Aqueous Extracts Prepared with Young <em>E. globulus L</em>eaves as a Biocide - A Novel Post-Fire Management Strategy of Eucalyptus Stands

Along with climate change, the native forest replacement by exotic species, such as Eucalyptus globulus, is contributing to a highly fire-prone environment. Since E. globulus detains several post-fire regeneration strategies, sustainable practices are needed to manage eucalyptus stands. Thus, eucalyptus allelopathic potential can be used for weed control. Therefore, this study aimed at assessing the herbicidal potential of post-fire regenerated E. globulus leaves in Portulaca oleracea, and unraveling the main physiological processes disturbed by biocide application. For this, an aqueous extract prepared with fresh leaves (FLE; 617 gfresh weightL-1) and other with oven-dried leaves (DLE; 250 gdry weightL-1) were prepared and foliar-sprayed twice-a-week at different dilutions in 7-days-old purslane plants. As positive control, glyphosate was used. After five weeks, results revealed that DLE at the highest dose detained the greatest herbicidal activity against P. oleracea. To understand how DLE impacted weed physiology, several biochemical and redox-related parameters were evaluated in purslane plants treated with DLE highest dose. Results suggested an overproduction of hydrogen peroxide, causing severe oxidative damage in roots. Overall, this study showed that young E. globulus dried leaves had powerful herbicidal properties against P. oleracea and can represent a feasible approach for weed management, while reducing fire hazard.

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Herbicidal Effects and Cellular Targets of Aqueous Extracts from Young Eucalyptus globulus Leaves - A Novel Post-Fire Management Strategy of Eucalyptus Stands

10.20944/preprints202103.0047.v3 ◽

2021 ◽

Author(s):

Mafalda Pinto ◽

Cristiano Soares ◽

Maria Martins ◽

Bruno Sousa ◽

Inês Valente ◽

...

Keyword(s):

Weed Management ◽

Eucalyptus Globulus ◽

Management Strategy ◽

Fire Hazard ◽

Positive Control ◽

Herbicidal Activity ◽

Native Forest ◽

Allelopathic Potential ◽

Cellular Targets ◽

Physiological Processes

Along with climate change, the native forest replacement by exotic species, such as Eucalyptus globulus, is contributing to a highly fire-prone environment. Since E. globulus detains several post-fire regeneration strategies, sustainable practices are needed to manage eucalyptus stands. Thus, eucalyptus allelopathic potential can be used for weed control. Therefore, this study aimed at assessing the herbicidal potential of post-fire regenerated E. globulus leaves in Portulaca oleracea, and unraveling the main physiological processes disturbed by biocide application. For this, an aqueous extract prepared with fresh leaves (FLE; 617 gfresh weightL-1) and other with oven-dried leaves (DLE; 250 gdry weightL-1) were prepared and foliar-sprayed twice-a-week at different dilutions in 7-days-old purslane plants. As positive control, glyphosate was used. After five weeks, results revealed that DLE at the highest dose detained the greatest herbicidal activity against P. oleracea. To understand how DLE impacted weed physiology, several biochemical and redox-related parameters were evaluated in purslane plants treated with DLE highest dose. Results suggested an overproduction of hydrogen peroxide, causing severe oxidative damage in roots. Overall, this study showed that young E. globulus dried leaves had powerful herbicidal properties against P. oleracea and can represent a feasible approach for weed management, while reducing fire hazard.

