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Use of Allelopathy in Agriculture

Authors:
  • Lahore Garrison University, Lahore

Abstract

Biorational alternatives are gaining increased attention to weed control because of concerns related to pesticide usage, degradation and buildup in the soils. Allelopathy offers potential for weed control through the production and release of allelochemicals from leaves, flowers, seeds, stems and roots of living or decomposing plant materials. Allelopathy is a challenge at present and allelochemicals a resource.
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... Phragmites australis often behaves like a weed, with its high intraspecific genetic variation, remarkable phenotypic plasticity, ecological niche breadth, and high productivity (Eller et al., 2017). A salt-tolerant weed like (Khalid et al., 2002;El-Darier and Youssef, 2017;Cirillo et al., 2018), as we observed here. In salt-tolerant plants, enzymatic activity associated with reactive oxygen species (ROS) scavenging is high, as a means of stress defense (Munns and Tester, 2008). ...
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Phragmites australis is highly adaptable with high competitive ability and is widely distributed in the coastal wetland of the Yellow River Delta. However, allelopathic effects of P. australis on the growth of neighboring plants, such as Suaeda salsa , are poorly understood. In this study, germination responses of S. salsa seeds collected from two different habitats (intertidal zone and inland brackish wetland) to the extracts from different part of P. australis were compared. Potential allelopathic effects on germination percentage, germination rate, radicle length, and seedling biomass were analyzed. The germination of S. salsa was effectively inhibited by P. australis extract. Extract organ, extract concentration, and salt concentration showed different effects, the inhibitory rates were highest with belowground extract of P. australis between the four different parts. Germination percentage and germination rate were significantly decreased by the interactive effect of salt stress and extract concentration in S. salsa from a brackish wetland but not in S. salsa from the intertidal zone. The impact of different extracts of P. australis on radicle length and seedling biomass of S. salsa showed significant but inconsistent variation. The response index results showed that the higher concentration of extract solution (50 g·L ⁻¹ ) of P. australis had stronger inhibitory effect on the seed germination and seedling growth of S. salsa while the belowground extract had the strongest negative effect. Our results indicated that allelopathy is an important ecological adaptation mechanism for P. australis to maintain a high interspecific competitive advantage in the species’ natural habitat.
... A. viridius shoot and root lengths were inhibited significantly by C. erectus leaf extracts at all concentrations in Petri dishes, and root lengths in pots were inhibited at all concentrations (Table 2). Root length was inhibited in pots significantly compared to shoot length, because roots are more sensitive to allelochemicals [36,47]. In another study, A. viridius significantly inhibited the growth of several aromatic plants by allelochemicals [48]. ...
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Utilization of plant allelopathic potential to control weed infestations provides an effective, cost-efficient, labor-free, and environmentally acceptable alternative to traditional chemical and mechanical methods. Conocarpus erectus, known as buttonwood, belongs to the Combretaceae family with high contents of phytochemicals and antioxidant activity. There have been no studies on the allelopathic potential of C. erectus. The present study (1) examined the allelopathic potential of C. erectus against selected weeds (Chenopodium murale and Amaranthus viridis) and crops (Solanum lycopersicum and Cucumis sativus) via investigating the growth inhibition ability of its aqueous extract, and (2) identified the potential allelochemicals found in this plant. Aqueous extracts were prepared from leaves, roots, and seeds of C. erectus by immersing the dried powder of the examined plant parts in sterile distilled water for 24 h on a shaker set to 180 rpm. The resulting filtrate was considered as 100% solution, and then dilutions were made to various concentrations (75%, 50%, and 25%). C. erectus leaves and seeds showed the highest rate of inhibition at all concentrations against Chenopodium murale and Amaranthus viridis grown in either Petri dishes or pots. Conversely, all the studied extracts did not show any toxic effects against tomato and cucumber plants grown in pots. In Petri dishes, a slight reduction in growth was observed. HPLC analysis of total phenolic contents in C. erectus methanolic extracts showed that leaves have the highest contents of gallic acid, caffeic acid, and ferulic acid (153.963, 69.135, and 39.801 ppm, respectively). The finding of the current study demonstrated that the part of the plant and the concentration of extraction have a significant effect on phytotoxicity. The positive results of this study might be used to develop environmentally-friendly herbicides for agricultural purposes.
