Alternative Control Methods Research Articles

Ecotoxicological effects of a glyphosate-based herbicide on Gryllus (Gryllus) assimilis (Orthoptera: Gryllidae) ontogeny: a study on antioxidant system, oxidative stress and cholinergic system.

Brazil is an important global agricultural producer and to increase production the country has extensively used glyphosate-based herbicides (GBH), surpassing consumption and sales records. Consequently, concerns have arisen regarding the potential impact of GBH on ecosystems and non-target organisms. Thus, the effects of GBH exposure were evaluated throughout the cricket Gryllus (Gryllus) assimilis ontogeny, with five developmental stages. Each period contained 3 control and 3 treated boxes, with 15 crickets each, resulting in 90 insects at a time. The control groups received water, while the treated ones were continuously exposed to GBH (0.864 mg.GBH.L-1), with the solutions changed every 48 h. After each exposure time the crickets' group were euthanized to assess the activity of antioxidant enzymes (GST, GR, GPx, and CAT), cholinergic enzymes (ChE), and lipid peroxidation (LPO). The results revealed changes in the systems throughout different developmental phases. Specifically, CAT activity exhibited a significant increase during the nymphal phase, associated with the dismutation of hydrogen peroxide. The GBH increased GST, indicating its role in cellular detoxification, particularly during adulthood. In the senescence stage there was a considerable rise in ChE enzymes, suggesting their involvement in both, choline esters breakdown and potential pesticide detoxification. The action of these enzymes to effectively control lipid peroxidation shows the adaptability of this species to environmental contamination. These findings underscore the long-term effects of agrochemical pollution and emphasize the importance of sustainable practices, effective regulations, and alternative weed control methods.

Alternative control of bacterial leaf blight of eucalypt using essential oils

Bacterial leaf blight, attributed to Xanthomonas citri pv. eucalyptorum comb. nov., poses a significant threat to eucalypt nursery and field conditions in Brazil, resulting in substantial annual losses. While various disease management practices are employed, the quest for alternative control methods and environmentally friendly antimicrobial agents remains imperative. Thus, this project was developed to assess the potential efficacy in vitro of essential oils derived from tea tree (Melaleuca alternifolia), copaíba (Copaifera officinalis), and lemongrass (Cymbopogon spp.) against X. citri pv. eucalyptorum. The sensitivity of the bacteria to these oils was examined via antibiogram testing, with each antibiogram subjected to different oil dilutions (6.25 %, 10.00 %, 12.50 %, 25.00 %, 50.00 %, and 100.00 %). Inhibition zones were assessed to determine the inhibitory capacity of each compound on microbial growth, and statistical analysis was conducted using the Mann-Whitney test. Copaíba oil did not exhibit any inhibitory effect on the pathogen growth in vitro. Conversely, both lemongrass and tea tree oils displayed inhibitory effects on the target bacteria, with a minimum inhibitory concentration of 12.50 %. Furthermore, no significant distinctions were observed between the utilization of 12.50 % and 25.00 % concentrations of tea tree, neither between 25.00 % of lemongrass or 50.00 % of tea tree dilutions. These findings may pave the way for new strategies in pathogen management.

Response of the tomato leaf miner Phthorimaea absoluta to wild and domesticated tomato genotypes.

Phthorimaea absoluta, a highly destructive invasive pest, poses a significant threat to tomato production globally. Exploring alternative control methods, such as host plant resistance can contribute to diminish reliance on insecticides and promote sustainable integrated pest management (IPM) practices. Thus, the identification of new P. absoluta-resistant tomato cultivars and potential wild sources for breeding programmes remains imperative. We evaluated the effect of 19 tomato genotypes, comprising 16 domesticated varieties and three wild tomato species, on oviposition output of female P. absoluta, as well as on larval performance under no-choice conditions using detached leaves. We also characterized and quantified glandular and nonglandular trichomes, exploring their potential correlation with the response of P. absoluta to the tomato plants. Generally, fewer eggs were oviposited on domesticated plants, whereas the wild tomatoes Solanum arcanum and S. neorickii and the domesticated tomato Corona F1 impaired larval development. The pest larvae consumed a limited area of leaflets from S. arcanum and S. neorickii compared to other genotypes, leading to the lowest weights in both male and female pupae. All tomato plants exhibited a prevalence of nonglandular over glandular trichomes, except for S. arcanum, which exhibited a higher abundance of glandular trichomes. Although higher trichome density correlated with longer larval settlement on the leaflets, it did not influence female oviposition. Our findings demonstrate that the wild tomatoes S. arcanum and S. neorickii could be considered as potential sources for breeding programmes, and the domesticated Corona F1 could offer IPM options against P. absoluta. © 2024 The Author(s). Pest Management Science published by John Wiley & Sons Ltd on behalf of Society of Chemical Industry.