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Crop Allelopathy for Sustainable Weed Management in Agroecosystems: Knowing the Present with a View to the Future

Agronomy ◽

10.3390/agronomy11112104 ◽

2021 ◽

Vol 11 (11) ◽

pp. 2104

Author(s):

Aurelio Scavo ◽

Giovanni Mauromicale

Keyword(s):

Weed Management ◽

Management Strategy ◽

Field Experiments ◽

De Novo ◽

Integrated Approach ◽

Integrated Weed Management ◽

Allelopathic Potential ◽

Cover Cropping ◽

The Face ◽

As Stress

In the face of yield losses caused by weeds, especially in low-input agricultural systems, and environmental pollution due to the excessive use of synthetic herbicides, sustainable weed management has become mandatory. To address these issues, allelopathy, i.e., the biochemical phenomenon of chemical interactions between plants through the release of secondary metabolites into the environment, is gaining popularity. Although many important crops are known for their allelopathic potential, farmers are still reluctant to use such knowledge practically. It is therefore important to assist advisors and farmers in assessing whether allelopathy can be effectively implemented into an eco-friendly weed management strategy. Here, we aim to give a comprehensive and updated review on the herbicidal potential of allelopathy. The major findings are the following: (1) Crops from different botanical families show allelopathic properties and can be cultivated alone or in combination with other non-allelopathic crops. (2) Many allelopathic tools can be adopted (crop rotation, intercropping, cover cropping as living or dead mulches, green manuring, use of allelochemical-based bioherbicides). (3) These methods are highly flexible and feature increased efficiency when combined into an integrated weed management strategy. (4) Recent advances in the chemistry of allelopathy are facilitating the use of allelochemicals for bioherbicide production. (5) Several biotechnologies, such as stress induction and genetic engineering techniques, can enhance the allelopathic potential of crops or introduce allelopathic traits de novo. This review shows how important the role of allelopathy for sustainable weed management is and, at the same time, indicates the need for field experiments, mainly under an integrated approach. Finally, we recommend the combination of transgenic allelopathy with the aforementioned allelopathic tools to increase the weed-suppressive efficacy of allelopathy.

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Herbicidal Effects and Cellular Targets of Aqueous Extracts from Young Eucalyptus globulus Labill. Leaves

Plants ◽

10.3390/plants10061159 ◽

2021 ◽

Vol 10 (6) ◽

pp. 1159

Author(s):

Mafalda Pinto ◽

Cristiano Soares ◽

Maria Martins ◽

Bruno Sousa ◽

Inês Valente ◽

...

Keyword(s):

Climate Change ◽

Weed Management ◽

Eucalyptus Globulus ◽

Redox Homeostasis ◽

Herbicidal Activity ◽

Aqueous Extracts ◽

Oxygen Species ◽

Cellular Viability ◽

Physiological Mechanisms ◽

Cellular Targets

Eucalyptus globulus Labill. is a widespread exotic species that contributes to the formation of fire-prone environments, a great concern under climate change conditions. Therefore, sustainable practices to help locals managing eucalyptus stands are needed. In this perspective, harnessing eucalyptus’ specialized metabolism as a source of allelochemicals can be a promising approach for weed control. Thus, the main goals of this work were to evaluate the herbicidal potential of post-fire regenerated E. globulus leaves against Portulaca oleracea L. and to unravel the physiological mechanisms behind this phytotoxic action. For this, aqueous extracts of fresh (FLE; 617 g FW L−1) or oven-dried leaves (DLE; 250 g DW L−1) were foliar-sprayed at different dilutions in purslane seedlings. After five weeks, results revealed that DLE at the highest dose detained the greatest herbicidal activity, affecting purslane growth and cellular viability. Moreover, biochemical data pointed towards an overproduction of reactive oxygen species, causing harsh oxidative damage in roots, where the upregulation of important cellular players, like sugars, amino acids, and proline, was not able to reestablish redox homeostasis. Overall, this study proved that dried leaves from young E. globulus had potent herbicidal properties against P. oleracea and can represent a feasible strategy for weed management.

