Herbicide-based Weed Management Research Articles

Optimizing cotton production through efficient weed management using herbicides: A promising solution for labour-scarce farming

Cotton, often referred to as ‘White gold’ and the ‘King of fibre crops’ holds a significant position as a cash and fibre crop in India. Weeds contribute to approximately 45 % yield reduction in cotton cultivation at the national lev?el, making weed management a critical factor in determining cotton productivity, particularly in high-density planting systems (HDPS). Effective weed control optimizes resource allocation, leading to improved growth parameters and higher yields. This study investigates the efficacy of various weed management practices, including pre-emergence and post-emergent herbicide applications, in enhancing cotton yield under HDPS. The results clearly demonstrate that a combination of PE Pendimethalin (1.0 kg a.i./ha), Metolachlor (1.0 kg a.i./ha), POE Pyrithiobac sodium (0.075 kg a.i./ha), and Quizalofop ethyl (0.075 kg a.i./ha) led to significantly greater plant height (113.4 cm) and dry matter production (7609 kg ha-1 ) . This treatment also resulted insignificantly improved yield parameters, with a higher seed cotton yield of 2098 kg ha-1 , and yielded higher net returns of Rs.141961 ha-1 and a Benefit Cost Ratio (BCR) of 3.09. In the face of increasing labour scarcity, these herbicide-based weed management practices offer a viable solution for maximizing cotton productivity under HDPS. This approach supports the rapid expansion of cotton acreage in the current era of farm mechanization.

Early detection and management of herbicide-resistant weeds

Small weed patches may be noticed in fields after herbicide application, but they typically do not have a significant impact on the season’s crop yield. As a result, they are usually not treated as a threat to future yields. However, if these patches harbour weed biotypes resistant to one or multiple herbicides, resistance alleles can spread both spatially (via various dispersal pathways, including seed transport by machinery and commodity contamination) and temporally (through seed persistence). This poses a significant threat to herbicide-based weed management. Once these populations spread and cover a large enough area, eradication becomes improbable despite all the resistance management efforts. Therefore, a proactive and collaborative endeavour is needed to detect and manage small and patchy resistant weed populations. In this paper, we review the current potential of weed resistance detection using imagery and molecular markers as well as possible weed management approaches. Finally, we advocate for the use of a combination of these techniques to manage herbicide-resistant weeds when populations are small. This multifaceted approach is presently not applicable to all resistance mechanisms, and all weed species located in any crop, but could initially focus on biotypes and species that are easy to detect and represent the greatest threat.

Challenges and Alternatives of Herbicide-Based Weed Management

Weeds are the most severe and widespread biological constraint on agricultural production systems and cause damage to cropped and non-cropped lands. They reduce crop yield and degrade the quality of the produce, besides raising the cost of production. The intensification of agriculture in the Green Revolution era attracted chemical fertilizers and dwarf varieties coupled with mono-cropping and irrigation practices, which enhanced crop-associated weeds and the widespread use of herbicides for easy control. Pesticides may kill many organisms, both target and non-target species, in the environment, causing an imbalance in the ecosystem. Despite the significant increase in productivity, the environmental repercussions of industrial agriculture, characterized by the use of high-yielding crop varieties and the extensive application of chemical fertilizers and pesticides, have prompted a quest for more sustainable agricultural practices worldwide. One potential alternative lies in innovative approaches that draw upon ecological insights gleaned from studying natural ecosystems. These approaches aim to create “ecologically intensive” agro-ecosystems. Developing ecologically intensive agro-ecosystems necessitates a deep understanding of the biological dynamics within ecosystems and the integration of traditional agricultural knowledge held by local farmers. Considering the potentiality of appropriate weed management technologies to substantially improve crop productivity, there is an opportunity for the development, popularization, and adoption of effective, economical, and eco-friendly weed management technologies.