The Glucanase Enzyme Activity from Rhizospheric Streptomyces spp. in Inhibiting Growth and Damaging the Cell Walls of the Mycelium of Fusarium oxysporum

Fusarium oxysporum, a phytopathogenic fungus responsible for fusarium wilt in more than 120 plant species, is primarily managed using synthetic fungicides, which pose environmental hazards. Therefore, alternative biological control methods are urgently needed. Actinomycetes isolated from maize rhizosphere, which produce β-1.3-glucanase enzymes that degrade fungal cell wall glucans, offer promising potential as biocontrol agents. This study aimed to evaluate glucanase activity, identify genes of actinomycetes, and assess their antifungal activity against F. oxysporum. Actinomycetes demonstrating glucanase production, Streptomyces sp. ARJ 22, Streptomyces tendae ARJ 42, Streptomyces sp. ARJ 44, and Streptomyces sp. ARJ 81, were selected. Streptomyces isolates exhibited activity values ranging from 10.38 to 24.08 U/mg of protein. The presence of the bglS gene, encoding endo-β-1.3-glucanase from glycoside hydrolase family 16, supports the production of glucanase. The amino acid sequence was constructed to 3D structural model. This model exhibited high similarity to endo-β-1.3-glucanase from Nocardiopsis sp. F96. In vitro assays demonstrated that all isolates inhibited hyphal growth of F. oxysporum. Direct inhibition assays showed an average inhibition of 26.18%, whereas the filtrate culture method showed 29.38% inhibition. Enzymes from Streptomyces sp. ARJ 44 was partially purified using acetone, resulting in a specific activity of 46.34 U/mg of protein and a purity increase of up to 1.92-fold. The purified enzyme inhibited the growth of F. oxysporum mycelia by 35.80%. This inhibition was confirmed by observing damage to F. oxysporum hyphae using scanning electron microscopy. The study concluded that the four Streptomyces sp. strains producing β-1.3-glucanase enzymes have potential as biocontrol agents against F. oxysporum.

Effectiveness of Essential Oils from Leaves of Two Plant Species in the Control of Anopheles gambiae

Background: The current method of controlling malaria vectors using synthetic chemicals has caused serious problems for human health and the environment. Hence, a need for alternative, cheap, readily available, and acceptable mosquito control methods. Objective: To evaluate the bioinsecticidal efficacy of Ocimum gratissimum and Mesosphaerum suaveolens against Anopheles gambiae using the bioassay method. Methods: Oil extracts in 5 ml, 25 ml, and 75 ml serially diluted twice in 100 ml of olive oil formed 0.05%, 0.25%, and 0.75%, while 1 m in 100 ml formed 1%. Olive oil only served as a control. Twenty-five female Anopheles mosquitoes, aged 2-4 days, were blown into tubes containing filter paper-coated essential oils of various concentrations in quadruplicates. Results: Over 50% mortality was recorded in mosquitoes exposed to 0.75% and 1% O. gratissimum compared to others (p <0.05). Knockdown time (KDT) was higher in mosquitoes exposed to 1% O. gratissimum compared to others (p <0.05). Generalized linear regressions showed that the essential oils of O. gratissimum and M. suaveolens contributed 4% (f2 = 0.042) and 14% (f2 = 0.167) to the variability of mortality with time. KDT50 (9.34 - 131.5 minutes) and KDT95 (77.6 - 275 minutes) of O. gratissimum as well as KDT50 (162.8 - 233.6 minutes) and KDT95 (302.8 - 415 minutes) of M. suaveolens were recorded. Stigmastane; 4,22-Stigmastadiene-3-one (Area: 45.88%) in O. gratissimum and gamma-Sitosterol (16.02%) in M. suaveolens were identified by Gas Chromatogram as the highest dose of chemical compounds. Conclusion: The low bioinsecticidal activities of these plant extracts could be attributed to the low occurrence of terpenoids and alkaloids.