... Weed control via biorational approaches is becoming more popular as increased chemical use leads to soil damage (Shahida et al., 2002;Aktar et al., 2009). Crops that release allelopathic substances may be incorporated into rotation schemes to limit the germination and emergence of certain weed species (Khan et al., 2005;Scavo et al., 2018). ...
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The world's population will continue to expand in the future, necessitating increased food production to meet people's nutritional needs. Weed infestation is a key stumbling block in increasing global food productivity. In conventional agriculture, herbicides are the primary weed-control tool. Herbicide use has, however, led in the emergence of herbicide-resistant weeds, making weed control difficult. Weed management practises that are both sustainable and environmentally benign favour crop plants by reducing weed-crop competition. Concerted efforts have been taken with the objective to formulate suitable cropping strategies for reducing weed niches. Hence, the current literature evaluation focuses on the extent to which cropping strategies aids to reduce weed habitat.
... It has presented an alternative for developing eco-friendly agricultural practices, enhancing crop productivity, and maintaining ecosystem stability 15 . Moreover, allelopathic interactions may be significant in ecosystems by influencing weed control and crop productivity 16 . ...
... Furthermore, strict legislation, less persistent or rapid degradation and variation in the composition of active ingredients with plants grown in different climatic conditions prevent the large scale adoption of botanical fungicides (Isman and Grieneisen, 2014). A group researcher reveals that the toxic effect of botanical fungicides normally disappears within 14-21 days (Khalid et al., 2002). For the production of botanical fungicides in commercial scale, it requires large biomass of selective plants (Isman, 2006). ...
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About 70-80% losses in agricultural production due to microbial disease is caused by fungal pathogens. There are around 8,000 fungal species that cause 100,000 diseases in plants. It is impossible to control such a large species of fungi with chemical fungicides alone. Even if it is made possible, it would bring negative impacts to the environment and human health. Thus, it is a high time to seek an alternative to chemical fungicides which should be eco-friendly. Botanical fungicides can be the viable and sustainable alternative in this regard. A number of researches have proved the fungicidal properties of phytochemicals. They are easily degradable; maintain soil properties and safe to the environment and human. In the present context, researchers are showing interest towards botanical fungicides. Nevertheless, their commercialization and wide-scale adoption have not yet achieved. Thus, this study aims to reveal the current status and fungicidal properties of various potential plants and, also to investigate challenges for its adoption in commercial scale through critical analysis of the related literatures. Lack of sufficient knowledge and extension facilities at the farmer's level and slow result as compared to chemical fungicides are the major reasons behind their poor adoption. Thus, it is a high time for the collaboration among researchers, policy makers, businessman and farmers for the exploration, legalization, proper marketing and wide-scale adoption of botanical fungicides. If the approaches like sustainable agriculture, organic farming and integrated pest management (IPM) need to be extended, focuses should be given towards botanical fungicides.
... The reason of low weed density in S-B cropping system is allelopathic potential of sorghum crop (Farooq et al. 2017;Jabran 2017;Khan et al. 2012;Weston et al. 2013), which significantly suppresses weed populations. Sorghum releases some weed suppressive compounds, including phenolic acids, hydrophilic compounds, hydrophobic substances e.g., sorgoleone and its analogues (Czarnota et al. 2003;Lehle and Putnam 1983), which suppress several weed species (Cheema and Khaliq 2000;Farooq et al. 2020;Jabran and Farooq 2013;Jabran 2017;Khalid et al. 2002;Weston et al. 2013). Higher weed diversity and density was recorded in multiple (e.g. ...