Herbicide-based weed management on weed prevalence, crop productivity and profitability in transplanted rice

Herbicide-based weed management on weed prevalence, crop productivity and profitability in transplanted rice

Response of Wheat (Triticum aestivum L.) to Nano Urea under Different Combinations of Herbicides

A field experiment was conducted during the winter (rabi) season of 2023–24 at Crop research Centre 1 (CRC-1) of ITM University Gwalior, (M.P.), to investigate the response of wheat (Triticum aestivum L.) to nano-urea under different combinations of herbicide. The experiment consisted a split-plot design involving 4 herbicide-based weed management treatments, H1- Mesosulfuron-methyl 3% + Iodosulfuron-methyl sodium 0.6 WG @ 400 g ha-1, H2- Clodinafop propargyl 15% + Metsulfuron-methyl 1% WP @ 400 g ha-1, H3- weed-free check and H4- weedy check in main plots and 4 nutrient management treatments, N0- control (no nitrogen), N1- 100% recommended dose of nitrogen (RDN), N2- 75% RDN + 1 Spray of Nano urea at 40 days after sowing (DAS), and N3- 50% RDN + 2 Spray of Nano urea (at 40DAS and 60 DAS) in sub plots and replicated thrice. Results revealed that maximum grain and straw yield were significantly higher in weed-free check, being at par with H2-Clodinafop propargyl 15% + Metsulfuron methyl 1% WP @ 400 g ha1 (3373.19 and 4232.63 kg ha-1), followed by H1- Mesosulfuron-methyl 3% + Iodosulfuron-methyl sodium 0.6 WG @ 400 g ha-1 (3086.44 and 3941.72 kg ha-1). Among nutrient management practices, grain and straw yield were significantly higher in N1-100% RDN (3610.96 and 4310.33 kg ha-1), which was being at par with N2-75% RDN + 1 spray of nano-urea (3409.74 and 4221.20 kg ha-1) over N3-50% RDN+ 2 sprays of nanourea, respectively.

Composition and diversity patterns of weeds in herbicide tolerant maize fields and margins in the Eastern Cape, South Africa

Abstract. Kwinda M, Siebert SJ, Coller HV, Masehela TS. 2023. Composition and diversity patterns of weeds in herbicide tolerant maize fields and margins in the Eastern Cape, South Africa. Biodiversitas 24: 399-414. Weeds are considered undesirable plants that grow where they are not wanted, as they often outcompete crops and other beneficial species. This study aimed to compare species composition and diversity of weedy plant communities in fields planted with herbicide tolerant maize and associated field margins in the Eastern Cape Province, South Africa. A total of 88 weed species, representing 31 families were recorded from 244 plots for maize fields and field margins combined. The maize fields and margins across the four sites shared 53% of species. Non-metric Multidimensional Scaling grouped maize fields and field margins separately based on weed species composition. Moreover, maize fields and margins differed significantly in terms of Simpson (p=0.044) and Shannon indices (p=0.003), with diversity being higher in the fields. This study confirms that maize fields have a dissimilar composition of weedy species and dissimilar diversity, which differs from those of field margins. This result enables farmers to know whether current herbicide use is sufficient for targeted weed control. The findings and knowledge will benefit maize farmers and future researchers working on weeds in Sub-Saharan Africa when it comes to the development, implementation, and prioritization of various herbicide-based weed management protocols to ensure maximum crop productivity.