SUSTAINABLE STRATEGIES FOR ODONATA MANAGEMENT IN FISH FARMING: REVIEW AND IMPLICATIONS

This study conducted a systematic review of the literature on predation of Odonata larvae in fish farming, using databases such as Google Scholar and SciELO. The results showed that predation can reduce the survival of fry by up to 30%, impacting the productivity of ponds. Alternative control methods, such as natural extracts and entomopathogenic fungi, were analyzed, which proved to be effective without the negative effects of agrochemicals, as well as the use of prey, such as Chironomidae. The research highlighted the importance of sustainable management strategies and the preservation of Odonata diversity, which are essential for the health of aquatic ecosystems. In addition, the use of water quality monitoring technologies was considered essential to optimize larval management.

The application of ozone within the food industry, mode of action, current and future applications, and regulatory compliance.

The food industry faces numerous challenges today, with the prevention and reduction of microbial contamination being a critical focus. While traditional chemical-based methods are effective and widely used, rising energy costs, the development of microbial tolerances, and growing awareness of the ecological impact of chemical biocides have renewed interest in novel biocides. Ozone, in both its gaseous and aqueous forms, is recognized as a potent disinfectant against bacteria, viruses, and fungi due to its high oxidation potential. Our review highlights several studies on the applications of ozone within the food industry, including its use for surface and aerosol disinfection and its capacity to reduce viable Listeria monocytogenes, a pertinent foodborne pathogen harbouring environmental and biocide stress tolerances and biofilm former. We also explore the use of ozone in food treatment and preservation, specifically on blueberries, apples, carrots, cabbage, and cherry tomatoes. While ozone is an effective disinfectant, it is important to consider material incompatibility, and the risks associated with prolonged human exposure to high concentrations. Nevertheless, for certain applications, ozone proves to be an efficacious and valuable alternative or complementary method for microbial control. Compliance with the biocide products regulation will require ozone device manufacturers to produce proven efficacy and safety data in line with British standards based on European standards (BS EN), and researchers to propose adaptations to account for ozone's unique properties.

The carrot cyst nematode Heterodera carotae: a major plant-parasitic nematode requiring more investigation

Summary The present study reviews the knowledge to date on the carrot cyst nematode Heterodera carotae, which has become the primary threat to the carrot sector following the withdrawal of the last chemical soil fumigants in Europe. A keyword co-occurrence network was used to structure this review into five research areas: i) biology and epidemiology of H. carotae; ii) molecular identification and phylogeny; iii) population genetics and genomics; iv) control methods and strategies; and v) root exudates and hatching stimulation. Our findings indicate that H. carotae is an under-studied plant-parasitic nematode species, with several identified alternative control methods that require further investigation.

Advancements in Bacteriophages for the Fire Blight Pathogen Erwinia amylovora.

Erwinia amylovora, the causative agent of fire blight, causes significant economic losses for farmers worldwide by inflicting severe damage to the production and quality of plants in the Rosaceae family. Historically, fire blight control has primarily relied on the application of copper compounds and antibiotics, such as streptomycin. However, the emergence of antibiotic-resistant strains and growing environmental concerns have highlighted the need for alternative control methods. Recently, there has been a growing interest in adopting bacteriophages (phages) as a biological control strategy. Phages have demonstrated efficacy against the bacterial plant pathogen E. amylovora, including strains that have developed antibiotic resistance. The advantages of phage therapy includes its minimal impact on microbial community equilibrium, the lack of a detrimental impact on plants and beneficial microorganisms, and its capacity to eradicate drug-resistant bacteria. This review addresses recent advances in the isolation and characterization of E. amylovora phages, including their morphology, host range, lysis exertion, genomic characterization, and lysis mechanisms. Furthermore, this review evaluates the environmental tolerance of E. amylovora phages. Despite their potential, E. amylovora phages face certain challenges in practical applications, including stability issues and the risk of lysogenic conversion. This comprehensive review examines the latest developments in the application of phages for controlling fire blight and highlights the potential of E. amylovora phages in plant protection strategies.

Diversity of culturable bacterial isolates and their potential as antimicrobial against human pathogens from Afar region, Ethiopia.