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POTENSI ALELOKIMIA DARI EXTRACT DAN MULSA BIOMAS TANAMAN SORGUM (Sorghum bicolor L. Moench)

Jurnal Ilmu-Ilmu Pertanian Indonesia ◽

10.31186/jipi.23.2.121-128 ◽

2021 ◽

Vol 23 (2) ◽

pp. 121-128

Author(s):

Advent F. Sitanggang ◽

Marulak Simarmata ◽

Bilman Wilman Simanihuruk ◽

Uswatun Nurjanah

Keyword(s):

Aqueous Extract ◽

Weed Management ◽

Plant Biomass ◽

Dry Weight ◽

Early Growth ◽

Integrated Weed Management ◽

Allelopathic Potential ◽

Vigor Index ◽

Test Plants ◽

Sorghum Bicolor L

[ALLELOCHEMICAL POTENTIAL OF AQUEOUS EXTRACT AND MULCH OF PLANT BIOMASS OF SORGHUM (Sorgum bicolor L. Moench)]. This study was aimed to examine the allelopathic potential of sorghum through aqueous extract and mulch from biomass on seed germination and early growth of three tested plants, namely rice, mustard and cucumber. The results showed that the aqueous extract of the sorghum biomass significantly inhibited the germination of mustard and cucumber seeds, reduced the vigor-index of the germination of rice, mustard and cucumber seeds, and suppressed the growth of radicle length of mustard sprouts. The same thing was seen when sorghum biomass was tested as mulch which also suppressed the early growth of the tested plants on the variables of stem height, fresh and dry weight of biomass of rice, mustard and cucumber. The higher the concentration of allelochemicals extract or sorghum mulch, the stronger the inhibition on germination and early growth of the three test plants. At a concentration of 10% allelochemicals suppressed the germination of mustard and cucumber to 76 and 79%, respectively, while a dose of 10% mulch suppressed early growth in the height of rice, mustard, and cucumber to 56, 55, and 68%; and dry weight to 53, 30 and 60%. The results of this study are important information about the allelochemical potential of sorghum as a natural herbicide in integrated weed management

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Allelopathic potential of Artemisia herba-alba and Anthemis arvensis to control Weeds in Wheat (Triticum aestivum) and Barley (Hordeum vulgare)

South Asian Journal of Experimental Biology ◽

10.38150/sajeb.6(3).p95-100 ◽

2016 ◽

Vol 6 (3) ◽

pp. 95-100

Author(s):

Nadi Awwad Al Harbi

Keyword(s):

Triticum Aestivum ◽

Hordeum Vulgare ◽

Aqueous Extract ◽

Weed Management ◽

Allelopathic Effect ◽

Weed Species ◽

Crop Species ◽

Allelopathic Potential ◽

Anthemis Arvensis ◽

Germination And Growth

The aim of the present study was to investigate the potentials for utilization of Artemisia herba-alba and Anthemis arvensis shoot aqueous extract at different concentrations (1%, 3%, and 5%) to suppress the germination and growth of Panicum turgidum and Portulaca oleracea (weeds of crop fields) in Petri dish experiment. Results indicated that the degree of inhibition on seed germination and growth of the recipient species was largely dependent on the concentration of A. herba-alba and A.arvensis shoot aqueous extract. The aqueous extract of A.herba-alba showed the highest allelopathic effect on the germination of the seeds of P. turgidum, (10%,10% and 0%) while the effect of A. arvensis shoot aqueous extract was greater on the germination of the seeds P. oleracea (40%,0% and 0%). Percentage germination of the two selected crop species Triticum aestivum and Hordeum vulgare also de-creased as the A.herba-alba and A.arvensis shoot aqueous extract concentra-tion increased from 1% to 5% (90%,80% and 70%),(40%,40% and 20%). But the inhibition percentage was largely less than that of weed species. The results also showed that H.vulgare was more sensitive than T. aestivum and responds more strongly to the increase of concentration of A. herba-alba shoot aqueous extract . Results also showed that the radicle length of almost all tested species was more sensitive to allelochemicals from A.herba-alba and A.arvensis shoot aqueous extract than plumule length. Therefore, A. herba-alba and A. arvensis shoot aqueous extract may offer promises for their usefulness as a tool for weed management.