Impact of Weed Management Practices on the Weed Dynamics, Nutrient Uptake Pattern of Weeds and Direct Seeded Rice

Herbicide based weed management is the emerging and effective method for controlling the weed flora of direct seeded rice. Weed growth often has an impact on crop development by interfering with plant nutrients. A two-year weed experiment with twelve treatments was set up at the University of Agricultural Sciences in Bangalore, Karnataka, India to know the effect of weed management practices on weed and nutrient dynamics in direct seeded rice. Significantly lower total weed density and biomass was observed with bispyribac sodium 10 SC 40 g a.i. ha-1 as post emergence which recorded statistically at par values with bensulfuron methyl + pretilachlor 6.6 GR 660 g a.i. ha-1 as pre-emergence during both the years of study. The allelochemicals used in the study performed well over unweeded control but it was far less when compared with chemical herbicides. Nutrient uptake by the direct seeded rice (82.17, 31.76 and 68.83 kg ha-1 NPK in 2020 and 89.38, 38.84 and 75.62 ha-1 NPK in 2021, respectively) and grain yield (4.98 t ha-1 in 2020 and 4.99 t ha-1 in 2021, respectively) was also reported to be higher with bispyribac sodium 10 SC 40 g a.i. ha-1 as post emergence which was on par with bensulfuron methyl + pretilachlor 6.6 GR 660 g a.i. ha-1 as pre-emergence. As the nutrient uptake by the crop and weeds are negatively correlated, the same treatments have recorded lower nutrient removal by the weeds. Higher weed biomass and rapid nutrient removal by weeds had resulted in poor soil nutritional status in unweeded control compared to all other treatments. Application of bispyribac sodium 10 SC 40 g a.i. ha-1 as post emergence or bensulfuron methyl + pretilachlor 6.6 GR 660 g a.i. ha-1 as pre-emergence were considered to be best management practices for weed management under direct seeded rice.

Narrowing maize yield gaps in the rainfed plateau region of Odisha

Abstract Maize is the primary staple crop cultivated during the monsoon season in eastern India. However, yield gaps are large because of multiple factors, including low adoption rates of good agronomic management practices. This study aimed to narrow the maize yield gap using diverse agronomic and varietal interventions through field experiments over 2 years (2013–2014) in the rainfed plateau region of Odisha. As a result, maize yield increased by 0.9, 0.74, and 0.17 Mg ha−1 under optimum plant population, fertilizer management, and herbicide-based weed management, respectively, over farmers’ current practices (Check). Moreover, when all three interventions were combined (‘best’ management practice), grain yields increased by 1.7 Mg ha−1 in conservation tillage and 2.2 Mg ha−1 in conventional tillage. We also observed that the combination of long-duration hybrids and best management practices (BMPs) increased grain yield by 4.0 Mg ha−1 and profitability by $888 ha−1 over farmers’ current practices. In addition, Nutrient Expert decision support tool-based fertilizer management along with BMPs increased grain yield by 1.7 Mg ha−1 and profitability by $314 ha−1 over farmers’ fertilizer practices (Check). These results suggest that the combination of maize hybrids and BMPs can improve the productivity and profitability of rainfed maize in the plateau region of Odisha. However, these entry points for intensification need to be placed in the context of varying investment requirements, input and output market conditions, and matched with farmer preferences and risk.

Bio-efficacy of sequential herbicide application for weed management in dry direct seeded rice

Weeds are the major biotic constraint in dry-direct seeded rice (DDSR), mainly due to the concurrent emergence and absence of water layer to suppress weeds. Therefore, strategy needs to be developed to get broad-spectrum weed control in DDSR. Experiments were conducted in rice (var. MTU 1010) during 2015-16 where sequential applications of pre- and post-emergence herbicides were evaluated for providing broad-spectrum weed management options in DDSR. Both the years, employing two-hand weedings at 15 and 30 DAS provided the lowest weed densities and weed dry weight at 75 DAS, whereas the maximum values of weeds were recorded in un-weeded plots. Among the herbicide-based weed management practices, application of pendimethalin 1000 g/ha fb bispyribac sodium 25 g/ha fb fenoxaprop 60 g/ha + chlorimuron + metsulfuron 4 g/ha at 30 DAS provided excellent weed control at 75 DAS, with 4.3% higher rice grain yield than two hand weedings at 15 and 30 DAS, pendimethalin 1000 g/ha fb bispyribac sodium 25 g/ha also provided good weed control and higher grain yield. Un-weeded plots noticed with considerable yield reduction of 79.5-83.3% over two hand weedings. Therefore, sequential application of pendimethalin 1000 g/ ha fb bispyribac sodium 25 g/ha is recommended along with need-based application of post-emergence herbicides (fenoxaprop 60 g/ha + chlorimuron + metsulfuron 4 g/ha) or one hand weeding to improve the weed control efficiency and provides economically higher productivity in DDSR.

