scholarly journals Recent Weed Control, Weed Management, and Integrated Weed Management

2013 ◽  
Vol 27 (1) ◽  
pp. 1-11 ◽  
Author(s):  
K. Neil Harker ◽  
John T. O'Donovan

Integrated weed management (IWM) can be defined as a holistic approach to weed management that integrates different methods of weed control to provide the crop with an advantage over weeds. It is practiced globally at varying levels of adoption from farm to farm. IWM has the potential to restrict weed populations to manageable levels, reduce the environmental impact of individual weed management practices, increase cropping system sustainability, and reduce selection pressure for weed resistance to herbicides. There is some debate as to whether simple herbicidal weed control programs have now shifted to more diverse IWM cropping systems. Given the rapid evolution and spread of herbicide-resistant weeds and their negative consequences, one might predict that IWM research would currently be a prominent activity among weed scientists. Here we examine the level of research activity dedicated to weed control techniques and the assemblage of IWM techniques in cropping systems as evidenced by scientific paper publications from 1995 to June 1, 2012. Authors from the United States have published more weed and IWM-related articles than authors from any other country. When IWM articles were weighted as a proportion of country population, arable land, or crop production, authors from Switzerland, the Netherlands, New Zealand, Australia, and Canada were most prominent. Considerable evidence exists that research on nonherbicidal weed management strategies as well as strategies that integrate other weed management systems with herbicide use has increased. However, articles published on chemical control still eclipse any other weed management method. The latter emphasis continues to retard the development of weed science as a balanced discipline.

2004 ◽  
Vol 18 (4) ◽  
pp. 1006-1012 ◽  
Author(s):  
K. Neil Harker ◽  
George W. Clayton ◽  
John T. O'Donovan ◽  
Robert E. Blackshaw ◽  
F. Craig Stevenson

Herbicide-resistant canola dominates the canola market in Canada. A multiyear field experiment was conducted at three locations to investigate the effect of time of weed removal (two-, four-, or six-leaf canola) and herbicide rate (50 or 100% recommended) in three herbicide-resistant canola systems. Weeds were controlled in glufosinate-resistant canola (GLU) with glufosinate, in glyphosate-resistant canola (GLY) with glyphosate, and in imidazolinone-resistant canola (IMI) with a 50:50 mixture of imazamox and imazethapyr. Canola yields were similar among the three canola cultivar–herbicide systems. Yields were not influenced by 50 vs. 100% herbicide rates. Timing of weed removal had the greatest effect on canola yield, with weed removal at the four-leaf stage giving the highest yields in most cases. Percent dockage was often greater for GLU and IMI than for GLY. In comparison with the other treatments, dockage levels doubled for GLU after application at 50% herbicide rates. The consistency of monocot weed control was usually greater for GLY than for GLU or IMI systems. However, weed biomass data revealed no differences in dicot weed control consistency between IMI and GLY systems. Greater dockage and weed biomass variability after weed removal at the six-leaf stage or after low herbicide rates suggests higher weed seed production, which could constrain the adoption of integrated weed management practices in subsequent years.


Agriculture ◽  
2018 ◽  
Vol 8 (9) ◽  
pp. 138 ◽  
Author(s):  
Hilary Sandler

Integrated weed management (IWM) has been part of cranberry cultivation since its inception in the early 19th century. Proper site and cultivar selection, good drainage, rapid vine establishment, and hand weeding are as important now for successful weed management as when the industry first started. In 1940, Extension publications listed eight herbicides (e.g., petroleum-based products, inorganic salts and sulfates) for weed control. Currently, 18 herbicides representing 11 different modes of action are registered for use on cranberries. Nonchemical methods, such as hand weeding, sanding, flooding, and proper fertilization, remain integral for managing weed populations; new tactics such as flame cultivation have been added to the toolbox. Priority ratings have been developed to aid in weed management planning. Despite many efforts, biological control of weeds remains elusive on the commercial scale. Evaluation of new herbicides, unmanned aerial systems (UAS), image analysis, and precision agriculture technology; investigation of other management practices for weeds and their natural enemies; utilization of computational decision making and Big Data; and determination of the impact of climate change are research areas whose results will translate into new use recommendations for the weed control of cranberry.