Antimicrobial resistance (AMR) is an escalating global health threat affecting humans, animals, and the environment, underscoring the urgent need for alternative pathogen control methods. Natural products, particularly secondary metabolites from bacteria, continue to be a vital source of antibiotics. However, microbial habitats and metabolites in Africa remain largely unexplored. In this study, we isolated and screened bacteria from Ethiopia's Afar region, characterized by extreme conditions like high temperatures, volcanic activity, high salinity, and hot springs to identify potential bioactive compounds. We discovered diverse bacterial isolates with antimicrobial activity against various pathogens, including strain Sl00103 (Bacillus sp. Sl00103), which demonstrated significant antimicrobial and antioxidant activities. GC-MS analysis identified several antimicrobial compounds, highlighting strain Sl00103 as a promising source of secondary metabolites with potential pharmaceutical applications and warranting further investigation.

Evaluation of Postemergence Weed Control Programs in Cotton Without the Addition of Glyphosate

Glyphosate has played an important role in agricultural production systems, especially after the release of glyphosate resistant crops. With increased usage and an overall reliance on chemical control, weed resistance to glyphosate has occurred and is now a major issue. The objective of this research was to investigate weed control levels provided by glufosinate, 2,4-D, and clethodim as an alternative to glyphosate. Multiple POST applications generally provided superior weed control in comparison to a single early-POST application. No programs provided greater than 80% warm-season grass control beginning 21 d after mid-POST application. Applications of glufosinate or glufosinate + 2,4-D fb clethodim + glufosinate, glufosinate + 2,4-D, or clethodim + glufosinate + 2,4-D provided adequate broadleaf weed control throughout the rating period. Although POST-only programs are an option, they are not a sustainable weed control practice. It remains important to incorporate residual herbicides into a weed control program as well as alternative weed control methods.

Fight or flight? responses of rodents to predator cues: a review

Rodents are common prey for a wide range of predators, including reptiles, birds, and mammals. Some of the predators (e.g., owls) depend solely on rodents for food, reducing their population significantly. Rodents respond to predators by changing behaviours to protect themselves against the enemies. Further, rodents have evolved advanced sensory capabilities that enable them to detect and effectively respond to predator cues to enhance their chances of survival. If rodents can detect their predators by chemical communication, these compounds can be extracted to repel rodents away from foods in farms and houses. However, the scientific community lacks knowledge of this phenomenon. Thus, we have reviewed the literature to get enough evidence to prove that rodents respond to predators by chemical communication. Our findings demonstrated that rodents react immediately to predatory threats by hiding or sleeping, exhibiting rapid eye movements, grouping, increased alertness, aggression, heightened anxiety, reduced activity, freezing, and avoidance. Furthermore, prolonged exposure to these cues can lead to gene changes and trigger the release of stress hormones such as corticosterone. Stress in rodents can cause hormonal imbalances, leading to decreased reproduction or smaller than normal litters. This knowledge can be used to develop alternative methods for rodent control, which can reduce reliance on poisons and promote eco-friendly and sustainable approaches to managing rodent populations. However, the majority of these ant-predatory responses have only undergone laboratory testing, providing limited field-based information. Therefore, further studies are recommended to investigate ant-predatory responses, especially those involving chemical communication, in real-world environments.

Nanoformulations containing rosemary oil for gray mold control in strawberries

Gray mold, caused by Botrytis cinerea, affects strawberry crops (Fragaria x ananassa) and can cause major losses. Managing the disease with fungicides can harm health and the environment and can lead to the selection of pathogens resistant to their active ingredients. The use of essential oils (EOs) represents an alternative control method due to their richness in antimicrobial compounds, such as rosemary EO (Rosmarinus officinalis). However, the high volatility of several components of these oils makes commercial use difficult, and nanoencapsulation presents a technology to increase stability. In the present study, three formulations containing rosemary EO—nanoemulsion (NE), nanostructured lipid carrier (NLC), and nanocapsules with chitosan (NC)—were evaluated on strawberry fruits and against the fungus. The nanoformulations retained their characteristics (mean values: size 142 nm; polydispersity index 0.131; pH 4.99; zeta potential -20.2 mV for NE and NLC, and 19.1 mV for NC) when stored at 40 °C for 60 days. All nanoformulations had a direct effect on spore germination and mycelial growth of B. cinerea, possibly due to damage caused to the cell wall and plasma membrane, and changes in the pathogen's oxidative balance. NE containing 2 % EO, when applied by immersion, reduced the incidence and severity of the disease by around 40 % and 70 %, respectively, 6 days after treatment. The fruits treated with this formulation maintained their physicochemical characteristics for longer. Thus, the use of rosemary oil from NE can be an option for managing gray mold and increasing the shelf life of the fruits.