Herbicide-Based Weed Management for Soybean Production in the Far Eastern Region of Russia

This study was conducted to establish a weed management system based on the sequential application of pre-emergence (PRE) and post-emergence (POST) herbicides for soybean production in Primorsky krai. Field experiments were conducted for two years in a field located in Bogatyrka, Primorsky krai, Russia (N43°49′, E131°36′). No herbicide application resulted in significant soybean yield loss, 0.03–0.3 t ha−1, which is more than 91.6% yield loss compared with that of the weed-free plot. The PRE application of acetochlor showed good weed control efficacy (greater than 90% weed control) with acceptable soybean safety (less than 10% soybean damage), while the other PRE herbicides performed poorly in terms of weed control. The POST application of bentazon + acifluorfen, bentazon, and imazamox at 30 days after soybean sowing (DAS) showed good weed control efficacy with good soybean safety. Neither the PRE nor POST application alone showed a sufficient soybean yield protection, resulting in much lower soybean yield than the weed-free plot. The sequential application of acetochlor (PRE), followed by either bentazon + acifluorfen (POST) at 30 DAS in 2012 or bentazon + imazamox (POST) at 60 DAS in 2013 showed the best performance in soybean yields, 1.7 t and 1.9 t ha−1, respectively, provided with 724.5 US$ and 1155.6 US$ ha−1 of economic returns. For alternative PRE herbicides of acetochlor, which is now banned, our tests of the sequential application of S-metolachlor with other POST herbicides and the sole application of other PRE herbicides revealed that S-metolachlor and clomazone could also be considered. Our results thus demonstrate that the sequential applications of PRE and POST herbicides should be incorporated into the weed management system for soybean production in Primorsky krai, Russia.

Fertilizer and Weed Management Options for Direct Wet Seeded Rice in Dry Season

Direct seeding of rice is an emerging technology. However, direct seeded rice culture in the main field is hindered by enormous weed infestation and it lacks judicious fertilizer management. So, experiments were conducted during dry seasons of 2010 and 2012 with three fertilizer packages and four weed control measures. Rice seed was sown in the field using drum seeder in wet soil. The results revealed that weed density and weed biomass were strongly influenced by weed control methods and fertilizer rates. Weed density was higher in unweeded plots with 140:36:43 kg NPK ha-1. Among the species Echinichloa crusgalli (L.) P. Beauv. was the dominant species. Three hand weeding controlled maximum weeds. Uses of herbicide for controlling weeds were above 80 and 70% effective. Strong negative correlation was recorded between grain yield and weed density. Herbicide with one hand weeding and BRRI weeder in combination with 160:46:53 kg NPK ha-1 produced about 81- 104% higher grain yield than no weeding. Weed free plot produced 112% higher yield with 160:46:53 kg NPK ha-1. Besides, herbicide with one hand weeding and BRRI weeder treated plot produced similar yield irrespective of fertilizer doses. The strong positive and linear relationship was found in case of yield and yield components. Herbicide with one hand weeding and 120:26:33 kg NPK ha-1 gave higher net return (1145 $/ha). The benefit cost ratio was also higher in herbicide based weed management with reduced rate of fertilizer. Direct seeded culture using herbicide with one hand weeding and 120:26:33 kg NPK ha-1 could be an option for reducing production cost in dry season along with satisfactory grain yield.Bangladesh Rice j. 2016, 20(1): 65-75