Weed management is a new term for the age-old practice of employing all available means, in a planned way, to keep weed populations under control. It seeks to distinguish the systematic approach to weed control, based on scientific knowledge and rational strategies, from the pragmatic destruction of weeds. The remarkable efficiency of herbicides has in recent years emphasized the latter and allowed revolutionary methods of crop production to be practised. These have, however, led to serious new weed problems which in turn require more intensive herbicide use. The need for a weed management approach is increasingly recognized. New opportunities for this are provided by the availability of numerous herbicides and plant growth regulators and a growing understanding of the biology, ecology and population dynamics of weeds in relation to crop production systems. Examples discussed include: systematic control of grass weeds in intensive cereals in Britain, weed control in rice and in soybeans, the control of aquatic weeds by biological and chemical methods and an experimental zero-tillage cropping system for the humid tropics based on herbicides, growth regulators and ground-cover leguminous crops. In such management systems, interference of weed behaviour by exogenous growth regulators is likely to be of increasing significance. Constraints on the adoption of weed management practices include lack of support for weed science as a discipline, limited appeal to the agrochemical industry and inadequate extension services in many countries.


2004 ◽  
Vol 44 (10) ◽  
pp. 993 ◽  
Author(s):  
R. S. Llewellyn ◽  
R. K. Lindner ◽  
D. J. Pannell ◽  
S. B. Powles

Greater adoption of integrated weed management, to reduce herbicide reliance, is an objective of many research and extension programmes. In Australian grain-growing regions, integrated weed management is particularly important for the management of herbicide resistance in weeds. In this study, survey data from personal interviews with 132 Western Australian grain growers are used to characterise the use and perceptions of integrated weed management practices. The main objective was to identify opportunities for improved weed management decision making, through targeted research and extension. The extent to which integrated weed management practices are used on individual farms was measured. Perceptions of the efficacy and reliability of various weed management practices were elicited for control of annual ryegrass (Lolium rigidum Gaud.), along with perceptions of the economic value of integrated weed management practices relative to selective herbicides. All growers were shown to be using several integrated weed management practices, although the use of some practices was strongly associated with the presence of a herbicide-resistant weed population. In general, both users and non-users were found to have high levels of awareness of integrated weed management practices and their weed control efficacy. Herbicide-based practices were perceived to be the most cost-effective. Opportunities for greater adoption of integrated weed management practices, to conserve the existing herbicide resource, exist where practices can be shown to offer greater shorter-term economic value, not necessarily just in terms of weed control, but to the broader farming system.


Weed Science ◽  
2012 ◽  
Vol 60 (SP1) ◽  
pp. 31-62 ◽  
Author(s):  
Jason K. Norsworthy ◽  
Sarah M. Ward ◽  
David R. Shaw ◽  
Rick S. Llewellyn ◽  
Robert L. Nichols ◽  
...  

Herbicides are the foundation of weed control in commercial crop-production systems. However, herbicide-resistant (HR) weed populations are evolving rapidly as a natural response to selection pressure imposed by modern agricultural management activities. Mitigating the evolution of herbicide resistance depends on reducing selection through diversification of weed control techniques, minimizing the spread of resistance genes and genotypes via pollen or propagule dispersal, and eliminating additions of weed seed to the soil seedbank. Effective deployment of such a multifaceted approach will require shifting from the current concept of basing weed management on single-year economic thresholds.