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Tillage is among the most important soil management practices, which exert strong impacts on weed flora composition in different cropping systems. The large-scale adoption of tillage and cropping systems warrants thorough investigation regarding their impacts on weed flora composition. Therefore, this study was aimed to assess weed flora composition of various barley-based cropping systems (BBCSs) under different tillage practices (TPs). Barley was sown in fallow-barley (F-B), maize-barley (M-B), cotton-barley (C-B), mungbean-barley (Mu-B) and sorghum-barley (S-B) cropping systems with zero tillage (ZT), conventional tillage (CT), minimum tillage (MT), strip tillage (ST) and CT with bed sowing (CTBS). Significant differences (p < 0.05) were recorded among study years and interactions among BBCSs and TPs. The C-B system with ST during 1st year recorded the highest density (35 m− 2) of broadleaved weeds, whereas the highest density (37.76 m− 2) of broadleaved weeds was noted for the same cropping system with MT. All TPs, except BS resulted in increased density of broadleaved weeds in 2nd year compared with 1st year of the study, whereas BS reduced broadleaved weeds’ density during 2nd year. Nonetheless, M-B cropping system with ST and S-B cropping system with CTBS recorded the lowest density of broadleaved weeds during 1st and 2nd year, respectively. Similarly, C-B cropping system with ZT (39.33 m− 2) and MT (24.00 m− 2) recorded the lowest density of grassy weeds during 1st and 2nd year respectively. Nonetheless, S-B system with CTBS and S-B and Mu-B systems with ST recorded no grassy weeds during 1st and 2nd year, respectively. The S-B and M-B cropping systems suppressed various broadleaved and grassy weed species due to their allelopathic potential. In conclusion, different BBCSs had varying weed flora composition under different TPs. Adapting ST and CTBS can lower weed infestation. Similarly, inclusion of sorghum in rotation could be a viable option for effective weed management of barley-based cropping systems. Moreover, long-term experiments are needed to infer the weed seed bank in different TPs and BBCSs.
... Moreover, in recent decades, studies were performed looking for alternatives to glyphosate. There is a rise in efficacy tests using different natural (or even modified) allelo-chemicals obtained from essential oils for pest-control [81][82][83][84][85][86][87][88][89][90][91][92][93][94][95][96], as well as in their use as herbicides [97][98][99][100][101][102][103][104][105][106][107][108][109][110][111][112]. ...
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Agro-industries should adopt effective strategies to use agrochemicals such as glypho-sate herbicides cautiously in order to protect public health. This entails careful testing and risk assessment of available choices, and also educating farmers and users with mitigation strategies in ecosystem protection and sustainable development. The key to success in this endeavour is using scientific research on biological pest control, organic farming and regulatory control, etc., for new developments in food production and safety, and for environmental protection. Education and research is of paramount importance for food and nutrition security in the shadow of climate change, and their consequences in food production and consumption safety and sustainability. This review, therefore, diagnoses on the use of glyphosate and the associated development of glyphosate-resistant weeds. It also deals with the risk assessment on human health of glyphosate formulations through environment and dietary exposures based on the impact of glyphosate and its metabolite AMPA-(aminomethyl)phosphonic acid-on water and food. All this to setup further conclusions and recommendations on the regulated use of glyphosate and how to mitigate the adverse effects.
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Allelopathic inhibition typically results from the combined action of a group of allelochemicals which, collectively, interfere with several physiological processes. The objectives of this paper are to summarize research that illustrates the joint action of allelochemicals, and to provide evidence that both the amount and detrimental action of these compounds depends an the extent of associated abiotic and biotic stresses. Allelopathy is strongly coupled with other stresses of the crop environment, including insects and disease, temperature extremes, nutrient and moisture variables, radiation, and herbicides. These stress conditions often enhance allelochemical production, thus increasing the potential for allelopathic interference. In the paradigm of interactions, the data indicate that crops are more sensitive to allelopathy when moisture, temperature, or nutrient conditions are less than optimal. For example, the inhibition threshold concentration for ferulic acid to affect seedling growth was reduced with even minor moisture stress (ψ = -0.15 MPa) or a growth temperature at the higher end of the normal range for a species. Under greenhouse conditions, additive inhibition resulted from the joint action of ferulic acid with low levels of alachlor [2-chloro-N-(2,6-diethylphenyl)-N-(methoxymethyl)acetamide], atrazine [6-chloro-N-ethyl-N'-(1-methylethyl)-1,3,5-triazine-2,4-diamine], or trifluralin [2,6-dinitro-N,N-dipropyl-4-(trifluoromethyl)benzenamine]. Interactions of multiple stresses in crop environments will determine the relative impact of allelopathy. Allelopathy-stress interactions also have implications for herbicide and residue management strategies, crop rotations, biological control measures, and tillage practices that can contribute to a more sustainable agriculture.