Exploring Cost effective Herbicide based Weed Management options for Sunflower in NW India

Field experiment was conducted during spring 2009 and 2010 in the Indo-Gangetic alluvial plains to evaluate the efficacy of different pre-emergence herbicides alone or in combination with hand weeding for effective weed management in sunflower. Season long competitional stress with weeds reduced the mean seed yield of sunflower by 43.5% in comparison to conventional practice of two hand weedings (3 and 6 weeks after sowing). Herbicide based weed management increased the sunflower yield by 52.6–71.6% in comparison to weedy check. Irrespective of herbicide dose, yield improvement to the tune of 5.5–12.5% was observed with weed management through either of the pre-emergence herbicide (oxydiargyl/alachlor) when compared with recommended herbicide application of pendimethalin @ 0.75 kg/ha. Integrated approach involving herbicides with one hand weeding 4 WAS resulted in better seed yields (3.1–4.4% superiority) but the profit margin gets reduced due to higher wages of human labour incurred. Alone application of alachlor 1.5 kg/ha resulted in highest monetary benefits with highest B: C ratio of 3.49 followed by oxydiargyl 0.1 kg/ha (3.35) which was as good as two hand weedings done 3 and 6 WAS. This study identifies pre-emergence application of alachlor 1.5 kg/ha or oxydiargyl 0.1 kg/ha as economically viable weed management strategy in sunflower considering the present situation of labour scarcity, quality of weed control, productivity and profitability concerns.

Herbicide-based Weed Management in Miscanthus sacchariflorus

Although miscanthus is well known for its fast growth and high biomass productivity, its plant establishment and early growth are sensitive to weed interference. Thus, greenhouse and field experiments were conducted to establish an herbicide-based weed management system with pre-emergence (PRE) and post-emergence (POST) herbicides and their sequential applications. The plant establishment and early growth of miscanthus in the first 2 years of planting were significantly affected by weed interference, resulting in a greater than 90 % biomass yield loss in an untreated weedy control in which no herbicide was applied. PRE applications of S-metolachlor, alachlor, and pendimethalin were safe for M. sacchariflorus under both greenhouse and field conditions and showed good weed control under field conditions. POST applications of all of the tested auxinic herbicides, bentazon, thifensulfuron, and mesotrione were safe for M. sacchariflorus and showed good weed control. Sequential applications of PRE (S-metolachlor, pendimethalin or isoxaflutole) and POST herbicides (dicamba, bentazon, or mesotrione) showed better weed control than did their sole applications, resulting in better establishment. In particular, the sequential application of either S-metolachlor or pendimethalin followed by mesotrione showed the most effective weed control (85 % less weeds than the untreated weedy control) with good safety for M. sacchariflorus and thus provided the best early establishment and biomass yield. The mesotrione-based sequential application achieved approximately 15.4 ton ha−1, 79 % of weed-free control in the second year of establishment. Therefore, our results suggest that the sequential applications of PRE and POST herbicides are essential for the first and second year of M. sacchariflorus cultivation.

Herbicide-Based Weed Management Programs in Erect, Thornless Blackberry

Field studies were conducted in 2009/2010 and 2011 in North Carolina to determine the influence of herbicide-based weed management programs on weed control and blackberry tolerance. Treatments consisted of five programs with a late fall-early winter herbicide application followed by (fb) an early spring herbicide application: flumioxazin fb flumioxazin, simazine fb terbacil, terbacil fb oryzalin plus simazine, norflurazon fb oryzalin plus simazine, and terbacil fb S-metolachlor plus simazine. A sixth program consisted of winter-applied dichlobenil. Crop tolerance and weed control were recorded at the physiological crop stages of budbreak, flowering, and harvest.