Weed Science ◽  
2014 ◽  
Vol 62 (3) ◽  
pp. 520-531 ◽  
Author(s):  
James J. DeDecker ◽  
John B. Masiunas ◽  
Adam S. Davis ◽  
Courtney G. Flint

Organic agricultural systems increase the complexity of weed management, leading organic farmers to cite weeds as one of the greatest barriers to organic production. Integrated Weed Management (IWM) systems have been developed to address the ecological implications of weeds and weed management in cropping systems, but adoption is minimal. Organic agriculture offers a favorable context for application of IWM, as both approaches are motivated by concern for environmental quality and agricultural sustainability. However, adoption of IWM on organic farms is poorly understood due to limited data on weed management practices used, absence of an IWM adoption metric, and insufficient consideration given to the unique farming contexts within which weed management decisions are made. Therefore, this study aimed to (1) characterize organic weed management systems; (2) identify motivations for, and barriers to, selection of weed management practices; and (3) generate guiding principles for effective targeting of weed management outreach. We surveyed Midwestern organic growers to determine how specified psychosocial, demographic, and farm structure factors influence selection of weed management practices. Cluster analysis of the data detected three disparate, yet scaled, approaches to organic weed management. Clusters were distinguished by perspective regarding weeds and the number of weed management practices used. Categorization of individual farms within the identified approaches was influenced by primary farm products as well as farmer education, years farming, and information-seeking behavior. The proposed conceptual model allows weed management educators to target outreach for enhanced compatibility of farming contexts and weed management technologies.


Weed Science ◽  
2017 ◽  
Vol 65 (4) ◽  
pp. 525-533 ◽  
Author(s):  
Collen Redlick ◽  
Hema S. N. Duddu ◽  
Lena D. Syrovy ◽  
Christian J. Willenborg ◽  
Eric N. Johnson ◽  
...  

Concern over the development of herbicide-resistant weeds has led to interest in integrated weed management systems that reduce selection pressure by utilizing mechanical and cultural weed control practices in addition to herbicides. Increasing crop seeding rate increases crop competitive ability and thus can enhance herbicide efficacy. However, it is unknown how increasing the seeding rate affects an herbicide’s efficacy. The objective of this study was to examine the interaction between increasing seeding rate and herbicide dose to control weeds. To meet this objective, the herbicide fluthiacet-methyl was applied to field-grown lentil, with Indian mustard, a proxy for wild mustard, used as a model weed. The experiment was a factorial design with four lentil seeding rates and seven herbicide rates. Overall the herbicide dose response was altered by changing lentil seeding rate. Increasing lentil seeding rate decreased the weed biomass production when herbicides were not applied. In two of the four site-years, increasing lentil seeding rate lowered the herbicide ED50, the dose required to result in a 50% reduction in weed biomass. Increasing the crop seeding rate altered the dose response to provide greater weed control at lower herbicide rates compared with normal crop seeding rates. Increased seeding rates also resulted in higher and more stable crop seed yields across a wider range of herbicide dosages. These results suggest that dose–response models can be used to evaluate the efficacy of other weed management practices that can interact with herbicide performance.


Plants ◽  
2021 ◽  
Vol 10 (6) ◽  
pp. 1212
Author(s):  
Mahmudul Hasan ◽  
Muhammad Saiful Ahmad-Hamdani ◽  
Adam Mustafa Rosli ◽  
Hafizuddin Hamdan

Weed management is an arduous undertaking in crop production. Integrated weed management, inclusive of the application of bioherbicides, is an emerging weed control strategy toward sustainable agriculture. In general, bioherbicides are derived either from plants containing phytotoxic allelochemicals or certain disease-carrying microbes that can suppress weed populations. While bioherbicides have exhibited great promise in deterring weed seed germination and growth, only a few in vitro studies have been conducted on the physiological responses they evoke in weeds. This review discusses bioherbicide products that are currently available on the market, bioherbicide impact on weed physiology, and potential factors influencing bioherbicide efficacy. A new promising bioherbicide product is introduced at the end of this paper. When absorbed, phytotoxic plant extracts or metabolites disrupt cell membrane integrity and important biochemical processes in weeds. The phytotoxic impact on weed growth is reflected in low levels of root cell division, nutrient absorption, and growth hormone and pigment synthesis, as well as in the development of reactive oxygen species (ROS), stress-related hormones, and abnormal antioxidant activity. The inconsistency of bioherbicide efficacy is a primary factor restricting their widespread use, which is influenced by factors such as bioactive compound content, weed control spectrum, formulation, and application method.


