scholarly journals Farming without Glyphosate?

Plants ◽  
2020 ◽  
Vol 9 (1) ◽  
pp. 96 ◽  
Author(s):  
Hugh J. Beckie ◽  
Ken C. Flower ◽  
Michael B. Ashworth

Recent statements from scientific organisations and court decisions have resulted in widespread public interest and concern over the safety of glyphosate, the most popular and effective herbicide used worldwide. Consequently, glyphosate-based products are under intense scrutiny from governments at all levels. Some jurisdictions have already banned or restricted its use, which will adversely impact international trade in bulk grain commmodities if glyphosate residues are detected. The possibility of farming without glyphosate is becoming an important issue facing the agri-food research and development sector. Contingency plans need to be formulated if that scenario becomes a reality. In this review, we briefly summarize international events that have led to this possible situation, describe current glyphosate usage in major agronomic field crops worldwide, outline possible alternatives to glyphosate in two agroregions and perform bioeconomic model scenarios of southern Australian broadacre cropping systems without the herbicide. Model predictions suggest that we can farm profitably without glyphosate by consistently utilizing key non-herbicidal weed management practices combined with robust pre-emergence soil residual herbicide treatments. However, maintaining low weed seed banks will be challenging. If the social license to use glyphosate is revoked, what other pesticides will soon follow?

2020 ◽  
pp. 1-10
Author(s):  
Émile Samson-Brais ◽  
Marc Lucotte ◽  
Matthieu Moingt ◽  
Gilles Tremblay ◽  
Serge Paquet

Repeated applications and combination of glyphosate-containing herbicides (GCH) with other herbicides are two weed management practices (WMP) used to compensate for GCH decreasing efficiency impacts in field crops. These practices may have serious impacts on soil functions because GCH affect soil biota and soil biological activity (SBA). Two field experiments, one with corn and one with soybean crops, were conducted during one growing season. SBA indicators, soil respiration (SR) and fluorescein diacetate (FDA) hydrolysis, were measured at two sampling times following six WMP. These WMP included one or two GCH applications (GCH alone or combined with other herbicides), applications of other herbicides only and mechanical weeding. WMP did not affect FDA neither for corn or soybean at either sampling times. In contrast, WMP affected SR in corn fields at both sampling times and SR in soybean field at the first sampling time. Repeating GCH applications and combining different herbicides led to lower SR, suggesting that these practices decreased SBA, whilst one single GCH application presented higher SR, suggesting that this practice stimulated SBA. Our study demonstrates that using GCH in combination with other herbicides or in multiple applications affects SBA in field conditions. Affecting soil functions and carbon cycle do bear serious weed management implications, and the choice of WMP should be taken into consideration to minimize their impacts on SBA for field crops sustainability.


Weed Science ◽  
2018 ◽  
Vol 66 (6) ◽  
pp. 729-737 ◽  
Author(s):  
Thomas R. Butts ◽  
Bruno C. Vieira ◽  
Débora O. Latorre ◽  
Rodrigo Werle ◽  
Greg R. Kruger

AbstractWaterhemp [Amaranthus tuberculatus(Moq.) J. D. Sauer] is a troublesome weed occurring in cropping systems throughout the U.S. Midwest with an ability to rapidly evolve herbicide resistance that could be associated with competitive disadvantages. Little research has investigated the competitiveness of differentA. tuberculatuspopulations under similar environmental conditions. The objectives of this study were to evaluate: (1) the interspecific competitiveness of three herbicide-resistantA. tuberculatuspopulations (2,4-D and atrazine resistant [2A-R], glyphosate and protoporphyrinogen oxidase [PPO]-inhibitor resistant [GP-R], and 2,4-D, atrazine, glyphosate, and PPO-inhibitor susceptible [2AGP-S]) with soybean [Glycine max(L.) Merr.]; and (2) the density-dependent response of eachA. tuberculatuspopulation within a constant soybean population in a greenhouse environment.Amaranthus tuberculatuscompetitiveness with soybean was evaluated across five target weed densities of 0, 2, 4, 8, and 16 plants pot−1(equivalent to 0, 20, 40, 80, and 160 plants m−2) with 3 soybean plants pot−1(equivalent to 300,000 plants ha−1). At the R1 soybean harvest time, no difference in soybean biomass was observed acrossA. tuberculatuspopulations. AtA. tuberculatusdensities <8 plants pot−1, the 2AGP-S population had the greatest biomass and stem diameter per plant. At the R7 harvest time, the 2AGP-S population caused the greatest loss in soybean biomass and number of pods compared with the other populations at densities of <16 plants pot−1. The 2AGP-S population had greater early-season biomass accumulation and stem diameter compared with the otherA. tuberculatuspopulations, which resulted in greater late-season reduction in soybean biomass and number of pods. This research indicates there may be evidence of interspecific competitive fitness cost associated with the evolution of 2,4-D, atrazine, glyphosate, and PPO-inhibitor resistance inA. tuberculatus. Focus should be placed on effectively using cultural weed management practices to enhance crop competitiveness, especially early in the season, to increase suppression of herbicide-resistantA. tuberculatus.