The Role of Ground Beetles (Coleoptera: Carabidae) in Weed Seed Consumption: A Review

Weed management is a challenge in all agroecosystems. Given the negative consequences associated with herbicide-based weed management, it is important to consider integrated weed management options with emphasis on strategies such as biological control. Postdispersal weed seed predation by granivorous and omnivorous carabid beetles results in substantial natural suppression of weed populations. Although the role of ground beetles as “generalist predators” in various agroecosystems is known, their contribution to weed management is not well recognized. In this context, this review presents an account of carabids and their granivorous nature, the importance of a seed diet in the life histories of different carabid groups, factors affecting granivory, and their potential role in weed seed management. Below, we discuss the interrelationships among various factors influencing weed seed consumption by carabids, its consequences for weed management, and the need for future research.

Management of herbicide resistance in wheat cropping systems: learning from the Australian experience

Herbicide resistance continues to escalate in weed populations infesting global wheat (Triticum aestivum L.) crops, threatening grain production and thereby food supply. Conservation wheat production systems are reliant on the use of efficient herbicides providing low-cost, selective weed control in intensive cropping systems. The resistance-driven loss of herbicide resources combined with limited potential for new herbicide molecules means greater emphasis must be placed on preserving existing herbicides. For more than two decades, since the initial recognition of the dramatic consequences of herbicide resistance, the challenge of introducing additional weed control strategies into herbicide-based weed management programmes has been formidable. Throughout this period, herbicide resistance has expanded unabated across the world's wheat production regions. However, in Australia, where herbicide resources have become desperately depleted, the adoption of harvest weed seed control is evidence, at last, of a successful approach to sustainable weed management in wheat production systems. Growers routinely including strategies to target weed seeds during crop harvest, as part of herbicide-based weed management programmes, are now realising significant weed control and crop production benefits. When combined with an attitude of zero weed tolerance, there is evidence of a sustainable weed control future for wheat production systems. The hard-learned lessons of Australian growers can now be viewed by global wheat producers as an example of how to stop the continual loss of herbicide resources in productive cropping systems.

Operational planning of herbicide-based weed management

• A conceptual operational planning model for weed control is proposed. • The model selects herbicides to be applied and determines their application times. • The objective is to maximize the economic benefit. • The environmental impact is quantified as an external cost. • Sensitivity analysis shows that the model solutions are robust. Weeds cause crop yield loss due to competition, interfere with agricultural activities and reduce grain quality due to seed contamination. Among the numerous methods for weed control, the use of herbicides is the most common practice. Nowadays, the optimization of herbicide application is pursued to reduce the environmental impact, delay the appearance of herbicide-resistant weed populations, and improve the cost/benefit ratio of the agronomic business. This work proposes an operational planning model, aimed at calculating the optimal application times of herbicides in no-tillage systems within a growing season in order to maximize the economic benefit of the activity while rationalizing the intensity of the applications with respect to expert-knowledge-based recommendations. The model can decide on herbicide applications on a daily basis, consistent with timing of agricultural activities, and provides an explicit quantification of the environmental impact as an external cost. The proposed approach was tested on a winter wheat ( Triticum aestivum )–wild oat ( Avena fatua ) system, typical of the semiarid region of Argentina. In all the studied scenarios at least two pre-sowing applications of non-selective herbicides were required to effectively control early emerging weed seedlings. Additional pre-sowing and post-emergence applications were also advised in cases when competitive pressure was significant.