Author(s):  
Nano Alemu Daba ◽  
Janmejai Sharma

The experiment was conducted to assess the integrated effects of pre-emergence herbicides and hand-weeding on weed control, yield components, yield, and their economic feasibility for cost effective weed control in faba bean. The experiment consisted of 12 treatments viz. pre-emergence s-metolachlor (1.0, 1.5 and 2.0 kg ha-1) and pendimethalin (1.0, 1.25 and 1.5 kg ha-1), each at three rates metolachlor, s-metolachlor + one-hand-weeding, pendimethalin + one-hand-weeding, two-hand-weeding, complete weed free and weedy checks arranged. The weed flora consisted of broadleaved and sedge with the relative densities of 81.02 and 18.98 % at Haramaya district, and 80.83% and 19.17%, at Gurawa district, respectively. Application of s-metolachlor and pendimethalin 1.0 kg ha-1 each supplemented with hand weeding 5 WAE significantly (p ≤0.01) affected the broadleaved weeds, sedges and weed dry weight at both sites. S-metolachlor 1.0 kg ha-1 supplemented with hand weeding 5 WAE gave the lowest total number of weeds (8.29 m-2) following the weed free check. Higher grain yield (3555.8 kg ha-1) was produced with s-metolachlor 1.0 kg ha-1 supplemented with one-hand-weeding 5 WAE following complete weed-free at Gurawa. The benefit gained from s-metolachlor and pendimethalin at 1.0 kg ha-1 each supplemented with one hand weeding 5 WAE were greater than the value recorded from the weedy check by 216% and 198 %, respectively. S-metolachlor 1.0 kg ha-1 supplemented with hand weeding 5 WAE treatment resulted in the highest grain yield and economic benefit. However, in case labour is constraint and s-metolachlor herbicide is timely available, pre emergence application of s-metolachlor at 2.0 kg ha-1 should be the alternative to preclude the yield loss and to ensure maximum benefit.


Author(s):  
A. A. Ajala ◽  
A. Muhammad ◽  
A. I. Yakubu ◽  
H. Y. Sanda

Rice is a weak competitor against weeds and the majority of African farmers have few options and resources available for effective weed control. Weed control is one of the most important and suggestive practices for potential rice production. Field trials were carried out during 2017/2018 dry season at the Teaching and Research Fadama farm of the Kebbi State University of Science and Technology located at Jega (Latitude 12º21ˈN; Longitude 4º36ˈE) and that of Usmanu Danfodiyo University Sokoto located at Kwalkwalawa (Latitude 13º01ˈN, Longitude 5º09ˈE) to study the effects of integrated weed management (IWM) and variety on weed occurrence and the growth of rice. Both locations lie within Sudan Savanna ecological zone of Nigeria. The treatments consisted of six (6) weed management options (Solarization/Orizo-plus (3 WAT)/Hoe-weeding (6 WAT), Round-up/Orizo-plus (3 WAT)/Hoe-weeding (6WAT), Solarization/Hoe-weeding (3 WAT)/Hoe-weeding (6 WAT), Round-up/Hoe-weeding (3 WAT)/Hoe-weeding (6 WAT), Weedy-check and Weed-free) and three (3) rice varieties (Jamila, Faro 44 and Faro 57). The factorial combinations of the treatments were laid out in a randomized complete block design (RCBD) with the split-plot arrangement and were replicated three times. Weed management options formed the main plots while rice varieties were assigned to the sub-plots. The result of the study indicated that combination of solarization, orizo-plus and hoe-weeding achieved an effective weed control (33.56 g weed dry matter per m2) close to the weekly hoe-weeding (16.13 g weed dry matter per m2). Faro 57 variety was noted with the potential to increase rice growth under good weed management practices. From the results, it could be concluded that for increased rice growth, Faro 57 under the combination of solarization, orizo-plus and hoe-weeding IWM option should be adopted.


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