In vitro assessment of antifungal activity of cinnamon leaves extract against the Colletotrichum sp. causes of anthracnose on tomato

Tomato is a horticultural plant widely cultivated in Bali. Over the three years, the productivity and quality of this plant have tended to decrease due to pathogen-derived diseases, such as anthracnose caused by Colletotrichum sp. Until recently, control of this pathogenic fungus has relied on chemical-based fungicides, which lead to many long-term complications, including pathogen resistance, environmental pollution, the extinction of non-target microorganisms, and negative impacts on human health. Therefore, alternative methods for plant disease control are urgently needed to combat these pathogen attacks. The use of plant-derived active compounds has been intensively researched worldwide as a more environmentally friendly alternative. The main objective of this research was to investigate the effectiveness of Cinnamomum burmanii acetone extract in inhibiting the growth of Colletotrichum sp., the causative agent of anthracnose in tomatoes, through an in vitro approach. A non-factorial randomized complete design was applied in the experiment. The results showed that the crude extract of cinnamon leaves inhibited the growth of the Colletotrichum sp. with an MIC value of 0.9%, an inhibition zone of 2.55 mm, and an optimal inhibitory concentration of 2%, producing an inhibition zone of 11.10 mm. A GC-MS analysis was conducted to identify the active compounds in the cinnamon leaf extract. Sixteen active compounds were identified, nine of which are known to have antimicrobial activity.

Effect of Volatile Compounds Emitted by an Endophytic Yeast Isolated from the Endemic Plant Echinopsis chiloensis against Botrytis cinerea

Our research group isolated an endophyte yeast from the endemic plant Echinopsis chiloensis. This yeast, identified as Naganishia sp, produces volatile organic compounds (VOC) with antifungal activity against Botrytis cinerea. Due to the need for alternative control methods for this pathogen, the effect of VOC on B. cinerea was analyzed. On the fourth day of cultivation, in the presence of VOCs, the mycelial growth of B. cinerea stopped. VOCs inhibited 32.8% of the conidia germination and reduced sporulation by 70.6%. These compounds promoted the formation of infection cushions. VOCs caused damage to the cell wall and plasma membrane in B. cinerea. On the other hand, the volatile compounds induced oxidative stress, and led to membrane lipid peroxidation after 16 and 24 h of incubation in the presence of VOCs, because an increased level of malondialdehyde content was observed. These compounds exerted a fungistatic effect on B. cinerea. The volatile compounds emitted by Naganishia sp were identified by gas chromatography coupled with mass spectrometry as 3-methylbutyl acetate, ethylbenzene, 1-ethyl-3-methylbenzene, 2-phenylethanol, 2-heptanone and (5E)-6,10-dimethylundeca-5,9-dien-2-one. The most abundant volatile compound, 2-phenylethanol, inhibited the mycelial growth of B. cinerea with an IC50 value of 0.21 µL mL−1. The effect of this pure compound was also fungistatic. Finally, it was shown that volatile compounds decreased the severity of B. cinerea infection in tomatoes and grapes by 64.7 and 43,1%, respectively. This is the first report identifying volatile compounds emitted by a Naganishia sp. and describing their mode of action against B. cinerea.

Molecular approaches for the management of papaya ringspot virus infecting papaya: a comprehensive review.

Papaya ringspot virus (PRSV) is a catastrophic disease that causes huge yield losses in papaya cultivation around the world. Yield losses in severely infected plants can be upto 100%. Because of this disease, papaya cultivation has been shifted to other crops in some areas of the world. Many conventional methods and breeding approaches are used against this disease, which turns out to be less effective. Considering the yield loss caused by PRSV in papaya, it is high time to focus on alternative control methods. To implement effective management strategies, molecular approaches such as Marker Assisted Breeding (MAS) or transgenic methods involving post-transcriptional gene silencing targeting the genome viz., coat protein, replicase gene, or HC Pro can be pursued. However, the public's reluctance to widely accept the transgenic approach due to health and environmental concerns necessitates a consideration of non-transgenic alternatives. Prioritizing safety and ensuring efficient virus control, non-transgenic approaches which encompass cross-protection, genome editing, and topical applications of dsRNA to induce gene silencing within the host, can be adopted. This review aims to provide comprehensive insights of various molecular tools used in managing PRSV which in turn will help in sustainable agriculture.

