weed density and weed biomass to injection vs. surface application of liquid manure through three growing seasons in barley and oats. The manure applications were combined with treatments of weed harrowing or herbicide spraying or no treatment at all. The levels of weed control and crop yield obtained by harrowing and herbicides were larger when slurry was injected compared with surface application. Without any weed control treatments, the injection method decreased the final weed biomass in barley. The influence of nutrient injection on yield and weed control seemed to be modulated by the time of emergence and the early growth rate of the crop relative to weeds. Thus, because of its early root growth and development, barley responded more quickly to the injection treatment than oats. Consequently, barley became a more competitive crop. 相似文献
15.
BUJAR HUQI KICO DHIMA IOANNIS VASILAKOGLOU REMZI KECO FATBARDH SALAKU 《Weed Biology and Management》2009,9(4):276-285
Weed flora were surveyed during 2000 and 2001 in 10 established olive groves that were located in the area of Vlora, in south‐western Albania. The effectiveness of six weed management treatments (soil tillage, straw mulch, cover cropping [a mixture of rye with peas], and grazing, as well as glyphosate and diuron application) on the weed flora, olive yield, and fruit quality also were investigated in two locations during 2000, 2001, and 2002. More than 80 weed species were recorded, representing a total of 14 families, in which the families Poaceae, Fabaceae, Asteraceae, Ranunculaceae, and Rosaceae predominated. The glyphosate application provided the highest and most consistent level of weed control, whereas diuron achieved sufficient weed control. The straw mulch provided acceptable weed control but the cover crop and the grazing did not sufficiently control the weeds. The highest fruit and oil yields were produced by the trees treated with the straw mulch as a result of the highest mean fruit weight in each year, followed by the soil tillage treatment. However, the olive trees in the plots treated with glyphosate or grazing provided lower or equal, respectively, fruit and oil yields than did those in the untreated plots (control). The results indicated that certain non‐chemical weed control methods, such as straw mulch, can be implemented successfully in established olive groves, providing satisfactory control of weeds and promoting the highest fruit and oil yields. 相似文献
16.
Impact of wetting agents,time of day and periodic energy dosing strategy on the efficacy of hot water for weed control 
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下载免费PDF全文 To further increase the cost‐effectiveness and sustainability of hot water weed control, the further optimisation of hot water efficacy is needed. Therefore, three dose–response experiments were carried out to evaluate the impact of wetting agents (an ethoxylated triglyceride, an esterified rapeseed oil and a liquid linseed oil‐based soap), time of day (2, 4, 6, 8, 10 and 12 h after sunrise) and treatment frequency (1–6 treatments in a 12 week period) on the hot water sensitivity of prevalent weed species (Lolium perenne, Festuca rubra, Taraxacum officinale and Plantago major) on public pavements. Generally, wetting agents did not improve hot water sensitivity. Taraxacum officinale with large planophile leaves showed a higher sensitivity than grasses with an erectophile growth habit. Festuca rubra was more sensitive than L. perenne due to its high leaf dry matter content. The plant species were most sensitive to hot water in the afternoon. This variation in sensitivity during the day was related to the variation in leaf thickness and dry matter content. In general, hot water weed control was highly efficient when conducted four times in a 12 week period at an energy dose of 589 kJ m?2. 相似文献
17.
Shan Huang Xiaohua Pan Yanni Sun Yi Zhang Xiaoning Hang Xichu Yu Weijian Zhang 《Weed Biology and Management》2013,13(1):10-18
The vegetation cover during the non‐cropping season could have important implications for the maintenance and recovery of soil fertility, as well as for biodiversity conservation in croplands. In this study, five fertilization regimes (control: non‐fertilization; N: inorganic N fertilization; P: inorganic P fertilization; NPK: balanced fertilization with inorganic N, P and K; NPKM: balanced NPK plus farmyard manure) were conducted from 1981 in a double‐rice (Oryza sativa L.)‐cropping system in subtropical China. The effects of long‐term fertilization were investigated on the weed growth, diversity and community structure during the fallow period. The results showed that, relative to the control, both inorganic fertilization alone (N, P and NPK) and NPKM in the rice‐growing season significantly increased the weed density and biomass during the fallow period in the paddy field. There was no significant difference in the weed species richness (the number of species) among the treatments. Compared with the control, fertilization tended to reduce the weed diversity (Shannon's H′) and evenness (Shannon's E), especially in the N treatment. Long‐term fertilization resulted in a significant shift in weed community's composition during the fallow period. The weed community's structure was affected by soil nutrients in the order P > N > K. 相似文献
18.
S SAUDY Hani 《干旱区科学》2020,12(4):630-639
The abundance of broad-leaved weeds in peanut fields represents the handicap in weed management programs, since limited specific herbicides can be recommended to control them. Moreover, the physio-biochemical constituents and nutritional status in peanut plants as affected by available herbicides, i.e., bentazone under water stress conditions are not well known. Therefore, field trials were conducted during the growing seasons in 2016 and 2017 to investigate the interactional impact of irrigation levels (I50, I75 and I100, representing irrigation by 50%, 75% and 100% of crop evapotranspiration, respectively) and weed control practices (bentazone, bentazone+hoeing once, hoeing twice and weedy check as control) on dominant broad-leaved weeds as well as peanut physiological and agronomic traits. Result indicated that the efficiency of weed control for each weeded treatment under I50 significantly equaled with its counterpart under I75 or I100. Bentazone+hoeing once diminished weed biomass by 89.3% and enhanced chlorophyll content of peanut plants by 51.2%. Bentazone relatively caused a reduction in carotenoides. Hoeing twice and bentazone+hoeing once under I100 in both growing seasons as well as hoeing twice under I75 in 2017 were the superior combinations for boosting pod yield of peanut plants. Treatment of bentazone+hoeing once and I75 recorded the lowest reduction in N utilization percentage and the highest increase in potassium utilization percentage of peanut plants. Eliminating weeds enhanced water use efficiency by 37.8%, 49.6% and 34.7% under I50, I75 and I100, respectively. In conclusion, peanut seems to be tolerant to bentazone at moderate water supply, thus it can be safely used in controlling the associated broad-leaved weeds. 相似文献
19.
The effects of cover crops on weeds and the underlying mechanisms of competition, physical control and allelopathy are not fully understood. Current knowledge reveals great potential for using cover crops as a preventive method in integrated weed management. Cover crops are able to suppress 70–95% of weeds and volunteer crops in the fall‐to‐spring period between two main crops. In addition, cover crop residues can reduce weed emergence during early development of the following cash crop by presenting a physical barrier and releasing allelopathic compounds into the soil solution. Therefore, cover crops can partly replace the weed suppressive function of stubble‐tillage operations and non‐selective chemical weed control in the fall‐to‐spring season. This review describes methods to quantify the competitive and allelopathic effects of cover crops. Insight obtained through such analysis is useful for mixing competitive and allelopathic cover crop species with maximal total weed suppression ability. It seems that cover crops produce and release more allelochemicals when plants are exposed to stress or physical damage. Avena strigose, for example, showed stronger weed suppression under dry conditions than during a moist autumn. These findings raise the question of whether allelopathy can be induced artificially. © 2019 Society of Chemical Industry 相似文献
20.
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