Weed management in cereals with cover crops - do they help of hinder?

Sustainable crop production calls for integrated weed management approaches. Cover crops (CCs) have been studied primarily in the context of soil fertility and soil structure but they might also supplement the weed management toolbox, particularly when adapted to long-term control strategies. The challenge in organic cropping is to provide strong weed suppression without severely compromising weed species diversity and crop yields. Several CC species, mainly sown in mixtures, were studied in organically cropped 3-year field experiments in southern Finland. The study was part of the PRODIVA project (Core Organic Plus 2015-2018) in which crop diversification for better weed management has been studied and presented in the 18th EWRS Symposium

Integrated Weed Management Effect on Weeds and Seed Cotton Yield

Integrated weed management is a system approach where by whole land use planning is done in advance to minimise the very invasion of weeds in aggressive forms and give crop plants a strongly competitive advantage over the weeds. Further, importance is given to involve more than one method of weed control in tackling the weeds so those broad spectrums of weeds are kept under check for longer period. A pre emergence herbicide take care of weeds only for a limited period and do not give long term weed control in a long duration crop like cotton where the problem of late emerging weeds arises and escape killing. So to attain a season long weed control, integration of chemical, mechanical and cultural methods holds a great promise in crop production. Hence, integrated weed management in cotton play important role in increasing crop production. Field experiments were conducted during 2013 and 2014, at Agricultural College and Research Institute, Madurai (Tamil Nadu Agricultural University) to study the effect of integrated weed management in rainfed cotton. The weed management practices consisted of pendimethalin (1.0 kg.ha-1) and (Calotropisgigantea leaf extract spray at three concentrations (10%, 20%, and 30%) in combination with power weeder operation twice and manual weeding twice. From the results of the experiments, it could be recommended that the integrated weed management practices like, application of PE pendimethalin at 1.0 kg ha-1 + power weeding on 40 DAS (T11) recorded higher seed cotton yield and economic return

ECONOMIC ANALYSIS OF ALFALFA INTEGRATED MANAGEMENT PRACTICES

Integrated pest management (IMP) initially focused on insect pest control. More recently, IPM encompasses a broader concept of management, one which crosses several disciplinary boundaries. This article reports results of research dealing with four integrated management decisions for alfalfa (cultivar selection, inset control, weed control, and end-of-season harvest options.Crop Production/Industries,

Economic impacts of high labour cost and herbicide resistance for the management of annual barnyardgrass (Echinochloa crus-galli) in rice production in the Philippines

Implications of increasing labour cost and development of herbicide resistance for profitable weed management in Philippine rice farming systems are investigated. The study employs RIMPhil (Resistance and Integrated Management in the Philippines), a bioeconomic simulation model developed to provide a comprehensive assessment of integrated weed management programmes for the control of annual barnyardgrass (Echinochloa crus-galli) in rice crops. Results indicate that herbicide application will become increasingly economically attractive, relative to manual weeding, as labour cost increases. This is important since urban migration in the Philippines continues to increase the scarcity of rural labour. Results also show that the onset of herbicide resistance results in substantial losses in farm profit. It may be worthwhile for farmers to take management actions to prevent or delay the onset of herbicide resistance, provided that these changes are effective and not too costly. The study highlights the complexity of decision making about integrated weed management on rice farms in the Philippines.Barnyardgrass, Bioeconomic model, Herbicide resistance, Integrated weed management, Rice production, Crop Production/Industries, Farm Management, Research and Development/Tech Change/Emerging Technologies,