Investigating the Human Dimension of Weed Management: New Tools of the Trade

The human dimension of weed management is most evident when farmers make decisions contrary to science-based recommendations. Why do farmers resist adopting practices that will delay herbicide resistance, or seem to ignore new weed species or biotypes until it is too late? Weed scientists for the most part have ignored such questions or considered them beyond their domain and expertise, continuing to focus instead on fundamental weed science and technology. Recent pressing concerns about widespread failure of herbicide-based weed management and acceptability of emerging technologies necessitates a closer look at farmer decision making and the role of weed scientists in that process. Here we present a circular risk-analysis framework characterized by regular interaction with and input from farmers to inform both research and on-farm risk-management decisions. The framework utilizes mental models to probe the deeply held beliefs of farmers regarding weeds and weed management. A mental model is a complex, often hidden web of perceptions and attitudes that govern how we understand and respond to the world. One's mental model may limit ability to develop new insights and adopt new ways of management, and is best assessed through structured, open-ended interviews that enable the investigator to exhaust the subjects inherent to a particular risk. Our assessment of farmer mental models demonstrated the fundamental attribution error whereby farmers attributed problems with weed management primarily to factors outside of their control, such as uncontrolled weed growth on neighboring properties and environmental factors. Farmers also identified specific processes that contribute to weed problems that were not identified by experts; specifically, the importance of floods and faulty herbicide applications in the spread of weeds. Conventional farmers expressed an overwhelming preference for controlling weeds with herbicides, a preference that was reinforced by their extreme dislike for weeds. These preferences reflect a typical inverse relationship between perceived risk and benefit, where an activity or entity we perceive as beneficial is by default perceived as low risk. This preference diminishes the ability of farmers to appreciate the risks associated with overreliance on herbicides. Likewise, conventional farmers saw great risk and little benefit in preventive measures for weed control. We expect that thorough two-way communication and a deeper understanding of farmer belief systems will facilitate the development of audience-specific outreach programs with an enhanced probability of affecting better weed management decisions.

Evaluating the Economic Risk of Herbicide-Based Weed Management Systems in Corn and Soybean Using Stochastic Dominance Testing

Herbicide evaluation trials are typically conducted with the objective of rating herbicide efficacy and assessing crop yield loss. There is little if any attempt to quantify the economic risk associated with each treatment. The objective of this research was to use second-degree stochastic dominance to evaluate the economic stability of corn and soybean weed management systems between two contrasting environments. Weed management systems were evaluated in small-plot replicated trials over a 3-yr time period at two locations in southern Minnesota. One location (Waseca) had a slightly cooler and wetter environment than the second location (Lamberton). The Waseca location also had higher weed density and greater weed species diversity. Adjusted returns from weed management were calculated for each system by measuring economic returns, as determined by deducting weed management costs from the product of crop price and grain yield. Stochastic dominance is a technique that considers the entire distribution of net returns from weed management and compares these cumulative distributions as a basis for analyzing risk. Climate, soils, and weed diversity dictated differences in risk efficiency and effectiveness of the various weed management systems evaluated between the Waseca and Lamberton sites. Stochastic dominance testing is a useful tool for understanding long-term risk across environments. Results can be used to develop effective long-term weed management systems that minimize risk while maximizing profit potential.

Risk-Efficiency Criteria for Evaluating Economics of Herbicide-Based Weed Management Systems in Corn

Evaluation of economic outcome associated with a given weed management system is an important component in the decision-making process within crop production systems. The objective of this research was to investigate how risk-efficiency criteria could be used to improve herbicide-based weed management decision making, assuming different risk preferences among growers. Data were obtained from existing weed management trials in corn conducted at the University of Minnesota Southern Research and Outreach Center at Waseca. Weed control treatments represented a range of practices including one-pass soil-applied, one-pass postemergence, and sequential combinations of soil and postemergence herbicide application systems. Analysis of risk efficiency across 23 herbicide-based weed control treatments was determined with the mean variance and stochastic dominance techniques. We show how these techniques can result in different outcomes for the decision maker, depending on risk attitudes. For example, mean variance and stochastic dominance techniques are used to evaluate risk associated with one- vs. two-pass herbicide treatments with and without cultivation. Based on these analyses, it appears that a one-pass system is preferred by a risk-averse grower. However, we argue that this may not be the best option considering potential changes in weed emergence patterns, application timing concerns, etc. The techniques for economic analysis of weed control data outlined in this article will help growers match herbicide-based weed management systems to their own production philosophies based on economic risk.