The effect of some vegetable origin oils used in different clove varieties against Meloidogyne incognita

Alternative control methods are needed against plant parasitic nematodes in Gerbera (Gerbera jamesonii L.) and Carnation (Dianthus caryophyllus L.) plants and one of these methods is the use of plant-based extracts against nematodes. Plant parasitic nematodes cause economic damage in cut flower production areas, so in order to reduce this damage, it is aimed to use different non-synthetic plant-based extracts as an alternative to chemical control methods within the scope of cultural control of nematodes. For this purpose, garlic, thyme, and terminator (70% thyme + 30% different plant mixture formation) were used to determine the resistance against M. incognita in two different clove cultivars, Turbo with standard flower type and Harnet with spray flower type. While the egg pack index was 1.40 ± 0.70 in the Harnet cultivar with garlic application, this rate was 16.00 ± 9.66 in the positive control. While the egg pack index was 1.20 ± 0.42 in the Turbo variety, in which garlic was applied, this value was 3.70 ± 0.48 in the control. When evaluated based on varieties, the egg package index was lower in the Turbo variety with garlic application compared to the Harnet variety.

Combining Masculinizing Resistance, Rotation, and Biocontrol to Achieve Durable Suppression of the Potato Pale Cyst Nematode: A Model.

The pale cyst nematode, Globodera pallida, is a pest that poses a significant threat to potato crops worldwide. The most effective chemical nematicides are toxic to nontarget organisms and are now banned. Alternative control methods are therefore required. Crop rotation and biological control methods have limitations for effectively managing nematodes. The use of genetically resistant cultivars is a promising alternative, but nematode populations evolve, and virulent mutants can break resistance after just a few years. Masculinizing resistances, preventing avirulent nematodes from producing females, might be more durable than blocking resistances, preventing infection. Our demo-genetic model, tracking both nematode population densities and virulence allele frequencies, shows that virulence against masculinizing resistance may not be fixed in the pest population under realistic agricultural conditions. Avirulence may persist despite the uniform use of resistance. This is because avirulent male nematodes may transmit avirulent alleles to their progeny by mating with virulent females. Additionally, because avirulent nematodes do not produce females themselves, they weaken the reproductive rate of the nematode population, leading to a reduction in its density by at least 20%. This avirulence load can even lead to the collapse of the nematode population in theory. Overall, our model showed that combining masculinizing resistance, rotation, and biocontrol may achieve durable suppression of G. pallida in a reasonable time frame. Our work is supported by an online interactive interface allowing users (i.e., growers, plant health authorities, researchers) to test their own control combinations.

Microwave-assisted sample preparation for screening of heavy metal elements in food additives by ICP-MS

The screening of heavy metals in food additives is important for public health due to their probable critical effects, induced by excessive intakes, and difficulties in tracing in food matrix. This study aimed to assess the applicability of microwave (MW)-based digestion and inductively coupled plasma-mass spectrometry (ICP-MS) for quantification of heavy metals in food additives. MW-assisted diluted acid digestion (1550 W at 220 °C, 0.79 mol/L of HNO3 solution) was applied as a pretreatment and ICP-MS was used for 19 different heavy metals at different concentrations, up to 20 ng/g. The optimized protocol was validated by spiking heavy metals to glycerin and applied to 18 food additives. The method was linear for 14 heavy metals (R2 > 0.990). For 11 heavy metals, both intra- and inter-day accuracies in glycerin were estimated to 88.5%–123.7%, with intra- and inter-day precisions of less than 5.5% and 4.9%, respectively, and their contents in food additives were discussed. The findings in this work provide an alternative analytical method for regulatory compliance and quality control in food industries.

Alternative control methods for Fall army worm in some agroecologies in Cameroon

Alternative control methods for Fall army worm in some agroecologies in Cameroon