2021 ◽  
Author(s):  
Marie-Charlotte Bopp ◽  
Elena Kazakou ◽  
Aurelie Metay ◽  
Guillaume Fried

Winegrowers have diversified their weed management practices over the last two decades changing the structure and the composition of weed communities. Complementary to taxonomic studies, trait-based approaches are promising ways for a better understanding of weed communities responses to environmental and agronomic filters. In the present study, the impacts of climate, soil characteristics, seasons and weed management practices (chemical weeding, tillage and mowing) were assessed on weed communities from 46 plots in three French wine-growing regions (Champagne, Languedoc and Rhone valley). These agro-environmental gradients structuring weed communities according to their combinations of traits were highlighted using multivariate analysis (RLQ). The impacts of these filters on Community Weighted Means (CWM) and Community Weighted Variance (CWV) of weed communities were analysed using mixed and null modelling. Our results showed that spatio-temporal and weed management practices variables explained from 13% to 48% of the total variance of CWM (specific leaf area, maximum height, seed mass, flowering onset and duration and lateral spread). Region, seasonality and management practices explained 53%, 28% and 19% of CWM marginal variance, respectively. Weed management impacted CWM and CWV through two main gradients: (i) a soil disturbance gradient with high mechanical disturbance of soil in tilled plots and low mechanical disturbance in chemically weeded plots and (ii) a vegetation cover gradient with high vegetation abundance in mowed plots compared to more bare soils in tilled and chemically weeded plots. In Languedoc, chemical weeding filtered weed communities with ruderal strategy trait values (low seed mass, small-stature) while mowed communities were more competitive (higher seed mass, higher stature and lower SLA). In Languedoc and Champagne, tillage favoured communities with high seed mass that increases the viability of buried seeds and high lateral spread values associated to the ability to resprout after tillage. This study demonstrated that trait-based approaches can be successfully applied to perennial cropping systems such as vineyards, in order to understand community assembly to better guide weed management practices.


Author(s):  
Muhammad Usman ◽  
Khalid Mehmood Ch. ◽  
Ijaz Ashraf ◽  
Asif Tanveer

This study was conducted in district Gujranwala with the major objective to identify factors impeding the awareness level and adoption of weed management practices among the farmers from Rice-Wheat, Rice-Potato, Rice-Maize and Rice-Peas cropping systems. Total 356 farmers, selected through the proportionate sampling technique from four cropping systems participated in the study. Data were collected through a structured and validated questionnaire through a face-to-face interview technique and analyzed with the help of Statistical Package for Social Sciences (SPSS). Findings indicated that, inadequate resources, knowledge and limited exposure to the information sources were the factors influencing the awareness level among farmers across the four cropping systems Shortage of finance, high cost of inputs, high cost of diesel and possession of inadequate knowledge were the barriers impeding adoption level. This study suggests that, in order to create awareness and foster the adoption of recommended weed management technologies to further curb the yield losses, the Extension Field Staff should strive to build technical knowledge among farmers through diversified teaching activities. The Integration of Information Communication Technologies (ICTs) could help EFS to meet farmers information needs. Furthermore, public-private partnership is also recommended especially for the effective weeds’ management on farm level.


2011 ◽  
Vol 62 (11) ◽  
pp. 1002 ◽  
Author(s):  
Jeff Werth ◽  
David Thornby ◽  
Steve Walker

Glyphosate resistance will have a major impact on current cropping practices in glyphosate-resistant cotton systems. A framework for a risk assessment for weed species and management practices used in cropping systems with glyphosate-resistant cotton will aid decision making for resistance management. We developed this framework and then assessed the biological characteristics of 65 species and management practices from 50 cotton growers. This enabled us to predict the species most likely to evolve resistance, and the situations in which resistance is most likely to occur. Species with the highest resistance risk were Brachiaria eruciformis, Conyza bonariensis, Urochloa panicoides, Chloris virgata, Sonchus oleraceus and Echinochloa colona. The summer fallow and non-irrigated glyphosate-resistant cotton were the highest risk phases in the cropping system. When weed species and management practices were combined, C. bonariensis in summer fallow and other winter crops were at very high risk. S. oleraceus had very high risk in summer and winter fallow, as did C. virgata and E. colona in summer fallow. This study enables growers to identify potential resistance risks in the species present and management practices used on their farm, which will to facilitate a more targeted weed management approach to prevent development of glyphosate resistance.