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Allelopathic potential of mustard crop residues on weed management and performance of transplant Aman rice

Journal of the Bangladesh Agricultural University ◽

10.3329/jbau.v15i2.35054 ◽

2017 ◽

Vol 15 (2) ◽

pp. 133-139

Author(s):

MN Hossain ◽

MR Uddin ◽

UK Sarker ◽

S Ferdousi ◽

MJ Uddin

Keyword(s):

Grain Yield ◽

Weed Management ◽

Crop Residues ◽

Block Design ◽

Crop Productivity ◽

Weed Species ◽

Allelopathic Potential ◽

Straw Yield ◽

Percent Inhibition ◽

Mustard Crop

Crop allelopathy may be useful to minimize serious problems in the present agricultural production such as environmental pollution, unsafe production, human health concerns, depletion of crop diversity, soil sickness and reduction of crop productivity. In this phenomenon an experiment was conducted at the Agronomy Field Laboratory, Bangladesh Agricultural University, Mymensingh to evaluate the effect of crop residues of mustard on weed management and crop performance of T. aman rice. The experiment consisted of three cultivars of T. aman rice viz., BR11, BR23 and BRRI dhan49 and five different level of mustard crop residues such as no crop residues, mustard crop residues @ 0.5, 1.0, 1.5 and 2.0 t ha–1. The experiment was laid out in a randomized complete block design with three replications. Five weed species belonging to three families infested the experimental plots. Weed population, weed dry weight and percent inhibition of weed were significantly influenced by mustard crop residues and cultivar. The maximum weed growth was noticed with the cultivar BR23 and the minimum was found in the cultivar BR11. The grain yield as well as the other yield contributing characters produced by BR11 was the highest among the studied varieties. The highest percent inhibition of 71.17, 69.19, 80.88, 70.48 and 86.97 was in Shama (Echinochlo acrusgalli), Panishapla (Nymphaea nouchali), Panichaise (Scirpus juncoides), Panikachu (Monochoria vaginalis) and Susnishak (Marsilea quadrifolia), respectively which was caused by the application of mustard crop residues @ 2 t ha–1. The highest loss of grain yield was obtained where no crop residues were incorporated. The highest numbers of tillers hill-1, numbers of grains panicle–1, 1000-grain weight, grain yield, straw yield were observed where mustard crop residues were incorporated @ 2.0 t ha–1. BR11 cultivar with all treatments produced the highest grain and straw yield among the treatment combination. The results of this study indicate that different amount of mustard crop residues showed potential activity to suppress weed growth.J. Bangladesh Agril. Univ. 15(2): 133-139, December 2017

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A linuron-free weed management strategy for carrots

Weed Technology ◽

10.1017/wet.2018.112 ◽

2019 ◽

Vol 33 (03) ◽

pp. 464-474

Author(s):

Tessa de Boer ◽

Peter Smith ◽

Kevin Chandler ◽

Robert Nurse ◽

Kristen Obeid ◽

...

Keyword(s):

Effective Dose ◽

Pest Management ◽

Weed Management ◽

Management Strategy ◽

Seedling Emergence ◽

Growing Season ◽

Field Trials ◽

Organic Soils ◽

Biologically Effective Dose ◽

And Control

AbstractThe development of a linuron-free weed management strategy for carrot production is essential as a result of the herbicide reevaluation programs launched by the Pest Management Regulatory Agency in Canada for herbicides registered before 1995 and the discovery of linuron-resistant pigweed species in Ontario. Field trials were conducted in one of Ontario’s main carrot-growing regions on high organic soils in 2016 and 2017. Pigweed species seedlings were effectively controlled with PRE treatments of prometryn, pendimethalin, S-metolachlor, or glufosinate. POST treatments of pyroxasulfone and metribuzin followed by predetermined biologically effective dose (≥90% control of pigweed seedlings) of acifluorfen, oxyfluorfen, fluthiacet-methyl, and fomesafen achieved excellent crop selectivity and commercially acceptable pigweed species seedling control under field conditions. Carfentrazone-ethyl or fomesafen applied PRE severely reduced seedling emergence and yield in the wet growing season of 2017. This study demonstrated clearly that an alternative linuron-free strategy can be developed for carrots. The strategy of exploring the potential to use the biologically effective dose of selected herbicides to achieve crop selectivity and control of pigweed species seedlings was verified.