Integrated weed management and weed species diversity

Les méthodes alternatives de gestion des mauvaises herbes, telles que la gestion intégrée, peuvent permettre la persistance de populations de mauvaises herbes sous un seuil économique déterminé. Une diversité accrue des espèces de mauvaises herbes peut aussi en résulter. Si la diversité ainsi que le nombre d'interactions écologiques augmentent, les espèces de mauvaises herbes devraient être considérées comme une communauté interactive plutôt que comme un ensemble disparate de cibles contre lesquelles lutter. Cet article de synthèse résume les méthodes d'évaluation de la diversité dans des systèmes non gérés, examine comment les techniques de gestion intégrée peuvent modifier la diversité des espèces de mauvaises herbes, et finalement, suggère des façons de développer des stratégies pour gérer la diversité des mauvaises herbes par la gestion intégrée de celles-ci. Les méthodes utilisées pour évaluer la diversité dans les systèmes naturels peuvent servir à évaluer la diversité des mauvaises herbes dans des systèmes alternatifs de gestion intégrée. Nous avons effectué des calculs préliminaires de diversité pour le labour réduit, l'utilisation modifiée des herbicides, les rotations culturales, la période critique d'intervention contre les mauvaises herbes, les techniques d'amélioration de la compétitivité des cultures et les méthodes de lutte alternatives. Plusieurs de ces techniques de gestion intégrée peuvent éventuellement résulter en des modifications de la diversité des espèces de mauvaises herbes. Nous avons examiné les effets potentiels de ces changements sur la diversité des mauvaises herbes à l'intérieur de six principaux éléments de l'écologie des communautés: la colonisation, la perturbation, l'environnement physique, les interactions inter- et intra-communautés, et la dynamique de ces communautés. Des occasions de développer des stratégies de gestion des communautés de mauvaises herbes existent à l'intérieur de chacun de ces éléments. Si la diversité pouvait être gérée tout en maintenant des rendements acceptables, certains bénéfices découlant de la présence des mauvaises herbes et non encore considérés pourraient être observés, tel que le prédisent les relations existant entre les plantes de communautés non gérées. De plus, l'objectif d'obtenir un système de production plus durable, tenant compte de la diversité des communautés de mauvaises herbes, pourrait être accompagné d'orientations vers une politique encourageant la biodiversité des agro-écosystèmes.Alternative practices for weed management, such as integrated weed management (IWM) may allow the persistence of weed populations below a given economic threshold. Increased species diversity of weeds also may result. If diversity increases, and the number of ecological interactions also increases, weed species should be viewed as an interactive community, rather than an unrelated set of targets for control. In this review we summarize how diversity is evaluated in unmanaged Systems, examine how IWM techniques may alter the diversity of weed species and suggest how strategies can be developed for managing weed diversity under IWM. Methods used to evaluate diversity in natural Systems may be used to evaluate weed diversity in alternative Systems of weed management. We made preliminary calculations of diversity for reduced tillage, modified herbicide use, crop rotation, critical period of weed control, techniques to improve crop competitiveness, and alternative control methods. Many of these IWM techniques potentially may result in changes in weed species diversity. We examined potential effects of these changes in weed diversity within six primary elements of community ecology: colonization, disturbance, the physical environment, interactions with other communities, community interactions and community dynamics. Opportunities to develop strategies of community management exist within each of these elements. If diversity could be managed while maintaining acceptable crop yields, some previously unrealized benefits of the presence of weeds could be seen, as predicted by relationships among plants of unmanaged communities. Moreover, the goal of producing a more sustainable System that incorporates the diversity of the weed community would be complemented by trends in policy towards encouraging biodiversity in agroecosystems

RIMPhil: a bioeconomic model for integrated weed management of annual barnyardgrass (Echinochloa crus-galli) in Philippine rice farming systems

This paper describes a complex, dynamic simulation model that has been developed for the analysis of integrated weed management programmes for the control of annual barnyardgrass (Echinochloa crus-galli) in rice farming systems in the Philippines. Users of the model may simulate any feasible combination of 49 weed treatments options across wet and dry cropping seasons over 5, 10, 15, and 20 year periods, subject to a predetermined sequence of planting methods. The main outputs of the model include weed seed and plant densities and seasonal and annualised profit over the simulated planning horizon. Model output emphasises the substantial economic benefits associated with effective long-term weed management strategies. In addition, the most-profitable weed densities are found to be much lower than those usually recommended to producers, indicating the importance of considering economic factors in the formulation of management recommendations. Results broadly indicate that a mixture of chemical and non-chemical treatments provides good weed control in rice crops, and maximises long-term profit for systems where the main weed is annual barnyardgrass. However, the performance of this strategy is influenced by crop establishment method and weed density level. These indicative results emphasise the value of the model for guiding the efficient control of annual barnyardgrass in rice crops in the Philippines.Barnyardgrass, Bioeconomic model, Integrated weed management, Rice farming systems., Agricultural and Food Policy, Crop Production/Industries, Environmental Economics and Policy, Farm Management,