Weed Science ◽  
2012 ◽  
Vol 60 (1) ◽  
pp. 27-33 ◽  
Author(s):  
D. O. Ferraro ◽  
C. M. Ghersa ◽  
D. E. Rivero

Weed composition may vary because of natural environment, management practices, and their interactions. In this study we presented a systematic approach for analyzing the relative importance of environmental and management factors on weed composition of the most conspicuous species in sugarcane. A data-mining approach represented byk-means cluster and classification and regression trees (CART) were used for analyzing the 11 most frequent weeds recorded in sugarcane cropping systems of northern Argentina. Data of weed abundance and explanatory factors contained records from 1976 sugarcane fields over 2 consecutive years. Thek-means method selected five different weed clusters. One cluster contained 44% of the data and exhibited the lowest overall weed abundance. The other four clusters were dominated by three perennial species, bermudagrass, johnsongrass, and purple nutsedge, and the annual itchgrass. The CART model was able to explain 44% of the sugarcane's weed composition variability. Four of the five clusters were represented in the terminal nodes of the final CART model. Sugarcane burning before harvesting was the first factor selected in the CART, and all nodes resulting from this split were characterized by low abundance of weeds. Regarding the predictive power of the variables, rainfall and the genotype identity were the most important predictors. These results have management implications as they indicate that the genotype identity would be a more important factor than crop age when designing sugarcane weed management. Moreover, the abiotic control of crop–weed interaction would be more related to rainfall than the environmental heterogeneity related to soil type, for example soil fertility. Although all these exploratory patterns resulting from the CART data-mining procedure should be refined, it became clear that this information may be used to develop an experimental framework to study the factors driving weed assembly.


1996 ◽  
Vol 76 (4) ◽  
pp. 795-797 ◽  
Author(s):  
Jianhua Zhang ◽  
Allan S. Hamill ◽  
Susan E. Weaver

In this study, corn yield was measured after 10 yr of various rotational sequences of corn, soybeans, and wheat or oats, and under three levels of weed management to determine the effects of land use history on crop yield. Corn yield varied significantly with both crop rotation and weed management. Com yields were lower after continuous corn or soybeans or immediately following corn, and higher after a cereal crop or a rotation including a cereal. Herbicide application alone maintained significantly higher corn yield than inter-row cultivation across cropping systems. Key words: Corn yield, crop rotation, Zea mays


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 ◽  
2019 ◽  
Vol 67 (6) ◽  
pp. 673-681 ◽  
Author(s):  
Margaret G. Ball ◽  
Brian A. Caldwell ◽  
Antonio DiTommaso ◽  
Laurie E. Drinkwater ◽  
Charles L. Mohler ◽  
...  

AbstractWeed management is a major challenge in organic crop production, and organic farms generally harbor larger weed populations and more diverse communities compared with conventional farms. However, little research has been conducted on the effects of different organic management practices on weed communities and crop yields. In 2014 and 2015, we measured weed community structure and soybean [Glycine max (L.) Merr.] yield in a long-term experiment that compared four organic cropping systems that differed in nutrient inputs, tillage, and weed management intensity: (1) high fertility (HF), (2) low fertility (LF), (3) enhanced weed management (EWM), and (4) reduced tillage (RT). In addition, we created weed-free subplots within each system to assess the impact of weeds on soybean yield. Weed density was greater in the LF and RT systems compared with the EWM system, but weed biomass did not differ among systems. Weed species richness was greater in the RT system compared with the EWM system, and weed community composition differed between RT and other systems. Our results show that differences in weed community structure were primarily related to differences in tillage intensity, rather than nutrient inputs. Soybean yield was lower in the EWM system compared with the HF and RT systems. When averaged across all four cropping systems and both years, soybean yield in weed-free subplots was 10% greater than soybean yield in the ambient weed subplots that received standard management practices for the systems in which they were located. Although weed competition limited soybean yield across all systems, the EWM system, which had the lowest weed density, also had the lowest soybean yield. Future research should aim to overcome such trade-offs between weed control and yield potential, while conserving weed species richness and the ecosystem services associated with increased weed diversity.


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