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Can results from a laboratory bioassay be used as an indicator of field performance of rice cultivars with allelopathic potential against Damasonium minus (starfruit)?

Australian Journal of Agricultural Research ◽

10.1071/ar06333 ◽

2008 ◽

Vol 59 (2) ◽

pp. 183 ◽

Cited By ~ 15

Author(s):

Alexa N. Seal ◽

James E. Pratley ◽

Terry Haig

Keyword(s):

Weed Management ◽

Dry Matter ◽

Field Performance ◽

Strong Relationship ◽

Dry Weight ◽

Integrated Weed Management ◽

Rice Cultivars ◽

Laboratory Bioassay ◽

Allelopathic Potential ◽

Control Comparison

Several weeds of rice in Australia have developed resistance to the main herbicide available for their control. Allelopathy is one phenomenon that could be incorporated into an integrated weed-management system as a supplement or alternative to synthetic herbicides. Several rice cultivars were screened both in the laboratory and the field for allelopathic potential against a major rice weed, Damasonium minus. Results from the laboratory bioassay showed that there were significant differences among cultivars in their ability to inhibit D. minus root growth. D. minus root lengths ranged from 2.0% (cv. Hungarian #1) to 32.6% (cv. Rexmont) that of the control. In the field study, significant differences existed in the D. minus dry matter grown in association with different cultivars, ranging from 4.6% (cv. Tono Brea) to 72.2% (cv. Rexmont) that of the control. Comparison between laboratory and field results indicated a strong relationship between performance in the field and in the laboratory (r2 = 0.713). Those cultivars ranked as allelopathic in the bioassay tended to have associated lower D. minus dry weight in the field. Eight of the top 10 allelopathic cultivars in the bioassay were among the top 10 suppressive cultivars in the field trial. This important finding indicates that at least some of the variation in field performance of cultivars may be predicted by their performance in bioassays.

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Identifying Forest Fire Driving Factors and Related Impacts in China Using Random Forest Algorithm

Forests ◽

10.3390/f11050507 ◽

2020 ◽

Vol 11 (5) ◽

pp. 507

Author(s):

Wenyuan Ma ◽

Zhongke Feng ◽

Zhuxin Cheng ◽

Shilin Chen ◽

Fengge Wang

Keyword(s):

Random Forest ◽

Forest Fire ◽

Forest Fires ◽

Fire Management ◽

Fire Hazard ◽

Management Strategies ◽

Driving Factors ◽

Socioeconomic Variables ◽

Forest Fire Management ◽

Geographical Regions

Reasonable forest fire management measures can effectively reduce the losses caused by forest fires and forest fire driving factors and their impacts are important aspects that should be considered in forest fire management. We used the random forest model and MODIS Global Fire Atlas dataset (2010~2016) to analyse the impacts of climate, topographic, vegetation and socioeconomic variables on forest fire occurrence in six geographical regions in China. The results show clear regional differences in the forest fire driving factors and their impacts in China. Climate variables are the forest fire driving factors in all regions of China, vegetation variable is the forest fire driving factor in all other regions except the Northwest region and topographic variables and socioeconomic variables are only the driving factors of forest fires in a few regions (Northwest and Southwest regions). The model predictive capability is good: the AUC values are between 0.830 and 0.975, and the prediction accuracy is between 70.0% and 91.4%. High fire hazard areas are concentrated in the Northeast region, Southwest region and East China region. This research will aid in providing a national-scale understanding of forest fire driving factors and fire hazard distribution in China and help policymakers to design fire management strategies to reduce potential fire hazards.

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