Key aspects on the biology, ecology and impacts of johnsongrass [Sorghum halepense (L.) Pers] and the role of glyphosate and non-chemical alternative practices for the management of this weed in Europe

Sorghum halepense (L.) Pers is a common and noxious worldwide weed of increasing distribution in many European countries. In the present review, information on the biology, ecology, agricultural, economic and environmental impact of johnsongrass is given, and the current status of this weed in Europe is discussed. Furthermore, special attention is given to the important role of field trials using glyphosate to control weeds in arable and perennial crops in many European countries. Some of the factors which affect control efficacy and should be taken into account are also discussed. Finally, several non-chemical alternative methods (cultural, mechanical, thermal, biological, etc.) for johnsongrass management are also presented. The adoption of integrated weed management (IWM) techniques such as glyphosate use, crop rotation, and deep tillage is strongly recommended to control plant species that originate from both seed and rhizomes.This research was funded by Bayer Agriculture BVBA, grant number 140319

Controlling Phalaris Minor in the Indian Rice-Wheat Belt

The ACIAR-managed project CS1/1996/013, Herbicide-resistant weeds of wheat in India and Australia: integrated management, was designed to find a long-term method of control of Phalaris minor, a problem weed of the rice–wheat cropping system of north-western India. By 1993, the weed had developed resistance to isoproturon, a herbicide which had delivered effective weed control for 15 years. The short-term solution, implemented before the ACIAR project commenced, involved identification and registration of a new set of herbicides. But these new herbicides were expensive. To ensure high adoption they needed to be combined with changes in wheat-growing techniques that would provide cost savings to help farmers pay for them. And to avoid the re-emergence of chemical resistance, they needed to be used sparingly as one element in a broader approach to weed management. The project team used these circumstances to field-test and encourage adoption of zero tillage, a technology that agronomists had been advocating for many years, but which had failed to capture the interest of Indian farmers. Zero tillage has the potential to deliver big cost savings. In addition, it provides prospects for yield increases by allowing early sowing of wheat and avoiding soil degradation. Project research established that zero tillage also provided effective weed control with only a moderate reliance on chemicals, making the re-emergence of herbicide resistance remote. We calculate a gain to the Indian economy of around $1800 million in net present value terms over the next 30 years from the adoption of zero tillage to control Phalaris minor infestation in the rice–wheat areas of north-western India. This leads to an extremely high ratio of benefits to project costs. Zero tillage by itself is clearly a profitable technology. It does not need a weed problem to justify its introduction. Without the ACIAR project, zero tillage would have been introduced to the region, though somewhat later than what has occurred. On the assumption that the ACIAR project has advanced the adoption profile of zero tillage by 3 years, we calculate gains that can be attributed to ACIAR’s role of$238 million in net present value terms over the next 30 years. This gain has been achieved with total expenditures on the ACIAR-managed project amounting to only $1.3 million in present values.herbicide-resistant weeds, wheat, weed, India, Australia, integrated management, phalaris minor, rice-wheat cropping systems, chemical resistance, weed management, zero tillage, cost saving, net present economy, high benefits, profitable technology, Agribusiness, Crop Production/Industries, Farm Management, Food Consumption/Nutrition/Food Safety, International Development, Production Economics,

Combining physical and cultural weed control with biological methods – prospects for integrated non-chemical weed management strategies

The paper deals with the possibilities of combining physical weed control with biological weed control